ORCHIDACE^E, terrestrial. 



197 ORCHIDEOUS EPIPHYTES. 



and thus they are enabled to sustain 

 heat that would dry up and "wither 

 any plants not succulent. On the 

 other hand, these very qualities ren- 

 der them easily injured by a super- 

 abundance of moisture, as they have 

 no means of getting rid of it ; and it 

 soon occasions them to damp off, or, 

 in other words, to rot. The best soil 

 to grow Opuntias in, is a mixture of 

 very sandy loam with broken bricks 

 and rubbish from old walls ; they re- 

 quire but little water at any season, 

 except when going into flower, and 

 then less than any of the other kinds 

 of cacti. They are propagated by cut- 

 tings, which must be taken off at a 

 joint and laid on a shelf for two or 

 three days to dry before planting ; in 

 order that the superfluous moisture 

 may escape. When planted they 

 should not be watered ; and when 

 young plants are raised from seed, 

 they also should not be watered when 

 they are transplanted. See Cactus. 



Orangery. — A house intended 

 only for orange trees may be opaque 

 at the back, and even the roof, with 

 lights only in front, provided the 

 plants be set out during summer. In 

 fact, so that the plants are preserved 

 from the frost, they will do with 

 scarcely any light during winter ; and, 

 In many parts of the Continent, they 

 are kept in a cellar. 



Orange Thorn. — Ciiriobatus. — 

 Spinous shrubs, belonging to Pitto- 

 sporacese, natives of Port Jackson and 

 other parts of Australia, which, from 

 bearing small orange-coloured fruit, 

 are called Orange Thorn by the colo- 

 nists. 



Orange Tree. — See Citrus. 



Orchidace^, terrestrial. — The 

 terrestrial Orchidacese are, as their 

 names import, those plants belong- 

 ing to this extensive order which grow 

 in the ground, in contra-distinction to 

 the epiphytes or those which grow with 

 their roots exposed to the air. The 



terrestrial Orchid ex are of four kinds, 

 viz., those from the tropics, which re- 

 quire a stove in England ; those from 

 the Cape of Good Hope, which require 

 a greenhouse ; those from the south 

 of Europe, which only need a slight 

 protection during winter; and the 

 hardy kinds, most of which are natives 

 of Great Britain. The stove species 

 require nearly the same treatment as 

 the epiphytes (see Orchideous Epi- 

 phytes) ; and the greenhouse species 

 only differ from other greenhouse 

 plants in requiring particular care to 

 be paid to their drainage. For this 

 purpose, the pots should be filled one 

 quarter of their depth with broken 

 potsherds or cinders, and the soil 

 should consist of turfy peat broken 

 into pieces, and sand mixed with 

 about a third of vegetable mould. 

 The half hardy and hardy kinds may 

 be grown either in pots or in the open 

 ground. — See Orchis. 



Orchideous Epiphytes. — The 

 plants thus designated should, pro- 

 perly speaking, only be those which 

 in their native countries are found 

 hanging from the branches of trees, 

 with their roots exposed to the air ; 

 as these only can be called air plants. 

 It is, however, very difficult to draw 

 a line of demarcation, as regards cul- 

 ture, between these plants, and the 

 terrestrial orchidese of the tropics, as 

 several of the epiphytes may be grown 

 to great perfection in pots ; and others, 

 though in a state of cultivation, they 

 can only be grown well on branches 

 of trees, are found growing naturally 

 on exposed rocks. All the true epi- 

 phytes, that in their wild state are 

 found with their roots hanging down 

 in the air, grow in dense forests, 

 where shade, moisture, and excessive 

 heat, seem essential to their existence ; 

 and these plants in a state of culture 

 should generally be grown in baskets, 

 (such as those figured in p. 104 and p. 

 105,) or in husks of cocoa-nuts, half 



