350 ORCHIDACE^. 



the column, deflected at the apex, bearded inside. Pollen 

 angular. 



A. hulhosa Linn. 



Sphagnous swamps. Can. to Car. May, June. %.. — Scape 6 — 10 inches 

 high, with a globose tuber at the base, the lower part bearing 3 — 4 loosely- 

 sheathing scales, from the upper of which there is often a linear-lanceolate 

 nerved leaf. Flowers mostly solitary, (rarely 2,) terminal, large, bright-purple. 

 Lip curled, crenulate on the margin, yellow and while, bearded in the middle. 



Bulbous Arethusa. 



13. CALOPOGON. 2??Yn<?».— Calopogon. 



(From the Greek koXos, beautiful, and Trwywi/, a heard ; in allusion to the beard 

 of the flower.) 



Flowers resupinate. Perianth with the segments distinct 

 and spreading. Lip on the upper side of the flower, erect, un- 

 guiculate, bearded in front. Column free. Pollen angular. 



C. pulcheUus Brown. Cymbidium pulchellum Willd. 



Swamps. Can. to Flor. W. to Lake Superior. June, July. %. — Root tu- 

 berous. Scape 12 — 18 inches high, slender. Leaf generally solitary, 8 — 10 

 inches long, sheathing the base of the stem. Flowers 3 — 4, in a terminal brac- 

 teate spike, large, bright-purple. « Calopogon. 



V. Neotte^. Pollen poivdery, granular or sectile. Anther dorsal 



14. LISTERA. Brown.— TwayhlsLde. 

 (In honor of Martin Lister, an eminent British naturalist.) 

 Perianth irregular. Lip 2-lobed or 2-cleft, without callous 

 processes. Column wingless, (minute.) Anther fixed by its 

 base. Pollen powdery. 



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

 raceme loose ; column without any appendage behind ; lip elongated, 2- 

 toothed at base, deeply bifid, the segments divaricate and acute. Ophrys 

 cordata Mich. 



Sphagnous swamps. Can. to N. J. May. %.—Stem 4 — 8 inches high. 

 Leaves roundish, cordate, veined, smooth, mucronate. Raceme 7 — 15-flowered. 

 Flowers distant, minute, green and purple. Heart-leaved Twayblade. 



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

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

 lip oblong, dilated and obtusely 2-lobed at the extremity. Epipactis con- 

 vallarioides Pursh. 



Swamps. N. Y. to Car. May. %. — Stem 6 inches high and very slender. 

 Flowers dark-brown and green, larger than in the preceding. 



Large-flowered Tkoayblade; 



15. SPIRANTHES. i2icA.— Ladies' Tresses. 



(From the Greek cireipa, a cor<^, and avOos, aflower ; the flowers being spiral 

 like the strands of a rope.) 



Spike spiral ; inner segments of the perianth connivent. Lip 



unguiculate, parallel with the column, with 2 callous processes 



