In praise of the colour yellow



Taiwan 2018c
Bicycles for rent in the city of Taichung, Taiwan. (Photo copyright © by Kaj Halberg)



Californien 2011
California sister (Adelpha californica) is a butterfly of the brushfoot family (Nymphalidae), distributed from Oregon and Nevada, south through California to northern Baja California. It is easily identified by the yellow or orange patch near the wingtip. This one was observed at Kings Canyon River, Sierra Nevada, California. (Photo copyright © by Kaj Halberg)



Tyrkiet 2018a
Jylland 2006-12
Yellow everlasting (Helichrysum arenarium) is widely distributed, from western Europe east to Mongolia, and thence south to the Mediterranean and northern Iran. Formerly, in Russia, it was called ‘immortality herb’ due to its medicinal properties. Its leaves were also used as flavouring in meat dishes. These pictures are from the Karaburun Peninsula, near Izmir, Turkey (top), and from Mols Bjerge, Jutland, Denmark. (Photos copyright © by Kaj Halberg)



Costa Rica-2
As the sun sets, a fierce wind is blowing clouds over a ridge in the Cordillera de Tilarán, Costa Rica. (Photo copyright © by Kaj Halberg)



Lotus is a huge genus of the pea family (Fabaceae), comprising at least 130 species. The popular name of these plants is bird’s-foot trefoil, the ‘trefoil’ part referring to the tripartite leaves, while ‘bird’s-foot’ refers to their triple pods, which spread out from a common point, hereby resembling a bird’s foot. Some DNA studies indicate that North American plants, which were formerly included in Lotus, should be placed in other genera, while other studies indicate that they should be retained in Lotus. Four species of this genus are native to Denmark, all presented below. They often grow in profusion in areas of low vegetation, their bright yellow flowers forming brilliant ‘carpets’.


Fanø 2001-12
Fanø 2001-12
The common bird’s-foot trefoil (Lotus corniculatus) is very common in all drier habitats with low vegetation. As the flowers of this species age, they often become bright orange. (Photos copyright © by Kaj Halberg)


Vorsø 2000-15
The greater bird’s-foot trefoil (Lotus pedunculatus, formerly L. uliginosus) is found in wetter habitats than the common bird’s-foot trefoil. It can be identified by its broad leaflets. (Photo copyright © by Kaj Halberg)


Sjælland 1969-2005
The narrow-leaved bird’s-foot trefoil (Lotus glaber, formerly L. tenuis) is salt-tolerant, mainly growing in littoral meadows. (Photo copyright © by Kaj Halberg)


Bornholm 2016
Dragon’s teeth (Lotus maritimus, also known as Tetragonolobus maritimus) was named after its sharply pointed calyx lobes. The generic name Tetragonolobus is from the Greek, tetragonus = square, and lobos = pod, referring to its angular pods, while the specific name maritimus is Latin, meaning ‘growing at the sea’. In Denmark, this plant is quite rare, mainly found on the island of Bornholm, in the Baltic Sea, where this picture was taken. The orange lichen on the rock is Xanthoria aureola. (Photo copyright © by Kaj Halberg)




Costa Rica-2 
The Montezuma oropendola (Psarocolius montezuma), a bird of the family Icteridae, is distributed in Central America, from southern Mexico south to Panama. It lives in colonies, easily identified by the long nests, hanging down from branches. This bird in Tortuguero National Park, Limón, Costa Rica, is preening its bright yellow tail feathers. (Photo copyright © by Kaj Halberg)



Taiwan 2014c
Taiwan 2013
Golden-rain tree, or flamegold (Koelreuteria elegans) is a smallish tree, named for its gorgeous inflorescence of countless small, yellow flowers, which, at a distance, may resemble ‘golden rain’. It is endemic to Taiwan, but is wide planted in the tropics and subtropics as a city tree. These pictures are from the city of Taichung, Taiwan. A clearwing moth, probably of the family Sesiidae, is seen in the lower picture. (Photos copyright © by Kaj Halberg)



Emberiza is a large genus of c. 41 extant species of passerines, distributed in Europe, Africa, and Asia. Males of many species are bright yellow, such as the yellowhammer (Emberiza citrinella), which breeds in all of Europe, east to Lake Baikal and northern Mongolia, with isolated populations in Ukraine and the Caucasus Mountains, the black-headed bunting (E. melanocephala), which is found from Italy, eastwards across Turkey and the Caucasus to Iran and western Pakistan, and the black-faced bunting (E. spodocephala), breeding in southern Siberia, Mongolia, and north-eastern and south-western China.


Sjælland 2006-11
Singing male yellowhammer (Emberiza citrinella), photographed at Stevns, Zealand, Denmark. The name yellowhammer is from Old English geolu (‘yellow’) and hama (‘covering’), in allusion to the bright yellow plumage of this bird. (Photo copyright© by Kaj Halberg)


Tyrkiet 2006
Singing male black-headed bunting (Emberiza melanocephala), Pergamon, western Turkey. (Photo copyright© by Kaj Halberg)


Yunnan 2007
Singing male black-faced bunting (Emberiza spodocephala), Lashe Hai Lake, Yunnan Province, China. (Photo copyright© by Kaj Halberg)




Californien 2011
The rough horsetail (Equisetum hyemale), also called scouring rush, has an enormous distribution, found in Europe, northern Asia, and North America. The name scouring rush stems from its former usage as a scouring remedy, and as sandpaper, due to its high content of silica. This picture from Kings Canyon National Park, Sierra Nevada, California, shows the American subspecies, E. hyemale ssp. affine, which is often yellow above each sheath. (Photo copyright © by Kaj Halberg)



In Ancient Greek mythology, Medusa was a Gorgon, a female winged monster with living venomous snakes on her head instead of hair. It was said that if you happened to look at her, you would turn into stone. According to Greek historian Herodotus (c. 484-425 B.C.), Medusa originated as part of the religion of the Berbers of North Africa. Medusa was killed by the hero Perseus, who used her head as a weapon, as it had retained its ability to turn onlookers to stone, until he turned it over to the goddess Athena, who placed it on her shield.


