Dendrobium 



( 2S5 



Dendrobium 



DENDROBIUM. 



Description. This very large genus (ord. Orchid- 

 ace;i') is confined entirely to the Old World, and 

 forms, under cultivation in our stoves, one of the 

 most generally useful groups of plants we have. 

 All are epiphytes. The growths may be slender, as 

 in Lowii or lutecium ; tall and stout, as in pul- 

 chcllum and h'mbriatum ; club-shaped, as in 

 thyrsiflorum; hairy, as in formosum giganteum ; 

 pseudo-bulbous, as in aggregatum ; or rounded and 

 flattened, ;is in linguiforme. Some are quite 

 deciduous, and others are perfectly evergreen, the 

 former usually having thin leaves as compared 



Hybridisation. This genus is almost as popular 

 with the hybridiser as is Cypripedium. Artificial 

 fertilisation is easily managed, but the stigmntic 

 surface must not be unduly irritated, or the ovary 

 may swell up and appear to be full of seed, only to 

 eventually give disappointment by the chaff it 

 contains. Pollination is seldom effective if done as 

 soon as the flower opens ; it is better to wait a day 

 or two, as the pollen does not readily lose its vitality. 

 Another point to remember is that abundance of 

 water given at or immediately after pollination is 

 likely to cause failure. As a rule, the hybrids are 

 more easily grown and flowered than their parents. 



I'lwto : 1'iuaeU <( Cbuipituy, LM. 



DEXDROHIUM FORMOSUM OIOANTEVM (see p. 287). 



with the tough ones of the latter. In inflorescence 

 there is great variety ; many produce blooms all 

 along the growths of the preceding year, and others 

 have pendulous, many-flowered racemes. The 

 Mowers themselves vary largely, from the long- 

 spurred, tiny-flowered species of purely botanical 

 interest, to the large, spreading blooms of I). I'hahe- 

 nopsis ; the colour range is from pure white 

 through varying shades of yellow, rose, and lilac to 

 crimson purple of deepest dye. 



Geographical Distribution. Dendrobiums are 

 routined to Asia and Australasia, and are most 

 abundant in Moulmcin and Upper Burmah. The 

 southern limit is reached by striolatum in Tas- 

 mania, and the northern limit by amoenum in 

 North-West India. There is also a remarkable 

 difference of altitude at which species are found. 



Cultural Remarks. On the whole, Dendrobiums 

 are not difficult to manage, and their chief require- 

 ments are plenty of heat and moisture when 

 growing freely ; cooler and drier conditions when 

 growtli has finished for the season ; plenty of light, 

 only affording shade during the hottest part of a 

 bright summer day or to preserve the flowers as long 

 as possible ; and a moderate amount of compost 

 placed over ample drainage. Ventilation must 

 largely be governed by external conditions, but. 

 where a house is devoted to Dendrobiums it shouM 

 be closed early during tlio growing period, anil 

 walls, paths, pots, and plants freely syringed. 



Potting. As the rhizomes of Dendrobiums 

 extend slowly, it is not necessary to make much 

 provision of space for future growth. IVtini,' or 

 basketing ought never to be done unless new 



