Trichosanthes epibracteata Duyfjes & Nuraliev, 2016

Duyfjes, B. E. E., Nuraliev, M. S., Luu, H. T., Huynh, N. T., Ngo, V. C., Kuznetsov, A. N. & Kuznetsova, S. P., 2016, Two new species and one new species record of Trichosanthes (Cucurbitaceae) from Vietnam, Blumea 61 (3), pp. 267-271 : 268-270

2. Trichosanthes epibracteata Duyfjes & Nuraliev , sp. nov. ― Fig. 2 , 3a, b

Distinct from Trichosanthes villosa Blume in the much deeper lobed lamina and 3-branched tendril (4–7-branched in T. villosa ). — Type: Nuraliev 1222 (holo MW; iso L L.3955617), S Vietnam, Kon Tum Province, Sa Thay District, Ro Koi Municipality , Chu Mom Ray National Park , 33 km WNW of Kon Tum, N14°29'45" E107°43'35", 900 m elevation, 30 Mar. 2015, male fl .

Etymology. The specific epithet refers to the bract shifted up along the floral pedicel (Greek: epi = upon).

Stout perennial climber, c. 10 (?) m long; leafy stem ± grooved on drying, not reddish tinged, glabrous (glabrescent from minute hairs), c. 4 mm diam; dioecious. Probract absent, but a brown hairy wart c. 2 mm diam present ( Fig. 2 ). Tendrils 3-branched, one branch strongest, point of branching c. 2 cm from the base, brown hairy, hairs c. 0.5 mm long, glabrescent. Leaves: petiole stout, hairy, c. 8 cm long, c. 3 mm diam; lamina brown on drying, (sub)coriaceous, deeply 5-lobed to 1/2–2/3 deep, outer lobes smaller, in outline subcircular, 14–17 cm diam, finely bullate and hairy on the veins above, densely hairy all over beneath, glands absent, cystoliths not obvious, base deeply cordate, margin entire, apex of lobes long acute-acuminate; veins and veinlets sunk above, distinctly raised beneath. Male raceme finely brown hairy, co-axillary at the node or slightly adnate to base of peduncle with a single pedicel c. 80 mm long, the flower not present in the material; peduncle 8–9 cm long, c. 3 mm thick, about halfway with 1‒3 sterile bracts up to 1.5 cm long; rachis not thickened, 6–12 cm long, 2.5–3 mm thick, c. 10- flowered; bracts persistent, inserted on the pedicel 1–2 cm from the base, elliptic, 2–2.5 by 1–1.2 cm, margin subentire, glands numerous. Male flowers: brown hairy; pedicel 20–30 mm long, persistent, with bract inserted at c. 2/3 from the base; receptacle tube (25–) 30 mm long, at throat c. 7 mm wide, bulging to 10 mm wide above the middle, at base slightly broadened where demarcated with the pedicel; sepals long-triangular to lanceolate, c. 7 mm long, entire, petals white, obovate or obovate-oblong, 40–50 mm long including threads c. 20 mm long; synandrium not seen. Female flower, fruit, and seed not known.

Distribution ― S Vietnam, known only from the type locality.

Habitat & Ecology ― Forest margin in logging area; 900 m elevation; flowering in March.

Note ― Trichosanthes epibracteata keys out in the key for Trichosanthes in Indochina ( De Wilde & Duyfjes 2012) beside T. villosa Blume , a species also with the male bract considerably shifted upwards on the pedicel. The latter species is readily distinct in an overall weaker appearance, and more precisely in e.g. indumentum of longer hairs, c. 1 mm long, leaves not or hardly lobed, tendril 4‒7(‒9)-fid, and missing the hairy wart at the node.

Figures

Fig. 2 Trichosanthes epibracteata Duyfjes & Nuraliev. a. Portion of twig with male inflorescence; b. male flower bud with bract; c. detail of male bud; d. bract ad- and abaxially, note bract shifted upwards along the pedicel; e. hairy wart at leaf axil (all: Nuraliev 1222). ― Drawn by Jan van Os.

Fig. 3 a, b. Trichosanthes epibracteata Duyfjes & Nuraliev. a. Leaf; b. male flower. ― c–f. Trichosanthes laceribractea Hayata. c. Male inflorescence; d. detail of male bud; e. male flower;f. idem, longitudinally opened,showing hairy tube inside and prolongations of the connectives. ― Photos: Maxim Nuraliev.