Tyrkiet 2006
Artificial light illuminates a head of Medusa, which has toppled in the underground cistern Yerebatan Sarnıcı, Istanbul, Turkey – the largest of several hundred ancient cisterns in this city, built during the reign of Emperor Justinian I (c. 482-565). (Photo copyright © by Kaj Halberg)



Kassinas, or running frogs, are a genus of brightly coloured frogs of the family Hyperoliidae, living in the entire sub-Saharan Africa. They are called running frogs, as they prefer to walk instead of hopping, like most other frogs do.


Tanzania 1993
Bubbling kassina (Kassina senegalensis), sitting on a bulrush stem in the Ngorongoro Crater, Tanzania. Each male emits a popping sound, and the name ‘bubbling kassina’ was given in allusion to the continuous bubbling sound, stemming from many male frogs, responding to each other’s calls. (Photo copyright © by Kaj Halberg)



Chile 2011
The trunk of this cactus, of the species Copiapoa carrizalensis, growing in Parque Nacional Llanos de Challe, Atacama Desert, Chile, is overgrown by a bright yellow lichen or alga. – More pictures of cacti are found on this website, see Gallery: Plants – Cacti. (Photo copyright © by Kaj Halberg)



Most smaller herons of the genus Egretta have black legs with bright yellow toes. The little egret (E. garzetta) has a very wide distribution, found in most tropical and subtropical areas of Europe, Africa, Asia, and Australia. In 1994, it also colonized the Caribbean island of Barbados, where a small population is still found. Its near-identical relative from the New World, the snowy egret (E. thula), is distributed in South and Central America, and also in parts of North America, where some populations are migratory, wintering further south. The name of the genus, Egretta, is from a French word, aigrette, meaning ‘little heron’. In 1782, the specific name of the snowy egret, thula, was given to this bird by a mistake by Chilean Jesuit priest and naturalist Juan Ignacio Molina (1740-1829), who didn’t realize, that in fact thula was the local Mapuduncun name for the black-necked swan (Cygnus melancoryphus).


Taiwan 2018
Little egret (Egretta garzetta), landing in a river in Taichung, Taiwan. More pictures of this species may be seen elsewhere on this website, see Animals: Birds in Taiwan. (Photo copyright © by Kaj Halberg)


USA 1998-99
An immature snowy egret (Egretta thula), photographed in J.N. Darling National Wildlife Refuge, Florida, identified by the yellow line running down the back of its legs. (Photo copyright © by Kaj Halberg)




Chile 2011a
Stinging loasa (Loasa acerifolia), found in the Andes Mountains, has very pretty flowers – but do not touch this plant, as it is equipped with stinging hairs, just like the familiar stinging nettle (Urtica dioica). – Reserva Nacional Altos de Lircay, Chile. (Photo copyright © by Kaj Halberg)



Zambia 1993
The African wattled lapwing (Vanellus senegallus) is named after the yellow wattles at the base of its bill. On its wings, it has a tiny, blackish spur. This species is quite common in sub-Saharan Africa, except in areas with rainforest. – Lochinvar National Park, Zambia. (Photo copyright © by Kaj Halberg)



USA-Canada 1992
The upright prairie coneflower (Ratibida columnifera) is distributed in much of North America, especially in grassy areas. The shape of its flower heads has given it the popular name ‘Mexican hat’. – Badlands National Park, South Dakota, United States. (Photo copyright © by Kaj Halberg)



Liocichlas are colourful birds, found from northern India east to southern China, Taiwan, and Vietnam. Today, together with e.g. laughing-thrushes (Garrulax), sibias (Heterophasia), minlas (Minla), barwings (Actinodura), and leiothrixes (Leiothrix), they constitute the laughing-thrush family (Leiothrichidae). In former days, these genera were all placed in the babbler family, Timaliidae, which was previously a true ‘waste-bin of systematics’, in which hundreds of bird species were placed. Today, most of these species have been moved to other families.


Among the liocichla species, Steere’s liocichla (Liocichla steerii) is the one with the most ancient lineage. At a distance, the plumage of this species, which is endemic to montane areas of central Taiwan, appears uniformly green, but at close quarters it shows various shades of blue and brown, besides a bright yellow spot in front of the eye. This bird was photographed in Dasyueshan National Forest Recreation Area. (Photo copyright © by Kaj Halberg)



Arizona-Utah 2001
Mexican squawroot (Conopholis alpina var. mexicana) – also called Mexican cancer-root – is a member of the broomrape family (Orobanchaceae), growing in northern Mexico and south-western United States. It lacks chlorophyll, obtaining nutrients by being parasitic on roots of oak trees. – Lake Powell, Arizona. (Photo copyright © by Kaj Halberg)



Taiwan 2012
Lion sculptures are often placed at Daoist graves in Taiwan, guarding the grave against evil forces. – Read more about Daoism on this website, see Religion: Daoism in Taiwan. (Photo copyright © by Kaj Halberg)



Costa Rica
Costa Rica
The buttercup tree, or poro-poro (Cochlospermum vitifolium), variously placed in the families Cochlospermaceae and Bixaceae, is native to Central America and northern South America. Its gorgeous flowers appear after its leaves have been shed. – These pictures were taken in the Guanacaste Region of Costa Rica. (Photos copyright © by Kaj Halberg)



Taiwan 2013
Yellowish morning light on high-rise buildings (top), and on shops and restaurants along a street, Taichung, Taiwan. (Photos copyright © by Kaj Halberg)



The first acacia species, Acacia nilotica, was described in 1758 by Swedish naturalist Carl von Linné (1707-1778), also called Carolus Linnaeus, the name Acacia being a Latinized version of the Greek word akakia, from akis = thorn, referring to the prominent thorns of A. nilotica. The specific name refers to the locality, where the species was first found, the Nile.

