Argyreia suddeeana Traiperm & Staples, 2014

Argyreia suddeeana Traiperm & Staples View in CoL , sp. nov. ( Fig. 1 View FIGURE 1 , 2 View FIGURE2 )

Similar to A. variabilis Traiperm & Staples (in Staples & Traiperm 2008: 98) in having a showy, bell-shaped corolla and glabrous sepals, but differing from that species by larger, broadly elliptic-ovate to rhombic, or triangular-ovate, pinkish bracts; the acute sepals 10–15 mm long; and the smaller pendent corolla, 4.5–6 cm long.

Type:— THAILAND. Ratchaburi: Mae Nam Pa Chee Wildlife Sanctuary, ca 1.5 km from Huay Muang ranger substation along open ridge top , 19 October 2010, Staples, Suddee & Bongcheewin 1416 (holotype BKF! ; isotypes A! , BKF! , K! , QBG! , SING! ).

Twiner 1.5–8 m high, base of stem ± woody, upper stems herbaceous; stems cylindrical, glabrous to softly hairy; indumentum of 2 types: longer, stiff, straight trichomes and undercoat of shorter, velvety, puberulent trichomes. Leaf blade oblong-lanceolate to ovate-lanceolate, 6–15 by 1.5–5.5 cm, base usually truncate or rarely subcordate, entire, apex acute, mucronate, chartaceous when dry, both sides hairy, upper side olivaceous and darker, scabrid with appressed, swollen-based hairs, underside paler, with long, yellowish, bristly, appressed hairs, and undercoat of shorter, wavy whitish hairs; venation pinnate, secondary veins 7–9 per side, more prominent underneath. Inflorescence axillary or terminal on side branch from leaf axil, cymose, pendent, capitate, enclosed in pinkish bracts, 5- to many-flowered; peduncle stout, 2–3.5 cm long, cylindrical; outer bracts broadly elliptic-ovate to rhombic, or triangular-ovate, pinkish, covering flower buds and tube base of open flowers, 2–3 cm long and about as broad; bracteoles shaped and coloured like bracts, only progressively smaller, persistent in fruit and reddening. Flowers diurnal, odourless; buds ellipsoid to broadly ellipsoid, widest at middle and tapering strongly at both ends, glossy. Sepals ± equal, elliptic to broadly elliptic, 10–15 mm by 4–4.5 mm, apex obtuse to acute, fleshy in life, chartaceous when dry, enlarged in fruit, glabrous, venation not visible. Corolla showy, campanulate, 4.5–6 cm long by 2.5–4 cm diameter, rose-pink, darker inside tube, limb flaring, ruffled, paler, glabrous inside and out. Stamens included, ± equal, filaments 2–2.8 cm long, basally fused to corolla tube for 6–7 mm, with cupular “pocket” at attachment point, free and filamentous above, glabrous except for 2–3 mm around and above attachment point, hairs multicellular, uniseriate; anthers linear-oblong, dehiscing lengthwise, drying blackish, bases sagittate; pollen globose, minutely spinulose. Pistil included in corolla; disc cupular, ca 1.5 mm high, 3 mm diameter; ovary sunken in center of disc, broadly ovoid, ca 1 mm high, 2-celled, 2 ovules per cell, apex abruptly narrowing into style base, glabrous; style filamentous, ca 2.7 cm long, glabrous; stigma 2-globose. Fruit (immature) globose, green, glossy, tightly enclosed in calyx. Seeds not seen.

Phenology:—Flowering and fruiting in October.

Ecology:—on hill sides in disturbed, recently burned, dry deciduous dipterocarp forest with patches of bamboo, on quartzite-granitic substrate. The canopy varied in height from 3–7 m, was fairly open, admitting a lot of light down to ground level, which had a substantial layer of herbs, grasses, ferns, and creepers.

Distribution: —known so far from two discrete populations within Mae Nam Pha Chee Wildlife Sanctuary, Ratchaburi province, Thailand.

Elevation:— 190–250 m.

Conservation assessment:—There is not yet enough information about the distribution, abundance, nor threats to this species; we consider it Data Deficient (DD) at this time.

Etymology:—we take great pleasure in naming this new species after our colleague, Dr Somran Suddee, senior botanist in the Forest Herbarium (BKF), who first collected it.

Specimens examined:— THAILAND. Ratchaburi: Mae Nam Pha Chee Wildlife Sanctuary, along unpaved dirt track near Huay Muang ranger substation , 13 October 2008, Suddee, Trisarasri & Karaket 3860 ( BKF) , same locality, 19 October 2010, Staples, Suddee & Bongcheewin 1414 ( BKF) .

Somran Suddee first collected this species in 2008 on a shady hill slope above a dirt track in the wildlife sanctuary; two years later he brought Staples back to the same place to recollect it. Thus the two paratypes cited above are from one population (and possibly the same plant, the only one seen there), whereas the type gathering was from a larger population ca 1–2 km away on a more exposed ridge that was discovered during a more extensive survey in 2010.