34 ONCIDIUM. 



On. divaricatum. 



Pseudo-bulbs sub-orbicular, very much compressed, almost discoid, 

 1 — 1^ inches in diameter, monophyllous. Leaves narrowly oblong, 9 — -12 

 inches long, very coriaceous. Peduncles dull purple mottled with pale 

 green, 4 — 6 feet long, much branched, the branches slender, many 

 flowered. Flowers an inch in diameter ; sepals and petals clawed, 

 chestnut-brown with a golden yellow blotch at the apex, the sepals 

 obovate, the dorsal one concave, the lateral two divaricate ; the petals 

 longer, oblong, obtuse ; lip three-lobed, the side lobes the largest, sub- 

 orbicular entire, yellow spotted with chestnut-brown ; the intermediate 

 lobe transversely oblong, emarginate, yellow with a chestnut spot in front 

 of the - crest ; crest cushion-like, four-lobed. Column wings rounded. 



Oncidium divaricatum, Lindl. in Bot. Reg. t. 1050 (1827). Id. Gen. et. Sp. Orch. 

 p. 205 (1833). Id. Fol. Orch. Oncid. No. 119. Paxt. Mag. Bot. III. p. 4 (1837). 



One of the first of the Brazilian Oncids cultivated iu Great 

 Britain, and one of the most tractable under cultivation. It first 

 became known to science in the early part of the pi'esent century 

 through the French traveller, Descourtilz, who detected it growing 

 on the trunks of large trees on the Sen-a das Argoas in the 

 district of Ilha Grande, and at Corcovado near Rio de Janeiro. 

 It was introduced to British gardens by Mr. Heatherly, the 

 British Vice- Consul at Rio de Janeiro, who sent plants to the 

 Horticultural Society of London, one of which flowered for the first 

 time in the Society's garden at Chiswick in October, 1826. It was 

 subsequently imported by Loddiges, Knight and other horticultural 

 firms. 



Oncidium divaricatum is one of a group of Oncids including 

 four species forming Lindley's sub-section Pulvinata, characterised 

 chiefly by the papillose cushion-like crest of the lip. The other 

 three are On. sjjhmjiferum, On. i?ulvinatiim, and On. Harrisonianum. 

 These members of the Pulvinata group may thus be distinguished 

 from each other : — 



In On. divaricatum the crest is distinctly four-loljed, the lateral lobes 

 of the lip flat and entire. 



In On. sinliegiferum the crest is oblong and entire, the side lobes of 

 the lip denticulate. 



In On. pulvinaturn the crest is circular, the side lobes of the lip 

 fimbriate ; and generally, the leaves are broader than those of the 

 other three species. 



In On. Harrisonianum the crest is five-toothed, and the habit and 

 aspect of the plant very diff'erent from all the others. 

 The variability in the colour of the flowers of Oncidium divaricatum 



