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Card. Bull. Singapore 69(2) 2017 
may flower when only the macrocotyledon has developed and can be mistakenly 
interpreted as unifoliate, a common state in Microchirita hamosa for example. 
Generally this is very variable, even within a single population, with a mixture of 
plants flowering at different sizes and stages of development. The macrocotyledon can 
be much larger than the paired leaves, leading to broad ranges of leaf size and number 
of secondary veins. 
Much variation can be observed in the corolla of Microchirita. The tube is 
generally narrow at the base, often bent downwards, and widens more or less abruptly, 
into a campanulate, funnel-shaped or tubular upper corolla. The colour of the corolla 
varies substantially from pure white to a lilac-purple-blue palette, or to a pale yellow- 
yellow-dark orange range. The colour is rarely uniform throughout the corolla. Some 
species (e.g. Microchirita albocyanea C.Puglisi) have lobes of a different shade from 
the tube; most species (e.g. M. tubulosa (Craib) A.Weber & D.J.Middleton) have a 
ventral yellow line running from the base of the ventral lobe to the throat; many species 
(e.g. M. bimaculata (D.Wood) A.Weber & D.J.Middleton) have lines or spots either at 
the base of the lateral lobes or at the base of the upper lip; finally, in few taxa (e.g. M. 
rupestris (Ridl.) A.Weber & Rafidah), the venation of the petals is visible in the form 
of fine purple lines running along the lobes and anastomosing terminally. The colour 
and patterning of the corolla are taxonomically significant. Some species appear to 
have a purple/blue form and a white equivalent (e.g. M. hypocrateriformis C.Puglisi). 
Where this variation was not substantiated by allopatry or further morphological 
differentiation, no taxonomic distinction is made. 
Anthers of Microchirita species can be free, coherent face-to-face, or apically 
joined by a ligament. Furthermore, anthers can be glabrous or bear an indumentum, 
especially dorsally at the filament insertion. The indumentum is usually of long, 
somewhat woolly, eglandular hairs, but in some species additional, shorter and straight 
hairs are seen. 
In this account, Microchirita in Thailand is revised and 29 species, two of which 
have three varieties each, are recognised. Of these, eight species and three varieties are 
newly described. 
Material and methods 
This revision is based on a study of the specimens from the herbaria A, AAU, ABD, 
BK, BKF, BM, CMU, CMUB, E, K, KEP, L, P, PSU, QBG, SING, US (Thiers et 
al., 2017, continuously updated), and Mahidol University, Kanchanaburi Campus 
(MUKA). All specimens have been seen unless otherwise noted. Measurements of 
all but the floral parts were taken from dry specimens. Flower measurements are from 
rehydrated or pickled flowers. When no additional material of the recently published 
species (Middleton & Triboun, 2013; Puglisi et al., 2016) was obtained, we give 
measurements from the original descriptions. Measurements of the flowers were taken 
with a microruler and should be considered accurate to 0.05 mm. 
Conservation assessments follow the guidelines laid out in IUCN (2012). 
