344 MONOCOTYLEDONOUS PLANTS. 



.petioles, sometimes falling off before the plant flowers. Flowers 

 white, in a twisted spike. According to Dr. Bigelow, the spike 

 is sometimes unilateral and scarcely twisted, and the flowers? 

 more slender, when it forms his var. secunda. Ladies Ti> 



3. *S. cernua Rich. : leaves lanceolate, nerved ; stem sheathing ; 

 flowers in a dense spike, cernuous ; lip oblong, entire, acute. Neottia 

 cernua Wittd. 



HAB. Moist grounds. Can. to Car. July, Aug. 21. Scape 

 6 inches to 2 feet high, sometimes a little leafy. Leaves vary- 

 ing from linear-lanceolate to oblong-lanceolate. Flowers green-- 

 ish-white. It is liable to considerable variation. Sec Torr. 

 Comp. 320, 



3. LISTERA. Brown. 



Perianth irregular. Lip 2-lobed, sessile, with no calli. 

 Column wingless, (minute.) Anther fixed by its base. Pollen 

 farinaceous. . Gynandria. Monandria. 



1. L. cordata Brown : stem with only 2 opposite roundish cordate 

 leaves ; raceme loose ; column without any appendage behind ; lip 

 elongate, 2-toothed at base, deeply bifid, the segments divaricate and 

 acute Ophris cordata Mich. 



HAB. Sphagnous swamps. Can. Ver. N. J. May. If. Stem 

 48 inches high. leaves roundish, cordate, veined, smooth, 

 mueronate. Raceme 7 15-flowered. Fltnccrs distant, minute, 

 green and purple. Tway -blade. 



2. L. conrallarioides Nutt. : stem with only 2 opposite oval-roundish 

 leaves, pubescent above ; raceme few-flowered, (4 6) ; column por- 

 rected ; lip oblong, dilated, and obtusely 2-lobed at the extremity. 

 Epipactis convallarioidcs Pursh. excl. syn. 



HAB. Swamps. Can. to Car. May. "U.Stem 6 inches high 

 and very slender. Flowers dark brown and green, larger than 

 in the prece/ling. These two species have been confounded by 

 many of our botanists when in fact they are entirely distinct, 

 and it is even doubtful whether they belong to the same genus. 

 Ophris cordata of Michaux given by Pursh as a synonym of his 

 Epipactis convallarioides, belongs to the former. 



4. POGONIA. Brown. 



Lip sessile, cucullate, internally crested ; 5 segments of 

 the perianth distinct, without glands. Pollen farinaceous. 



Gynandria. Monandria. 



1. P. ophioglossoidcs Brown : root fibrous ; stem with an oval-lance- 

 olate leaf and a foliaceous bract near the flower ; lip fimbriate. Are- 

 thusa ophioglossoidcs Linn. 



HAB. Sphagnous swamps. Can. to Car. July. Z. Root fas- 

 ciculate. Stem 812 inches high. Flower solitary, pale pur- 

 ple, nodding. 



