ONCIDIUM. 13 



and its smaller flowers with a difPerently-shaped labellutn and crest. 

 It is widely distributed over the West Indian Islands and adjacent 

 parts of the South American continent, notably in British Guiana, 

 where it was gathered by the brothers Schomburgk during their 

 exploration of the colony in 1840-44.* It appears to have been 

 first cultivated by Mr. Colville, of Chelsea, who received a medal 

 for it from the Horticultural Society of London in 1833 under the 

 name of On. altissimum. The species is dedicated to Francis Bauer, 

 the eminent botanical draughtsman of that period. 



On. bicallosum. 



Pseudo-bulbs none. Leaves oblong-lanceolate, 8 — 12 inches long, 

 complicate at base, keeled at the back, very leathery. Scapes stoutish, 

 erect, longer than the leaves, usually racemose along the upper half, 

 but sometimes branched, many flowered. Flowers about 2 inches across 

 vertically ; sepals and petals similar, obovate-spathulate with undulate 

 margin, yellow toned with brownish green, the dorsal sepal concave, 

 almost galeate, the lateral two narrower ; lip bright canary-yellow, three- 

 lobed, the basal lobes small, sub-spathulate ; the front lobe large and 

 spreading, transversely oblong with a shallow sinus in the anterior 

 margin ; crest white dotted with red, bipartite, the posterior part sub- 

 reniform, the anterior part with three rounded tubercles. Column 

 wings small, decurved. 



Oncidium bicallosum, Lindl. in Benth. Plant. Hartw. p. 94 (1839). Bot. Meg. 

 1843, t. 12. Fol. Orch. Oncid. No. 135. Bot. Mag. t. 4148. Illus. hort. XII. t. 

 458. 



A native of Guatemala. It was first detected by Mr. G. Ure 

 Skinner, who sent plants to Woburn Abbey gardens and to Mr. 

 Bateman, and afterwards by Hartweg while collecting orchids in 

 Central America for the Horticultural Society of London. It flowered 

 for the first time in this country in Mr. Bateman^s collection at 

 Knypersley in the autumn of 1842, and in the following year in 

 the Royal Gardens at Kew, whither the Woburn collection of orchids 

 had been removed. It is very near Oncidium Gavendishianum, from 

 which it is distinguished by its larger and differently coloured flowers, 

 and especially by the form of its column wings and crest, that of 

 the latter suggesting the specific name. 



* Ueber die ganze Region verbreitet au den Ufern der Fliisse auf Baumstamnien. Bliitht. in 

 April und Mai. Keisen III. p. 913. 



