234 ORCHIDS 



DISA. 



Over a hundred distinct species of the genus Disa 

 {Berg.), belonging to the tribe Oplirydecv, have been 

 described. All of them are natives of Africa, mostly in 

 the south temperate region. Of this number scarcely half- 

 a-dozen are in cultivation in gardens here, and only two 

 of these maj' be considered really good garden Orchids. 

 The origin of the generic name is unknown. There is no 

 doubt about the beauty of many of the species that as 

 )-et are unknown in English horticulture ; but all efforts 

 to establish them in gardens have invariabl}- resulted in 

 failure. This is due to the difficulty — impossibility, one 

 might say — of reproducing artificially anj'thing approxi- 

 mating to the conditions under which these plants grow 

 naturally. 



Flowers variously disposed, large or small ; sepals much 

 larger than the petals, the dorsal one erect, hooded, and 

 ha\ing a spur ; petals small, polymorphous ; lip small, 

 spurless, linear, acute, projecting forward ; column short, 

 rather thick ; bracts usually shorter than the flowers. 

 Stems sometimes tall and leaf)-, sometimes slender and 

 few-leaved, or with lea\-es reduced to sheathing bracts. 



The utilit}' of this lovely genus has been considerably 

 increased of late }'ears b)' the successful introduction of 

 several beautiful hybrids. These have proved far more 

 amenable to culture than the imported species, and are 

 often found to thrive well where failure has followed every 

 endeavour to cultivate the African kinds. They .should 

 be fully represented, for they are ver)' striking subjects 

 \\hen used for grouping \\-ith other Orchids at 

 exhibitions ; while for cut-flower work they are most 

 useful. 



Culture. — Disas are not so extensively cultivated as 

 their merits deserve. No doubt this is due to the 

 difficult)' experienced in obtaining satisfactory results from 

 D. gramiiflora ''Fig, 76). The cause of such failure is 

 due rather to unsuitable climatic conditions than to any 

 lack of ability on the part of the cultivator. Instances 

 are known where, without any exceptional attention, these 

 plants have been ever\'thing that could be desired. In 

 one instance the plants were placed by the writer on a 

 dry slate stage of a Heath-house, and he had the pleasure 



