Rhododendrons

 

 

 

 

 

 

 

 

 

 

 

 

 

China is the absolute stronghold of the genus, with no less than about 571 species, of which 409 are endemic.

The Himalaya is home to about 100 species, the vast majority growing in the eastern part of the mountain chain. A tiny country like Bhutan, for instance, harbours more than 60 species. The further west you travel in the Himalaya, the fewer species you encounter. Eastern Nepal is home to c. 30 species, western Nepal to 7, and Pakistan to only 4.

In tropical regions, the genus is mainly restricted to mountains, but a few species are found in areas with a genuine tropical climate, including one in Queensland, Australia.

Montane areas of Borneo hold about 55 species of rhododendron, of which about half are restricted to the highest mountains on the island, around Gunung Kinabalu (4094 m). The interesting flora and fauna in this area is described on the page Travel episodes – Borneo 1985: A hike up Gunung Kinabalu.

In North America, 27 rhododendron species are found, with the highest concentration in the eastern part of the continent, mainly in the Appalachian Mountains. Europe, including the Caucasus, is home to 12 species, and a few species are distributed in Arctic areas.

The inflorescence of most species is an umbel-like cluster, corolla funnel- or bell-shaped, with five lobes. The commonest flower colours are various shades of red, pink, or lilac. White and yellow flowers are also frequent, whereas greenish is only seen in a few species.

Previously, species of Labrador tea, or muskeg tea, were placed in a separate genus, Ledum, but genetic analyses have revealed that they are in fact rhododendrons. The names Labrador tea and muskeg tea refer to the usage of the leaves of these plants for tea, and they were also formerly added to beer. Due to their powerful fragrance, they were also utilized to deter moths from clothes.

The word rhododendron is derived from Ancient Greek rhodon (‘rose’) and dendron (‘tree’), thus ‘rose tree’. Until the 1600s, this name was used for oleander (Nerium oleander), which is described on the page Plants: Flora in Turkey. In 1753, the name was transferred to rhododendrons by Swedish naturalist Carl Linnaeus (1707-1778).

The genus contains evergreen as well as deciduous species, the latter often called azalea. European species are usually called by their German name, Alpenrose (‘rose of the Alps’). This name and another German name, Bergrose (‘mountain rose’), were already used for these plants in the 1500s by Swiss physician and naturalist Conrad Gessner (1516-1565), although they are not at all related to roses. In those days, the term rose was applied to many plants with attractive flowers.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

It grows in shrubberies, and on open slopes and rocks, at altitudes between 3,000 and 5,100 m, from Pakistan eastwards to Bhutan and south-eastern Tibet.

In Nepal, where it is called sun pathi, dried flowers are utilized as tea, and the branches are burned as dhup (incense) in temples and on house altars. Vapours from boiled leaves are inhaled to relieve cough and colds.

The specific name derived from Ancient Greek anthos (‘flower’) and pogon (‘beard’), probably alluding to the hairy throat of the flower.

 

 

 

 

 

 

 

The flowers are bright red, pink, or white, in clusters of 10-20, corolla bell-shaped, to 5 cm long and across, with 5 lobes to 1.7 cm long. The intensity of the red colour decreases with altitude, and white flowers are only observed near the upper limit of its distribution.

It is very common in the Himalaya, growing in forests and on open slopes at elevations between 1,500 and 3,800 m. It blooms between February and May, and in March-April, when the flowering is at its peak, it adds a reddish or pinkish tinge to the forest in numerous places, stemming from millions of flowers.

It is the national plant of Nepal, called lali guras (‘red rhododendron’), and the flowers are brought as offerings in Hindu and Buddhist shrines. The petals are edible, utilized for sore throat and cough, and also pickled. Juice of the bark is taken for diarrhoea, dysentery, and cough, a paste of the leaves for headache, juice of the flowers for menstrual problems and dysentery. Juice of the leaves is spread on beds to get rid of vermin, and young leaves are used to stupefy fish in streams. The wood is utilized for making furniture, fences, and charcoal, and as fuel, and dried leaves serve as compost.

In its widest sense, this species has an extensive distribution in Asia, from Pakistan eastwards to montane areas of northern Thailand and Vietnam, with isolated subspecies in mountains of South India (nilagiricum) and Sri Lanka (zeylanicum), which are regarded as separate species by some authorities.

