350 CLASS XX. ORDER II. 



DIANDRIA. 



364. CYPRIPEDIUM. 

 Cypripedium acaule. Ait. Ladies' Slipper. 



Scape leafless, one flowered ; root leaves two, ob- 

 long, obtuse ; lobe of the style round-rhomboidal, acu- 

 minate, deflexed ; petals lanceolate ; lip longer than 

 the petals, cleft before. Willd. sub. syn. 

 Syn. Cypripedium humile. Siv. Salish. Willd. 



This singular genus are readily known by their large, inflated 

 nectary. The present species differs from the rest in having no 

 stem leaves. The leaves are two, springing from the root, large, 

 oval-lanceolate, plaited, downy. Flower commonly single, ter- 

 minal, nodding. Spathe lanceolate. Petals four, spreading, 

 green with a tinge of purple, the upper and under ones lance- 

 ovate, the two lateral ones narrower, longer, hairy inside, slightly 

 waved and twisted. Nectary a large, purple, inflated bag, veined, 

 villous, and longer than the petals. Style over the base of the 

 nectary, supporting two lateral anthers on the inside, and ending 

 in a broad, roundish, deflexed, acute lobe, carinated on the inside. 

 Capsule oblong, acute, it sides unequally curved, crowned with 

 the style, opening at the three principal angles by a double fis- 

 sure, between which the suture or frame work is included. — 

 Woods. — May, June. — Perennial. 

 Cypripedium parviflorum. Willd. Yellow Ladies' Slipper. 



Stem leafy ; lobe of the style triangular, acute ; 

 exterior petals ovate-oblong, acuminate ; inner petals 

 linear, twisted: lip shorter than the petals, com- 

 pressed. 

 Syn. Cypripedium calceolus. Mx. 



Stem erect, downy. Leaves alternate, clasping, oval, nerved, 

 downy. Upper and lower petal ovate-lanceolate, acuminate, 

 green, striped and spotted with dark purple ; lateral petals linear, 

 twisted, striped and spotted, hairy inside at base. Nectary ob- 

 long-oval, yellow, dotted inside, its aperture roundish with an 

 inflexed margin. Lobe of the style triangular or deltoid, de- 



