A revision of Microchirita in Thailand 
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Caulescent herb to 40 cm tall, internodes 4-13 cm. Stems succulent, pale green or red 
at base, sometimes branching from basal petiole, with sparse sessile glands. Leaves 
opposite, apart from the basal leaf; petioles 0.3-2.2 cm long, very sparsely eglandular 
hairy; blades mid green above, paler beneath, ovate, 4.2-35 x 1.3-18.8 cm, 1.3-3.3 
times as long as wide, base rounded to cordate, apex acuminate, sparsely eglandular 
hairy above and beneath, sparsely ciliate along the margin, margin entire, 6-22 pairs of 
secondary veins, venation slightly sunken above and raised beneath in fresh material, 
flat in dry specimens, tertiary venation laxly reticulate. Inflorescences cristate; 
peduncles fused, 2.5-5 mm long, fused together, glabrous; bracts absent; pedicels 
green, 4.4-11 mm long, sparsely hairy. Calyx green, bilabiate, the two lips completely 
divided, ventral tube c. 0.1 mm long, dorsal tube to c. 3.5-5 mm long, lobes ligulate, 
dorsal lobes 7.4-8 mm long, lower lobes 3-5 mm long, apex acute, margin entire, 
irregular towards the tip, sparsely hairy outside, hairier at the tip, sparsely glandular 
inside. Corolla 10-12 mm long, tube white, lobes pale lilac, tube narrow, straight or 
just slightly curved, lobes not always spreading, eglandular hairy outside, glabrous 
inside; tube c. 8 mm long dorsally, c. 10 mm long ventrally; lobes broadly orbicular, 
apices rounded or obtuse, upper lobes c. 2.6 x 3.7 mm, lateral lobes c. 2.4 x 4 mm, 
ventral lobe c. 1.8-3 x 4 mm. Stamens arising 3.2-4 mm above the corolla base, 
filaments slightly curved, glabrous, 2.2-2.5 mm long, c. 0.3-0.4 mm wide; anthers 
with an abundant indumentum at the sides and dorsally, 2.2-2.5 x 1.1-1.2 mm, apically 
joined by a weak connective. Disk a small ventral lobe, 0.1-0.6 mm high. Pistil c. 10 
mm long; ovary 5.5-6.5 mm long, papillose in the bottom half, densely pubescent 
above; style white, 3.3^1 mm long, densely pubescent; stigma white, c. 1 mm long. 
Immature fruit 2-3 cm long, c. 1 mm diameter, glabrous, straight. Seeds not seen. 
Distribution. Northern Thailand. 
Habitat. On limestone in evergreen or mixed deciduous and bamboo forest. 
Provisional IUCN conservation assessment. Vulnerable VU Blab(iii) + B2ab(iii). 
The EOO is almost 10,000 km 2 , well within the boundary for Vulnerable. However, 
the AOO is within the boundary for Endangered, not all of the localities are within 
protected areas, and limestone sites are degraded throughout the region. Since there 
are five known localities and there are likely to be more, an assessment of Vulnerable 
is more appropriate than Endangered. 
Additional specimens examined. THAILAND: Lampang: Ngao, near Tham Pha Thai, 520 
m, 24 Sep 2008, Middleton, D.J. et al. 4580 (BKF, E, P); Chae Horn, Ban Sa village, 15 Oct 
2006, Palee, P. 1027 (A, CMUB). Phrae: Long, Doi Pha Klong National Park, Bah Gah Lahn 
Hill, 26 Oct 2005, Palee, P. 846 (A). Tak: Tha Song Yang, Doi Noi, 242 m, 6 Sep 2013, 
Phaosrichai, P. & Wongnak, M. 23 (QBG). 
Notes. The floral characters reported are taken from the original description of 
Microchirita suddeei (Middleton & Triboun, 2013), as no new material has been 