The specific name is Latin, meaning ‘tree-like’, referring to the large size.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The crimson flowers are clustered in a dense umbel, to 13 cm across, the bell-shaped corolla to 3.6 cm long, with 5 blackish-red nectar pouches at the base. Flowering occurs April-June.

It is very common in forests in the Himalaya, found from Uttarakhand eastwards to Bhutan and south-eastern Tibet, often forming pure stands at altitudes between 2,400 and 3,600 m.

The specific name is Latin, meaning ‘bearded’, alluding to the bristles on twigs and leaf-stalk.

 

 

 

 

 

 

 

 

 

 

 

It was named in honour of Sir James Brooke (1803-1868), a British soldier and adventurer, who helped the Sultan of Brunei to suppress a revolt, and as a reward became governor of Sarawak, titled Rajah Brooke, from 1841 until his death in 1868.

Many authorities regard this plant as a subspecies of the widespread R. javanicum.

 

 

 

 

 

This beautiful species is common on Mount Kinabalu, Sabah, Borneo, but is not found anywhere else. It grows at elevations between 3,100 and 3,900 m.

 

 

 

 

 

It is a shrub or small tree, sometimes growing to 10 m tall, leaves ovate or elliptic, to 8 cm long and 3 cm wide, the colour of the corolla varying from orange to bright red, hence its common name.

The specific name means ‘resembling Calendula‘, referring to the colour of marigold (Calendula officinalis) flowers, which are orange or reddish.

 

 

 

 

 

 

 

It is very common in the Himalaya, from Pakistan eastwards to Bhutan and south-eastern Tibet, often forming dense thickets at altitudes between 2,800 and 4,300 m.

In Nepal, the wood is collected for fuel, and juice of the leaves is used for rheumatism and syphilis.

 

 

 

 

 

 

 

 

 

 

 

 

 

Young branches are greenish, older branches greyish, with flaking bark. Leaves are green, shining on the upperside, greenish below, rounded or elliptic, to 8.5 cm long and 4 cm wide, margin slightly recurved, tip rounded. Flowers are in terminal umbels, up to 7 together, bell-shaped, pale yellow, to 4 cm long and across, with 5 lobes, to 2 cm long. Flowering takes place May-June.

The specific name is derived from Ancient Greek kampylos (‘curved’) and karpos (‘fruit’), alluding to the curved capsules of this plant.

 

 

 

 

 

 

 

It is native to the eastern United States, from Maryland and Kentucky southwards to Alabama and Georgia, forming dense thickets on rocky slopes in the Appalachian Mountains, from the lowlands to elevations around 1,000 m, especially in North Carolina and Virginia.

The specific name refers to the Catawba River, which originates in western North Carolina, flowing into South Carolina.

 

 

 

 

 

This plant has a rather limited distribution, found from eastern Nepal eastwards to Bhutan and south-eastern Tibet, growing at altitudes between 2,700 and 3,900 m.

The specific name is Latin, meaning ‘hairy’, alluding to the bristly leaf margin and flower-stalk.

 

 

 

 

 

It grows in forests and shrubberies at altitudes between 3,000 and 4,000 m, from eastern Nepal eastwards to Myanmar and the Yunnan Province.

In Nepal, the wood is collected for fuel.

The specific name is derived from Ancient Greek kinnabaris, indicating a bright red colour, tinted with orange. The name of course alludes to the flower colour.

 

 

 

 

 

 

 

 

 

This plant is distributed in western North America, from British Columbia southwards to California, eastwards to Alberta, Montana, Wyoming, Utah, and Colorado. It is partial to wet places, from sea level up to altitudes around 3,600 m.

It was first collected by Scottish gardener and botanist David Douglas (1799-1834), who explored the North American flora during three expeditions. He died under mysterious circumstances while climbing Mauna Kea in Hawaii in 1834. Apparently, he fell into a pit trap and was possibly crushed by a bull that fell into the same trap. He was last seen at the hut of Englishman Edward ‘Ned’ Gurney, a bullock hunter and escaped convict. Gurney was suspected of causing Douglas’s death, as Douglas was said to have been carrying more money than Gurney subsequently delivered with the body. (Source: Nisbet, J. 2009. The Collector: David Douglas and the Natural History of the Northwest. Sasquatch Books)

Previously, this plant was named R. neoglandulosum, and prior to that Ledum columbianum. As its popular names imply, tea was formerly brewed on the leaves.

