PL. CCXCVI. 
DIACRIUM BICORNUTUM benth. 
THE TWO-HORNED DIACRIUM. 
DIACRIUM. Sepala subaequalia, libéra, patentia, crassiuscula, petaloidea. Petala sepalis subsimilia. Labellum 
a basi columnae patens, sepalis subaequilongum ; lobi latérales patentes v. reflexi, médius longius ; discus inter 
lobos latérales elevatus ; supra bicornutus, cornubus subtus excavatis. Columna brevis, lata, leviter incurva, in alas 
angustas crassiusculas expansa; clinandrium obliquum, obtusum. Anthera terminalis, opercularis, incumbens, semi- 
globosa, 2-locularis, loculis septo longitudinali 2-locellatis ; pollinia 4, cerea, lato-ovata, aequalia, a latere parallèle 
compressa, i-seriata, in quoque loculo appendicula granuloso-viscosa lineari a basi marginibus applicita connexa. 
Herbae epiphyticae, caule carnoso in pseudobulbum elongatum incrassato. Folia pauca, ad apicem conferta, 
rigide coriacea, subcarnosa, cum vagina brevi articulata. Pedunculus terminalis, simplex, vaginis paleaceis distantibus 
arcte appressis. Flores speciosi, laxe racemosi, breviter pedicellati. Bracteae parvae. 
Species descriptae 4, Guianae Americae centralis et Mexici incolae. 
Diacrium Benth. in Journ. Linn. Soc., XVIII (1881), p. 312. — Benth. et Hook. f. Gen. Plant., III, p. 526. 
Diacrium bicornutum. Pseudobulbis subfusiformibus apice 3-4-foliatis, foliis lineari-oblongis obtusis coriaceis, 
sepalis ovato-lanceolatis acutis, petalis conformibus latioribus concavis, labello libero trilobo, lobo medio elongato 
lanceolato acuto, lobis lateralibus oblongis obtusis, disco supra basi alte bicornuto, columna clavata. 
Diacrium bicornutum, Benth. in Journ. Linn. Soc., XVIII (1881), p. 312. — Benth. et Hook. f., Gen. Plant., III, 
p. 526. — Rolfe in Gard. Chron., 1887, pt. 1, pp. 44, 45, fig. 11. — Veitch Man. Orch. PL, pt. 6. p. 79, cum xylogr. 
Epidendrum bicornutum Hook. Bot. Mag., LXI (1834), t. 3332. — Paxt. Mag. Bot., V, p. 245, cum. ic. 
— Lindl. Fol. Orch. Epidendr., p. 27. — Rchb. f. in Walp. Ann., VI, p. 345. — Jenn. Orch., t. 21. — Warn. 
et Will. Orchid Albtim, IV, t. 157. 
his handsome Orchid was originally introduced by Messrs Shepherd, 
of Liverpool, in 1833, from Trinidad, where it grows on rocks or small 
islets close to the sea. It flowered for the first time in Europe in the 
collection of Barl Fitzwilliam, at Wentworth, in April of the following year. 
It was originally described by Sir William Hooker, in the Botanical Magazine, 
from the same source, as Epidendrum bicornutum. Lindley referred it, with two 
other allied species, to a distinct section of the genus, which he called Diacrium , 
and this was raised to the rank of a genus by Bentham, on the ground that the 
peculiar bicornute labellum, which is neither adnate to, nor parallel with the 
column, gives the flower a very different aspect from that of the true species of 
Epidendrum , and cannot be included among them without doing violence to the 
generic characters. 
In a note in the Kew Herbarium D r Bradford remarks : “ This most beautiful 
species is found in the greatest abundance on the coast and on the adjacent 
islands of the Boca de Moros, at Trinidad. The rocks and stumps of decaying 
trees are in some places covered with it. It flowers chiefly in the early part of the 
year, from January to April. ” 
In 1837 it was met with by Schomburgk at the River Berbice, in British 
