198 
21. ORCHIDEAS. 
PI. end . ph, 
A. Pollen longitudinally divided ; caudicle with a 
retinacle. 
a. Retinade bursiculale , single and common to loth the 
pollen masses . 
Perigonium galeate ; lip long, linear ; 
base with a short scrotiform spur .... Loroglossum. 1 35. 
Perigonium galeate ; Up long, linear; 
lase flat, or very slightly gibbous Aceras. 156. 
Perigonium galeate; lip spurred; 
claw bearing 2 scales longitudinally . . . Anacamptis. 137. 
b. Retinacles bursiculate , 2. 
Per. arched or galeate ; lip spurred ; 
lursicles undivided Orchis. 138. 
Perig . spread; lip spurless, convex; 
rostellum split into 2 bursicules Ophrys. 139. 
c. Retinacles naked . 
Perigon. arched; lip spurred, 3-cut; 
spur bristlelike ; rostellum split Gymnadenia. 140. 
Perigon . galeate ; lip spurred, 3-cut ; 
short; rostellum split Entaticus. 141. 
Per. arched or galeate ; lip spurred, 
undivided; cells of the anther distant; 
rostellum 0 Peatantheka. 142i 
Per. nearly bellshape ; inner sepales longest ; 
lip many-cut, purselike at the bottom . . Herminium. 143. 
B. Pollen longitudinally divided ; retinacle 0. 
Per. connivent below; lip enclosed, 
spurless, undivided ; pollen unarmed .... Goodyera. 144. 
C. Pollen granular ; anther 1 . 
Per. oblong, connivent ; lip obovate ; 
gynizus rather elliptic; spike spiral .... Spiranthes. 145, 
Per. globose, connivent ; lip obcordate ; 
gynizus rather elliptic ; stem leafless ...... Neottia. 146, 
Per. globose, connivent ; lip linear, 2-parted ; 
gyjiizus rather elliptic; stem 2-leaved Listera. 147. 
Per. erect, connivent; lip embracing, entire; 
ovary sessile; rostellum 0 Cephalanthera. 148, 
Per. spread ; lip spread, interrupted ; 
ovary pedicel led; rostellum on the apex Epipactis. 149, 