Acacias belong to the huge pea family (Fabaceae), subfamily Mimosoideae, which is characterized by flowers with very small petals and numerous stamens. Formerly, the genus Acacia comprised no less than c. 1500 species, but according to the latest update of the Angiosperm Phylogeny Group’s classification for flowering plants, the APG IV, this genus is polyphyletic, today being divided into five genera: Acacia, comprising c. 980 mainly Australian species; Vachellia, a genus of c. 193 tropical and subtropical species, most of which (c. 83) are found in Africa and on Madagascar; Senegalia, a genus of about 220 species, distributed worldwide in tropical and subtropical areas (except Australia), with the majority in Africa; Acaciella, a small Neotropical genus of 15 species, most of which are found along the Mexican Pacific coast; and, finally, Mariosousa, comprising 13 species, found mainly in Mexico and Central America, with a few species extending into the United States. (Source:

The pictures below show four acacia species, three with yellow flowers, and one with yellow bark.


Taiwan 2018
An abundance of flowers in a Taiwan acacia, or small Philippine acacia (Acacia confusa), Taichung, Taiwan. This species has a disjunct distribution, found in southern China, Taiwan, Vietnam, the Philippines, Indonesia, and South India. It is very common in lowland Taiwan. (Photo copyright © by Kaj Halberg)


Nordindien 1982
Fallen flowers of Egyptian acacia, or babul (Vachellia nilotica), in a pond, Keoladeo National Park, Rajasthan, India. This species, which has been introduced to northern India from Africa, has become an invasive in many areas. (Photo copyright © by Kaj Halberg)


Sydafrika-Namibia 1993
Flowering acacia with wattled starlings (Creatophora cinereal), Kalahari Gemsbok National Park, South Africa. (Photo copyright © by Kaj Halberg)


Zimbabwe-Kenya 1994
The yellow-barked acacia (Vachellia xanthophloea) is common in eastern Africa, from Somalia south to South Africa. A popular name of this tree is ‘fever tree’, so named by early European travellers in Africa, who noticed that you would often get malaria when camping beneath these trees. The reason for this was that the yellow-barked acacia mainly thrives in swampy areas, where also malarial mosquitos thrive. This picture from Lake Naivasha, Kenya, shows a close-up of the bark, on which a grey-backed fiscal shrike (Lanius excubitoroides) is sitting. (Photo copyright © by Kaj Halberg)




Kenya 1988-89
The male golden palm weaver (Ploceus bojeri) is bright yellow with an orange head. This bird has a fairly wide range, found in eastern Africa, from Ethiopia south to Tanzania. This male is displaying, sitting on a galingale stem in Meru National Park, Kenya. (Photo copyright © by Kaj Halberg)



The bladderpod (Peritoma arborea, formerly named Isomeris arborea or Cleome isomeris) is a bush in the spider-flower family (Cleomaceae), growing in the Mojave and Colorado Deserts of southern California and Baja California Peninsula. It has a foul smell, which discourages insects from eating it. Another common name of this plant is burro-fat, presumably in allusion to its butter-yellow flowers. (In Spanish, burro can mean butter, as well as donkey.)


Arizona-Utah 2001 
This picture is from Joshua Tree National Park, California, where bladderpod is very common. (Photo copyright © by Kaj Halberg)



Choughs, of the genus Pyrrhocorax, are jet-black members of the crow family (Corvidae), identified by their brightly coloured bill and feet, and by their calls, which have given them their English name. The Alpine, or yellow-billed, chough (P. graculus) is a bit smaller than the red-billed (P. pyrrhocorax), with a shorter, bright yellow bill. Both species are widely distributed in Europe, northern Africa, and Asia, the yellow-billed found in Morocco, the Pyrenees, the Alps and other Central European mountains, on Crete, and in Turkey, the Caucasus, Iran, and the Himalaya. – The red-billed chough is presented in depth elsewhere on this website, see: In praise of the colour red.


Alperne 2016
The yellow-billed chough (Pyrrhocorax graculus) is often very confiding, like this bird. After being drenched during a heavy rain shower, it is now searching for food on a restaurant table near Grossglockner, Austria. (Photo copyright © by Kaj Halberg)


Nepal 1985
A flock of yellow-billed choughs, searching for food in the Jarsang Valley, Annapurna, Nepal. (Photo copyright © by Kaj Halberg)


Annapurna 2007
Yellow-billed chough, taking off from a rock in Annapurna Sancturary, Nepal. (Photo copyright © by Kaj Halberg)



Turkish warty-cabbage (Bunias orientalis) is a member of the cabbage family (Brassicaceae), named after its warty siliques (fruits). This species is probably native to the Caucasus, central and southern Russia, western Siberia, and south-eastern Europe, north to Slovakia and Hungary. Today, however, it is very widespread in Asia, Europe, and North America, in some places being invasive.


