ONCIDIUM. 5 



doubtless extremely local, some more widely distributed, while there 

 are not wanting instances, as Oncidium Cebolleta, that have been reported 

 from places thousands of miles from each other.* So far as at 

 present known, the species are also very unequally scattered over 

 this region. On the Organ Mountains and in the parts of the 

 provinces of Rio de Janeiro, Minas Geraes and San Paulo immediately 

 contiguous to them, a large number of species are aggregated ; another 

 aggregation of species occurs on the Andes of Ecuador, and thence 

 northwards along the Cordilleras Oncids are comparatively numerous ; 

 but in other parts of South America and north of the Isthmus they 

 appear to be much dispersed and even isolated in places. The diversity 

 of station they affect is also very great : some occur only in the 

 hottest and dampest river valleys or in proximity to the coast, of 

 such is the group of which On. carthaginense and On. Lanceanum 

 are well-known types ; while in strong contrast to these the 

 beautiful Ecuadorean varieties of On. cucullatum ascend to near the 

 snow-line on the Andes near Quito. The Oncids included in the 

 section Microchila as limited by Bentham are also alpine; they are 

 all found on the Cordilleras of Peru and Colombia, rarely ascending 

 above 9,000 feet or descending below 5,000 feet. The species with 

 equitant leaves are confined to the West Indian Islands and the 

 maritime region of South America in their immediate neighbour- 

 hood. The most northern species known to us are On. tigrinum 

 and On. hastatum, the most southern On. bifolium and On. viperinum ; 

 the most southern Andean species is probably On. heteranthum or 

 On. Weddelli 



Cultural Notes. — In our introductory notes above we have intimated 

 that Oncidiums generally are not regarded horticulturally as an unmixed 

 gain in consequence of the comparatively small number of them that 

 have, as yet, proved to be sufficiently tractable under cultivation for 

 several years in succession. Of those species that rank among the most 

 long-lived, the following are well known : — ampliatum, cheirophorinn, 

 divaricatum, Jfexuosum, hastatum, incurvum, leucochilum, longijies, 

 macranthum, ornithorhynchum, ^)/i?/»?a^0(-/«7?<???, ^:*?<?i'mr<f«?/?, serraftai}, 

 sphacelatum, tigrinum, trulliferum, Wentworthianum ; to these should 

 be added the less frequently seen auriferum, Batemanianum, excavatum, 



* We have seen herbarium specimens of the little Oncidium indifolium from Panama, 

 British Guiana, Trinidad, Bahia and Para in Brazil, the Andes of Quito, and Ibagne in New- 

 Granada — indeed, this plant appears to be ubiijuitous in tropical America from Bauanal in 

 Brazil northwards. 



