Parasitic plants

 

 

The archetype of parasitic plants is the common mistletoe (Viscum album), which has a prominent position in European folklore. In this picture, it grows on poplar trees near Le Blanc, central France. (Photo copyright © by Kaj Halberg)

 

 

A typical representative of holoparasites is this unidentified species of dodder (Cuscuta), which has completely enveloped a bush in Monumento Natural El Morado, central Chile. (Photo copyright © by Kaj Halberg)

 

 

A typical representative of hemiparasites is the whorled lousewort (Pedicularis verticillata), which grows in mountains of Europe, Central Asia, China, Japan, and arctic areas of Russia, Alaska, and Canada, here photographed near the Sölkpass, Austria. (Photo copyright © by Kaj Halberg)

 

 

Cactus mistletoe (Tristerix aphylla), growing on the trunk of a quisco cactus (Echinopsis chiloensis), Parque Nacional La Campana, Chile. (Photo copyright © by Kaj Halberg)

 

 

 

Parasitic plants are divided into two main groups: holoparasites, which derive all their nutrients from another living plant or from a fungus, and hemiparasites, which to some extent are able to produce nutrients through photosynthesis. In the Greek, hemi means ‘half’. To me, the term half-parasite seems rather odd. Either you are a parasite, or you are not!

About 20 families of parasitic plants, comprising c. 4,500 species, are known, distributed across almost the entire planet. Almost all species have sucking organs, named haustoria, which are modified roots, penetrating the host plant and extracting water and nutrients from it.

 

 

Balanophoraceae
This family contains 17 genera with c. 44 species, some of which superficially resemble fungi. These plants contain no chlorophyll, being holoparasites that obtain all necessary nutrients from tree roots. They are found in subtropical and tropical areas around the globe, with a few species extending into temperate regions.

 

Balanophora
This genus, comprising about 20 species, is found in tropical Africa, Madagascar, southern Asia, Southeast Asia, and Indonesia, and on some Pacific Islands. Some species emit an odour, which attracts flies as pollinators. Several species are utilized in traditional medicine in certain Asian countries.

The generic name stems from the inflorescence of some members of this genus, which is covered by bumps, resembling barnacles (family Balanidae).

 

Balanophora dioica
The stems of this plant are pink or purple, cylindric, to 10 cm tall. Leaves are scale-like, clasping the stem, to 4 cm long and 2.5 cm broad. Inflorescences are ovoid or ellipsoid, to 3.5 cm long. This species has a wide altitudinal range, found between 400 and 2,600 m, from central Nepal eastwards to China and Taiwan.

 

 

Nepal 2009
Balanophora dioica, near Bamboo Lodge, Lower Langtang Valley, central Nepal. (Photo copyright © by Kaj Halberg)

 

 

 

 

 

Convolvulaceae Morning-glory family
Dodders (Cuscuta), between 100 and 170 species, used to constitute a separate family, Cuscutaceae, but have now been moved to the morning-glory family – the only parasitic members of that family. Dodders are distributed almost worldwide, with the greatest concentration in the tropics and subtropics. Temperate areas have much fewer species, including northern Europe, where only four species are native. In hot climates, dodders are perennials, growing more or less continuously, while in colder areas they are annuals.

These plants twine around other plants, often completely enveloping them in their yellow or reddish stems. A dodder seed starts its life like most other seeds by sending roots into the soil, from which grow stems, whose leaves are reduced to scales. When a stem gets into contact with a suitable plant, it wraps itself around it, inserting haustoria into the plant, through which the dodder obtains water and nutrients. Its root in the ground then dies.

Their strange appearance taken into consideration, it is hardly surprising that dodders have many folk names, including strangleweed, scaldweed, beggarweed, lady’s laces, wizard’s net, devil’s guts, devil’s hair, devil’s ringlet, goldthread, hailweed, hairweed, hellbine, pull-down, angel’s hair, and witch’s hair.

The generic name is derived from the Arabic name of dodders, kusuta, or kuskut, which, in the form Cuscuta, was applied to them by Rufinus, an Italian monk and botanist, who was the author of De virtutibus herbarum, completed c. 1287, which listed nearly a thousand medicinal materials, mostly plants.

 

Cuscuta australis Southern dodder
This species is very widely distributed, found from Africa across the Middle East to India and the Far East, and thence southwards through Southeast Asia and Indonesia to New Guinea and Australia.

 

 

Southern dodder is very common in Taiwan. In this picture, it covers most of the embankment along the Agongdian River, between Mituo and Yongan, southern Taiwan. The plant with violet flowers is another member of the morning-glory family, Ipomoea pes-caprae. (Photo copyright © by Kaj Halberg)

 

 

Southern dodder readily grows in abandoned plots in cities, in this case in Taichung, Taiwan. (Photos copyright © by Kaj Halberg)

 

 

 

Cuscuta californica Californian dodder
This plant, also known as chaparral dodder, is common in western North America, found in grasslands, pine forests, and chaparral, a community of shrubby plants, adapted to dry summers and moist winters, which is typical of southern California.

 

 

This Californian dodder has enveloped a bladderpod bush (Peritoma arborea), near Amboy, California. (Photo copyright © by Kaj Halberg)

 

 

 

Cuscuta epithymum Lesser dodder
Lesser dodder is native to Europe, northern Africa, the Middle East, and northern Asia, eastwards to central Siberia and Sinkiang, but has been accidentally introduced to many other parts of the world. The commonest host plants of this species are heather (Calluna vulgaris), gorse (Ulex europaeus), and clover species (Trifolium).

 

 

Lesser dodder, growing on a species of knapweed (Centaurea), Valle Hecho, Pyrenees, Spain. (Photo copyright © by Kaj Halberg)

 

 

 

Cuscuta europaea Greater dodder
This species is partial to common nettle (Urtica dioica), although it can grow on plants of many other families. The stems are red or yellow. The small, pink or whitish, urn-shaped flowers, 2.5-3 mm long, with 4 or 5 lobes, sit in dense clusters along the stems. This plant is very widely distributed, found in temperate areas of Europe and Asia, eastwards to Japan, in North Africa, and occasionally in North and South America.

 

 

The commonest host of greater dodder is common nettle, as in these pictures from the Lauterbrunnen Valley, Berner Oberland, Switzerland (top), and the island of Møn, Denmark. (Photos copyright © by Kaj Halberg)

 

 

 

Cuscuta reflexa Giant Asian dodder
Widely distributed, found from Afghanistan across the Indian Subcontinent and southern Tibet to south-western China, and thence southwards through Southeast Asia to Indonesia. In some areas, this proliferate plant is regarded as a serious pest, including in the Valley of Flowers National Park, Uttarakhand, northern India.

 

 

This giant Asian dodder has completely enveloped a bush at Angkor Wat, Cambodia. (Photos copyright © by Kaj Halberg)

 

 

In this picture, it has enveloped a bush in Keoladeo National Park, Rajasthan, India. (Photo copyright © by Kaj Halberg)

 

 

This shrub of the genus Lindera, growing at Tharke Ghyang, Helambu, Nepal, has been enveloped by giant Asian dodder. (Photo copyright © by Kaj Halberg)

 

 

The small, bell-shaped flowers of giant Asian dodder, Marsyangdi Valley, central Nepal. (Photo copyright © by Kaj Halberg)

 

 

 

 

 

Cynomoriaceae

 

Cynomorium coccineum
Formerly, this genus was regarded as belonging to the family Balanophoraceae (above). However, genetic research indicates that it constitutes a separate family. The genus contains one or two species, C. coccineum of the Mediterranean region, eastwards to Afghanistan and Iran, and C. coccineum var. songaricum (or C. songaricum) of Central Asia.

