00. Hyptianthera[1]

Wight & Arn., Prodr. Fl. Ind. Orient.: 399. 1834.

Evergreen, glabrous shrubs or small trees. Leaves opposite, shortly petiolate; stipules interpetiolar, deltoid-lanceolate. Inflorescences consisting of sessile, paired, axillary, much congested cymes; individual flowers subtended by a pair of bracteoles. Flowers sessile, 4-5-merous, bisexual.  Calyx with a short basal tubular part and lanceolate lobes. Corolla hypocrateriform, tube about as long as the lobes, the latter contorted in bud; glabrous on the outside, the inside with short hairs on the lobes and below the anthers. Stamens subsessile, inserted at or just below the throat; anthers basally hairy, almost completely included. Ovary 2-celled, each locule with several ovules pendulous from the apical part of the septum, crowned by a ring-like disk; style with 2 stigma lobes, the latter and the upper part of the style hairy. Fruit a drupe with a thin endocarp, 2-celled, each cell with usually up to 4-5 seeds.

A monotypic genus occurring from Nepal and E. India to China (Yunnan) and Indochina.— Classification: subfamily Cinchonoideae, tribe Octotropideae (syn. Hypobathreae), [CHECK].

Hyptianthera stricta (Roxb. ex Schult.) Wight & Arn., Prodr. Fl. Ind. Orient.: 399. 1834; Hook. f., Fl. Br. Ind. 3: 121. 1880 (pro parte); Pitard in Fl. Gιn. I.-C. 3(2): 266. 1923; Craib in Fl. Siam. En. 2(1): 127. 1932.— Macrocnemum strictum Roxb. ex Schult., Roem. & Schult., Syst. Veg. 5: 6. 1819.— Rondeletia stricta (Roxb. ex Schult.) Roth, Nov. Pl. Sp.: 140. 1821.— Solena stricta (Roxb. ex Schult.) D.Dietr., Syn. Pl. 1: 800. 1839.— Hypobathrum strictum (Roxb. ex Schult.) Kurz, For. Fl. Burm. 2: 50. 1877.— Randia stricta (Roxb. ex Schult.) Roxb., Fl. Ind. ed. 2: 145. 1924.— Hyptianthera bracteata Craib, Bull. Misc. Inform. Kew 1911: 393. 1911; Pitard in Fl. Gιn. I.-C. 3(2): 266. 1923; Craib in Fl. Siam. En. 2(1): 127. 1932.

A several-stemmed shrub c. 1-3 m tall or small tree to 6(10) m high; bark thin, flaking, brown; younger branches  4-angled, glabrous. Leaves chartaceous to thinly coriaceous, lanceolate or oblong-lanceolate, 4-17 by 1-4 cm, base cuneate, apex acuminate, glabrous; 6-9 pairs of lateral veins, impressed on the upper leaf surface; petioles 0.5–1cm long; stipules 5–10 mm long. Flowers in dense, sessile fascicles at leaf axils; bracts up to c. 3.5 mm long, bracteole pairs immediately below flowers often smaller. Calyx: basal tubular portion to c. 1 mm high, lobes glabrous to ciliate, 1.5-3 mm long. Corolla white to yellowish-white or pale yellow, tube 1.5-2 mm long, lobes broadly elliptical, obtuse to emarginate at apex, c. 2 mm long. Stamens subsessile, anthers c. 1-1.5 mm long, hairy around the base. Ovary c. 2 mm high; style c. 1-3 mm long, often densely white-hairy above, stigma lobes c. 1-2 mm long, often densely white-hairy along their entire length. Drupe turning reddish brown when fully mature, crowned by persistent calyx, ovoid to subglobose, greatest length c. 5-8(10) mm; seeds compressed and angled, usually < 5 mm long. 

T h a i l a n d.— NORTHERN: Chiang Mai (Doi Suthep, types H. bracteata: Kerr 1145, 1792), Chiang Rai, Nan, Lampang, Phrae, Uttaradit, Sukhothai, Kamphaeng Phet; NORTH-EASTERN: Phetchabun, Loei, Nong Khai; EASTERN: Chaiyaphum; SOUTH-WESTERN: Kanchanaburi, Phetchaburi; SOUTH-EASTERN: Prachin Buri, Chanthaburi.

D i s t r i b u t i o n.— Nepal, E. India (type), Bangladesh, upper Myanmar, China (Yunnan), Laos (?), Vietnam.

E c o l o g y.— In dry evergreen forest and seasonal rain forest; occasionally in dry dry dipterocarp forest and pine forest, but then in wetter places such as in shaded gullies; not uncommon in gallery forest and, in general, along streams and associated with rheophytes such as Kailarsenia lineata [see page 000], Homonoia riparia (Euphorbiaceae), etc. Altitude: c. 100–1000 m. Flowers December – May; fruits January – February, June – August.

V e r n a c u l a r.— ??.

N o t e s.— 1. Deb’s view [Deb, J. Bomb. Nat. Hist. Soc. 86: 121. 1989] that Hyptianthera is to be merged with Hypobathrum (syn. Petunga) [see page 000] is not generally accepted; it is not followed here.
2. Hyptianthera stricta is variable; H. bracteata cannot be upheld as a separate species on the basis of longer stipules and bracteoles.

[1] C. Puff