DENDROBIUM. 13 



those with sub-evergreen foliage, as Dendrobiuni nobile, D. Linawianum, 

 etc., may be grown in pots. The pots should be filled to two-thirds 

 of their depth with clean broken crocks for drainage, which should be 

 secured by a layer of sphagnum ; the remainder must be filled with 

 compost (sphagnum and peat) mixed with a sprinkling of small broken 

 crocks and charcoal to facilitate drainage. In potting, the base of 

 the plant should stand above the rim of the pot, and no portion of 

 the stems should be buried in the compost, which should be pressed 

 firmly around the base but not rammed down. The plants may be made 

 secure in their place by sticks. 



It is well to note here that the Calostachyce group, Dendrdbium densi- 

 flarum, D. Farmeri, D. thyrsiflorum, D. chrysotoxum, D. suavissimum, etc., 

 etc., take a longer season of rest than many others ; these Dendrobes are 

 late in starting into growth, but when once started their growth is 

 rapid. The watering of these plants must thence be regulated 

 accordingly. 



The Formosce (nigro-hirsute) group has, with the exception of a few 

 of its included species, proved less tractable under cultivation than 

 most other Dendrobes. The typical species, D. formosum, as may be 

 implied from the localities it affects in a wild state, is a heat-loving 

 plant. It may be grown in a pot or basket, or even on a bare 

 block of wood, where it has the advantage of more closely imitating 

 the manner in which it grows in its native country — an advantage, 

 however, that is more than counterbalanced by drawbacks, such 

 as deficiency of moisture, etc. D. Infundibulum and its variety 

 Jamesianum, coming from a higher altitude, will grow and flower in 

 a lower temperature ; the cool end of the Cattleya house, for example, 

 will do for them, or still better, the Odontoglossum house. 



The Australian Dendrobes, included in the sub-section Speciosce, require 

 but a very little lower temperature than the East Indian species, 

 especially those from North Australia, as D. bigibbum, D. Fhalcenopsis, 

 D. superbiens, etc., but as much light as possible. Notwithstanding 

 the drier climate of Australia, they are found to require in the glass 

 houses of Great Britain a copious supply of water whde growing, and 

 even when at rest, the compost in which they are planted should 

 never be otherwise than moist. 



The best time to re-pot or re-basket Dendrobes is when the new 

 growths are starting, which usually occurs within a short time after 

 flowering. Like all other orchids cultivated in glass structures, 

 Dendrobes are subject to the attacks of insect pests, from which they 

 must at all times be kept as free as possible. Plants attacked by red 

 spider should be dipped into tobacco- water or some similar insecticide, 

 or syringed with sulphur water ; mealy bug and scale may be kept 

 under by frequent sponging ; yellow and black thrip can be checked by 

 fumigation, but this remedy should be applied lightly and frequently, that 