Both have been widely used in folk medicine throughout their area of distribution. To some early herbalists, following the Doctrine of signatures, the phallic shape of the inflorescence suggested that it could be used as a cure for impotence and other sexual problems, and its colour suggested that it could cure blood diseases. (For a list of sources, see en.wikipedia.org/wiki/Cynomorium)

Cynomorium coccineum is sometimes called Maltese fungus due to its fungus-like appearance, and other names include desert thumb and red thumb. It is quite rare, growing in rocky or sandy soils, often near the coast. It is parasitic on roots of various shrubs of the cistus family (Cistaceae), the amaranth family (Amaranthaceae), and the tamarisk family (Tamaricaceae).

 

 

Cynomorium coccineum, photographed in Zaranik Protected Area, Sinai, Egypt. (Photos copyright © by Kaj Halberg)

 

 

 

 

 

Ericaceae Heath family
This huge family contains a few parasitic genera, which used to constitute a separate family, Monotropaceae. However, following genetic research, this family has now been reduced to a subfamily, Monotropoideae, in the heath family.

 

Allotropa virgata Candystick
This striking plant, which may grow to 50 cm tall, is found in forests up to an elevation of 3,000 m, from California northwards to British Columbia and eastwards to Montana. The popular names candystick, sugarstick, and barber’s pole all refer to its peculiar red-and-white-striped appearance, the latter name alluding to the poles with a helix of red and white stripes (in America also often blue), which used to signify a barber’s shop.

 

 

Candystick, Mount Rainier, Washington. Note the bluish-green caterpillar on the inflorescence. (Photo copyright © by Kaj Halberg)

 

 

 

 

Monotropa
This genus of 5 species is native to temperate areas of the Northern Hemisphere. The generic name is from the Greek monos (‘single’) and tropos (‘to turn’), referring to the flowers of M. hypopitys, which all point in the same direction.

 

Monotropa hypopitys Pinesap
Also known as Dutchman’s pipe or yellow bird’s-nest, this plant is found throughout Europe, in northern Asia, southwards to the Himalaya and Thailand, and throughout North America, southwards to Mexico. It is parasitic on mycorrhiza of the genus Tricholoma.

The name yellow bird’s-nest refers to its thick, tangled root, which somewhat resembles a bird’s nest, and the part yellow from its yellowish flowers. Dutchman’s pipe, of course, refers to the flower shape.

There is some controversy about the specific name of this plant. Swedish botanist Carolus Linnaeus (1707-1778), also known as Carl von Linné, spelled the name hypopithys. In the Greek, hypo means ‘under’, whereas Pithys was the name of a wood nymph in Ancient Greek mythology, thus ‘under the nymph’. Linnaeus was known to be sometimes a bit of a prankster. Was he referring to the tangled root, which may resemble the tangled pubic hairs of a woman? Or did he simply misspell the name? Modern taxonomists spell the name hypopitys (without an h), where pitys (‘pine’) refers to one of the habitats of this species, as it often grows in dark pine forests.

Recent DNA research suggests that this species should be placed in a separate genus, named Hypopitys monotropa. (Source: M.I. Bidartondo & T.D. Bruns, 2001. Extreme specificity in epiparasitic Monotropoidiae (Ericaceae): widespread phylogenetic and geographical structure. Molecular Ecology)

 

 

Pinesap, photographed on the island of Møn, Denmark. (Photo copyright © by Kaj Halberg)

 

 

 

Monotropa uniflora Ghost plant
This species differs from pinesap in being pure white, hence its popular name. Another name is Indian pipe, which, of course, refers to the flower shape. The specific name means ‘one-flowered’. As opposed to pinesap, each inflorescence of this species only has a single flower.

Ghost plant is native to North and Central America, southwards to Columbia, and in eastern Asia, from the Himalaya eastwards to Japan and Sakhalin, and thence southwards to Taiwan. It grows in forests, being parasitic on mycorrhiza of the family Russulaceae. It has been widely used in western herbal medicine to calm the nerves.

 

 

Ghost plant, Great Smoky Mountains National Park, Tennessee, United States. (Photo copyright © by Kaj Halberg)

 

 

Ghost plant, Dasyueshan National Forest, central Taiwan. (Photo copyright © by Kaj Halberg)

 

 

 

 

Sarcodes sanguinea Snow plant
This plant, which derives its nutrients from underground fungi, is distributed from the Cascade Range of Oregon southwards through montane areas of California to northern Baja California, Mexico.

American botanist, chemist, and physician John Torrey (1796-1873) found the colour of this plant so striking that he named it Sarcodes sanguinea, from the Greek sarkos (‘flesh’) and the Latin sanguis (‘blood’), thus ‘the blood-coloured fleshy one’. The common name refers to the early flowering of this species, which often appears, when snow is still covering the ground.

 

 

Snow plant, photographed in the Siskiyou Mountains, Oregon. (Photo copyright © by Kaj Halberg)

 

 

 

 

 

Loranthaceae Showy mistletoe family
Previously, a number of parasites on trees were all called mistletoes, placed in the family Viscaceae. However, extensive DNA research has caused this family to be abolished, and the vast majority has been moved to this family, which contains about 75 genera and 950 species. All are hemiparasites, with the exception of three terrestrial species, which are non-parasitic, and Tristerix aphylla (see below), which is holoparasitic. Most species are found in tropical and subtropical regions.

As the family name implies, many species have beautiful, often brightly coloured flowers. The fruit is a berry, rarely a drupe or capsule. As in Santalaceae, the seeds are surrounded by a sticky substance, being spread by birds or, rarely, by small mammals.

 

 

This unidentified fruiting showy mistletoe was encountered near Upington, South Africa. (Photo copyright © by Kaj Halberg)

 

 

 

Agelanthus
This is the largest genus of showy mistletoes in Africa, containing about 61 species. They are parasitic on various trees, including species of Acacia and Combretum.

 

Agelanthus ziziphifolius
This plant is distributed in eastern Africa. The specific name means ‘with leaves like Ziziphus‘, a genus of spiny shrubs and small trees in the buckthorn family (Rhamnaceae).

 

 

Agelanthus ziziphifolius, encountered at Lake Naivasha, Kenya. (Photo copyright © by Kaj Halberg)

 

 

 

 

Oncocalyx
This genus contains 13 species, distributed from Arabia southwards through eastern Africa to South Africa.

 

Oncocalyx ugogensis
An East African species, distributed in Somalia, Kenya, Uganda, and Tanzania.

 

 

Oncocalyx ugogensis, observed at Lake Bogoria, northern Kenya. (Photo copyright © by Kaj Halberg)

 

 

 

Plicosepalus
A genus of 12 species, extending from the Middle East southwards through eastern Africa to southern Africa, including Angola.

 

 

An unidentified species of Plicosepalus, Same, northern Tanzania. (Photo copyright © by Kaj Halberg)

 

 

 

Plicosepalus curviflorus
Widely distributed, from the Middle East, the Arabian Peninsula, and southern Egypt southwards along the Red Sea to Ethiopia, Somalia, Kenya, Uganda, and eastern Zaire.

