Trichosanthes khasiana Kundu

Pradheep, K., John, K. Joseph, Singh, P. K., Rathi, R. S. & Pandey, A., 2021, A new subspecies and new records of Trichosanthes (Cucurbitaceae) for India, and notes on T. khasiana, Blumea 65 (3), pp. 233-243 : 241-242

Trichosanthes khasiana Kundu — Fig. 2c–g ; Map 4

Trichosanthes khasiana Kundu (1939) 11. — Lectotype (designated here): J. D. Hooker & T. Thomson 617 (lecto K000102019 , http://www.kew.org/ herbcatimg/505008.jpg), India, Meghalaya, Khasia Hills. — Fig. 4 .

Trichosanthes inthanonensis Duyfjes & Pruesapan (2004) 86;W.J. deWilde & Duyfjes (2008) 520; (2011) 271. — Type: P. Phonsena et al. 3930 (holo BKF;iso L), Thailand, Chiang Mai, Doi Inthanon NP, 1330 m, 16 Sept.2003.

Trichosanthes lepiniana auct. non (Naudin) Cogn.: Kundu p.p. (1943) 380 (only Naga Hills);S.K. Chen (1986) 226;(1995) 356;Lu Q.Huang & C.Jeffrey (2011) 41.

Medium-sized perennial, dioecious climber. Stems glabrous, purple-red-tinged, deeply striate, slightly zigzag; young twigs purplish red; probract ovate-elliptic, 5–8 by 3–4 mm, margin subentire, glands 2 or 3, pink or green, variable in size; tendrils pinkish, glabrous, 3-fid. Leaves: petiole (5–) 7–8 cm, furrowed, striate; lamina suborbicular, 13–17(–20) by 12–17(–19) cm, chartaceous, glabrescent, minutely hairy on both sides, strongly 3-lobed up to 1/3 to middle, with small subtle side basal lobes, each lobe apically acuminate, nerve-tipped, ± dentate-serrate, upper surface green to dark green, white-hairy along nerves, lower surface pale green, nerves pinkish, glands small, green or pinkish, 8 or 9, mostly at base. Staminate inflorescence 15–20 cm long, rarely occurring with a co-axillary flower; peduncle (5–)7–10(–12) cm long, glabrous, robust, striate, sometimes twisted; rachis slightly zigzag; bracts cucullate, suborbicular, 3–3.5(–3.8) by 3–3.5 cm, laciniate, glands 2 or 3; opening buds (dark) greenish. Staminate flowers: pedicels c. 5 mm long; calyx lobes laciniate, irregularly broader at base, c. 1.2 by 0.3 cm; corolla lobes whitish, anthers 9–10 mm long. Pistillate flowers: pedicel 3–3.5 cm long, c. 2 mm wide; calyx lobe entire, triangular, 0.8–0.9 cm long, c. 0.25 cm wide at base; calyx tube brownish red, 3.5–4 cm long, slightly crooked, with two projections; ovary ovate, 2–2.3 cm long, glabrous, style 3–3.5 cm long; stigmas 3, lobes completely free, greenish. Fruits: pedicel 3–6 cm long; exocarp turbinate-ovate, 5–8(–10) by 4–7(–8) cm, red, with acuminate tip, distal umbo 4–6 mm long, pericarp 10(–12) mm thick, pulp greenish black. Seeds 30–50, brownish, compressed, irregularly elliptic, 12–15 by 7–10 by c. 2.5 mm, apex subtruncate, base cuneate, the edge ± angular, marginate.

Distribution — China, India (Arunachal Pradesh, Assam, Meghalaya, Mizoram, Nagaland), Laos and Thailand; most probably in Myanmar also.

Habitat & Ecology — Wet places in forest openings; at 900–1700 m altitude. Flowering: May to July; fruiting: August to November.

Note — Earlier collections from NE India were mostly misidentified as T. lepiniana . A closer look at the syntypes of T. lepiniana (at BM, P) indicated that it is not convincingly distinguish- able from the highly variable T. bracteata . Clarke (1879) did not mention T. lepiniana (originally described as Involucraria lepiniana Naudin in 1868 from Pondicherry, South India) for India, though Cogniaux (1881) reported it from the Eastern Himalayas. Thereafter, T. lepiniana was reported from Naga Hills (now Nagaland) ( Kundu 1943).All the Chinese specimens/ material kept under the name T. lepiniana by Huang & Jeffrey (2011), and later by De Wilde & Duyfjes (2011) as T. inthanonensis , belong to this species. Critical study of protologue and all the virtual herbarium specimens (including the isotype) of T. inthanonensis at L, indicates that its distinction from T. khasiana is untenable. Trichosanthes khasiana is distinguished from T. bracteata by pinkish leaf nerves (at base), less lacerate bracts, long slender pistillate flowers, ovoid fruits with narrow short beak, and broad obovate seeds. Its field identification characters include glabrous lower leaf surface, long pedicel of pistillate flower, fruits with typical apical umbo, and uniformly flat, broad obovate seeds.Also, often 3-lobed tender leaves and pigmented nerves in lower leaf surface were noticed.

Figures

Map 4 Distribution of Trichosanthes khasiana Kundu in north-east India.

Fig. 2 Trichosanthes dunniana H.Lév. subsp. dunniana from a. Manipur and b. Mizoram (inset: seed). — c–g.Trichosanthes khasiana Kundu. c. Pistillate flowering twig; d. staminate flowering twig (inset: distal part of staminate flower showing dissected calyx lobes); e. pistillate flower (note the probract); f. longi- tudinal section of pistillate flower exposing style and stigma; g. fruits and seeds. — Photos by K. Pradheep.

Fig. 4 Designated lectotype of T. khasiana Kundu (http://specimens.kew.org/herbarium/K000102019) (Reproduced with the kind permission of authorities of Royal Botanic Gardens (K), Kew).