It is easily distinguished from R. tomentosum (below) by its smooth stems and leaves.

 

 

 

 

 

It is distributed from central Nepal eastwards to Arunachal Pradesh and south-eastern Tibet, and it is also found in Bangladesh. In the Himalaya, it occurs at elevations between 1,500 and 2,600 m, mainly growing on trees, but occasionally on rocks.

Elsewhere, it is cultivated as an ornamental, and it is threatened by excessive collecting.

In Nepal, juice of young leaves is applied to wounds on cattle.

It was named by British botanist Joseph Dalton Hooker (see below) in honour of Lady Dalhousie, wife of George Ramsay, the 9th Earl of Dalhousie, who was governor-general in India in the first half of the 1800s. Lady Dalhousie was an avid collector of plants.

Rhododendron lindleyi is similar, but the calyx is fringed with soft white hairs.

 

 

 

 

 

 

 

In 1865, he was appointed Director of the Royal Botanic Gardens, Kew, holding the post for twenty years. He was a close friend of the famous Charles Darwin (1809-1882).

During his stay in Asia, he described no less than 22 new rhododendron species from Sikkim and other parts of the eastern Himalaya.

 

 

 

 

 

It is quite similar to R. arboreum (above), and some authorities regard it as a subspecies of that species. Leaves to 14 cm long and 2.5 cm wide, tip sharply pointed, underside covered in whitish or brownish hairs. Corolla usually deep crimson or carmine.

The specific name was given in honour of French missionary, explorer, and botanist Père Jean-Marie Delavay (1834-1895), who was an avid plant collector, sending over 200,000 herbarium specimens back to France, from which numerous new genera and over 1,500 new species were described.

 

 

 

 

 

It is easily identified by the small, red, tubular flowers and the tiny leaves, which are reminiscent of leaves of heather (Erica) or crowberry (Empetrum nigrum).

The specific name is Latin, meaning ‘resembling Erica‘, referring to the leaves.

 

 

 

 

 

It is a heavily branched, evergreen shrub, to 1.3 m tall, with stout branches, which may be up to 2 cm in diameter. Research has found that individuals with such branches may be almost 100 years old. Leaves are alternate, often clustered at the end of branches, leathery, to 4 cm long and 1 cm wide, lanceolate to narrow-elliptic, margin serrated, tip pointed, dark green and glossy above, young leaves yellowish below, older leaves with a felt-like layer of rusty-brown hairs. Inflorescences are terminal clusters of dark pink to red flowers, each to 8 mm long, petals 5, fused to form a bell-shaped corolla with ovate lobes, tip rounded.

In folk medicine, the plant has been used for treatment of rheumatism and kidney stones.

The specific name is derived from the Latin ferrugineum (‘rust-coloured’), derived from ferrum (‘iron’), like the common name alluding to the rusty scales on the underside of the leaves.

 

 

 

 

 

 

 

 

 

 

 

Leaves are leathery, oblong or broadly ovate, to 11 cm long and 7 cm wide, base rounded or heart-shaped, tip rounded, glossy-green above, covered in reddish-brown felt below. Flowers are blood-red, bell-shaped or tubular, to 4 cm long and across, with 5 dark nectar pouches in the throat. Anthers are chocolate-brown. It flowers between April and June.

In Nepal, the wood is used as fuel.

The specific name is Latin, meaning ‘shining’, probably alluding to the glossy leaves.

 

 

 

 

 

It closely resembles rusty-leaved alpenrose, but is easily identified by the ciliate leaves, and the flowers are pale pink. Where the distribution area of the two species occasionally overlaps, hybrids between them are frequent.

Like the previous species, this plant was used in traditional medicine to treat rheumatism and kidney stones.

The specific name is Latin, meaning ‘hairy’, alluding to the leaf margin.

 

 

 

 

 

 

 

 

 

 

 

Flowers are arranged in very dense, flat-topped clusters, 15-20-flowered, corolla tubular or bell-shaped, magenta, purple, pink, pale pink, or whitish, to 4 cm long and 5 cm across, with 7-8 small lobes and darker basal blotches in the throat. It blooms from April to June.

It has a rather limited distribution, from eastern Nepal eastwards to Arunachal Pradesh and south-eastern Tibet, often forming pure stands in forests at altitudes between 3,000 and 4,000 m.

