Polystachya. | CXXXIII, ORCHIDEE (ROLFE). 129 
broadly triangular-oblong, slightly bidentate, dorsally flattened. Column 
stout, 1} lin. long, Chin oblong, obtuse, 3} lin. long. 
Upper Guinea. Cameroon Mountains, 5000 ft., Mann, 2110! 
67. P. elastica, Lindl. in Journ. Linn. Soc. vi. 131. Plant 6 in. 
high. Stems short, slightly thickened at the base, 2~3-leaved. Leaves 
linear-lanceolate, subacute, 2-3 in. long, 2-24 lin. broad. Scapes 6 in. 
long, pubescent; racemes simple, few-flowered. Bracts very broadly 
ovate, acute or apiculate, ?-1 lin. long. Pedicels 5 lin. long. Dorsal 
sepal ovate-oblong, acute, 34 lin. long; lateral broadly and obliquely 
triangular-ovate, mucronate. Petals subspathulate-oblong, obtuse or 
apiculate, 34 lin. long. Lip doubly curved into the form of an S, 
trilobed, } in. long; the basal third broadly unguiculate, with a high 
callus, narrow and apiculate in front; the middle third oblong, covered 
with a longitudinally-grooved hairy cushion, and bearing a pair of 
rounded, crenulate side lobes near its apex; the apical third incurved, 
obovate, truncate, very concave, and with an apiculate tooth on the 
back at its base. Column stout, 14 lin. long. Chin triangular-oblong, 
54 lin. long.—Dendrobium roseum, Sw. in Schrad. Neues Journ. i. 97 ; 
Pers. Syn. Pl. ii. 523; Lindl. Gen. & Sp. Orch. 92. 
Upper Guinea. Sierra Leone: Bagru River, Mann, 902! and without precise 
locality, Afzelius! 
A very remarkable species with a large mass of thin, flat roots like those of the 
leafless Angrecums. Lindley says that its labellum, which is a long, narrow, yellow 
body with an inflexed terminal lobe, is thrown back forcibly when the flower expands, 
so as to hang down over.the hood formed by the united lateral sepals. By what 
mechanical contrivance this is effected I have been unable to determine. In the bud 
State the tooth on the back of the lip is exactly opposite to the apex of the sepals and 
petals, and the concave front lobe of the lip is tucked away behind the column in a 
remarkable manner, 
_ 68. P. fusiformis, Lindl. Bot. Reg. 1824, sub t. 851. Plant 6-9 
in. high. Pseudobulbs fusiform-oblong, superposed, 2-3 in. long, 3-4- 
leaved. Leaves oblong or oblong-lanceolate, subacute, 2-5 in. long, 
4-7 lin. broad. Panicles 2-21 in. long. Bracts triangular, acuminate, 
3-1 lin. long. Pedicels 2 lin. long. Dorsal sepal ovate, apiculate, 1 
lin. long ; lateral resembling the dorsal, but broader. Petals oblong 
or subspathulate-oblong, subacute, 1 lin. long. Lip 1 lin. long, un- 
guiculate, trilobed ; side lobes rounded-oblong, obtuse : front lobe ovate, 
subobtuse or apiculate; disc subglabrous, without a callus. Column 
stout, 4 lin. long. Chin saccate, obtuse, 1 lin. long. Capsule oblong, 
4 lin. long.—Kriinzl. in Engl. Pü. Ost-Afr. C. 155. Dendrobium 
fusiforme, Thou. Orch. Des Afr. t. 86. 
Mozamb, Dist. German East Africa: Usambara; Mascheua (ex Kréinzlin). 
Also found in Madagascar, Mauritius, Reunion, and the Seychelles. I have seen 
no Tropical African specimens, and the description is made from Mascarene ones. 
69. P. superposita, Reichb. f. Otia Bot. Hamb. ii. 111. Pseudo- 
bulbs slender, cylindric, superposed, each arising from above the 
middle of the previous one, 2-34 in. long, 3-4-leaved. Leaves linear 
VOL. VII. K 
