Chroesthes lanceolata (T. Anderson) B. Hansen Fig. 6

Chroesthes lanceolata (T. Anderson) B . Hansen, Nordic J . Bot. 3: 209. 1983; Hu, J. C ., Deng, Y. F ., Daniel, T . & Wood, J. R. I . Acanthaceae . In: Wu, Z. Y ., Revan, P . & Hong, D. Y. ( Eds.) Flora of China 19: 472. 2011. Basionym: Asystasia lanceolata T . And., J . Linn. Soc., Bot. 9: 524. 1867. Type: Myanmar, Pegu, Thaungyin, Brandis s.n. (holotype CAL) .

Description.

Shrubs 0.5-3 m tall, anisophyllous. Stems terete, slender, rarely branched, glabrous. Leaves petiole 1-2.5 cm; leaf blade elliptic to oblanceolate to lanceolate, 10-16 × 3-7 cm, both surfaces glabrous, secondary veins 6-9 on each side of mid-vein, base cuneate, margin entire or sub-sinuate, apex acuminate. Inflorescence thyrses 3-7 cm; cymes sessile, 1-3-flowered; peduncles ca. 2 cm; bracts elliptic to broadly lanceolate, 3-9 × 1-3 mm, apex acute, glandular-pubescent; bracteoles narrowly elliptic to broadly lanceolate, 4-9 × 0.7-1.2 mm; pedicel 1-5 mm long. Calyx 1-1.6 cm, outside glandular-pubescent; posterior lobe lanceolate, ovate or subelliptic; anterior lobes connate to two-thirds of their length. lateral lobes linear-lanceolate. Corolla white with pink or purple spots, ca. 2.5 cm, outside pubescent; tube basal portion ca. 9 mm, throat ca. 1.5 cm; upper lip two-lobed; lower lip three-lobed. Stamens 4, included in throat; filaments 1-1.2 cm, glabrous; anther thecae 2.1-2.3 mm, pubescent at the apex and along sides, basal spur pointed; ovary apex pubescent; style ca. 2.5 cm. Capsule subellipsoid to obovoid, 1.2-1.6 cm, glabrous or only at apex pubescent, four-seeded. Seeds subcircular in outline.

Distribution.

Myanmar, N Thailand, N Laos, N Vietnam, SW China (Yunnan), Malaysia. In Peninsular Malaysia, recorded from one specimen collected from the trail to Gunung Padang, Ulu Brang, Terengganu in 2010 (FRI 66129) (Map 1).

Ecology.

In Peninsular Malaysia, found in a lowland dipterocarp forest at 473 m a.s.l., under a canopy near a small river. (Trail to Gunung Padang).

Conservation status.

Critically Endangered B 2 ab(ii). Following the IUCN Red List Categories and Criteria (IUCN 2019), this species is assessed as critically endangered at a national level in Peninsular Malaysia because it is currently known from only one specimen in one locality. It is certainly a very rare species. The forest area is lowland dipterocarp forest which was previously logged in the past and it is not a Totally Protected Area. Globally, its conservation status possibly lists it as least concern (LC), by its wide range distribution.

Specimen examined.

Terengganu: Hulu Terengganu, Ulu Brang, Ummul-Nazrah et al. FRI 66129 (KEP) .