Bornholm 2008a
Bornholm 2016a
On the island of Bornholm, Denmark, Turkish warty-cabbage is a very common escape, especially in the harbor area of the town of Gudhjem. (Photos copyright © by Kaj Halberg)



White-eyes are a group of small passerines, most of which belong to the genus Zosterops, from the Greek zoster = girdle, and ops = eye, referring to the white eye-ring of most species of this genus. Traditionally, they have been placed in a family of their own, Zosteropidae, but recent genetic studies indicate that they are closely related to the nine remaining genera in the babbler family, Timaliidae – previously a true ‘waste-bin of systematics’, in which hundreds of bird species were placed. (Today, most of these species have been moved to other families.) Some phylogenetic experts point out that further studies have to be made, before the true relationship of white-eyes with other birds can be determined.

The Japanese white-eye (Zosterops japonicus) has a bright yellow throat, crown, and vent, while the back is olive-green and the underside greyish. This bird is also found in Japan, eastern China, Vietnam, and the Philippines, and it has been introduced to other areas, e.g. Hawaii, where it is outcompeting native bird species, such as honeycreepers.


Taiwan 2018
Japanese white-eye is very common in the lowlands of Taiwan. This bird is feeding in a flower of Taiwanese cherry tree (Prunus campanulata), Taichung. (Photo copyright © by Kaj Halberg)


Taiwan 2018a
Japanese white-eye, feeding on fruits of Chinese tallow-tree (Triadica sebifera), Taichung. – Read about this tree elsewhere on this website, see: In praise of the colour red. (Photo copyright © by Kaj Halberg)



Araguaney (Tabebuia chrysantha) – also called ipê-amarelo (‘yellow ipê’ in Portuguese) – is a native of Central America and north-western South America, widely cultivated for its abundance of bright yellow flowers, which emerge before the leaves. It is the national tree of Venezuela, chosen because the yellow colour of its flowers resembles one of the colurs on the Venezuelan flag.


Taiwan 2015
Taiwan 2018b
Araguaney is a very commonly planted ornamental tree in warmer parts of the world. These pictures are from the city of Taichung, Taiwan. (Photos copyright © by Kaj Halberg)


Taiwan 2018b
In this picture, school children are sweeping fallen araguaney flowers in front of their school in Taichung, Taiwan. (Photo copyright © by Kaj Halberg)




Californien 2011a 
A huge species of kelp, several stories high, in the Monterey Aquarium, California, United States. (Photo copyright © by Kaj Halberg)



The orange weaver ant (Oecophylla smaragdina) has a wide distribution, found in India, Southeast Asia, and the Philippines, south through Indonesia to northern Australia. The name weaver ant stems from their nest, which is made by ‘weaving’ together leaves, using larval silk. A colony of these ants may include several nests in a single tree, or the nests may be spread over several adjacent trees. In one instance, a colony occupied 151 nests, distributed among 12 trees. A colony may count up to half a million individuals. Each colony has a single queen in one nest, from which her progeny is carried to other nests. (Source:, with a list of references).


Cambodia 2010
Orange weaver ants (Oecophylla smaragdina), sitting on their nest, Siem Reap, Cambodia. (Photo copyright © by Kaj Halberg)



Costa Rica 
Yellow barleria (Barleria oenotheroides) – also called giant yellow shrimp plant – belongs to the acanthus family (Acanthaceae). Of the nearly 300 types of Barleria, it is the only indigenous species in the New World (Mexico, Central America, and Colombia). This one was observed in Parque Nacional Palo Verde, Costa Rica. (Photo copyright © by Kaj Halberg)



USA 1992
A male yellow-headed blackbird (Xanthocephalus xanthocephalus) marks his territory by singing from a fence post in California. The male of this species is black with a bright yellow head and breast, while the female is brown with a yellowish breast. This bird is found in western United States, breeding in cattail marshes (Typha). (Photo copyright © by Kaj Halberg)



Vorsø 1975-87 
Yellow fairy cups (Bisporella citrina), or lemon discos, is a sac fungus, belonging to the family Helotiaceae. It has an almost worldwide distribution, being very common on dead tree trunks, in Europe especially in the autumn. – Jutland, Denmark. (Photo copyright © by Kaj Halberg)



Egypten 1999
Lemon tree (Citrus limon), Wadi Feiran, Sinai, Egypt. – Read more about this species on this website, see Traditional medicine – Citrus. (Photo copyright © by Kaj Halberg)



Kenya 1988-89 
An abundance of butterflies, of the genus Dixeia, sucking moist from wet sand on a dirt road, Meru National Park, Kenya. (Photo copyright © by Kaj Halberg)



Sverige 2015
British yellowhead, or meadow fleabane (Inula britannica), of the composite family, is indigenous to parts of Europe and northern Asia, and is also locally naturalized in North America. The butterfly, feeding in the flowers, is a peacock (Aglais io). – Öland, Sweden. (Photo copyright © by Kaj Halberg)



USA 1992 
The desert spiny lizard (Sceloporus magister) is native to the Chihuahuan and Sonoran Deserts of North America. It is easily identified by its rough scales and the yellow spots on its sides. – Grand Canyon, Arizona, United States. (Photo copyright © by Kaj Halberg)



Everest 2010
The yellow-billed blue magpie (Urocissa flavirostris) is a gorgeous member of the crow family (Corvidae). It feeds mainly on large insects and other invertebrates, but is also a notorious plunderer of eggs and young from smaller birds’ nests. – Khumbu, eastern Nepal. (Photo copyright © by Kaj Halberg)