In Nepal, the wood is used as fuel.

The specific name was applied by Joseph Dalton Hooker (see R. dalhousiae above) in honour of his friend, British naturalist and ethnologist Brian Houghton Hodgson (1801-1894), who described numerous new species of birds and mammals in the Himalaya.

 

 

 

 

 

 

 

 

 

 

 

This species is restricted to the Philippines, growing in humid forests at elevations between 1,000 and 2,300 m.

It was named after German zoologist Otto Koch, who collected plants and animals in the Philippines.

 

 

 

 

 

It is a much-branched, prostrate or erect shrub, to 1 m tall, leaves to 2 cm long and 9 mm wide, oblong, elliptic, or ovate, tip rounded, base narrowly triangular, underside fawn or ferrugineous, scaly. Inflorescence short-stalked, with 3-6 flowers, calyx tiny, corolla broadly funnel-shaped, rose-coloured, violet, or purple, occasionally white, to 1.4 cm long.

Martin Henrichsen Vahl (1749-1804) was a Danish-Norwegian naturalist, who studied botany at the University of Copenhagen, and also at Uppsala University under the famous Carl Linnaeus. Vahl was a lecturer at the University of Copenhagen Botanical Garden 1779-1782, and was the editor of several botanical works, including Flora Danica, Vol. XVI-XXI, Symbolæ Botanicæ, Vol. I-III, Eclogæ Americanæ, Vol. I-IV, and Enumeratio Plantarum, Vol. I-II.

In 1787, Vahl travelled to Norway in search of plants to be illustrated in Flora Danica. (Norway was then a Danish territory.) From Copenhagen, he went by ship to Christiania (Oslo), then north through the Gudbrand Valley and further on to the town of Lom, situated at the foot of the highest peaks of Norway, in Jotunheimen and Dovre. In 1792, Vahl wrote enthusiastically about a botanical trip near the town: “One of the rarest Norwegian plants, Azalea lapponica, was ample reward for struggling towards the peak of a high mountain, through snow and morass. The pleasure of having seen this plant alive was further increased by the fact that it might easily have escaped my attention, as only two bushes were growing here.” (Source: H. Knudsen 2014. Fortællingen om Flora Danica. Lindhardt & Ringhof, in Danish)

The specific name is Latin, meaning ‘found in Lapland’.

 

 

 

 

 

The leaf shape also varies quite a lot, obovate, elliptic, oblong, or lanceolate, to 3.8 cm long and 1.8 cm wide, scaly on both surfaces, tip rounded or pointed, sometimes with a short spine.

This is one of the most widespread and common Himalayan rhododendron species, distributed from Pakistan eastwards to south-western China. It also has a wide altitudinal range, found between 2,000 and 4,700 m. Habitats include open slopes, shrubberies, and open forests.

In Nepal, dried leaves are burned as dhup (incense) in temples. Tea made from the leaves is taken as a blood purifier. Pounded leaves are spread on beds to get rid of vermin.

The specific name is derived from Ancient Greek lepís (‘scale’), alluding to the abundance of scales on both sides of the leaves.

 

 

 

 

 

 

 

 

 

 

 

It is endemic to the province of Sabah, Borneo, where it grows on Mount Kinabalu and a few other places, at elevations between 2,700 and 3,650 m.

It was named in honour of British naturalist Hugh Low (1824-1905), who was also colonial administrator of the Malay Peninsula. He made the first documented ascent of Mount Kinabalu in 1851, and the highest peak is named after him.

 

 

 

 

 

Yellow azalea is distributed from Poland southwards through Austria to the Balkans, and thence eastwards to the Caucasus. It grows in forests and on grassy slopes, from sea level to elevations around 2,000 m.

Its sweet-smelling flowers attract bees, but the honey produced from them is actually toxic, and reports of people being poisoned by consuming this honey date as far back as Ancient Greece.

 

 

 

 

 

 

 

It is a large evergreen shrub or a small tree, to 9 m tall, leaves thick, leathery, broadly elliptic, to 23 cm long and 7.5 cm wide, tip pointed, base narrowly triangular, both surfaces smooth. Inflorescences are terminal pyramidal clusters of 10-20 stalked flowers, calyx tiny, corolla broadly bell-shaped, to 4 cm long, pink or white with yellowish or brownish dots.

