30 Orchidaceae 



Ovary inferior, 3 or i-loc with numerous, minute ovules. 

 Endosperm present or absent. 



Suborder Gynandrae. Flowers always zygomorphic, 

 no endosperm. 



Family Orchidaceae. Perennial herbs. Flowers 

 homo- or heterochlamydeous, typically 3-merous, almost 

 invariably monoclinous, zygomorphic, usually resupinate 

 by twisting of the ovary so that the posterior petal 

 occupies an anterior position and is often developed 

 into a labellum. Of the stamejis usually only the an- 

 teriort one of the outer whorl is fertile. In subfamily 

 Diandrae the two lateral stamens of the inner whorl are 

 usually fertile. Frequently (e.g. in Orchis) the two 

 anterior stamens of the inner whorl are represented by 

 staminodes on the sides of the column. Pollen cohering 

 in masses {Pollinid). Carpels (3) sunk in the floral axis 

 which is prolonged beyond the insertion of the perianth 

 into a column which bears the stamens. Stigmas 3, 

 usually on the surface of the column, the posterior one 

 rudimentary or developed into a beak-like structure 

 {rostellum) beneath the anther or between its cells. 

 Ovary mostly i-loc with 3 parietal placentae and 

 00 ovules. Fruit a capsule with very numerous, minute 

 seeds without endosperm. Embryo not, or only slightly, 

 differentiated. 



Subfamily i. Pleonandrae (Diandrae). The two 

 lateral (rarely all 3) stamens of the inner whorl fertile. 

 All three stigmas similar and receptive. 



t The terms anterior and posterior in this description refer to 

 position before the occurrence of resupination. 



