ORCHID ACE AE (ORCHID FAMILY) 123 



viscid disk (gland). Stigma a broad glutinous surface facing the lip or in a 

 cavity between the anther sacs. Ovary inferior, 1-celled, usually twisted, 

 many-ovuled. Capsule 3-valved. 



Anthers 2; lip a large inflated sac 1. Cypripedium. 



Anthers solitary. 



Flowers solitary-terminal ........ 2. Calypso. 



Flowers more than one, generally racemose or spicate. 

 Green leaves present. 



Stem leafy, at least below. 



Leaves alternate and more than 2. 

 Capsule erect or ascending. 

 Spike not spirally twisted. 



Petals lanceolate ....... 3. Limnorchis. 



Petals very narrow ....... 4. Coeloglossum. 



Spike spirally twisted. 



Long and slender; flowers greenish .... 5. Piperia. 



Short and crowded; flowers white .... 6. Spiranthes. 



Capsule deflexed at maturity ...... 7. Epipactis. 



Leaves opposite, a single pair just below the raceme . . 8. Listers. 

 Leaves all basal. 



Only one 9. Lysiella. 



Several . . . . . . . . . .10. Peramium. 



No green leaves present 11. Corallorhiza. 



1. CYPRIPEDIUM L. LADY'S SLIPPER 



More or less glandular pubescent herbs with leafy stems and thick fascicled 

 roots. Leaves many-nerved and usually large. Flowers solitary or several, 

 large and showy, with an inflated sac-like lip. Anthers 2, one on either side 

 of the column and a sterile one above covering the summit of the style. Pol- 

 linia granular; the caudicle and glands wanting. Stigma 3-lobed. 



Flowers yellow, usually solitary . . . . . . . .1. C. paryiflorum. 



Flowers dark purple, 2-3 in a cluster 2. C. Knightae. 



1. Cypripedium parviflorum Salisb. Trans. Linn. Soc. 1: 77. 1791. Stem 

 2^4 dm. high: leaves several, oval or ovate-lanceolate, acute or acuminate: 

 sepals from ovate to ovate-lanceolate: lip flattish from above, bright yellow, 

 2-3 cm. long: sterile stamen triangular and purple spotted like the lip. In 

 damp woods and thickets; Colorado, far northward and east to the Atlantic. 



2. Cypripedium Knightae A. Nels. Bot. Gaz. 42: 48. 1906. Stem short, 

 3-7 cm. high, sparsely and coarsely villous, bearing a single pair of nearly 

 opposite leaves at its summit: leaves oval, generally rounded and obtuse, 

 thickish, 4-7 cm. long: peduncle glandular-viscid, 3-10 cm. long, usually 

 naked, rarely with a lanceolate bract near the middle: floral bracts rather 

 large, elliptic-lanceolate: flowers 2 or 3 in a cluster, dark purple or dark 

 brownish-purple: lower sepals united nearly to the tip, ovate-lanceolate, the 

 two together no broader than the other sepal: petals similar, a little broader 

 than the sepals: lip 10-12 mm. long, somewhat shorter than the sepals and 

 petals, the deeply infolded free margin deep purple, the lower part of the sac 

 ochroleucous or greenish-yellow: sterile anther elliptic, obtuse, much shorter 

 and smaller than the large conspicuous stigma. In the Medicine Bow Moun- 

 tains of Colorado and Wyoming. 



2. CALYPSO Salisb. 



A low herb, in wet or boggy woods, with showy flowers, a scaly-sheathed 

 stem, and a single radical broad thin leaf. Petals and sepals ascending, similar 

 and nearly equal; lip with two short spurs below the apex. Column petaloid, 

 oval and concave. Lower pair of pollen masses smaller, compressed. 



1. Calypso bulbosa (L.) bakes, Cat. Ver. PI. 28. 1842. Stems 6-12 cm. 

 high, with two or three membranaceous brownish-green sheaths, and a linear 

 acuminate bract at the summit: the radical leaf broadly ovate or slightly 

 cordate: flower drooping: sepals and petals light rose-color: lip usually longer, 