 

 

Plicosepalus curviflorus, growing on an acacia, Lake Baringo, Kenya. (Photo copyright © by Kaj Halberg)

 

 

 

 

Psittacanthus Parrot-flower
These plants, comprising about 67 species, are found from Mexico through Central America to parts of South America. They differ from most other showy mistletoes by their large haustoria, flowers, and fruits. The flowers frequently “light up the host tree in brilliant hues of red or red and yellow.” (Source: J. Kuijt, 2009. Monograph of Psittacanthus (Loranthaceae). Systematic Botany Monographs, vol. 86, pp. 1-361)

The generic name is from the Greek psittakos (‘parrot’) and anthos (‘flower’), presumably referring to the gorgeous flower colours.

 

Psittacanthus ramiflorus
This species grows in montane areas at altitudes between 1,000 and 2,500 m, mostly in humid forests. It is distributed from Mexico eastwards to Panama.

 

 

Psittacanthus ramiflorus, Parque Nacional Rincon de la Vieja, Cordillera de Guanacaste, Costa Rica. (Photo copyright © by Kaj Halberg)

 

 

 

 

Scurrula
This genus, containing about 50 species, is found in the Indian Subcontinent and Southeast Asia.

 

Scurrula elata
This Himalayan species is distributed from Himachal Pradesh eastwards to south-eastern Tibet. It is parasitic on various broad-leaved trees, especially oaks (Quercus), Rhododendron, and Viburnum.

 

 

Scurrula elata, growing on a Viburnum, Khumbu, eastern Nepal. (Photo copyright © by Kaj Halberg)

 

 

 

 

Tapinanthus
A genus of about 40 species, almost all endemic to Africa, a single species also found in Yemen. Some species, formerly placed in this genus, have been moved to other genera, including Agelanthus (above).

 

 

This picture probably shows a species of Tapinanthus, photographed at Spitzkoppe, Namibia. (Photo copyright © by Kaj Halberg)

 

 

 

 

Tristerix
This genus, comprising 12 species, is native to the Andes, from Colombia south to Chile and Argentina. These species are pollinated by hummingbirds and flowerpiercers (Diglossa), while the seeds usually are dispersed by various birds.

 

Tristerix aphylla Cactus mistletoe
This bright red plant differs from other showy mistletoes in being holoparasitic. It is partial to two cactus species of central Chile, copao (Eulychnia acida) and quisco (Echinopsis chiloensis). Its seeds are dispersed by the Chilean mockingbird (Mimus thenca), which often deposits the seeds on the spines, where they sprout, the seedling growing up to 10 cm to reach the stem of the cactus. (Source: llifle.com/Encyclopedia/CACTI/Family/Cactaceae/7067/Eulychnia_acida)

These two species of cacti, and many others, are described on the page Plants: Cacti.

 

 

Cactus mistletoe, growing on the trunk of a copao, Valle del Encanto, Ovalle (top), and on a quisco, south of Vallenar. (Photos copyright © by Kaj Halberg)

 

 

 

Tristerix corymbosus
This gorgeous plant is restricted to the Andes in Chile and Argentina, found at elevations between 500 and 2,000 m. It is parasitic on various plants, mainly in humid forests of southern beech (Notofagus). Its seeds are not only dispersed by birds, but to a great extent by tiny marsupials of the genus Dromiciops.

 

 

Tristerix corymbosus, Reserva Nacional Altos de Lircay, Chile. (Photo copyright © by Kaj Halberg)

 

 

 

 

 

Misodendraceae
Previously, a number of parasites on trees were all called mistletoes, placed in the family Viscaceae. However, extensive DNA research has caused this family to be abolished, and some of its members have been moved to this family.

 

Misodendrum Feathery mistletoe
The only genus of the family, containing 8 species, which are restricted to South America. These plants are parasitic on various species of southern beech (Nothofagus).

The generic name is from the Greek misos (‘hatred’) and dendron (‘tree’), thus ‘hates trees’, referring to the parasitic habit of this genus.

 

Misodendrum linearifolium
The common name of these plants was given in allusion to the feathery look of this species, which grows on Nothofagus antarctica and N. betuloides, from Tierra Del Fuego northwards to central Chile. It was formerly used medicinally, being rubbed on sore muscles.

 

 

Misodendrum linearifolium, Reserva Nacional Altos de Lircay, Chile. (Photos copyright © by Kaj Halberg)

 

 

 

 

 

Moraceae Fig family

 

Ficus Fig
Certain members of this genus, called strangler figs, are not true parasites, as they do not possess haustoria. Instead, they begin their life as an epiphyte in a tree, the seed often sprouting in a pile of bird dung, delivered by the bird which ate the fig fruit. Over the years, aerial roots of the young strangler fig grow down to the ground, where they take root, while other roots wrap themselves around the host tree, over time completely enveloping the tree, which is eventually strangled to death. As the trunk of the host tree decays, it leaves the fig tree as a hollow cylinder of aerial roots. Many strangler figs also readily grow on buildings.

Other species of fig trees are described on the pages Plants: Ancient and giant trees, and Plants: Pipal and banyan – two sacred fig trees.

 

 

This strangler fig in Bedugul Botanical Garden, Bali, Indonesia, stands alone, after its host tree has died. (Photo copyright © by Kaj Halberg)

 

 

As the trunk of the host tree decays, it leaves the fig tree as a hollow cylinder of aerial roots, as in this picture from Ubud, Bali, Indonesia. (Photo copyright © by Kaj Halberg)

 

 

 

Ficus chirindensis
A massive tree, up to 50 m tall, with many aerial roots, growing in montane evergreen forest at altitudes between 700 and 1,600 m. It is distributed from Kenya and eastern Zaire southwards to Malawi, Zimbabwe, and Mozambique.

 

 

In this picture, I am standing inside a hollow cylinder of aerial roots of Ficus chirindensis, Chirinda Forest, Zimbabwe. (Photo copyright © by Uffe Gjøl Sørensen)

 

 

 

Ficus tinctoria Dye fig
This species, also known as humped fig, is widely distributed, found in the Indian Subcontinent, southern China, Southeast Asia, Malaysia, Indonesia, northern Australia, and on numerous Pacific islands. The name tinctoria is Latin, meaning ‘used for dyeing’. It was named in allusion to the traditional usage of the fruits to produce a dye.

 

 

This huge dye fig, subspecies gibbosa, envelops a Khmer ruin at Ta Prohm, Angkor Wat, Cambodia. Other pictures, depicting giant trees among these ruins, may be studied on the page Plants: Ancient and giant trees. (Photo copyright © by Kaj Halberg)

 

 

 

 

 

Orchidaceae Orchid family
Most orchids live in symbiosis with the mycelium of underground fungi, which is attached to the rhizome or root of the plants. When an orchid seed is about to germinate, it is completely dependent on this mycelium, as it has virtually no energy reserve, obtaining the necessary carbon from the fungus. Some orchids are dependent on the mycelium their entire life, but their relationship is symbiotic, as the orchid delivers crucial water and salts to the fungus.

A few orchids, however, are parasitic on the fungus. As they do not possess chlorophyll, they are not able to deliver nutrients to the fungus. Three examples are shown below.