The specific name is derived from Ancient Greel makros (‘long’) and phyllon (‘leaf’), thus ‘long-leaved’.

 

 

 

 

 

A shrub or small tree, to 8 m tall, leaves short-stalked, lanceolate or elliptic, to 14 cm long and 3.5 cm broad, tip pointed, base rounded, smooth above, hairy along the midrib below. Inflorescences are dense or lax terminal clusters of 5-12 flowers, calyx tiny, corolla broadly bell-shaped, white or pink, with many red dots and usually a red blotch near the throat.

It was named in honour of Japanese anthropologist and naturalist Ushinosuke Mori (1877-1926), who went to Taiwan as an army interpreter and began to conduct research in fields of anthropology, history, folklore, archaeology, botany, and geography, his main interest being Taiwan aboriginals. In 1926, he disappeared while on board the steamship Kasadomaru. According to the authorities, he committed suicide by jumping into the sea.

Previously, this plant was regarded as a subspecies of R. pseudochrysanthum (below). It differs by being larger, with larger leaves.

 

 

 

 

 

 

 

A low, compact, many-branched shrub, prostrate or sometimes to 90 cm tall, leaves to 1.5 cm long and 6 mm wide, elliptic, ovate, or rounded, tip blunt, base broadly triangular, scaly on both sides, underside yellowish or fawn. Flowers are solitary or up to 3 together, calyx tiny or missing, corolla varying in colour, purple or lilac, occasionally magenta or pink, broadly funnel-shaped, to 1.3 cm across, tube to 6 mm long. Flowering takes place June-August.

It is quite similar to R. setosum (below), but the leaf margin of that species usually has bristles, and its flowers are larger.

The specific name is derived from the Latin nix (‘snow’) and‎ the suffix alis, thus ‘found in snow’, referring to the fact that this plant grows at very high altitudes.

 

 

 

 

 

 

 

 

This species is found in coastal ranges of western North America, from Oregon southwards to the Mexican border. It is not known to occur east of the Cascade and Sierra Nevada Mountains. It grows in forests and shrubberies, often along streams, from sea level to altitudes around 2,700 m.

The specific name is Latin, meaning ‘western’.

 

 

 

 

 

It is a many-branched shrub, growing to 3 m tall, leaves ovate or lanceolate, to 6 cm long and 2.5 cm wide, both surfaces with pale brown hairs, tip pointed, sometimes with a short spine, base rounded or broadly triangular, margin entire. Flowers are solitary or up to 4 together, calyx small, glandular-hairy, corolla funnel-shaped, to 3.5 cm long, brick-red, orange-red, or coral-pink, with darker red dots.

The specific name was given in honour of British gardener and plant collector Richard Oldham (1837-1864), who was sent to the Far East in 1861 by the Royal Botanic Gardens, Kew. He collected plants in Manchuria, Korea, Japan, and Taiwan, but suffered many hardships. Despite this, he managed to send back about 14,000 plants, including many species new to science. While on Taiwan, he fell ill and succumbed to dysentery in 1864.

 

 

 

 

 

 

 

A shrub to 5 m tall, leaves short-stalked, ovate, obovate, or elliptic, to 9 cm long and 3 cm wide, base and tip pointed or blunt, both surfaces smooth or sparsely hairy, margin entire, with very short hairs. Inflorescences, which appear before or with the leaves, are racemes of 6-15 short-stalked, fragrant flowers, sepals tiny, corolla deep pink, sometimes white or pale pink, tube to 2 cm long, lobes to 2 cm long and 1.5 cm wide.

The specific name refers to the similarity of the flowers to those of the common honeysuckle (Lonicera periclymenum).

The common name is derived from the Dutch word Pinksteren, meaning Pentecost, a Christian feast, which falls on the seventh Sunday after Easter, in remembrance of the descent of the Holy Spirit upon the apostles at the Feast of the Harvest, which enabled them to spread the news of Christ in all languages. The text in Exodus, 23:16, says about this feast: “You shall keep the Feast of Harvest, of the firstfruits of your labour, of what you sow in the field.”

In America, Pinkster (or Pinxter) refers to the festivals held by the black population of New York and New Jersey, particularly in the early 19th Century. For slaves, it was a time when they didn’t have to work, and had a chance to gather with family and friends.

Pinxter flower was named due to the fact that it typically blooms around this time.

