Qla. 
22. 
22a, 
28a. 
29a. 
30. 
30a. 
lobe; column short, erect . . . .. . . . . . O. boinensis 
Sepals and petals dissimilar, linear-lanceolate, 
acute; lateral lobes of lip as large as midlobe; 
column elongate, arcuate ......... . . O. Rauhii 
Lip as long as or shorter than wide; terminal lobe 
separated from the lateral lobes by acute, indented 
or rounded sinuses .... . a a ae ee ee 
Lip as long as or longer than wide: terminal lobe 
separated from the lateral lobes by a distinct 
isthmus... . . . « O. monophylla 
Spur eapelonece: ee of lip bilobed . . . . O. ambongensis 
. Spur clavate to cylindric; callus of lip bilamellate . . . . 24 
Sepals and petals acute: lip as long as wide; sinuses 
in middle of lip; inflorescence always racemose . O. maculata 
Sepals and petals obtuse; lip shorter than wide; 
sinuses one-third from apex of lip; inflorescence 
racemose or subpaniculate .. . » . . « « OF Mackeni 
Pseudobulbs narrowly cylindrical, often stem-like, 
terete, two-leaved; lateral sepals longer than dor- 
sal sepal; lip equally 4-lobed . . . . . . . O. Saundersiana 
Pseudobulbs ovoid to conical, 1-leaved; sepals of 
same length; lip flabellate or unequally 4-lobed . . . . . 26 
Lateral lobes of lip larger than median lobe. . . . . . . 27 
Lateral lobes of lip much smaller than median 
lobe, ear-like . ... . & ; : ; ee 4 ee 
Leaves lanceolate, joni-abeenuaie, si bachametes 
sepals and petals apiculate . . . fu ea 4 0. sansibarica 
Leaves lanceolate-elliptic or Sacco elliptic, 
acute to subobtuse; sepals and petals obtuse O. alismatophylla 
Callus of lip and the disc in front of it puberulent . . . . 29 
Callus of lip and dise glabrous. . ‘5 - A moo 
Leaves broadly elliptic, large, 7- caened. with esti 
30-50 em. long; column-wing ciliolate-hirsute along 
margins; lateral lobes of lip rounded. . .  O. cordylinophylla 
Leaves narrowly ovate-lanceolate, 1-3 nerved, with 
petiole 13-20 cm. long; column-wings glabrous along 
margins; lateral lobes of lip obliquely triangular- 
faleate ... . 2. 2. . O. analamerensis 
Lip donuheleted 4 in aaidale. sccicniate: basal part 
suborbicular, apical part divergingly bilobed with 
rounded lobes; disc bilamellate at base in front 
of which are 8 thickened veins . ..... . . O. pettolata 
Lip not pandurate, 3-lobed; lateral lobes obtusely 
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