A revision of Microchirita in Thailand 
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1. Microchirita albiflora D.J.Middleton & Triboun, Thai Forest Bull., Bot. 41: 19 
(2013). - TYPE: Thailand, Chiang Rai, Mae Fa Tuang District, Road to Doi Tung 
Royal Residence, 1000 m alt., 23 September 2008, Middleton, D.J., Karaket, R, 
Triboun, P., Kawatkul, U. & Meeboonya, R. 4567 (holotype BKF; isotypes BK, E 
[E00629491], K, P [P00966762], QBG, SING [SING0229831]). (Fig. 2A-C) 
Caulescent herb to 50 cm tall, with internodes to c. 10 cm, unbranched. Stems fleshy, 
glabrescent or with very sparse short eglandular hairs, pale green or sometimes purple- 
brown at the base. Leaves opposite, except for the basal leaf; petioles 0.2-1.7 cm 
long, basal leaf often sessile, glabrescent; blades mid-green above, pale green beneath, 
ovate, 2.6-23 x 1.7-11 cm, 1.5-2.2 times as long as wide, base cordate, apex acute to 
shortly acuminate, eglandular tomentose above, hispid beneath, margin entire, 7-12 
pairs of secondary veins, tertiary venation laxly reticulate. Inflorescences cristate, 
peduncles reduced or emerging to 1-3 mm long, fused with each other, glabrous, bracts 
absent; pedicels 5-10 mm long, glabrescent or sparsely eglandular hairy. Calyx green, 
bilabiate; tube 0.5-3.7 mm dorsally, c. 0.2 mm ventrally, lobes narrowly lanceolate 
to ligulate, upper lobes 5-7.8 mm long, lower lobes 4-7.8 x 0.5-1.2 mm, sparsely 
eglandular pubescent especially on midrib and tip, glabrous inside, apex acuminate. 
Corolla 7-15 mm long, white, sometimes with a ventral yellow line, tube curved 
downwards, trumpet-shaped, lobes not spreading, outside glabrous basally, eglandular 
tomentose above, inside glabrous, with a glandular patch below the upper lobes; tube 
6.5-13 mm long, equal dorsally, laterally and ventrally; lobes broadly orbicular, upper 
lobes 1.6-1.9 x 2.2-3.1 mm, lateral lobes 1.6-2.7 x 2-3 mm, lower lobe 1.4-2 x 2.6 
mm. Stamens arising 2.7-4.7 mm above the corolla base, filaments straight, minutely 
glandular (glabrous in protologue), 2.1-3.1 mm long, 0.2-0.5 mm wide; anthers 
glabrous, 0.6-1.1 x 1-2 mm, free or coherent by a weak ligature, thecae divergent; 
lateral staminodes c. 0.6 mm long, arising near the corolla base, central staminode c. 
0.4 mm long, arising near the corolla base. Disk partial, ventral, lobed, 0.3-0.7 mm. 
Pistil c. 12 mm long; ovary 4.7-6 mm long, c. 0.6 mm diameter, glabrous or papillose 
in lower 2/3, densely pubescent in upper 1/3, many ovules; style c. 4 mm long, densely 
pubescent; stigma deeply bilobed, 0.7-1 mm long. Fruit green, 2-5 cm long, 1-1.7 
mm diameter, with sessile glands at base, then becoming sparsely eglandular hairy, 
curved. Seeds dark brown, elliptic, 0.6-0.7 x 0.3-0.4 mm. 
Distribution. Northern Thailand. India, (Myanmar?), Laos. 
Habitat. On rocks in mixed forest. 
Provisional IUCN conservation assessment. Near Threatened NT. In Middleton & 
Triboun (2013) this species was given a conservation status of Endangered. Since then 
specimens have also been identified from NE India and Myanmar. From the known 
localities, the AOO is still within the threshold for an Endangered assessment but large 
swathes of territory within the large EOO, particularly in Myanmar, have not been 
adequately explored to base an assessment on this. As limestone areas throughout the 