Fanø 2001-12 
Evening-primroses (Oenothera) are American plants. In the late 1800s, in an area around the mouth of the Elbe River, northern Germany, a powerful mutation took place in an introduced species. In 1905, it was described as a new species, named Oenothera ammophila (’sand-loving’), which was later changed to O. oakesiana. This new species quickly spread northwards to Denmark, and today it is found along the entire west coast of peninsula Jutland. – This picture is from the island of Fanø, Denmark. (Photo copyright © by Kaj Halberg)



Californien 2011
Californien 2011
Californien 2011
Californien 2011
In autumn, the foliage of quaking aspens (Populus tremuloides) adds vivid splashes of yellow to numerous areas in western North America. These pictures are from a mountain slope near Conway Summit, Sierra Nevada, California. The lower two pictures also show the snow-white trunk of this iconic species. (Photos copyright © by Kaj Halberg)



Myanmar 2007
Buddhist pagodas in morning mist, Bagan, Myanmar. – Read more about these pagodas – and about Buddhism in general – on this website, see Religion: Buddhism. (Photo copyright © by Kaj Halberg)



Taiwan 2012 
Taiwan yellow pond-lily (Nuphar shimadai) is a Taiwan endemic, growing in marshes and ponds, here in the Guantian Jacana Reserve, near Madou, southern Taiwan. (Photo copyright © by Kaj Halberg)



Guatemala 1998
Three members of the tyrant-flycatcher family (Tyrannidae), two of which are bright yellow, the great kiskadee (Pitangus sulphuratus) (lower part of the picture) and tropical kingbird (Tyrannus melancholicus) (upper part, right). The birds with long tails are scissor-tailed flycatchers (Tyrannus forficatus). – Monterico, Guatemala. (Photo copyright © by Kaj Halberg)



Bornholm 2008a 
Stonecrops (Sedum) are creeping plants, which store water and nutrients in their succulent leaves, thus being adapted to a life in dry surroundings, such as rocks and sandy areas. This picture shows biting stonecrop (S. acre), growing on coastal rocks on the island of Bornholm, Denmark. This species is named after the bitter, peppery taste of its leaves, caused by their content of slightly toxic alkaloids. (Photo copyright © by Kaj Halberg)



The poppy family (Papaveraceae) is dealt with in depth elsewhere on this website, see: In praise of the colour red. Below, a number of species with yellow flowers are presented, among these two species of the wonderful genus Meconopsis, comprising c. 43 species, almost all of which are restricted to China and the Himalaya. Many species are cultivated as ornamentals in the West. The generic name is from the Greek mekon (‘moon’) and opsis (‘resembling’), referring to the round, yellow petals of the Welsh poppy, which French botanist Louis Viguier (1790-1867) separated from the genus Papaver in 1814, calling it Meconopsis cambrica, mainly due to the structure of its style. However, a phylogenetic study from 2011 suggests that the Welsh poppy is closer related to Papaver species than to other species of Meconopsis, restoring the former name of the species, Papaver cambricum, which was published in 1753 by Swedish naturalist Carl von Linné (1707-1778), also called Carolus Linnaeus. (Source: J.W. Kadereit, C.D. Preston & F.J. Valtueña. Is Welsh Poppy, Meconopsis cambrica (L.) Vig. (Papaveraceae), truly a Meconopsis? New Journal of Botany, Vol. 1, 2011, pp. 80-88)


Rolwaling 2004
The wonderful Meconopsis paniculata, growing to almost 2 metres tall, is found in the Himalaya, from Uttarakhand east to south-eastern Tibet. It is very common, especially on nutritious soils, such as cattle grazing grounds. This photograph shows a very lush mountain meadow in the Rolwaling Valley, central Nepal. M. paniculata is growing next to my guide Ganga Thapa, and in the background. Also seen are a tall umbellifer, Pleurospermum benthamii, a red lousewort, Pedicularis megalantha, and various ferns. (Photo copyright © by Kaj Halberg)


Nepal 2002
Much hybridization takes place among Himalayan poppies. It is not clear, whether Meconopsis dhwojii, here photographed in Langtang National Park, central Nepal, is to be considered a hybrid or a full species. (Photo copyright © by Kaj Halberg)


Frankrig-Spanien 2007
As described above, the Welsh poppy (Papaver cambricum) was formerly regarded as belonging to the Himalayan poppies (Meconopsis). This species is restricted to montane areas of the Iberian Peninsula, southern France, south-western England, Wales, and Ireland. This picture is from Col d’Aubisque in the French Pyrenees. (Photo copyright © by Kaj Halberg)


Kirgisien 1999
The ice poppy (Papaver croceum), which was formerly regarded as a subspecies of the Siberian poppy (P. nudicaule), is a Central Asian plant with a wide distribution, found from southern Siberia south to the northern outskirts of the Himalaya, and from Kyrgyzstan east to northern China. In this picture, it grows on a mountain pass above the Yrdyk Valley, Kyrgyzstan. (Photo copyright © by Kaj Halberg)


Alperne 2016a
The Rhaetian poppy, variously regarded as a separate species, Papaver aurantiacum, or as a subspecies of the widespread Alpine poppy, as P. alpinum ssp. rhaeticum, is found in eastern Switzerland, Austria, and northern Italy. This picture is from Passo di Valparola in the Dolomites. (Photo copyright © by Kaj Halberg)


