TROPICAL AMERICAN ORCHIDS 
No. 29016.); Standley 32983 (a small specimen): Province of 
Cartago, Alto de La Estrella, Standley 39584, March 26, 
27, 1924. On trees. (Flowers passe.) 
Maxillaria semiorbicularis A. A A sp. nov. Herba 
caulescens, valida. Caulis vaginis distichis arete imbri- 
cantibus obtectus. Pseudobulbus complanato-ovoideus, 
monophyllus. Folia oblonga, apice ipso rotundata. Sepala 
lateralia lanceolata, acuminata. Sepalum dorsale oblongo- 
lanceolatum. Petala oblique lanceolato-elliptica. Labellum 
semiorbiculare, antice trilobatum; lobi laterales falcato- 
triangulares, patentes; lobus intermedius ovato-triangularis; 
discus in basi tuberculorum fasciculo et in medio lamella 
semilunata dentata ornatus. 
Plant caulescent, very stout. Stem woody, entirely in¬ 
vested by distichous closely imbricating leaf-bearing sheaths. 
Pseudobulbs (but one present) apparently remote, mono- 
phyllous, ellipsoid, strongly complanate in the dried state, 
nearly 4 cm. long, conspicuously rugose, yellowish and shin¬ 
ing. Leaves (the larger blades near and on the pseudobulb) 
oblong, 12.9-32.3 cm. long, 2.75-3.6 cm. wide, subacute 
with an abruptly rounded minutely apiculate apex, gradually 
narrowed below (the leaf on the pseudobulb with a distinct 
slender laterally compressed channelled petiole which is 
about 6 cm. long), chartaceous, the mid-nerve somewhat sul- 
cate above and conspicuously carinate beneath; the blades 
on the stem smaller,, conduplicate, arcuate, sometimes 2 cm. 
long, 1.6 cm. wide when unfolded. Inflorescences numerous, 
1-flowered, solitary in the axils of the sheaths. Peduncles 
strict, 7-8 cm. long, subflexuous, mostly concealed by scari- 
ous tubular sheaths which waste into fibres. Flower medi¬ 
um-sized for the genus. Lateral sepals lanceolate, about 2.25 
cm. long and 7.9 mm. wide below the middle, acuminate, 
complicate-acute, 7-15-nerved. Dorsal sepal similar, ob¬ 
long-lanceolate, 2.5 cm. long, 7 mm. wide near the middle, 
sharply complicate-acute. Petals obliquely oblong-elliptic, 
about 2.2 cm. long, 6.5-6.9 mm. wide near the middle, acu¬ 
minate, dorsally carinate at the apex, with seven prominent 
nerves. Labellum much smaller than the sepals and petals. 
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