 

 

 

 

 

The nominate subspecies is native to the Caucasus, Turkey, Syria, Lebanon, and Bulgaria, whereas small populations of subspecies baeticum are distributed in south-western Spain and Portugal. It grows in broad-leaved forests, at elevations between 150 and 1,800 m.

It is a large shrub, occasionally to 10 m tall, leaves elliptic or obovate, to 17 cm long and 4.5 cm wide, initially downy below, later almost smooth, but glandular hairs are persistent. The terminal inflorescences have up to 20 stalked, bell-shaped flowers, pink, purplish, or sometimes white with purplish base, tube to 2.5 cm long, with 5 spreading lobes to 2.5 cm long, pointed or rounded, one of which has yellow dots. The fruit is a capsule, to 2.8 cm long.

In 1763, Pontic rhododendron was introduced to Britain as an ornamental, and it was also planted as cover for game birds. It quickly became naturalized, spreading by suckers on the tips of the branches. Today, in England, Wales, and Ireland, it is a widespread menace, which has colonized numerous hillsides, moorlands, and shady woodlands, often replacing local plant species.

 

 

 

 

 

 

 

 

 

 

 

This gorgeous plant grows on open slopes at very high altitudes in the central mountains of Taiwan, at elevations between 3,100 and 3,900 m.

The specific name is derived from Ancient Greek pseudes (‘false’), khrysos (‘gold’), and anthos (‘flower’), thus ‘the one with false golden flowers’. It is not clear what it refers to. The flowers are definitely not golden.

 

 

 

 

 

The pink, tubular or bell-shaped flowers, on scaly stalks to 2.6 cm long, are solitary or up to 3 together, nodding, corolla to 2 cm long, downy on the outside. It flowers from April to July.

It is distributed from eastern Nepal eastwards to Myanmar and south-western China, growing on open slopes and rocks at altitudes between 3,300 and 4,300 m.

 

 

 

 

 

It is restricted to the province of Sabah, Borneo, growing on the mountains Kinabalu and Alab, at elevations between 2,000 and 2,700 m.

 

 

 

 

 

It is restricted to the mountains of Taiwan, found at altitudes between 1,800 and 3,300 m, often forming dense thickets at higher altitudes.

The specific name is derived from the Latin ruber (‘red’) and pilosus (‘hairy’), like the common name alluding to the reddish-brown hairs found on many parts of this plant.

 

 

 

 

 

It occurs on Borneo, on mountains in the province of Sabah, and possibly also a single place in Sarawak, at altitudes between 2,000 and 3,500 m.

The specific name is Latin, meaning ‘wrinkled’, alluding to the leaves having a wrinkled appearance due to the deeply impressed nerves.

 

 

 

 

 

It is found in grasslands and shrubberies, and on open slopes, at altitudes between 3,600 and 4,800 m, from central Nepal eastwards to Bhutan and a single place in southern Tibet. It is very common in the Khumbu area, eastern Nepal.

In Nepal, dried leaves are used as tea.

The specific name is derived from the Latin saeta (‘bristle’), referring to the bristly leaf margin.

It is quite similar to R. nivale (above), but its leaf margin usually has bristles, and the flowers are larger and more pinkish.

 

 

 

 

 

 

 

 

 

It is a much-branched shrub, growing to 3 m tall, young branches densely covered with shining brown hairs. There are two kinds of leaves, the spring leaves being deciduous, to 7 cm long and 2 cm wide, linear, lanceolate, or elliptic, tip pointed, base narrowly triangulate, margin entire. Summer leaves are persistent, oblong or elliptic, to 2 cm long and 1 cm wide, tip blunt. Inflorescences have 2-6 flowers, calyx to 7 mm long, with ovate-lanceolate, hairy lobes, corolla broadly funnel-shaped, to 6 cm long, dark red, brick-red, rose-pink, or white, upper lobes with darker dots.

The specific name commemorates English botanist and physician John Sims (1749-1831), who was the second editor of Curtis’s Botanical Magazine, after botanist and entomologist William Curtis (1746-1799), who founded it in 1787. This magazine has been published ever since, today by the Royal Botanical Gardens, Kew.

 

 

 

 

 

It grows in forests and shrubberies, and on open slopes, preferably near streams, at altitudes between 2,900 and 4,000 m, from eastern Nepal eastwards to Bhutan and south-eastern Tibet.

