GENERA AND SPECIES 93 
species and a large number of hybrids. Primarily the 
genus may be divided into two classes—the evergreen ; and 
the deciduous, which lose their leaves after the completion 
of the growths, and should have a protracted dry resting 
reason. The evergreen species have a shorter and less 
rigorous resting season accorded them. The deciduous 
class is exemplified by D. nobile, D. Wardianum, D. cras- 
sinode, and the plants associated with them, and _ their 
hybrids ; and the evergreen species by D. densiflorum, 
D. Farmeri, and D. chrysotoxum. D, Wardianum, with 264 
flowers, is illustrated in Plate III. 
Next, the genus may be divided into two further classes— 
those requiring a high temperature, such as D, Phalaenopsis, 
D. superbum, D. atro-violaceum, &c. ; and those which may 
be grown comparatively cool, which include D, speciosum 
(an excellent plant for a sunny conservatory), D. moniliforme 
from Japan, D. aggregatum, D. Jenkinsii, and many others. 
All the species require a high temperature, moist atmos- 
phere, and an abundance of water during the growing 
season, but should be kept drier and cooler after the growth 
is completed to prepare them for flowering. The species 
with pendulous growths should be grown in baskets or 
suspended pans. 
Diacrium.—A section of Epidendrum, with hollow 
pseudo-bulbs, and white, wax-like flowers. D. bicornutum 
is a very fine species for the warm house. 
Disa.—A genus of terrestrial Orchids from Africa, best 
represented in gardens by the fine Scarlet Disa grandiflora, 
which, with the others of its section, D. racemosa and D. 
tripetaloides, have produced many beautiful hybrids. These 
are cool-house plants, and should be potted in a mixture 