Fanø 2001-12
Fanø 2001-12
Horned poppies, genus Glaucium, are named after their horn-shaped fruits. The yellow horned poppy (G. flavum), which often grows on seashores, is native to Europe, North Africa, the Middle East, and the Caucasus. These pictures are from the island of Fanø, Denmark. (Photo copyright © by Kaj Halberg)


Indien 2003
About 32 species of prickly poppies, genus Argemone, are distributed in North America and the West Indies, with a single species endemic to Hawaii. As its name implies, the Mexican prickly poppy (A. mexicana) is a native of Mexico, but has been widely naturalized in many parts of the world, as this specimen, photographed in Gujarat, India. (Photo copyright © by Kaj Halberg)


Californien 2013
Californien 2013b
Californian bush-poppy (Dendromecon rigida) occurs along the North American west coast, from northern California south to Baja California. This species is one of the few shrubby members of the poppy family, found on drier mountain slopes up to an altitude of c. 1,800 metres. It is partial to newly burned areas. These pictures are from the Pinnacles National Monument (top) and Torrey Pines State Park. (Photos copyright © by Kaj Halberg)




Plants of the genus Calochortus can be divided into three distinct groups: mariposa tulips, or mariposa lilies, which have open, wedge-shaped petals; globe lilies with globe-shaped flowers; and cat’s ears and star tulips, which have erect, pointed petals. These gorgeous lilies are almost exclusively found in the western United States. The generic name is from the Greek kalos (‘beautiful’) and chortos (‘grass’). – More pictures of these lilies may be seen elsewhere on this website, see: Quotes on nature.


Arizona-Utah 2001 
Yellow form of Kennedy’s mariposa tulip (Calochortus kennedyi), Colossal Cave Mountain Park, Arizona. (Photo copyright © by Kaj Halberg)



The Canary bird (Serinus canaria) is a native of the Canary Islands, Madeira, and the Azores. In the 1600s, sailors brought the first specimens to Europe, where they quickly became popular as cage birds due to their beautiful song. Through mutations, a number of colour varieties have evolved, e.g. yellow, white, red, brown, and bronze. The wild form is yellowish-green with grey parts on the sides and wings.

Most people think that the Canary Islands were named after this bird. However, this is not the case. Roman historian Pliny the Elder (23-79 A.D.) relates that these islands were populated by large wild dogs, after which they were referred to as the Canaria islands (in Latin, canis means ‘dog’). Thus, the bird is actually named after the islands – not the other way around!


Kanariske Øer 2006
Wild Canary bird, photographed on the island of Tenerife, Canary Islands. (Photo copyright © by Kaj Halberg)



Californien 2011a 
Yellow, or coastal, sand-verbena (Abronia latifolia) is a member of the four o’clock family (Nyctaginaceae), growing along the North American west coast. Its roots are edible, formerly eaten by people of the Chinook tribe. The name four o’clock family is caused by the flowers of a member of the family, marvel of Peru (Mirabilis jalapa), which do not open until late in the afternoon. – California. (Photo copyright © by Kaj Halberg)



Tanzania 1993
The red-and-yellow barbet (Trachyphonus erythrocephalus) is aptly named, as its plumage is predominantly red and yellow. This gorgeous bird is found in East Africa, from South Sudan, Ethiopia and Somalia, south to northern Tanzania. Its feathers are used ornamentally by several tribal peoples, e.g. the Masaai. It is often quite confiding, as this bird, sitting on the shaft of a shovel in our camp in Tarangire National Park, Tanzania. (Photo copyright © by Kaj Halberg)



In the Greek, rhododendron means ‘rose tree’. However, these trees and shrubs are not at all related to roses, but belong to the heath family (Ericaceae). From a distance, however, the flower clusters of certain species somewhat resemble roses. Rhododendron is a very large genus, comprising c. 1,025 species worldwide, the largest concentrations encountered in China, the Himalaya, Malaysia, Borneo, and New Guinea. – More pictures of rhododendrons are found on this website, see Plants – Rhododendrons.


Everest 2010 
Rhododendron campylocarpum, identified by its pale-yellow flowers, is very common in eastern Nepal. (Photo copyright © by Kaj Halberg)



Lolland-Falster-Møn 1970-86
The golden crocus (Crocus chrysanthus) is native to the Balkans and Turkey, but is widely cultivated because of its gorgeous flowers. – This picture was taken in Denmark. (Photo copyright © by Kaj Halberg)



Violets (Viola) are a huge genus, comprising maybe 600 species, found in most parts of the world, with the largest concentration in the northern temperate zone. Most violet flowers are white or various shades of blue, but some species have bright yellow flowers. Five examples are shown below.


Alperne 2016a
Arctic yellow violet (Viola biflora), photographed in the Dolomites, northern Italy. This species has a very wide distribution, found in Europe, Siberia, Central Asia, the Himalaya, China, Korea, Japan, and western North America. (Photo copyright © by Kaj Halberg)


Californien 2013b
California golden violet (Viola pedunculata) grows in grasslands, chaparral and woodlands along the Californian coast, and in the coastal ranges up to an altitude of c. 1,000 metres, south to northern Baja California. This photograph is from Santa Rosa Plateau Ecological Reserve, California. (Photo copyright © by Kaj Halberg)


Everest 2010
Viola wallichiana is fairly common in humid forests of the Himalaya, from central Nepal east to Bhutan and south-eastern Tibet. This picture is from the Khumbu area, eastern Nepal. (Photo copyright © by Kaj Halberg)