 

Neottia nidus-avis Bird’s-nest orchid
This plant is distributed in the major part of Europe, eastwards to central Siberia, and also in north-western Africa, Turkey, and northern Iran. Its name stems from the thick, tangled root, which somewhat resembles a bird’s nest. To germinate, seeds of this plant are completely dependent on a species of fungus, Rhizoctonia neottiae (family Ceratobasidiaceae).

 

 

Bird’s-nest orchid is easily identified by its brownish inflorescence. This picture is from Berner Oberland, Switzerland. (Photo copyright © by Kaj Halberg)

 

 

 

 

Corallorhiza Coralroot
A genus of 11 species, all but one, the circumboreal common coralroot (C. trifida), restricted to North and Central America, and the Caribbean. These plants are entirely dependent on fungi to obtain nutrients, again with the exception of common coralroot, which contains some chlorophyll. The generic and popular names allude to the entangled rhizomes of these plants, which resemble corals.

 

Corallorhiza maculata Spotted coralroot
This species is widespread, found from Canada southwards through most of the United States to Mexico and Guatemala, and also on some Caribbean islands. It is mentioned in the poem On Going Unnoticed, which appears in a collection of poems, West-Running Brook (1928), by American poet Robert Frost (1874-1963):

 

Less than the coral-root you know
That is content with the daylight low,
And has no leaves at all of its own;
Whose spotted flowers hang meanly down.

 

Previously, several indigenous tribes made a decoction of the dried stems to treat colds, pneumonia, and skin problems.

 

 

Spotted coralroot, Buttle Lake, Vancouver Island, Canada. (Photos copyright © by Kaj Halberg)

 

 

 

Corallorrhiza mertensiana Pacific coralroot
This plant, also known as Mertens’s coralroot, is native to damp coniferous forests of north-western North America, from Alaska southwards to California, and eastwards to Alberta, Montana, and Wyoming. The specific name was given in honour of German botanist Franz Carl Mertens (1764-1831), who undertook several scientific expeditions throughout Europe. He also published the third edition of Deutschlands flora, a five volume treatise on German flora, written by German botanist Johann Christoph Röhling (1757-1813).

 

 

Pacific coralroot, Kruse State Forest, California (top), and Mount Rainier, Washington State. (Photos copyright © by Kaj Halberg)

 

 

 

 

 

Orobanchaceae Broomrape family
This family is huge, containing about 90 genera and more than 2,000 species. Many members are hemiparasites, which were formerly included in the figwort family (Scrophulariaceae). However, following extensive genetic research, they have since been moved to the broomrape family.

 

Aeginetia
This small genus of c. 3 species is distributed in open areas on the Indian Subcontinent, eastwards to Japan and Korea, and thence southwards through Southeast Asia to Indonesia and New Guinea.

 

Aeginetia indica Indian broomrape
This plant is parasitic on roots of various grass species, including bamboo, rice, maize, and sugarcane. It is widely distributed, found from the Indian state of Uttarakhand, in the western Himalaya, eastwards to China and Japan, and in tropical areas of Asia. In the Himalaya, it grows up to an altitude of 1,700 m. In Nepal, root and flowers are utilized medicinally to treat infections and skin problems.

 

 

Rolwaling 2004
Indian broomrape, Tamba Kosi Valley, central Nepal. (Photo copyright © by Kaj Halberg)

 

 

 

 

Bartsia Bartsia
Previously, this genus contained 49 species, 45 of which are endemic to the Andes. Recent genetic studies, however, have led to a revision of this genus, placing most species in a new genus, Neobartsia, and leaving only one species in Bartsia. The genus was named in honour of a Prussian botanist, Johann Bartsch (1709-1738) of Königsberg. The famous Swedish botanist Carolus Linnaeus (1707-1778), also called Carl von Linné, advised him to participate in an expedition to present-day Suriname as a physician, but, unfortunately, he perished during this journey.

 

Bartsia alpina Alpine bartsia
This species, also called alpine bells, is distributed in arctic areas, from Scandinavia eastwards to central Siberia, and also in Iceland, Greenland, and north-eastern Canada. In southern Europe, it is restricted to mountains, found in the Pyrenees, the Alps, mountains of eastern Europe, and on the Balkans. Populations in the Black Forest and the Vosges, as well as on the Swedish island of Gotland, are regarded as ice-age relics. It is common in the Alps, growing on calcareous soil in grasslands and on rocks, at altitudes between 1,000 and 3,000 m.

The purple colour of this plant is an adaptation to repel harmful UV-radiation in the open places, where it grows.

 

 

Large growth of alpine bartsia, Cabane de Prarochet, Col du Sanetsch, Valais, Switzerland. (Photo copyright © by Kaj Halberg)

 

 

Alpine bartsia, Turracher Höhe, Austria. (Photo copyright © by Kaj Halberg)

 

 

 

 
Boschniakia Ground-cone
A small genus, comprising three species, which are native to western North America and extreme north-eastern Asia. The part above ground is a very compact cone-shaped cluster of flowers, which gave rise to their popular name. The flower colour may be yellow, red, brown, or purple.

 

Boschniakia hookeri Small ground-cone
This plant is distributed in forests, from British Columbia southwards to northern California. It is parasitic on salal (Gaultheria shallon) and huckleberry species (Vaccinium). In former days, coastal tribes ate the potato-like base of the stem raw.

 

 

Yellow-flowered small ground-cone, Crest Mountain Trail, Vancouver Island, Canada. The lower picture with withered flowers gives a clear impression of the common name ground-cone. (Photos copyright © by Kaj Halberg)

 

 

 

 

Castilleja Indian paintbrush
The major part of these plants, comprising about 200 species, have brilliant red flowers and bracts, giving rise to their popular names Indian paintbrush and prairie-fire. The flowers of a few species are orange, yellow, or violet. They are native to the western parts of the Americas, from Alaska southwards to the Andes, with one species, C. pallida, distributed across Siberia, westwards to the Kola Peninsula, and southwards to the Altai Mountains.

The flowers of some species are edible and were formerly consumed by various native tribes, but as these plants tend to absorb and concentrate selenium in their tissue, roots and green parts can be very toxic. (Source: en.wikipedia.org/wiki/Castilleja)

A number of pictures, depicting various Castilleja species, are presented on the page In praise of the colour red.

 

Castilleja chromosa Desert paintbrush
This plant, also called C. angustifolia, is quite common in arid areas, from the Pacific States eastwards to Wyoming and Colorado, and from northern Idaho southwards to the Mexican border.

 

 

In this picture, desert paintbrush grows in a barren area in front of a natural bridge, named Owachomo Bridge, which spans the White River, Natural Bridges National Monument, Utah. (Photo copyright © by Kaj Halberg)

 

 

Desert paintbrush, Monument Valley, Arizona. The striking rock in the background is called Elephant Butte. (Photo copyright © by Kaj Halberg)

 

 

 

Castilleja exserta Purple owl’s clover
Previously, this plant, also called red owl’s clover, was placed in the genus Orthocarpus, named O. purpurascens. It is native to north-western Mexico and to the American states of California, Arizona, and New Mexico. In former days, indigenous peoples of California harvested the seeds for food. Incidentally, this species is crucial as a host plant for the Bay checkerspot butterfly (Euphydryas editha ssp. bayensis), a threatened subspecies of the family Nymphalidae, which is endemic to the San Francisco Bay area.

