.;:y, 



Orchidaceae Cypripedium 



Blades large and usually nearly orbicular, or elliptic, not fleshy; flowers greenish 



yellow or greenish white, usually expanding after May 



1422. Habenaria, p. 339. 



Leaves'all c'aul'ine: '. '. '.'.'. '.'.'.'. '.'.'.'• '.'.'.'. '•'•['•'■'■ ' • 1422. Habenaria, p. 339. 



Flower without a spur. 



Plants with only one leaf. (Bracts not to be confused with leaves.) 



Leaves ovate; flowers greenish white, about 3 mm long 1552. Malaxis, p. 349. 



Leaves linear or lance-oval; flowers rose or purplish. 



Flowers solitary, rarely 2, terminal, subtended by a large, green bract almost 



as long as the flower; leaves lance-oval 1464. Pogonia, p. 344. 



F lowers generally 3-12, rarely solitary in depauperate plants, not subtended by 



a large, green bract; leaves linear, usually 15-30 cm long 



1534. Calopogon, p. 348. 



Plants with more than one leaf. 

 Flowers in racemes. 



Leaves all near the base and conspicuously marked with white veins 



1504. Goodvera, p. 347. 



Leaves not conspicuously veined. 



Stems with bulbous bases; leaves 2, basal; flowers madder purple or yellowish 



green 1556. Liparis, p. 350. 



Stems without bulbous bases. 



Flowers white; leaves of a linear type, mostly less than 1 cm wide, at 



least the lower ones petiolate; plants mostly 2-5 dm. high 



1490. Spiranthes, p. 345. 



Flowers greenish, suffused with madder purple; median leaves of an ovate 

 type, the largest usually 2-4 cm wide, sessile; plants usually 3-7 dm. 



high 1482. Epipactis, p. 345. 



Flowers not in racemes. 

 Plants with a whorl of 5 obovate or lanceolate leaves at the summit; flowers 



terminal, solitary, rarely 2, purplish 1467. Isotria, p. 344. 



Plants not as above, 

 Leaves usually very large and long; flowers inflated, slipper-shaped, yellow, 



pinkish or white 1391. Cypripedium, p. 336. 



Leaves small, about 1 cm long, clasping, broadly ovate; flowers not inflated 



or slipper-shaped, usually pinkish or nearly white 



1466. Triphora, p. 344. 



Plants without green leaves at flowering time, rarely a withered basal one persisting. 



Flower solitary, terminal, rose purple 1474. ARETHUSA, p. 344. 



Flowers not as above. 



Stems bulbous at the base. 



Flowers with long spurs; basal leaf purplish beneath. . . .1560. Tipularia, p. 350. 



Flowers without spurs; basal leaf green beneath 1642. Aplectrum, p. 351. 



Stems not bulbous at the base. 



Plants with 1-several long, tuberous roots; flowers white 



1490. Spiranthes, p. 345. 



Plants with scaly or corallike rootstocks; flowers not white. 



Flowers cadmium orange 1629. Hexalectris, p. 351. 



Flowers more or less purplish 1548. Corallorriiiza, p. 348. 



1391. CYPRIPEDIUM L. Ladyslippeb 



Plants with leafy stems; flowers 1 or 2, rarely several. 



Sepals and petals shorter than the lip; tall plants of only cold, springy, and boggy 

 places; flowers white except the variegated crimson lip 1. C. reginae. 



Sepals and petals equalling or longer than the lip, 



Leaves 3 or 4, strongly overlapping at the base, rather narrow-elliptic or 

 lanceolate; outside of lip white, in dried specimens generally less than 



