''Hypericum assamicum'' is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in the St. John's wort family,

Hypericaceae Hypericaceae is a plant family in the order Malpighiales, comprising six to nine genera and up to 700 species, and commonly known as the St. John's wort family. Members are found throughout the world apart from extremely cold or dry habitats. '' ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to India. ''Hypericum assamicum'' is one of two species of ''

Hypericum ''Hypericum'' is a genus of flowering plants in the family Hypericaceae (formerly considered a subfamily of Clusiaceae). The genus has a nearly worldwide distribution, missing only from tropical lowlands, deserts and polar regions. Many ''Hype ...

'' in the

section Section, Sectioning or Sectioned may refer to: Arts, entertainment and media * Section (music), a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents ** Section sign ...

''Hypericum'' sect. ''Sampsonia''.

Description

''Hypericum assamicum'' is an erect, perennial or suffruticose (woody at the base) herb tall. The stems are terete with internodes , shorter than or exceeding the leaves. The oblong to oblanceolate leaves are perfoliate, in pairs, thinly papery, up to long and broad, with glaucous undersides and obtuse to rounded tips. The margin of the leaf is entire, or rarely glandular-crenate, with dense, black glands. The leaves have broadly cuneate or rounded leaf bases. The flowerheads produce 12–18 flowers in corymbiform or subpyramidal branching patterns. Each flower is approximately with 5 sepals, 5 yellowish petals, and approximately 15

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

s. The cylindric to subglobose fruiting capsules reach in length with reddish-brown seeds, each seed long. It flowers and fruits between March and April.

Taxonomy

''Hypericum assamicum'' was described in 1971 by Samarendra Nath Biswas in ''Webbia, Journal of Plant Taxonomy and Geography''. The type specimen was collected in Nowgong (now

Nagaon Nagaon (previously Nowgong; Assamese নগাঁও), is a town and a municipal board in Nagaon district in the Indian state of Assam. It is situated east of Guwahati. History This division was organised on the both banks of Kalang river by ...

Assam Assam (; ) is a state in northeastern India, south of the eastern Himalayas along the Brahmaputra and Barak River valleys. Assam covers an area of . The state is bordered by Bhutan and Arunachal Pradesh to the north; Nagaland and Manipur ...

, India in July 1848. It was named for its type locality, Assam, India. It is placed in the section ''Hypericum'' sect. ''Sampsonia'', along with '' Hypericum sampsonii'', based on the combination of perfoliate leaves and vesicular-glandular capsule valves. ''Hypericum assamicum'' is distinguished from ''H. sampsonii'' by its leaves that are shortly connate-perfoliate at the base (vs. broadly perfoliate bases), spatulate-oblong unequal sepals (vs. oblong subequal sepals), petals shorter than the sepals (vs. petals as long as the sepals), ovaries with 3-parietal placentas (vs. 3-celled with an axile placenta), and subglobose to oblong capsules with rounded or obtuse apices (vs. ovoid capsules with narrowed to acute apices). The closest population of ''H. sampsonii'' to ''H. assamicum'' is approximately away.

Distribution and habitat

''Hypericum assamicum'' is endemic to eastern India. A 1915 collection noted that it was "common in jungles". It occurs at altitudes up to in riparian areas, open grasslands, roadsides, agricultural fields, and fallow places in the eastern

Himalayas The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...

References

{{Taxonbar, from=Q17565878 assamicum Flora of Assam (region) Plants described in 1971