 

 

Purple owl’s clover, Lake Saguaro, Arizona. (Photo copyright © by Kaj Halberg)

 

 

 

Castilleja latifolia Monterey paintbrush
An endemic plant, restricted to a small area along the Californian Pacific Coast, from San Francisco Bay southwards to Monterey, where it grows in coastal shrubs and on sand dunes. The bracts are usually red, but a yellow form is sometimes seen. A picture, depicting a plant with red bracts is shown on the page In praise of the colour red.

 

 

A form of Monterey paintbrush with yellow bracts, observed in Andrew Molera State Park, California. (Photo copyright © by Kaj Halberg)

 

 

 

 

Cistanche
This genus, comprising 23 species, is indigenous to northern and eastern Africa, southern Europe, the Arabian Peninsula, the Middle East, and Central and South Asia. Two species, C. deserticola and C. salsa, in Chinese 肉苁蓉 (rou cong rong) constitute an important ingredient in Chinese herbal medicine. The former is grossly over-collected and has become rare, partly due to loss of its host, Haloxylon ammodendron, which is widely used for firewood. (Source: urbol.com/cistanche-tubulosa-and-deserticola)

 

Cistanche phelypaea
Native to the Iberian Peninsula, Italy, northern Africa, Somalia, the Arabian Peninsula, Jordan, Syria, and Cyprus, this plant is a parasite on bushes in sandy soils. It is used medicinally in Somalia for diarrhoea and menstrual disorders.

 

 

Cistanche phelypaea, growing on roots of Tetraena alba (formerly called Zygophyllum album), a shrub of the family Zygophyllaceae, Zaranik Protected Area, Sinai, Egypt. (Photo copyright © by Kaj Halberg)

 

 

 

Cistanche tubulosa Desert broomrape
As its popular name implies, this species is found in deserts, from northern and eastern Africa eastwards to India. Favourite hosts include bushes of the genera Salvadora, Haloxylon, Zygophyllum, and Cornulaca. In Chinese medicine, this species is sometimes used as a substitute for C. deserticola.

 

 

Cistanche tubulosa, Buffalo Springs National Park, Kenya. The small blue flowers in the foreground are Blepharis linariifolia, of the acanthus family (Acanthaceae). (Photo copyright © by Kaj Halberg)

 

 

 

 

Conopholis Squawroot
This genus contains only two members, both found in North America.

 

Conopholis alpina Alpine squawroot
This plant, also known as alpine cancer-root, is native to Texas, Colorado, New Mexico, Arizona, and northern Mexico. Despite the name cancer-root, there is no evidence that it has any anti-cancer properties. A variety of this species, var. mexicana, called Mexican squawroot, is parasitic on roots of various species of pine (Pinus) and oak (Quercus). It was formerly used by indigenous tribes against tuberculosis.

 

 

Mexican squawroot, Lake Powell, Arizona. (Photo copyright © by Kaj Halberg)

 

 

 

 

Cycnium
A genus of about 17 species, indigenous to sub-Saharan Africa. These plants are usually parasitic on grass roots.

 

 

A species of Cycnium from the Sao Hills, southern Tanzania. (Photo copyright © by Kaj Halberg)

 

 

 

 

Epifagus
This name is derived from the Greek epi (‘on’) and the Latin Fagus, the generic name of beeches, alluding to the host of the sole member of the genus.

 

Epifagus virginiana Beech-drops
This species, which is parasitic on roots of the American beech (Fagus grandifolia), is distributed in the eastern half of North America, from Hudson Bay southwards to Texas and Florida.

In her book Nature’s Garden: An Aid to Knowledge of Our Wild Flowers and Their Insect Visitors (Doubleday, Page & Co., 1900), American historian and nature writer Neltje Blanchan de Graff Doubleday (1865-1918) gives this characteristic of beech-drops: “Nearly related to the broom-rape is this less attractive pirate, a taller, brownish-purple plant, with a disagreeable odor, whose erect, branching stem without leaves is still furnished with brownish scales, the remains of what were once green leaves in virtuous ancestors, no doubt. But perhaps even these relics of honesty may one day disappear.”

 

 

Beech-drops, encountered in Blydenburgh County Park, Long Island, New York State. (Photo copyright © by Kaj Halberg)

 

 

 

 

Euphrasia Eyebright
These plants are mainly found in northern temperate, subarctic, and arctic areas, some also in southern temperate regions. The generic name is derived from Euphrosyne (’gladness’), the name of one of the three graces of Ancient Greece, who was distinguished for her joy and mirth. The name was probably given to the plant because of its properties as a medical herb.

The usage of these plants for eye problems goes back to medieval Europe. Followers of the Doctrine of Signatures claimed that the Great God had made all plants, so that humans would recognize the usage of them. To them, the red streaks on the petals of eyebright resembled bloodshot eyes, and for this reason, this plant would be an effective remedy for eye diseases. Matthaeus Sylvaticus (1285-1342), a physician of Mantua, recommended it for disorders of the eyes, whereas Jervis Markham (1568?-1637), in his Countrie Farm (1616), advises people to “drinke everie morning a small draught of eyebright wine.” In the 18th Century, eyebright tea was drunk, and in Queen Elizabeth’s time a drink called ‘eyebright ale’ was produced.

English herbalist John Gerard (c. 1545-1612) says that powdered eyebright, mixed with mace, “comforteth the memorie,” whereas another herbalist, Nicholas Culpeper (1616-1654), recommends the following recipe for “an excellent water to clear the sight: Take of fennel, eyebright, roses, celandine, vervain, and rue, of each a handful, the liver of a goat chopt small, infuse them well in eyebright water, then distil them in an alembic, and you shall have a water will clear the sight beyond comparison.”

For once, the followers of the Doctrine of Signatures hit the nail on the head, as the plant is still recommended for conjunctivitis (‘red eyes’), infection of the eyelid, and discharge from the eyes. It is also used for indigestion, and for inflammation of the trachea. The dried herb is an ingredient in British Herbal Tobacco, which smoked is useful for chronic bronchial colds.

A popular French name of these plants is casse-lunettes, which loosely translates as ‘throw away your glasses’.

Most eyebright species are very similar, thus being very difficult to distinguish.

 

 

This unidentified eyebright was encountered near Ibon de Piedrafita in the Spanish Pyrenees. (Photo copyright © by Kaj Halberg)

 

 

Another unidentified eyebright, observed in Lahaul, Himachal Pradesh, northern India. (Photo copyright © by Kaj Halberg)

 

 

 

 

Ghikaea speciosa
The sole member of the genus, distributed in dry habitats of south-eastern Ethiopia, Somalia, and northern Kenya.

 

 

Ghikaea speciosa, Shaba National Park, northern Kenya. (Photo copyright © by Kaj Halberg)

 

 

 

 

Lathraea Toothwort
This small genus contains five to seven species, native to Europe and Asia. The generic name is derived from the Greek lathraios (’clandestine’), alluding to the fact that the entire plant is hidden underground, except when it is flowering. Its whitish underground stem is covered in thick, fleshy leaves with rows of tooth-like scales, giving rise to the popular name of the genus.