The specific name was applied by Joseph Dalton Hooker (see R. dalhousiae above) in honour of his friend, British surgeon and botanist Thomas Thomson (1817-1878), who assisted in writing the first volume of Flora Indica.

 

 

 

 

 

This plant, previously called Ledum palustre, is very common and widespread in wetter areas of the boreal zone in the Northern Hemisphere. It comes in two subspecies, tomentosum, found from Scandinavia eastwards to the Taimyr Peninsula, and decumbens, which is distributed from the Taimyr Peninsula eastwards across Siberia to Alaska, Canada, and Greenland. A former third subspecies, subarcticum, is now regarded as synonymous with decumbens.

The specific name is Latin, meaning ‘having numerous hairs’, alluding to the woolly young branches and underside of leaves.

 

 

 

 

 

The flowers are terminal among new shoots, in clusters of 3, as indicated by the specific name, corolla pale yellow with a greenish tinge, green- or brown-spotted within, bell-shaped, to 3.5 cm long and 5 cm across. It blooms in April-May.

This species occurs in forests and shrubberies, from eastern Nepal eastwards to Bhutan and the Yunnan Province, growing at altitudes from 2,400 to 3,700 m.

In Nepal, the wood is used as fuel.

 

 

 

 

 

This plant has an extremely limited distribution, found only in the eastern United States, on several locations in the Appalachian Mountains, North Carolina, growing on slopes in open forest, at elevations between 900 and 1,830 m.

The specific name was given in honour of two botanists, George Vasey (1822-1893) and his son George Richard Vasey (1851-1921), the latter collecting the plant in 1878. The elder George Vasey collected many plants in Illinois before joining the United States Department of Agriculture, where he became chief botanist and curator of the National Herbarium.

 

 

 

 

 

It is distributed from eastern Nepal eastwards to Bhutan and south-eastern Tibet, growing in forests and shrubberies, and on open slopes, at elevations between 3,000 and 4,300 m.

Some authorities, including Kew Gardens, do not accept this species, but regard it as conspecific with R. campanulatum, and Kew Gardens does not even acknowledge it as a variety.

The specific name was given in honour of Danish physician and botanist Nathaniel Wallich (see below).

 

 

 

 

 

Wallich was involved in the early development of the Royal Botanic Garden, Calcutta, serving there until 1846, when he retired from the service. He went on numerous expeditions, and also offered his assistance to many plant collectors, who made a stop in Calcutta on their way to the Himalaya. Wallich prepared a catalogue of more than 20,000 plant specimens, and he published two books, Tentamen Florae Nepalensis Illustratae and Plantae Asiaticae Rariores.

After his retirement he stayed in London, where he became vice-president of the Linnean Society.

 

 

 

 

 

The leaves are large, leathery, oblong or elliptic, pointed, to 20 cm long and 7 cm wide, with felt-like, rusty hairs beneath. The bell-shaped flowers are in lax, 10-20-flowered umbels, corolla to 4.5 cm long and 5 cm across, very pale yellow with crimson blotches in the throat. It blooms in May-June.

In Nepal, the wood is collected for fuel.

The specific name was given in honour of Scottish surgeon and botanist Robert Wight (1796-1872), who spent most of his life in southern India, where he was the leading botanical taxonomist, describing 110 new genera and 1,267 new species. He published a series of illustrated works in Madras, including the six-volume Icones Plantarum Indiae Orientalis (1838–53), the Illustrations of Indian Botany (1838–50), and Spicilegium Neilgherrense (1845–51).

 

 

 

 

 

The generic name is derived from Ancient Greek rhodon (‘rose”) and thamnos (‘bush’). The common name is adapted from the German Alpenrose (‘rose of the Alps’).

 

 

It is an evergreen dwarf shrub with ascending branches, to 30 cm long. Leaves are alternate, clustered at the end of branches, leathery, to 1.5 cm long, margin toothed and bristled. Flowers are terminal, in groups up to 4, stalked, to 3 cm across, petals pale pink with red streaks near the throat, only fused at the base, style white with a carmine tip, filaments white, anthers purplish-black.

The specific name is derived from Ancient Greek khamai (‘on the ground’, i.e. ‘low’), and the generic name Cistus (rockroses), a group of plants in the family Cistaceae. The name alludes to the flowers, which superficially resemble those of rockroses.