374 SYSTEMATIC BOTANY. 



whole of the interncdes of a long jointed leafy axis, &c. The roots which 

 hang down from them are soft and delicate at the apex ; and the epithelial 

 cells exhibit spiral-fihrous thickening of a peculiar kind. Angrcecum funale 

 has neither true roots nor leaves. Neottia nidus avis has buds on the ex- 

 tremity of the roots (Van Tieghem). Epipocjon Gmelini and Corattorhiza 

 innata are also rootless. The embryo is a mere cellular globule borne on 

 a suspensor. 



Distribution. Orchids are very numerous, and occur in almost all 

 parts of the globe, except the very coldest or in very dry regions. In tem- 

 perate climates they occur chiefly in shady woods, damp pastures, or open 

 calcareous downs ; but they are most abundant in. damp situations in the 

 tropics. 



Qualities and Uses. The properties of these plants are generally un- 

 important. The subterranean tubers of some form nutritious food, from 

 the presence of a gummy substance : that of a native species, Orchis mas- 

 culttj was f ormerly coUected and sold for the preparation of Salep ; and 

 other kinds are eaten in India. Some of the South- American yield a kind 

 of vegetable glue ; Aplecti'um hyemale, the North-American Putty-root, is 

 used for making a cement for china. The most important plants, perhaps, 

 are Vanilla planifolia and other species, and a species of Sobralia, the dried 

 pulpy pods of which furnish the Vanilla used for flavouring chocolate and 

 confectionary. A few others are described as having medicinal properties 

 of various kinds. 



APOSTASIACE^E is a small Order of perennial herbs nearly related to 

 Orchidaceae, bearing a regular perianth and 2 or 3 stamens which are con- 

 fluent by their filaments with the lower part of the style (the anthers free), 

 forming a kind of column, prolonged above into a filiform process with a 

 3-lobed stigma ; ovary 3-celled, with axile many-seeded placentas ; seeds 

 apparently as in Orchidaceae. These plants differ from Orchids chiefly in 

 the free condition of the upper part of the style and the 3-celled ovary ; 

 but as the latter character is inconstant in some Monocotyledonous Orders, 

 probably this Order should be united with Orchidaceas ; they are near to 

 Burmanniaceae also ; but that Order has free stamens. Lindley regards 

 this Order as connecting Orchidaceae with Amarylhdaceae through Hypox- 

 idaceae. They are natives of damp woods in tropical India, and are with- 

 out known properties. Genera : Apostasia, BL, &c. 



BURMANNIACEJE are small annual herbs, often with minute and scale- 

 like leaves, or those near the root grass-like ; the flowers perfect, with a 

 6-cleft petaloid perianth, the tube of which adheres to the 1-celled or 3- 

 celled ovary ; stamens 3, distinct, introrse, and superposed to the inner seg- 

 ments of the perianth, or 6 and extrorse ; stigmas 3 ; capsule many-seeded ; 

 the seeds very minute, with a homogeneous nucleus in a loose membran- 

 ous testa. Natives of the tropics of America, Africa, and Asia. Some are 

 probably parasitical. The affinities of these plants are rather obscure ; 

 they apparently agree with Iridaceae in the character of the flowers, but 

 differ in the position and number of the stamens ; while, by the seeds 

 resembling those of Orchidaceae, they form a connecting link between 

 these two Orders. They are also related through Taccacese to Aristolo- 

 chiacese. They are said to be bitter and astringent, but are unimportant 

 in these respects. Genera : Burmannia, L. ; Thismia, Griff., &c. 



