(one to three according to Ostlund’s notes), 1-3 cm. a- 
part, near the upper end of the peduncle. Lateral sepals 
about 3.5 em. long, about 7.5 mm. wide, greenish be- 
coming brownish yellow, rather firm in texture, nervose 
when dry, narrowly oblong, acute. Dorsal sepal similar. 
Petals 3.7 cm. long, about 5 mm. wide, linear-oblong, 
acute, similar to the sepals in texture, greenish yellow. 
Labellum lightly pandurate, about 5.5 em. long, 8.3 cm. 
wide near the deeply bilobed apex with the lobes 1.3 em. 
long and 1.5 cm. wide, white with yellow-green nerves 
in the throat, the texture firm but membranaceous. Disc 
conspicuously unicarinate for one half its length along 
the middle with a raised nerve on each side of the keel 
which is white and much broader at the base than else- 
where, the basal part being strongly concave. Column 
about 2 cm. long, simple, free from the lip almost to the 
base, greenish near the base, white above the middle. 
Pollinia four, strongly complanate. 
This remarkable species is in the alliance formed by 
Kpidendrum Ghiesbreghtianum A. Rich. & Gal. and FE. 
hastatum Lindl. From EF. Ghiesbreghtianum, with which 
it is most closely allied, it differs in the structure of the 
labellum and in the much larger flowers with differently 
colored sepals and petals. The type possesses three flowers 
on the elongated peduncle, but in the notes sent to me 
by Mr. Ostlund there is a reference to plants that produce 
a one-flowered inflorescence. In some of the specimens 
observed by Mr. Ostlund the labellum attained a length 
of 7.5 em. and a width of 4.8 em., so that #. Mariae is 
one of the largest flowered species of the genus. 
Mexico, San Luis Potosi, region of Las Canoas in oak and cypress 
forest at 1000 meters altitude. November 27, 1935. Erik Ostlund 5103 
(Collector O. Nagel). Flowering under cultivation at Colonia del 
Valle, D. F. June and July 1937. (Tyezin Herb. Ames No, 45825.) 
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