A revision of Microchirita in Thailand 
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Caulescent perennial herb to 40 cm tall, internodes 1-10 cm, occasionally branching 
from the basal portion of the basal petiole. Stems purple or green, strigose, more densely 
so at the nodes. Leaves opposite; petioles 2-10 mm long, c. 1.5 mm diameter, strigose; 
blades elliptic to lanceolate, green above, pale green beneath, 2.1-15 x 1.6-8.4 cm, 
1.1-2.3 times as long as wide, base shortly attenuate to rounded to subcordate, apex 
acute, eglandular tomentose above, hispid beneath, ciliate along the margin, margin 
entire (can be serrate in some Malaysian specimens), 6-11 pairs of secondary veins 
in the opposite leaves, venation slightly sunken above and raised beneath in fresh 
material, tertiary venation lax and seldom visible. Inflorescence cristate, 1-6-flowered; 
peduncles reduced; bracts absent; pedicels 7-20 mm long, eglandular hairy. Calyx 
green, succulent at the base, lobes almost free to base, narrowly lanceolate, c. 6-10 x c. 
1 mm, apex narrowly acute, outside eglandular hairy, inside with sparse hairs becoming 
denser at the tip. Corolla 17-21 mm long, tube yellowish white inside, lobes blue- 
purple with with dark blue lines, tube narrow at base, bent downwards, then gradually 
expanding, with sessile glands inside, elongated glands at the base of the upper lobes 
and very minute glandular hairs on the lower lip; tube 13 mm long dorsally, 16 mm 
ventrally, 12 mm laterally between lips; upper lobes c. 2.5 x 4 mm, lateral lobes, c. 
3.5 x 4.3 mm, lower lobe c. 5 x 4.5 mm. Stamens arising c. 8.5 mm above the corolla 
base; filaments straight, glabrous, c. 3 mm long, c. 0.3 mm wide; anthers sparsely 
hairy dorsally, c. 2 x 1 mm, apically coherent but not joined by a connective, thecae 
divergent; lateral staminodes c. 1.2 mm long, central staminode not seen. Disk annular, 
margin slightly lobate, c. 0.3 mm high. Pistil c. 14 mm long, densely eglandular hairy 
throughout except at the base of the ovary; ovary c. 5.5 mm long, c. 0.6 mm diameter; 
style c. 6.5 mm; stigma deeply bilobed, lobes c. 0.9 x 0.4 mm, shortly plumose inside. 
Fruit 1^1.5 cm long, 0.9-1 mm diameter, densely eglandular hairy, straight or slightly 
curved. Seeds brown, broadly elliptic, 0.4-0.5 x 0.2-0.3 mm. 
Distribution. Peninsular Thailand. Malaysia. 
Habitat. On limestone in evergreen forest. 
Provisional IUCN conservation assessment. Vulnerable VU Blab(iii). This species 
occurs on Langkawi in Malaysia and has also previously been collected on the 
mainland in Kedah. Rafidah (2017) reports that no recent collections have been made 
from the Kedah mainland and suggests a conservation assessment of Near Threatened 
as the species is reported to be common and protected on Langkawi. In Thailand, 
however, most of the known localities are not in protected areas and are subject to high 
disturbance. The EOO and number of collection localities, coupled with these threats, 
suggest an assessment of Vulnerable. 
Additional specimens examined. THAILAND: Krabi: Ao Luek, c. 50 m, 17 Nov 1959, 
Smitinand, T. & Abbe, E.C. 6151 (BKF, K (2)); Muang, Krabi Noi, Wat Tham Suea, 25 m, 17 
Sep 2010, Middleton, D.J. et al. 5467 (E); Kasoom, Nov 1896, Curtis 3221 (K). Phangnga: 
s.L, 28 Feb 1929, Kerr 17563 (K); Mueang Phangnga, Sri Nakharin Park, 1 m, 18 Nov 2014, 
