526 FLOWERS OF GARDEN AND GREENHOUSE 
numerous named varieties, and some of them are among the most 
valuable Orchids known. Spring. 
O. Rosstt (Ross’). Flowers 1 to 2 inches across, white, spotted and 
barred with brown ; lip with a lemon-yellow crest ; two- to five-flowered. 
There are numerous named varieties; winter. 
O. TRIUMPHANS (triumphant). Habit of O. crispum. Scape tall, 
arching, many-flowered ; flowers 3 inches across, yellow, with large brown 
blotches; lip white or yellow, with a large chestnut-brown blotch in 
front; spring. 
All the Odontoglossums known may be grown in a 
cool greenhouse, where the temperature is never lower 
than 45° Fahr. The range of temperature for the whole year most 
suitable for these plants is from 70° to 45°, the former being the maxi- 
Cultivation. 
mum to be aimed at in the hottest weather. Fire-heat should never be — 
used for them, except to prevent the temperature from falling below 
45°. Asa rule they continue to grow more or less all the year round, so 
that they must not be allowed to get dry, although in preceding genera 
a dry resting period is necessary. Where possible, they should pass the 
summer in a house having a northern aspect, or even be hung up under 
trees outside, where they will enjoy good light whilst being protected 
from the direct rays of the sun. In the winter they should be placed in 
a house having a southern aspect, and given all the sunshine possible. 
In summer they should be syringed in the evening after a hot day and 
allowed to lave plenty of air whenever the temperature admits of it. 
O. citrosmum requires slightly warmer treatment, and should be wintered 
almost without water, until the new shoots and flower spikes appear, when 
water may be given. They should be grown in pots two-thirds filled 
with drainage, the other part with a mixture of peat-fibre and living 
sphagnum in equal proportions. September is the best time to repot 
them. They like to be kept moderately moist at the roots at all times. 
Description of Odontoglossum erispum. Fig. 1, a plant greatly 
Plate 241. reduced; 2, flowers, natural size; 3, the column, detached ; 
4, the same, side view: 5, 5, pollen-masses, natural size and enlarged. 
ONCIDS 
Natural Order OrncHIDER. Genus Oncidium 
Oncrpium (Greek, ogkos,a tumour: referring to the warty crest at base of 
lip). A genus of about two hundred and fifty species, in many respects 
