Melastomataceae

Melastomataceae

Melastoma malabathricum

Melastomataceae

Oxyspora paniculata

Melastomataceae

Sarcopyramis nepalensis

Melastomataceae

Osbeckia nutans

Melastomataceae

Melastomataceae

Osbeckia capitata

by G & P Jürgens

Benth. ex Naudin

Bhutan2012 538
Bhutan Wangdi 2600m, September
Bhutan2012 539
Bhutan Wangdi 2600m, September

Description

Osbeckia capitata Benth. ex Naudin is a subshrubby herb of the eastern Himalaya, recorded by GBIF (69 occurrences) from China, India, Bhutan and Bangladesh. It occupies open grassy slopes, forest clearings, scrub margins and disturbed banks in the subtropical to lower temperate hill zone, flowering through the late monsoon. The photographed plant from Wangdue Phodrang (Wangdi) in western Bhutan at 2600 m in September is characteristic of its occurrence on warm, humid mid-elevation slopes among grasses and low shrubs.

The plant is an erect to ascending perennial herb with quadrangular, bristly stems bearing opposite, sessile to shortly petiolate leaves. The blades are ovate to lanceolate, setose on both surfaces, with the strongly arcuate three-to-five longitudinal nerves diagnostic of the family. As the epithet capitata indicates, the flowers are aggregated into dense terminal heads or capitate clusters; each flower has four pink to purple petals, a setose, urceolate hypanthium, and the typical melastomataceous androecium of curved stamens whose elongate, beaked anthers open by apical pores. The fruit is a setose urceolate capsule retained within the persistent hypanthium.

Osbeckia is a palaeotropical genus of around 50 species best developed in tropical Asia, separated from Melastoma by its smaller, dry, poricidal-anthered flowers and capsular fruits; the capitate inflorescence distinguishes O. capitata within the Himalayan members. The poricidal anthers are adapted to buzz-pollination by bees, and several congeners have local medicinal use. The species is not assessed as threatened, persisting in open and lightly disturbed montane habitats across its eastern Himalayan range.

Author: Benth. ex Naudin · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Melastomataceae of the Indian Subcontinent, Hansen monograph on Osbeckia

Melastomataceae

Osbeckia nepalensis

by GP Jürgens

Hook.

Nepal 95 22 P31 ergebnis
Nepal Darondi-Khola 630m, Octobre

Description

Osbeckia nepalensis is a subtropical to warm-temperate herb or subshrub of the eastern Himalaya and southeastern Asia, ranging through China, Nepal, India, Bhutan, Bangladesh, Myanmar, Thailand, Vietnam, Malaysia and Indonesia; its roughly 563 GBIF occurrences trace a broad Sino-Himalayan to Indochinese arc. In Nepal it descends to low elevations along river valleys, as recorded along the Darondi Khola at about 630 m in October, when the post-monsoon period brings peak flowering. It favours open, sunny situations on grassy hillsides, forest margins and roadside banks, behaving as an early-successional colonist of seasonally humid foothill habitats.

The plant is an erect, branched herb or soft subshrub with four-angled stems clothed, like the foliage, in stiff bristly hairs. The leaves are opposite, ovate-lanceolate, and bear the curved-parallel primary veins diagnostic of Melastomataceae. The handsome flowers are clustered in terminal heads, each with a bristly urn-shaped hypanthium and usually four broad, rounded petals of rich rose-purple to magenta; within are twice as many stamens with geniculate filaments and elongate, beaked, poricidal anthers adapted for buzz-pollination by bees. The fruit is a bristly capsule enclosed in the persistent hypanthium, releasing many minute seeds.

Osbeckia is closely allied to Melastoma, from which it is separated by its smaller, dry, poricidal capsules rather than fleshy berries. O. nepalensis is among the most ornamental species of the genus, valued horticulturally and used locally in herbal medicine. As a common, weedy coloniser of disturbed ground over a very large area, it carries no significant conservation concern.

Author: Hook. · Sources: POWO (Kew), GBIF, Flora of China Vol. 13, Flora of Bhutan Vol. 2, Flora of Nepal, A Revision of Osbeckia (Melastomataceae)

Melastomataceae

Osbeckia stellata

by G & P Jürgens

Buch.-Ham. ex D.Don

Bhutan2012 530
Bhutan Tserang 1300m, September
Bhutan2012 660
Bhutan Tserang 1600m, September
Bhutan2015 206
Bhutan Zhemgang 1000m, October
Bhutan2015 207
Bhutan Zhemgang 1000m, October

Description

Osbeckia stellata Buch.-Ham. ex D.Don is a shrub of the melastome family ranging across the Himalaya and tropical Asia, recorded from China, India, Nepal, Bhutan, Myanmar, Thailand, Vietnam, Malaysia and Laos, with about 704 GBIF occurrences. It grows on open hillsides, forest margins, scrub, grassy banks and disturbed slopes in the subtropical and warm-temperate belt, generally between about 900 and 2000 m. It was recorded in Bhutan at Tserang at 1300 and 1600 m and at Zhemgang around 1000 m, flowering in September and October, when its conspicuous magenta blooms colour the autumn hill vegetation of the outer ranges.

