ONCIDIUM. 3 



have leaves that are much larger and thicker in texture than the 

 pseudo-bulbous species. On. Ceholleta, On. Jonesianum, and three or 

 four other species not known to be at present in cultivation, have 

 terete, fleshy leaves, channelled on one side. Another deviation from 

 the usual ensiform leaves of Oncidium is seen in On. lyulcliellum, On. 

 tetrapetalmn. On. ui^ophyllum, and three or four others that are now 

 but rarely if ever seen in cultivation ; all these have rigid, triquetral, 

 equitant leaves. The inflorescence of many Oncids is remarkable for the 

 extraordinary length attained by the peduncle, which sometimes rambles 

 in a flexuose, irregular manner for several yards, branched at irregular 

 intervals, and bearing flowers that may be sometimes counted by the 

 hundred. ^NTo species of Odontoglossum is yet known with a peduncle 

 longer than 3 — 4 feet. 



The genus Oncidiura, as above stated^ was founded by Swartz, the 

 Swedish botanist^ at the beginning of the present century on the West 

 Indian species altissimum, cartliaginense, Ceholleta, tetrapetalum and 

 variegatum, which he separated from the Linnsean genus Epidendrum. 

 The name is derived from the Greek word oy/coc (onkos), "a 

 tumour or swelling," in reference to the warty excrescences always 

 present on the labellum.* 



Lindley distributed the species known to him, two hundred in all, 

 into fourteen series or sections,! by far the greater number of which 

 are founded upon characters so artificial that it is not surprising that 

 a better acquaintance with many of the species and the subsequent 

 introduction of new ones should tend to break down the sectional 

 framework which Lindley so laboriously put together. Accordingly 

 when Mr. Bentham revised the genus for the Genera Plantarum he 

 reduced the sections to four, retaining only one founded on floral 

 characters, viz., Microchila, and restricting it to those species in 

 which the front lobe of the labellum is small, narrow, and entire, as 

 in Oncidium macranthum, On. superbieiis, On. serratum, On. zehrinum, and 

 other well-known and admired kinds, f The characters of the other 

 three sections are derived from the leaves ; these are Equitantia, 

 including those species Avith distichous, equitant leaves, as On. pulehellum, 

 On. tetrapeiahmi, On. uroplujllum, etc. ; Teretifolia, including On. 

 Ceholleta, the type, On. Jonesianum, and three or four others with long 

 fleshy terete leaves ; and Planifolia, to which is referred all the 

 species with flat leaves, except those included in Microchila, thus 

 lumping together a large majority of the species, some of which difi'er 

 as much from each other in habit and inflorescence as they do from 



* Swartz derived Oncidium from 'oyd^iov, a word that does not occur in classical literature, 

 but is rightly formed as a diminutive of oyicog, 



t Folia Orchidacea, published in 1855. + The genus Cyrtochilum of Humboldt and Kunth. 