 

Lathraea squamaria Common toothwort
This species is distributed in almost all of Europe and in Turkey, with an isolated population in the Western Himalaya, which may very well be a separate species. It is parasitic on roots of hazel (Corylus), occasionally on elm (Ulmus), ash (Fraxinus), alder (Alnus), walnut (Juglans), and beech (Fagus).

 

 

Common toothwort may bloom as early as March, when snow occasionally covers the ground. This picture is from Jutland, Denmark. (Photo copyright © by Kaj Halberg)

 

 

 

 

Melampyrum Cow-wheat
This genus, comprising about 38 species, is distributed in arctic and temperate regions of the Northern Hemisphere, southwards to Spain, Turkey, China, and the Carolinas in America.

The generic name is from the Greek melampyron, derived from melas (‘black’) and pyros (‘wheat’), alluding to the black seeds, which somewhat resemble wheat grains. An ancient belief has it that the seeds, when mixed with wheat and ground into flour, tend to make the bread black. In the Middle Ages, it was also believed that the seeds were capable of being converted into wheat, supposedly because of the sudden appearance of these plants among wheat, planted on recently cleared land. Cows and sheep readily eat these plants, hence the name cow-wheat. (Source: M. Grieve, 1931. A Modern Herbal. Jonathan Cape, here taken from botanical.com)

In his Cruydeboeck (‘Herbal Book’), Flemish physician and botanist Rembert Dodoens (1517-1585) tells us that “the seeds of this herb taken in meate or drinke troubleth the braynes, causing headache and drunkennesse.”

 

Melampyrum arvense Field cow-wheat
As its name implies, this species is partial to agricultural lands. Previously, it was a troublesome weed, as its seeds contain the toxic aucubin. Today, the species has become rare due to more effective treatment of crop seeds. It is distributed almost throughout Europe, eastwards to the Ural Mountains and Kazakhstan. In Central Asia, it grows in grasslands.

 

 

Field cow-wheat, photographed on the island of Gotland, Sweden (top), and on Røsnæs Peninsula, north-western Zealand, Denmark. (Photos copyright © by Kaj Halberg)

 

 

 

Melampyrum nemorosum Wood cow-wheat
Some popular names of this plant include natt-och-dag (‘night-and-day’ in Swedish) and Ivan-da-Marya (‘Ivan-and-Maria’ in Russian), both names referring to its striking inflorescence with yellow flowers and bright purplish-blue bracts. It is mainly a plant of eastern Europe, found from Denmark, Germany, and Italy eastwards to north-western Russia.

 

 

Large growth of wood cow-wheat, Småland, Sweden. (Photo copyright © by Kaj Halberg)

 

 

Wood cow-wheat, growing along a hedge near Halltorps Hage, Öland, Sweden. (Photo copyright © by Kaj Halberg)

 

 

 

Melampyrum pratense Common cow-wheat
This plant is found in all of Europe, eastwards to central Siberia, all the way north to the Arctic coast. Formerly, it was readily eaten by cows, giving rise to the common name of the genus. It contains large quantities of dulcit, a saccharide, and the fact that it also contains a toxic glycoside, rhinanthin, did not seem to harm the cattle. The seeds are dispersed by ants of the genus Formica, which eat a fleshy structure on the seed, called elaiosomes.

 

 

In Sweden, common cow-wheat is extremely common. These pictures are from a pine forest near Friseboda, Skåne. The lower picture shows a plant, which has rooted among reindeer lichens (Cladonia). (Photos copyright © by Kaj Halberg)

 

 

 

Melampyrum sylvaticum Small cow-wheat
This plant resembles common cow-wheat, but may be identified by its smaller, golden-yellow flowers. It is partial to coniferous forests, growing all over Europe, including Iceland and north-western Russia.

 

 

Small cow-wheat is quite common in the Alps, here photographed in the Stubai Valley, Austria. (Photo copyright © by Kaj Halberg)

 

 

 

 

Odontites Red bartsia, false bartsia
This genus, numbering about 37 species, is distributed in all of Europe, north-western Africa, the Middle East, and northern Asia, southwards to Mongolia and Kazakhstan. Formerly, these plants were included in the genus Bartsia (above), which is the reason for their popular names.

 

Odontites litoralis Salt bartsia
Distributed in northern Europe, from Norway and Finland southwards to Holland, Germany, and Poland, this plant always grows near the coast, preferably on littoral meadows, but sometimes on rocks.

 

 

Salt bartsia, growing on a littoral meadow on the island of Fanø, Denmark. (Photo copyright © by Kaj Halberg)

 

 

 

 

Orobanche Broomrape
A genus of over 200 species, native mainly to temperate areas of the Northern Hemisphere. The generic name is derived from the Greek orobos (‘bean’) and ankhein (‘to strangle’), alluding to the bean broomrape (Orobanche crenata), which is a common parasite on the fava bean (Vicia faba). This species is presented below.

 

Orobanche alba Thyme broomrape
As its popular name implies, this species is partial to thyme (Thymus), but may occasionally grow on species of oregano (Origanum) and savory (Satureja). It has a wide distribution, found in the major part of Europe, eastwards through Russia and south-western Asia to Tibet and the Himalaya. In the Alps, it is found up to an altitude of 1,900 m, whereas in Asia it has been encountered up to 3,700 m.

 

 

Thyme broomrape, Lake Gosau, Austria. (Photo copyright © by Kaj Halberg)

 

 

 

Orobanche anatolica Anatolian broomrape
This plant, found from Turkey and Iraqi Kurdistan eastwards to the Caucasus, grows exclusively on species of sage (Salvia).

 

 

Anatolian broomrape is rather common in central Turkey, here observed near Bulanik, south of Çay. (Photo copyright © by Kaj Halberg)

 

 

 

Orobanche crenata Bean broomrape
This species is a native around the Mediterranean, and in North and East Africa. As mentioned above, it is a common parasite on the fava bean (Vicia faba), but also on various other plants. In Apulia, southern Italy, its stems are eaten, called sporchia. (Source: E. Luard, 2004. European peasant cookery, Grub Street)

 

 

Bean broomrape, growing on an umbellifer among boulders along the sea front, Sultanahmet, Istanbul, Turkey. (Photo copyright © by Kaj Halberg)

 

 

 

Orobanche elatior Knapweed broomrape
This large species, which may grow to 70 cm tall, is partial to greater knapweed (Centaurea scabiosa), but is occasionally found on other species of knapweed and rarely on members of the daisy family (Asteraceae) and buttercup family (Ranunculaceae). Growing in open areas, only on alkaline soils, this plant is found in the major part of Europe, eastwards through West and Central Asia to the Gansu Province of China.

 

 

Knapweed broomrape, photographed in northern Jutland, Denmark. (Photo copyright © by Kaj Halberg)

 

 

 

 

Pedicularis Lousewort
The number of plants in this genus differs enormously according to various authorities, from about 350 to 600. They are distributed across almost the entire Northern Hemisphere, from the Arctic coasts southwards to Columbia, north-western Africa, Iran, the Himalaya, and southern China. The highest diversity is in China, which, according to eflora of China, has 352 species, of which 271 are endemic.

The generic name is derived from the Latin pediculus (‘louse’). According to an old superstition, louseworts could transfer lice to people and cattle, or, according to another belief, the exact opposite was the case, namely that they were able to rid people and cattle of lice! In Denmark, a decoction of these plants was used to expel lice from clothes. Usually, animals do not graze on these plants, as they contain poisonous glycosides.