It is an erect, branched shrub with quadrangular, often reddish stems bearing appressed, bristly stellate or strigose hairs. The leaves are opposite, ovate-lanceolate, entire, and conspicuously three- to five-nerved with the characteristic curved-convergent venation of Melastomataceae, both surfaces rough with stiff hairs. The flowers are large and showy, borne in terminal cymose clusters; the four broad obovate petals are rose-purple to magenta, surrounding eight stamens with distinctively geniculate, beaked anthers, set on an urceolate hypanthium clothed in branched, stellate-tipped bristles. The fruit is an urn-shaped capsule enclosed by the persistent bristly hypanthium, releasing numerous minute cochleate seeds.

Osbeckia is distinguished from the related Melastoma by its smaller seeds and capsular fruit, and O. stellata is among the most ornamental and widespread Himalayan species, sometimes grown for its vivid flowers. Its poricidal anthers are buzz-pollinated by bees, while the small seeds are dispersed from the dry capsules. Common in disturbed and secondary habitats, it readily colonises cleared ground and is of no conservation concern.

Author: Buch.-Ham. ex D.Don · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of British India, Melastomataceae monograph (Hansen revision of Osbeckia)

Melastomataceae

Pseudodissochaeta assamica

by G & P Jürgens

(CB.Clarke) Nayar

Bhutan2012 632
Bhutan Tserang 1600m
Bhutan2012 1239
Bhutan Tserang 1600m

Description

Pseudodissochaeta assamica is a forest shrub of the Sino-Himalayan and Indo-Burmese region, recorded from China, Vietnam, India, Laos, Bhutan, Myanmar and Bangladesh, with a moderate body of data (c. 126 records in GBIF). It is a plant of warm, humid broad-leaved evergreen and semi-evergreen forest, growing in shaded understorey, along streamsides, ravines and forest margins, typically in the subtropical to lower montane belt around 1000–2000 m. The photographed individual from Tserang in Bhutan, at 1600 m, is representative of this moist, shaded mid-elevation forest habitat where members of the family flourish.

The plant is an erect to scrambling shrub with quadrangular young stems and the opposite, decussate leaves typical of Melastomataceae. The leaves are large, ovate to elliptic-lanceolate, with the characteristic curvinerved (acrodromous) venation of several main veins arising near the base and converging at the apex, the lamina often scabrous or sparsely setose. The flowers are borne in terminal or axillary panicles; each has a campanulate hypanthium, four small petals, and conspicuous stamens that are markedly dimorphic or unequal, with appendaged, often geniculate connectives and poricidal anthers adapted to buzz-pollination. The fruit is an urceolate, several-seeded capsule or berry-like structure crowned by the persistent calyx.

The genus Pseudodissochaeta (tribe Dissochaeteae) was segregated by Nayar from Dissochaeta on differences in stamen and connective structure. This taxon was based on a Clarke name and has a complex synonymy; the source page links to Oxyspora paniculata, an allied melastome with which it has at times been confused, underscoring the taxonomic intricacy of the group. As a fairly widespread forest shrub it is not regarded as threatened, though it depends on intact mid-elevation forest.

Author: (CB.Clarke) Nayar · Sources: POWO (Kew), GBIF, Flora of China (Melastomataceae), Flora of Bhutan, A Revision of the Asiatic Melastomataceae

Melastomataceae

Sonerila khasiana

by GP Jürgens

C.B.Clarke

Bhutan2015 138
Bhutan Galephug 600m, October
Bhutan2015 142
Bhutan Galephug 600m, October

Description

Sonerila khasiana is a small herb of the eastern Himalayan and northeast Indian region, recorded from India, Nepal, Bhutan, China and Myanmar, with comparatively few documented collections. It is a shade-loving plant of moist, humus-rich forest floors, shaded rock faces and damp banks in subtropical and lower montane forest, typically below about 1500 m. The illustrated plant from Galephug in southern Bhutan, at around 600 m and flowering in October, is characteristic of its lowland, post-monsoon flowering habit in warm, perpetually humid foothill forest where deep shade and constant moisture prevail.

The species is a delicate, often somewhat succulent annual or short-lived perennial with slender, ascending, frequently reddish stems. The leaves are opposite, ovate to elliptic, serrulate and traversed by the curved, parallel-converging nervation diagnostic of the Melastomataceae, the lamina often sparsely setose. The inflorescence is a short, terminal, scorpioid cyme of few flowers. The flowers are trimerous, with three pink to rose-purple petals and typically three stamens bearing the conspicuous, yellow, beaked anthers characteristic of the genus; the fruit is a small, three-angled, top-shaped capsule releasing numerous minute seeds.

The epithet refers to the Khasi Hills of Meghalaya, a centre of diversity for the genus. Sonerila is a large palaeotropical genus notable for its consistently trimerous flowers, unusual within a predominantly pentamerous family, and for its many narrow-range, forest-floor endemics. With relatively few records and a dependence on undisturbed shaded forest, such species are potentially sensitive to deforestation, although its full conservation status remains insufficiently assessed.

Author: C.B.Clarke · Sources: POWO (Kew), GBIF, Flora of China Vol. 13, Flora of Bhutan Vol. 2, Flora of Nepal, Revision of Sonerila (Melastomataceae)