Chile 2011a
Viola maculata grows in forests of the Andes, from south of Santiago, Chile, and the Neuquén Province, Argentina, south to Tierra del Fuego. It is also found in the Falkland Islands (Islas Malvinas). Formerly, this species was used by the Mapuche tribe as a stimulant, for skin problems, and as a lavage in eye diseases. This one was observed in Parque Nacional Conguillio, Chile. (Photo copyright © by Kaj Halberg)


Californien 2013
The redwood violet (Viola sempervirens) is a native of coniferous forests along the American west coast, north to British Columbia. It can be identified by its leathery leaves. This picture is from Julia Pfeiffer Burns State Park, California. (Photo copyright © by Kaj Halberg)




Pitcher-plants are carnivorous plants of five different genera, which have one character in common: their leaves are highly modified, creating tube-shaped traps, called pitchers, which contain fluid. These plants emit fragrance, luring insects and other tiny animals into the trap. If these animals do not drown in the fluid, they are prevented from escaping by various means. Glands produce enzymes which can extract nutrients from the prey. One genus of pitcher-plants is Sarracenia, comprising 11 species, which are distributed in eastern North America, from Newfoundland and Labrador in the north to Florida in the south, and westwards to the Great Lake area. – Read more about Sarracenia and other carnivorous plants elsewhere on this website, see Plants: Carnivorous plants.


USA 2012
Yellow pitcher-plant (Sarracenia flava), Carolina Beach State Park, North Carolina. (Photo copyright © by Kaj Halberg)



The gorgeous Shwedagon Pagoda is an enormous Buddhist shrine in Yangon, Myanmar. Especially in the evening, many local Buddhists come to this pagoda to pray, give offerings, or participate in cleaning the surrounding platform. Read more about this pagoda – and about Buddhism in general – elsewhere on this website, see Religion: Buddhism.


Myanmar 2007
The platform, surrounding the Shwedagon Pagoda, is illuminated by the evening sun. (Photo copyright © by Kaj Halberg)


Myanmar 2007
When this picture was taken, one of the lesser Shwedagon pagodas was undergoing renovation, and a bamboo scaffold had been erected around it. (Photo copyright © by Kaj Halberg)



Great yellow gentian (Gentiana lutea) is a native of montane areas of central, southern, and eastern Europe. Its root contains one of the most bitter-tasting substances known. A few drops of gentian-root tincture will stimulate the function of liver and pancreas, and also increase the appetite. The name gentian derives from King Gentius, who ruled in Ancient Illyria 181-168 B.C., and who allegedly discovered the medicinal value of the yellow gentian. – Read more about this species elsewhere on this website, see Traditional medicine: Gentiana lutea.


Alperne 2017
Great yellow gentian (Gentiana lutea) is very common in Switzerland. This picture is from the Lauterbrunnen Valley, Berner Oberland. (Photo copyright © by Kaj Halberg)


Alperne 1968-2001
Close-up of yellow gentian flowers, Säntis Mountain, Sankt Gallen, Switzerland. (Photo copyright © by Kaj Halberg)



Clouded yellows (Colias) are colourful members of Coliadinae, called sulphurs or yellows, a subfamily of butterflies, counting about 300 species worldwide, within the huge family whites (Pieridae).


Frankrig-Spanien 2007
The common clouded yellow (Colias croceus) has a very wide distribution, from southern Europe and North Africa, through the Middle East to northern India. This one was observed in Navarra, Spain, feeding on a red star-thistle (Centaurea calcitrapa). (Photo copyright © by Kaj Halberg)


Nepal 1987
Mating pair of eastern pale clouded yellow (Colias erate ssp. lativitta), Langtang National Park, central Nepal. This species is found from south-eastern Europe, across Asia to Japan and Taiwan, and in Africa south to Somalia. Subspecies lativitta is restricted to the Himalaya. (Photo copyright © by Kaj Halberg)




Californien 2011
The yellow rabbitbrush (Chrysothamnus viscidiflorus) is a shrub of the composite family, which is widespread in western North America. This one was found in Sequoia National Forest, Sierra Nevada, California. (Photo copyright © by Kaj Halberg)



Arizona-Utah 2001
Greater yellowlegs (Tringa melanoleuca), a common bird in North America, is very similar to greenshank (Tringa nebularia), which replaces it in the Old World. – This bird was photographed along the Salt River, near Phoenix, Arizona. (Photo copyright © by Kaj Halberg)



Black-eyed Susan (Thunbergia alata) is a vine of the acanthus family (Acanthaceae). It is native to East Africa, but is widely cultivated as an ornamental, and it has escaped and become naturalized in most warmer regions of the world. This species is included in the Global Compendium of Weeds and is regarded as an aggressive invasive plant in a number of countries, including the United States, Costa Rica, Cuba, Brazil, Colombia, Paraguay, Australia, Japan, and Taiwan, besides numerous islands in the Pacific. The name Black-eyed Susan is thought to have come from a character, who figures in many traditional ballads and songs. In Ballad of Black-eyed Susan, by John Gay (1685-1732), Susan goes aboard a ship in-dock to ask the sailors, where her lover, Sweet William, has gone. She says:


O! Where shall I my true-love find?
Tell me, ye jovial sailors, tell me true,
if my sweet William sails among the crew.


Incidentally, the name Sweet William was given to another plant, Dianthus barbatus, a species of pink, or carnation.


