Parasitic plants

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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.

Many parasitic plants are presented on the pages Plants: Flora of the Alps and the Pyrenees, and Plants: Himalayan flora 1, 2, and 3.

 

 

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

 

 

 

 

 

 

 

They are distributed almost worldwide, with the greatest concentration in the tropics and subtropics. Temperate areas have much fewer species, including northern Europe, where only 4 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.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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 rockrose family (Cistaceae), the amaranth family (Amaranthaceae), and the tamarisk family (Tamaricaceae).

 

 

 

 

 

 

Formerly, C. hypocistis was used in herbal medicine for dysentery, throat tumors, and as an astringent, and young specimens may be eaten as a substitute for asparagus.

 

 

 

 

 

 

 

 

 

 

 

 

 

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

There is some controversy regarding the specific name of this plant. Swedish botanist Carl Linnaeus (1707-1778) 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)

 

 

 

 

 

 

 

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.

 

 

 

 

 

 

 

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.

 

 

 

 

 

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 (below), the seeds are surrounded by a sticky substance, being spread by birds or, rarely, by small mammals.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The generic name is from the Greek misos (‘hatred’) and dendron (‘tree’), thus ‘hates trees’, referring to the parasitic habits of this genus. The common name refers to the feathery look of some species, especially M. linearifolium (below).

 

Previously, it was used medicinally, rubbed on sore muscles.

 

 

 

 

 

This plant is native to the southern half of Chile and adjacent areas of Argentina, growing up to elevations of about 2,000 m.

 

 

 

 

 

 

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.

A number of fig trees, including strangler figs, are described on the pages Plants: Ancient and giant trees, and Plants: Pipal and banyan – two sacred fig trees.

 

 

 

 

 

 

 

 

 

 

 

 

The specific name is Latin, meaning ‘used for dyeing’. The tree was named in allusion to the traditional usage of the fruits to produce a dye.

 

 

 

 

 

A few orchids, however, are parasitic on the fungus, as they do not possess chlorophyll, thus being unable to deliver nutrients to the fungus.

 

 

 

 

 

 

 

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

This plant is mentioned in a poem, written by American poet Robert Frost (1874-1963) (see top of this page).

 

 

 

 

 

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).

 

 

 

 

 

 

 

In Nepal, root and flowers are utilized medicinally to treat infections and skin problems.

 

 

 

 

 

The genus was named in honour of Prussian botanist Johann Bartsch (1709-1738) of Königsberg. The famous Swedish botanist Carl Linnaeus (1707-1778) advised him to participate in an expedition to present-day Suriname as a physician, but, unfortunately, he perished during this journey.

 

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

 

 

 

 

 

 

 

 

 

 

 

 

 

These plants 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)

 

This plant is native to the Pacific States, from Washington southwards to Baja California, growing on slopes along the coast, and also a little inland.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In former days, indigenous peoples of California harvested the seeds for food.

This species is crucial as a host plant for a threatened subspecies of the Bay checkerspot butterfly (Euphydryas editha ssp. bayensis), of the family Nymphalidae, which is endemic to the San Francisco Bay area.

 

 

 

 

 

 

 

 

 

 

 

 

A widely distributed plant, found from California eastwards across Arizona and New Mexico to Texas, growing in rocky areas and shrubberies.

The specific name is derived from the Latin lana (‘wool’), alluding to the woolly hairs covering stem and leaves.

 

 

 

 

 

The specific name is Latin, meaning ‘broad-leaved’.

 

 

 

 

 

 

 

 

 

 

 

 

 

In Chinese medicine, this species is sometimes used as a substitute for C. deserticola.

 

 

 

 

 

 

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.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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.” (Source: N. Doubleday 1900. Nature’s Garden: An Aid to Knowledge of Our Wild Flowers and Their Insect Visitors. Doubleday, Page & Co.)

 

 

 

 

 

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,” and 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, when 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’.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The generic name is derived from the Greek 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)

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.”

 

 

 

 

 

 

 

 

 

 

 

 

 

Formerly, this plant 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.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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.

 

 

 

 

 

Stem erect, slender, hairy, reddish, brownish, or yellowish, to 60 cm tall, leaves and bracts dark purple, scale-like, flowers in a dense terminal spike, corolla tubular, to 2.4 cm long, glandular-hairy, brownish-yellow outside, blood-red inside.

 

 

 

 

 

It is parasitic on hundreds of species in various families, but with a clear preference for the pea family (Fabaceae) and composites (Asteraceae). It is often common in clover fields, and is regarded as an agricultural pest in New Zealand and the United States.

 

 

 

 

 

As its name implies, the stem is branched, to 60 cm tall, and covered in glandular hairs. The flowers are blue with two white streaks on the lower lip.

 

 

 

 

 

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.

 

The flowers are utilized in Tibetan folk medicine for treatment of vaginal and seminal discharges. (Source: T.J. Tsarong 1994. Tibetan Medicinal Plants)

 

 

 

 

 

 

 

 

 

 

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, it was utilized by indigenous peoples to relax tired muscles, and buds and flowers were smoked as a mild intoxicant.

 

 

 

 

 

 

 

 

 

 

The specific name is derived from the Latin lana (‘wool’), alluding to the dense layer of woolly hairs, covering stem and leaves.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The generic name is derived 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 (below). 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)

 

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

 

 

 

 

 

 

 

 

 

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.

 

 

 

 

 

 

 

 

 

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

 

 

 

 

 

 

 

 

 

 

 

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.

 

 

 

 

 

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, Balder, the god of love, 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.