 

Pedicularis bicornuta Horned lousewort
This common species of the Tibetan Plateau is of  the same colour as long-tubed lousewort (below), but grows in drier areas. It is distributed from Afghanistan eastwards to the Indian state of Uttarakhand, at altitudes between 2,700 and 4,400 m. The flowers are utilized in Tibetan folk medicine for treatment of vaginal and seminal discharges. (Source: T.J. Tsarong, 1994. Tibetan Medicinal Plants)

 

 

Horned lousewort is abundant in Spiti, Himachal Pradesh, here photographed together with a blue species of vetch (Vicia) and a willowherb (Epilobium). (Photo copyright © by Kaj Halberg)

 

 

 

Pedicularis capitata Capitate lousewort
This stately plant is found in Canada, Alaska, and eastern Siberia, southwards to north-eastern China and Kamchatka. The arctic bumblebee (Bombus polaris) plays an essential role in the pollination of this species and the woolly lousewort (below). This bee is adapted in a way that allows it to work the spikes from the bottom towards the top. (Source: P.G. Kevan, 1972. Insect Pollination of High Arctic Flowers. Journal of Ecology, 60 (3): 831-847)

 

 

Capitate lousewort, observed near Anadyr Airport, Chukotka, north-eastern Siberia. (Photo copyright © by Kaj Halberg)

 

 

 

Pedicularis densiflora Indian warrior, warrior’s plume
The popular names of this species refer to its dense inflorescence, which somewhat resembles a Native American warrior’s plume. The specific name means ‘dense-flowered’.

This plant is parasitic on roots of other plants, mainly of the heath family (Ericaceae). It is restricted to California and Oregon, growing at low elevations in woodlands and chaparral, a community of shrubby plants, adapted to dry summers and moist winters, which is typical of southern California.

Formerly, this plant was taken by indigenous peoples to relax tired muscles, and buds and flowers were smoked as a mild intoxicant.

 

 

Indian warrior, Cache Creek Wilderness Area, California. (Photo copyright © by Kaj Halberg)

 

 

 

Pedicularis groenlandica Bull elephant’s head
Found in Arctic Canada and Greenland, and in high mountains of western North America, this plant is partial to wet areas, especially along riverbanks. The flowers have a long, pointed beak, which curves upward, resembling an elephant’s lifted trunk, while the lateral lobes resemble an elephant’s ears.

 

 

Bull elephant’s head, photographed during a heavy rain shower, Olympic National Park, Washington, United States. (Photo copyright © by Kaj Halberg)

 

 

 

Pedicularis lanata Woolly lousewort
Distributed in Alaska, northern Canada, and north-eastern Siberia, southwards to north-eastern China. Despite containing toxic glycosides, this species and Pedicularis capitata (above) are sometimes browsed by caribou (Rangifer tarandus).

 

 

This woolly lousewort was encountered near Anadyr Airport, Chukotka, north-eastern Siberia. (Photo copyright © by Kaj Halberg)

 

 

 

Pedicularis longiflora ssp. tubiformis Long-tubed lousewort
Often forming huge growths, this plant is ubiquitous in wet alpine meadows and along lake-sides in dry Tibetan country, from northern Pakistan eastwards to south-western China, at altitudes between 2,700 and 5,300 m. Some authorities regard it as a separate species, P. tubiformis.

 

 

An alpine meadow with thousands of long-tubed louseworts, Puga Marshes, Ladakh, northern India. (Photo copyright © by Kaj Halberg)

 

 

These long-tubed louseworts were encountered at Tso Kar, a saline lake in Ladakh, northern India. (Photo copyright © by Kaj Halberg)

 

 

 

Pedicularis palustris Marsh lousewort
As its name implies, this much-branched plant, growing to 40 cm tall, is found in wet marshes. It is widespread, occurring in all of Europe, except Iceland and areas around the Mediterranean, eastwards to central Siberia, Kazakhstan, Sinkiang, and Mongolia. It is also found in the easternmost part of Canada, east of Hudson Bay.

 

 

Marsh lousewort, photographed near Århus, Denmark. (Photo copyright © by Kaj Halberg)

 

 

 

Pedicularis rostrato-capitata Beaked lousewort
This species is distributed from eastern Switzerland eastwards to the Julian Alps and the Carpathians, growing on limestone screes and in grassland, at altitudes from 1,200 to 2,800 m. It is named after the beak on the upper lip of the flower, which is up to 5 mm long.

 

 

Beaked lousewort, Grossglockner, Austria. (Photo copyright © by Kaj Halberg)

 

 

 

 

Rhinanthus Yellow-rattle
There is great controversy as to how many species of yellow-rattle exist, as they vary a lot and are notoriously difficult to distinguish. Most authorities say between 30 and 40 species, distributed in Europe, northern Asia, and North America, the majority in Europe. They grow in grasslands, often abundantly. Their flowers are much visited by bumblebees (Bombus).

The name yellow-rattle refers to the yellow flowers of this genus, which turn into thin-walled capsules, surrounded by a dry, membrane-like calyx. When the wind blows, the seeds inside the capsule produce a rattling sound. The generic name is from the Greek rhinos (‘nose’) and anthos (‘flower’), referring to the nose-like upper lip of the corolla.

 

Rhinanthus major Greater yellow-rattle
This plant, also called R. angustifolius or R. serotinus, grows in grasslands in the major part of Europe, eastwards to central Siberia, Kazakhstan, and Mongolia.

 

 

This meadow near Århus, Denmark, displays an abundance of greater yellow-rattle, together with meadow buttercup (Ranunculus acris), common marsh orchid (Dactylorhiza majalis), common sorrel (Rumex acetosa), and narrow-leaved plantain (Plantago lanceolata). The bushes in the background are hawthorns (Crataegus), pruned by grazing cattle. (Photo copyright © by Kaj Halberg)

 

 

Greater yellow-rattle, photographed on the island of Fanø, Denmark. Common meadow-grass (Poa pratensis) is also seen in the picture. (Photo copyright © by Kaj Halberg)

 

 

 

 

Striga Witchweed
A genus of c. 34 species, distributed across Africa, on the Arabian Peninsula and the Indian Subcontinent, in Southeast Asia, and in northern Australia. These plants are parasitic on grass roots.

 

Striga asiatica Asiatic witchweed
Despite its name, this species is distributed in most of Africa, on the Arabian Peninsula, on the Indian Subcontinent, and in Southeast Asia. It is a serious pest on crops like sorghum, maize, rice, and sugarcane, especially among subsistence farmers in Africa.

 

 

Asiatic witchweed, observed near Kilwa Kisiwani, southern Tanzania. (Photo copyright © by Kaj Halberg)

 

 

 

 

 

Santalaceae Sandalwood family
Previously, a number of parasites on trees were all called mistletoes, placed in the family Viscaceae. However, extensive DNA research has caused this family to be abolished, and a large number of its members have been moved to this family.

 

Dendrophthora
A neotropical genus of 120-160 species, closely related to Phoradendron (below). These plants are distributed from southern Mexico and the Caribbean southwards to Peru and Bolivia.

 

Dendrophthora costaricensis
This montane species is found at elevations between 1,100 and 3,500 m, from southern Mexico southwards to Ecuador.