Taiwan 2017a
Taiwan 2016a
These pictures of black-eyed Susan (Thunbergia alata) are from Taiwan, where this species is extremely common. (Photos copyright © by Kaj Halberg)



Zimbabwe-Kenya 1994
Trees, silhouetted against a rock wall, covered in yellow lichens, Matobo National Park, Zimbabwe. (Photo copyright © by Kaj Halberg)



Californien 2011a
The yellow bush lupine, or tree lupine (Lupinus arboreus), is endemic to California, but is widely cultivated as an ornamental, and often escapes cultivation. In some places, it is considered an unwanted invasive. – Andrew Molera State Park, California. (Photo copyright © by Kaj Halberg)



The attractive yellow trumpetbush (Tecoma stans), of the bignonia family (Bignoniaceae), has many other names, e.g. yellow bells, yellow elder, and Ginger Thomas. This species is widely distributed in the Americas, from south-western U.S., south through the Caribbean and Central America to the northern half of South America, but as it is widely cultivated as an ornamental, it is today found in most tropical and subtropical countries. It is the official flower of the U.S. Virgin Islands, and also the floral emblem of the Bahamas. Yellow trumpetbush was first described as Bignonia stans by Swedish naturalist Carl von Linné (1707-1778), also called Carolus Linnaeus, but was moved to the genus Tecoma in 1819 by French botanist Antoine Laurent de Jussieu (1748-1836). It seems that he made a mistake, as he named it after what he thought was the Aztec name of the plant, tecomaxochitl, which, however, is the name of another member of the bignonia family, the calabash tree (Crescentia cujete).


Myanmar 2007 
Yellow trumpetbush, Bagan, Myanmar. (Photo copyright © by Kaj Halberg)



Sri Lanka 1974-75
Seeking shelter under an umbrella, this Buddhist monk is waiting for the rain to stop. – Anuradhapura, Sri Lanka. (Photo copyright © by Kaj Halberg)



Hornbills, belonging to the family Bucerotidae, got this name from a strange protuberance, or casque, on the bill of the larger species. These large species are very noisy, and the casque probably increases the volume of their call. The smaller species do not have this casque. – Read more about hornbills on this website, see Animals: Hornbills.


Sydafrika-Namibia 1993 
Southern yellow-billed hornbill (Tockus leucomelas), Etosha National Park, Namibia. – This national park, and Namibian nature in general, are dealt with in elsewhere on this website, see Countries and places: Namibia – a desert country. (Photo copyright © by Kaj Halberg)



Taiwan 2010
This extremely hairy caterpillar is very well camouflaged, sitting on a yellow leaf. – Malabang National Forest, northern Taiwan. (Photo copyright © by Kaj Halberg)



Irises are a genus of wonderful plants, comprising 250-300 species. They are named after Iris, the Greek goddess of the rainbow, presumably because of the colourful flowers of many of the species. Yellow iris (Iris pseudacorus) is native to Europe, western Asia, and north-western Africa, and is also a common escape in North America. The specific name, pseudacorus, means ‘false acorus’, referring to the similarity of its leaves to those of sweet flag (Acorus calamus). – In his book Utkast till svenska växternas naturhistoria (1867-1868), Swedish botanist C.F. Nymann (1820-1893) writes, ”It is said that the root is effective against rabies, caused by the bite of a mad dog.” In former days, the root was boiled together with ferrous sulphate, producing a black liquid, which was used as ink.


United Kingdom 1992-2002
United Kingdom 1992-2002
Yellow iris (Iris pseudacorus), growing in the Avon Canal, Vale of Pewsey, Wiltshire, England. (Photos copyright © by Kaj Halberg)



Nepal 1985
A field of leaf mustard (Brassica juncea), southern Nepal. At night, from the watchtower, men shoo away wild boar (Sus scrofa), rhinos (Rhinoceros unicornis) and other grazers from the field, using burning torches. To the left a silk-cotton tree (Bombax ceiba), the branches of which have been lopped for fodder. (Photo copyright © by Kaj Halberg)



Tyrkiet 2006 
This western yellow-legged gull (Larus michahellis) has killed a domestic pigeon and is now eating it on a roof top in Istanbul, Turkey. This species, which resembles the widespread herring gull (L. argentatus), can be identified by e.g. its yellow legs and very powerful beak. – More pictures of this species are found elsewhere on this website, see: Nature – Urban nature. (Photo copyright © by Kaj Halberg)



The arrow-leaved balsamroot (Balsamorhiza sagittata), or Oregon sunflower, is widespread in western North America, from British Columbia and Alberta, south to California and Wyoming. It was first collected by Colonel Meriwether Lewis, on the Lewis & Clark Expedition, at the mouth of White Salmon River, Washington, in 1806. Many Native American peoples, including the Nez Perce, Kootenai, Cheyenne, and Salish, utilized this plant as food and medicine. The root can be eaten, raw or cooked, with a balsam-like taste. The Salish people claimed that its taste was best after being baked in a fire pit for three days. Young shoots were also cooked or added to salads. Seeds were ground and formed into cakes, which could be eaten raw. As a medicinal herb, this species was mainly used for stomach problems. (Source:


USA-Canada 1992
Arrow-leaved balsamroot, Yellowstone National Park, Wyoming. (Photo copyright © by Kaj Halberg)



Vorsø 1975-87
Field, full of blooming dandelion (Taraxacum officinale), Jutland, Denmark. – Read more about this species on this website, see Traditional medicine – Taraxacum officinale. (Photo copyright © by Kaj Halberg)



Nepal 2009-2
This newly hatched common grass yellow (Terias hecabe ssp. contubernalis) is still sitting on its cocoon. – Pokhara, Nepal. (Photo copyright © by Kaj Halberg)



(Uploaded March 2017)


(Revised continuously)