286 ORCHIDACE^. Listera. 



Willd. sp. 4. p. 88. E. convallarioides, Pursh, fl. 2. p. 591 ; Bigel. jl. Bost. p. 323, not 



of Svuartz. 



Root consisting of thick horizontal branching fibres. Stem 4-8 inches high, 4 - 5-angled, 

 almost filiform, with one or two small scales at the base. Leaves roundish-cordate, sessile, 

 half an inch long ; sometimes there is a third leaf above the other two. Peduncles slightly 

 pubescent, usually with a single small scale. Spike 10 - 20-flowered ; the flowers minute, 

 on slender pedicels which are about a line in length : bracts minute, ovate. Sepals greenish, 

 elliptical-ovate. Petals and lip pale dull purple. Lip with 2 small subulate spreading teeth 

 near the base : segments slender, acute. 



Sphagnous swamps : frequent. June - July. This plant seems to be identical with the 

 L. cordola of Europe, but in the Southern States it is replaced by a nearly allied species, 

 the L. Elliottii, Hook. The latter extends as far north as the neighborhood of Philadelphia, 

 in New-Jersey. It is the L. convallarioides, Bart. fl. N. Am. 2. t. 39. /. 1, and probably 

 also L. cordata, Nutt. 



Tribe VI. CYPRIPEDJEJE. Lindl. 

 Anthers 2, with a large dilated lobe {abortive stamen) between them. 



15. CYPRIPEDIUM. Linn.; Endl. gen. 1618. ladts-SLIPPER. 



[From tlie Greek, Kijpris, Venus, and podion, a shoe; i. e. Venus's slipper.] 



The two outer sepals usually combined. Lip large and inflated. Column short, cernuous, 

 3-lobed, the lateral lobes antheriferous underneath ; the middle lobe (abortive stamen or 

 "appendage of the column") dilated and petaloid. Pollen farinaceous. — Root consisting 

 of thick fibres. Flowers solitary or few, large and showy. 



1. Cypripedium pubescens, Sioartz. Large Yellow Lady s-slipper. 



Stem leafy ; sepals lanceolate ; lip shorter than the petals, convex and gibbous above and 

 below, laterally compressed ; sterile stamen triangular, acute (Hoo/c.). — Swartz in act. acad. 

 Holm. 1800; Willd. hort. Berol. 1. «. 13 ; Pursh, fl. 2. p. 594 ; Bart. fl. N. Am. 3. t. 74 ; 

 Ell. sk. 2. p. 507; Beck, hot. p. 351 ; Darlingt. fl. Cest. p. 513; Hook, in bot. mag. 

 t. 3024. A, and fl. Bor.-Am. 2. p. 205. 



Root consisting of numerous thick fibres. Stem 1 - 2 feet high, simple, pubescent. 

 Leaves 4-7 inches long, ovate and ovate-lanceolate, acuminate, pubescent on both sides, 

 contracted and sheathing at the base. Flowers solitary or in pairs, with a large foliaceous 

 bract at the base. Sepals and petals greenish stained witli purple, lA - 2^ inches long. 

 Upper sepal rather broadly lanceolate ; the two lower ones commonly united nearly to the tip, 

 but sometimes distinct. Petals lanceolate-linear, undulate and twisted. Lip yellow, 1 - IJ 

 inch long, somewhat obovoid, much inflated. 



Moist shady woods, and in swamps. Fl. May - June. 



