A revision of Microchirita in Thailand 
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The authors have seen more than half of the species in this revision in the 
field. Field characters have been instrumental in gaining a better understanding of 
the species to aid in species delimitation. In particular it becomes quite obvious in the 
field that plants flowering as early as the macrocotyledon stage are completely mixed 
into populations of much larger plants and that previous taxonomic distinctions based 
on plant size are untenable. We have not seen living plants of some of the species 
in the Northeast of Thailand but have been greatly aided by photographs taken by 
collectors. Many species of Microchirita are rather similar when pressed and dried 
and we urge collectors to ensure good collection notes, especially in corolla colour and 
colour variation characters, and to take photographs of the living plants. The species 
are presented in alphabetical order. 
Taxonomic treatment 
Microchirita (C.B.Clarke) Yin Z.Wang, J. Syst. Evol. 49: 59 (2011). - Chirita sect. 
Microchirita C.B.Clarke in Candolle & Candolle, Monogr. Phan. 5: 127 (1883). - 
Roettlera sect. Microchirita (C.B.Clarke) Fritsch in Engler & Prantl, Nat. Pflanzenfam. 
IV/3b: 148 (1895 ). - Didymocarpus sect. Microchirita (C.B.Clarke) Chun, Sunyatsenia 
6: 290 (1946). - TYPE: Microchirita hamosa (R.Br.) Yin Z.Wang, lectotype designated 
by Burtt (1954: 196). 
Annual or semiperennial herbs, often with succulent stems. First leaf (macrocotyledon) 
often persistent and single (not paired), second cotyledon rudimentary or suppressed; 
all other leaves in opposite pairs, sessile or petiolate. Inflorescences axillary or 
epiphyllous, often crested (see Introduction above); peduncles normally developed 
in axillary inflorescences, reduced and sometimes fused with each other in crested 
inflorescences; bracts present in axillary inflorescences, divided or somewhat fused; 
flowers 5-merous. Calyx lobes divided almost to base or short tube present. Corolla of 
a narrow lower tube, a wider upper tube and a bilabiate limb, upper lip 2-lobed, lower 
lip 3-lobed, variable in shape and colour. Stamens 2, filaments straight or bent, anthers 
often densely hairy and joined by a ligature; staminodes 3. Disk present, often annular, 
occasionally partial, or absent. Ovary unilocular with parietal placentation, mostly 
fusiform; style distinct; stigma chiritoid (see Introduction above); ovules many. Fruit 
a narrow, bivalved capsule. Seeds many. 
Key to Microchirita species in Thailand 
la. Inflorescence with distinct bracts in inflorescence, bracts free or fused together.. 
. 2 
lb. Inflorescence without distinct bracts in inflorescence.6 
2a. Glandular hairs present on pedicels and/or peduncles.3 
2b. Glandular hairs not present on pedicels and/or peduncles.4 