 

 

Dendrophthora costaricensis, Cordillera de Tilarán, Costa Rica. (Photo copyright © by Kaj Halberg)

 

 

 

Phoradendron Leafy mistletoe
This huge genus, containing between 235 and 240 species, is distributed in warmer regions of the Americas, with most species in the Amazon Basin.

The generic name is from the Greek phore (‘carrier’) and dendron (‘tree’), thus ‘carried on a tree’, referring to the epiphytic habits of this genus. It was named by Thomas Nuttall (1786-1859), a British printer, who came to the United States in 1808. Shortly after his arrival, he met botanist Benjamin Barton (1766-1815), who induced a strong interest in natural history in him. During the following years, until 1841, Nuttall undertook several expeditions in America, and numerous plants and animals are named after him.

Phoradendron flowers are greenish and very small, only 1-3 mm in diameter. The fruits and their dispersal are similar to those of Viscum (see above). They are a favourite food of silky-flycatchers (Phainopepla).

Leafy mistletoes sometimes severely reduce crop productions in fruit and nut trees. Foliage and berries of some species are toxic. (Source: en.wikipedia.org/wiki/Phoradendron, where a list of references is found)

 

Phoradendron californicum Desert mistletoe, mesquite mistletoe
This plant is found in the Mojave and Sonoran Deserts in southern California, Nevada, and Arizona, and in the Mexican states Sonora, Sinaloa, and Baja California, up to an elevation of 1,400 m. It grows on a wide selection of trees or shrubs, including mesquite (Prosopis), ironwood (Olneya tesota), catclaw acacia (Senegalia greggii), palo verde (Parkinsonia), and desert buckthorn (Condalia).

Formerly, the fruits of this species were consumed by various indigenous peoples, who harvested them by spreading a blanket beneath the plant, hitting it with sticks.

 

 

Fruiting mesquite mistletoe next to a Mojave yucca (Yucca schidigera), Joshua Tree National Park, California. The rock formation in the background, called Split Rock, consists of eroded Monzo granite. (Photo copyright © by Kaj Halberg)

 

 

This bush in Mohave National Preserve, California, is severely infested with mesquite mistletoe. (Photo copyright © by Kaj Halberg)

 

 

Berries of mesquite mistletoe, Colossal Cave Mountain Park, Arizona (top), and in Joshua Tree National Park, California, with raindrops. (Photos copyright © by Kaj Halberg)

 

 

 

Phoradendron juniperinum Juniper mistletoe
As its name implies, this species is partial to junipers (Juniperus). It is native to western United States, from Oregon and California eastwards to Colorado and Texas, and the Mexican states Chihuahua and Sonora.

Formerly, the berries of this plant were eaten by several indigenous peoples, while the leaves were used for tea, and also for treating various ailments, including stomachache, to relax tired muscles, and to diminish bleeding after childbirth.

 

 

This juniper (Juniperus) in Prescott National Forest, Arizona, is infested with juniper mistletoe. (Photo copyright © by Kaj Halberg)

 

 

Close-up of juniper mistletoe, Prescott National Forest, Arizona. (Photo copyright © by Kaj Halberg)

 

 

This juniper mistletoe (Phoradendron juniperinum) in Zion National Park, Utah, is full of yellowish berries. (Photo copyright © by Kaj Halberg)

 

 

 

Phoradendron villosum Oak mistletoe
This plant, also known as Pacific mistletoe, occurs in western United States, from Oregon and California eastwards to Texas, and in northern Mexico. It is partial to oak trees (Quercus), but may also be found on various other broad-leaved trees or shrubs, including manzanita (Arctostaphylos), California laurel (Umbellularia californica), and sumac (Rhus).

The specific name means ’hairy’, alluding to the dense cover of short hairs on the leaves.

 

 

This cottonwood (Populus), growing near Lake Isabella, California, is severely infested with oak mistletoe. (Photo copyright © by Kaj Halberg)

 

 

In this picture, oak mistletoe grows on a California sycamore (Platanus racemosa), Cleveland National Forest, California. (Photo copyright © by Kaj Halberg)

 

 

Oak mistletoe, growing on a blue oak (Quercus douglasii), Cache Creek Wilderness Area, California. (Photo copyright © by Kaj Halberg)

 

 

Close-up of oak mistletoe in morning light, Santa Rosa Mountains, California. (Photo copyright © by Kaj Halberg)

 

 

 

 

Viscum True mistletoes
This genus of about 70-100 species is native to Europe, Africa, Asia, and Australia. The fruit is a white, yellow, orange, or red berry, in which the seeds are embedded in a very sticky juice. The seeds are dispersed by birds, either with their dung, or when the bird tries to remove a seed from its bill by wiping it on a branch. The seeds are toxic to people.

The name mistletoe is from Old Germanic, mistel (‘dung’) and tan (‘twig’), thus ‘the twig in the dung’, which aptly describes seeds of these plants, sprouting in a bird dropping left on a branch.

 

 

Unidentified mistletoe of the genus Viscum, Matobo National Park, Zimbabwe. (Photo copyright © by Kaj Halberg)

 

 

 

Viscum album Common mistletoe
Widely distributed in Europe, except the far north, in north-western Africa, and across the Middle East to the western part of the Himalaya.

To the Celtic druids, mistletoes, growing on the sacred oak trees, possessed the power of the oaks, and they formed a part of their religious rituals. Mistletoes were only collected when the druids had visions, directing them to seek it. Carrying mistletoe branches, young men would walk around, announcing the coming of the new year. This custom was probably taken over by the British, and even after the introduction of Christianity it was preserved in a different form. On New Year’s Eve, branches of mistletoe were cut, adorned with fruits and brightly coloured ribbons, and hung from a beam at midnight, after which young men would lead young maidens beneath the mistletoe and wish them Happy New Year with a kiss.

In Brittany, this plant is called Herbe de la Croix. According to an old legend, the Cross of Christ was made from its wood, which caused it to be degraded to a parasite.

In Norse mythology, the god of love, Balder, son of Odin and Frigg, was troubled by ominous dreams, so his mother made all living and inanimate things swear that they would not harm him. The other gods tested the oath by shooting arrows and hurling stones at him, but he remained unscathed. However, Frigg had neglected to ask the mistletoe. This was noted by the evil and cunning Loke, who made an arrow from it and persuaded Balder’s blind brother Höðer to fire it at him, killing him.

Formerly, in its entire area of distribution, birdlime was made from the gluey berries, utilized to catch thrushes and other small birds – a practice still taking place in the Middle East and the Himalaya. Soap was produced from the berries in the 1800s.

A picture, depicting an abundance of common mistletoe, is seen at the top of this page.

 

 

Common mistletoe, Lac de Grand Lieu, Loire Atlantique, France. (Photo copyright © by Kaj Halberg)

 

 

 

Viscum coloratum Chinese mistletoe
The native range of this species is from Ussuriland, south-eastern Siberia, southwards to Korea, eastern China, and Taiwan.

 

 

Chinese mistletoe is quite common in Taiwan. In these pictures it grows on Taiwan alders (Alnus formosana) in the Taroko Gorge (top), and in Dasyueshan National Forest. (Photos copyright © by Kaj Halberg)

 

 

 

(Uploaded November 2018)

 

(Latest update August 2020)