224 
Card. Bull. Singapore 69(2) 2017 
and eglandular hairy. Calyx green, lobes divided almost to base, lanceolate, 13-15 x 
1.2-1.5 mm, apex acuminate, glandular and eglandular hairy outside, especially along 
margins and midrib, glabrescent inside. Corolla c. 23(-28 reported in literature) mm 
long, white at base, turning purple above, lobes purple inside and outside, throat with 
a yellow ventral line and lateral dark patches, tube slightly curved, broadening into 
a pouched upper corolla, indumentum outside sparsely eglandular hairy, densely so 
by the lobes, inside glandular hairy. Stamens with hairy anthers. Disk not seen. Pistil 
enantiostylous, white to pale purple, ovary densely hairy. Fruit 2.1-9.5 cm long, 1.2- 
1.8 mm diameter, densely eglandular hairy, straight or slightly curved. Seeds brown, 
elliptic, 0.6-0.7 x 0.2-0.3 mm. 
Distribution. Northeastern Thailand (Khon Kaen, Loei). Vietnam. 
Habitat. On limestone rock in shade. 
Provisional IUCN conservation assessment. Endangered EN B2ab(iii). This species is 
quite widespread but only known from rather few collections in Thailand and Vietnam. 
It is likely to also occur in Laos but the distribution is fragmented and the likelihood of 
the AAO being >500 km 2 , even with new localities being discovered, is rather remote. 
Throughout the region limestone habitats are threatened with mining, tourism and 
land use changes. The assessment is not altered by changes in the status of the dubious 
specimens below. 
Additional specimens examined. THAILAND: Loei: Nong Hin, Num Sow, Phu Pha Lorn 
Forest Park, 435 m, 5 Nov 2014, Tetsana, N. et al. 871 (BKF). Khon Kaen: Phuphaman NP, 
300 m, 24 Aug 2011, Norsaengsri, M. et al. 8086 (QBG). 
Dubious specimens. THAILAND: Loei: near Phu Kradung, Pha Nok Khao, 250-350 m, 6 Nov 
1970, Charoenphol, C. et al. 4585 (AAU, E, L). Khon Kaen: Pha Nok Khao, 600-700 m, 9 
Sep 1963, Smitinand, T. et al. 1129 (E, L). 
Notes. Microchirita aratriformis is a poorly known species. The placement of any Thai 
specimens into it has to be considered tentative and based on the presence of axillary 
shoots, cristate inflorescence, pedicels with mixed indumentum types, ventral yellow 
line, and an approximate match of calyx and corolla size. The flowering material 
available for this study was extremely limited, therefore the only thorough description 
of the inner flower parts remains that of Wood (1972, 1974). The specimens cited as 
‘dubious’ above are those placed in this species by Burtt (2001) which are not good 
collections and we cannot be entirely sure they belong here. 
4 . Microchirita bimaculata (D.Wood) A.Weber & D.J.Middleton, Taxon 60: 778 
(2011). - Chirita bimaculata D.Wood, Notes Roy. Bot. Gard. Edinburgh 31: 368 
(1972); Wood, Notes Roy. Bot. Gard. Edinburgh 33: 196 (1974); Burtt, Thai Forest 
