OKCHIDACEAE. 



83 



Order ORCHIDALES. 



Terrestrial or epiphytic herbs. Leaves usually fleshy, sometimes scale- 

 like. Flowers mostly perfect and complete, very irregular. Calyx of 3 

 sepals. Corolla of 3 petals. Gynoecium compound. Ovary inferior. 

 Seeds numerous. Endosperm wanting. 



FAMILY 1. ORCHIDACEAE. ORCHID FAMILY. 



Perennial mostly succulent herbs. Leaves basal or cauline, often 

 sheathing at the base. Sepals 3, one median, two lateral. Petals 3, one 

 median and often greatly specialized ("lip"), two lateral ("petals"). 

 Androecium of 1 or more stamens adnate to the style, the 2-8 pollinia 

 waxy or powdery. Gynoecium of 3 united carpels, the ovary twisted. 

 Fruit capsular. 



Anthers 2 : lip a large inflated sac. 



Plants caulescent : leaves several : lip with a rounded opening : sterile stamen 



glabrous : stigma broadest at the base. 1. CYPRIPEDIUM. 



Plants acaulescent : leaves 2, basal : lip with a fissure 

 down the front : sterile stamen glandular-pubescent : 

 stigma broadest at the apex. 2. FISSIPES. 



Anther 1 : lip various. 



Pollinia developing caudicles at the base of the anther 

 which are connected with the glands of the rostel- 

 lum : filament very short and broad : anther per- 

 sistent. 

 Stigma flat, unappendaged. 



Glands of the stigma enclosed in a pouch. 3. GALEORCHIS. 



Glands of the stigma naked, not enclosed in a 



pouch. 

 Glands covered with a thin membrane which 



is deciduous with them. 4. COELOGLOSSDM. 



Glands without a membrane. 



Valves of the anther not enclosing the 



glands below : lip not tubercled. 

 Lip entire or shallowly lobed. 

 Lip cut-toothed or fringed. 

 Valves of the anther enclosing the glands 

 below by the infolding of the margins : 

 lip with a median tubercle. 

 Stigma appendaged. 

 Pollinia without appendages : filaments mostly thin and 



brittle, the anther therefore usually deciduous. 

 Flowering branch terminating the main axis of the 



plant. 

 Leaves convolute in the bud. 



Anther rounded or very blunt, usually much 



exceeding the rostellum. 

 Lip free, spurless or with a short spur. 

 Plants scapose : leaves mere broad basal 

 scales : bracts whorled : lip promi- 

 nently 3-lobed. 



Plants caulescent : leaves solitary or 



several : bracts not whorled : lip 



entire, toothed or shallowly lobed. 



Flowers typically solitary, terminal : 



lip crested, sessile. 

 Flowers axillary, racemose : lip not 



crested, clawed. 

 Lip adnate to the base of the elongate 



column, gibbous at the base. 

 Anther as long as the rostellum and lying 

 upon it, rarely with a long tip and thus 

 exceeding the rostellum. 

 Pollinia not in distinct masses : petals nar- 

 row : lip not saccate. 

 Pollinia in several distinct masses : petals 



broad : lip saccate. 

 Leaves duplicate in the bud. 



Leaf-blades not plaited in the bud. 



5. LYSIAS. 



6. BLEPHARIGLOTTIS. 



7. PERULARIA. 



8. GYMNADENIOPSIS. 



9. ISOTRIA. 



10. POGONIA. 



11. TRIPHORA. 



12. ARETHDSA. 



13. IBIDIUM. 



14. PERAMIUM. 



