Order 138.— ORCHIDACEiE. 681 



TRIBES AND GKNEKA. 



§ CYPRIPEDIEJ5. Anthers 2, fertile, the 3rd a petal-like appendage over the 



stigma. Lip a large, inflated spurless sack Oypeipeohim, I 



$ OrilRYDEJS, <fcc. Anther only 1, terminal or dorsal on the stigma. (*) 



* Lip produced behind into a spur which is free from the ovary, (a) 



a Anther erect, terminal ; pollinia 2, granular, pedicellate and attached to as 

 many glands on the stigma, which glands are (b) 



b concealed in a pouch (Flowers large, rose-colored, lip entire) in Orchis. 2 



b naked and close together (Flowers small, lip entire or toothed) iii-.-Gymnadenia. 3 

 b naked and widely separated (Lip entire or lobed, or cleft or fringed.) Platanthera. 4 



a Anther bent over the end of the stigma like a lid. Pollinia 4 Tipularia. 5 



* Lip not produced into a spur behind, or the spur is adnate to the ovary, (c) 



C Lip a large, inflated sack with 2 spur-like points below the apex...... . .Calypso. 6 



C Lip not saccate. Plants brown, leafless, or with radical leaf, (d) 



d Lip hooded, i. e.. its margins involute. Pollinia 8. Fls. expanding.. . . . Bletia. 7 



d Lip concave, sessile, often with an adnate spur. Pollinia 4. ..Couallokihzba. 8 

 d Lip concave, raised on a claw. Pollinia 4. Plant with 1 late leaf. . . Aplectrum. 9 

 C Lip not saccate. Plants green and with leaves, (e) 



e Lip flat. Flowers obscure, in racemes nearly bractless. (f ) 



f Lip entire, dilated ; Column minute. (Leaf 1.) Mycrostylis. 10 



f Lip sagittate or cordate. Column lengthened. Leaves 2 Lippaeis. 11 



f Lip 2-lobed or cleft at apex. Lvs. 2, cauline opposite Listeea. 12 



© Lip channeled, recurved. Fls. whitish, in bracted spikes, (g) 



g Sepals reflexed. Lip arched and recurved, 3-lobed Cp.AJucnis. 13 



g Sepals erect. — Lip ascending, embracing the column Spiranthes. 14 



— Lip gibbous beneath, pointed at apex Goodyera. 15 



e Lip bearded or 3-lobed. Stamen lid-like. Flowers showy, (h) 



h Flowers several, purple, with a bearded lip posterior Calopocon. 16 



h. Flowers with the lip anterior (as in the order generally), (k) 



k Column free from the lip, clavate. Fls. purplish Pogxjnia. 17 



k Column adherent to the tip below. Fls. purple Aretiiusa. 18 



k Column adherent to the lip. Fls. yellow. On trees Epzdendrum. 18 



i. CYPRIPE V DIUM, L. Lady's Slipper. (Gr. Kv-rrpig, Venus, 

 tto&ov, a slipper ; from the slipper-like form of the lip.) The 2 lower 

 •sepals united into 1 segment, or rarely distinct ; petals spreading ; lip 

 inflated, saccate, obtuse ; column terminated by a petaloid lobe (barren 

 stamen) and bearing a 2-celled anther under each wing. — Fls. large, 

 very showy, distinguished for the large, inflated lower petal or lip ; lvs. 

 large, plaited, veined. 



§ Sepals 2, the lower compound of 2 united either wholly or near the tip. (*) 



* Stem leafy. — Flowers i to 3, mostly but 1, yellow Nc-s. 1, 2 



— Flowers solitary or several, white or rose-colored Nos. 8 4 



* Stem a leafless scape, 2-!eaved at base. Flower rose-colored No.' 5 



| Sepals 3, the 2 low«r entirely distinct ° .jfoi 6 



1 C. pubescens Swartz. Large Yellow Ladies Slipper. St. leafy, lvs. 

 broad-lanceolate, acuminate; sepals lanceolate; lip shorter than the linear, twisted 

 petals, compressed laterally, convex both above and below; sterile stamen triangular 

 acute ; plant pubescent. — Woods and meadows, Can. to Wis., S. to Ga. Sts. usu- 

 ally several from the same root, If or more high. Lvs. 3 to 6' by 2 to 3, many- 

 veined, clasping at base. Flower mostly solitary. Segm. 4, greenish with 

 purple stripes and spots, the lower bifid, composed of 2 united sepals, the lateral 

 2 to 3' by 3", wavy and twisted. Lip raoccasz'n-shaped, bright-yellow, spotted 

 inside, with a roundish aperture. May, Jn. 



2 C. parviflorum Salish. Smaller Yellow Ladies' Slipper. St. leafy; lvs. lan- 

 ceolate-acuminate ; sep. ovate or lance-ovate ; lip shorter than the petals, compressed 

 from above and beneath; sterile stamen triangular, acute; plant pubescent. — In 

 low woods and prairies, Can. to Wis. and Ga. (Miss Wyman)., More common 

 westward. Plant 8 to 12' high, rarely taller, very leafy. Flower a third smaller 

 than in No. 1. Petals 1 to 18", twisted or not. Upper sep. broadest. Lip evi- 

 dently flattened on tho upper side, convex laterally, dull yellow. May, Jn. 



