cxxv. oRcniDACE.i;;. G73 



pseudobiilb, flowering from the top, sides, or base of the pseadobulb ; 

 bracts usually present. Flowers hermaphrodite, irregular, ofteu showy. 

 Perianth superior, of 6 free or variously connate segments, 2-seriate ; 

 3 outer segments (sejjals) more or less similar, the 2 lateral sometimes 

 connate in a short or long sac or spur-like base (mentitm) ■ 3 inner seg- 

 ments dissimilar, the 2 lateral alike and often resembling the sepals, the 

 remaining petal {lij)) usually very differently shaped. Stamens and style 

 united in a column opposite the lip ; anther usually 1 (sometimes 2) on 

 the front, top, or back of the column and free or adnate to it, 2-celled or, 

 by subdivision, 4-celled ; top of the column sometimes produced towards 

 the lip into a beak {rostellum) ; pollen-grains usually coherent in each cell 

 into 1, 2, or 4 pairs of oblong or globose or pyriform waxy or powdery 

 masses {pollinia), which are free- or adnate by pairs or fours immediately 

 or by a stalk (caudicle) to a gland. Ovary inferior, 1 -celled, usually 

 linear or twisted ; ovules many, minute ; stiguia one or two viscid spots 

 on the top or concave face of the column, opposite the lip and below the 

 anther. Fruit a capsule, usually opening by 3 or 6 longitudinal fissures 

 (rarely fleshy and subindehiscent). Seeds very many, minute, with a lax 

 hyaline testa enclosing a homogeneous nucleus. — Distmb. Genera 340 ; 

 species about 5000, temperate and tropical (rarely arctic). 



Pollinia waxy. 



Pollinia free or those of each cell held together at the base 

 by a viscid appendage, not attached by their bases or 

 by a caudicle to the rostellum. 

 Pollinia 4. 



Leaves equitant 1. Oberonia. 



Leaves not equitant. 



Terresti'ial or epiphytic herbs ; leaves mem- 

 branous, usually sessile ; inflorescence 

 terminal ; flowers rather small, in racemes 

 or spikes ; column prolonged below into 

 a foot. 



Lip \rith basal auricles; column very 

 short with broad arms ; terrestrial 



herbs 2. Microstylls. 



Lip without basal auricles ; column 

 long with callosities or wings or both ; 

 rostellum sometimes double ; terres- 

 trial or epiphytic herbs 3. LiPARIS. 



Epiphytic herbs ; leaves chartaceous or 

 coriaceous ; column more or less prolonged 

 below into a foot. 



Stems solitary or cajspitose or composed 

 of discrete pseudubulbs basally at- 

 tached on a short or long rhizome. 

 Flowers from the stems or pseudo- 

 bulbs, terminal or axillary, soli- 

 tary or on short few-flowered 

 peduncles or in few- or many- 

 flowered racemes, usually large 

 and showy ; stems ciTjspitose with 

 more than 2 leaves, rarely a 

 creeping rhizome with distant 

 pseudobulbs and binary or 

 solitary apical leaves ; pollinia all 

 subequal, always free ; liji i-arely 

 mobile 4. Dendrouium, 



VOL. II. 2 y 



