VI. ORCHIDEiE. 773 



and coloTiring, frequently hollowed at the base into a sac or spur; Unib of the 

 labellum usually 3-lobed, sometimes entire ; dish naked, callousj glandular or lami- 

 nate. Andkoecium and style adnate into a column (gynostegmm), of which the 

 anterior face, opposite to the labellum, and terminated by the stigma, belongs to the 

 substance of the style, while the dorsal face, terminated by the anthers, belongs to 

 the andrceeium. Stamens usually normally one, opposite the upper sepal, and 

 accompanied by two rudimentary stamens, reduced to inconspicuous or obsolete 

 prominences, very rarely there are 2 normal stamens opposite to the 2 lateral petals 

 {Cypripedium) ; anther 2-celled (or 1-celled by absorption of the septum) or 4-celled 

 by more or less perfect secondary septa, sometimes divided or mnltilocellate by trans- 

 verse septa, erect, or inclined and covered by the concave top of the gynostegium 

 (clinandrium) ; pollen agglomerated into 2-4-8 masses (polUnia), lodged in the mem- 

 branous pockets of the anther, and composed of grains usually collected by fours 

 into numerous groups (masses), cohering by means of elastic filaments, or gathered 

 round a cellular axis; grains sub-pulverulent, easily separable or agglutinated into 

 a solid compact waxy tissue ; pollen-masses sometimes free, usually fixed, either 

 directly or by means of a cellular pedicel (cauddcle), to a viscous gland {retinaculum) 

 below the anther, naked, or enclosed in a membranous fold of the stylary surface 

 (lursicula). Ovaet inferipr, 1-celled (:piore rarely 3-celled), of 3 connate carpels 

 with parietal placentation, sometimes surmounted by a cupule (analogous to that of 

 Santalacece); style confluent with the stamens, occupying the face opposite to the 

 labellum, produced at the top into a prominence or fleshy beak (rostellum); stigmatic 

 surface (gynixus) oblique, concave, viscous, composed, according to E. Brown, of 3 

 stigmas, usually confluent, but sometimes distinct and opposite to the sepals ; ovules 

 numerous, shortly funicled, anatropous. Capsule membranous or coriaceous, 

 cylindric, ovoid or winged, 1-celled, dehiscence very various, mostly by 3 semi- 

 placentiferous valves, which separate from the 3 persistent midribs of the carpels, 

 the latter remaining united at the base and ape?. Seeds very numerous, very 

 minute; testa loose, reticulate, sometimes crustaceous and black {Vanilla, Cyrtosia). 

 Embkto exalbuminous, fleshy. 



Tkibe I. MALAXIDEM. 



Pollen coherent in waxy masses, applied directly to the stigma, without acces- 

 sory cellular tissue. Anther terminal or opercular. — Epiphytes, or rarely terrestrial 

 plants ; pseudo-bulbs formed by the connate leaf-bases and thickened stem. 



PEINCIPAL CULTIVATED GENEEA. 



Tribe II. EPIDENDBEJE. 



Pollen cohering in defined waxy masses. Cellular membrane prolonged into 

 elastic caudicles, often folded, without true glands. Anther terminal, opercular. — 



