PLANTS AND FERNS. 65 



C alpina, Linn. ?w. Ju. ^ 6— 10 i. With the last, from which it 



hardly differs enough to constitute a distinct species. 

 CisTUs canadensis, Linn. Rock Rose, y. J. ^ 12 i. Rocky 



woods. 

 C ranudiJlorum^Mx. y. Ju. 7/ 10 i. 



C. rosmarinifollum, Ph. y. Ju. ^ 10 i. The C. canadensis, Linn. 

 is so extremely variable that I am inclined to consider this and the 

 last as mere varieties of that species. 

 Claytonia virginica, Ait. r-w. Ap. 11 4 — 8 i. Damp woods. 

 Clematis virginiana, Linn. Virgin's Bower, w. Ju. l^ Thickets, 

 climbing. 



Clethra, alnifolia, Linn, Sweet Pepper Bush. w. Au. l^ 4 8 ft. 



River banks. 



Clinopodium ritZ^are, Linn. Wild Thyme, r-io. Ju. ^ 12 18 i. 



Dry meadows. 

 Clitoria mariana, Linn. Butterfly-weed. h. Ju. ^ Climbimr. 



Sandy banks of streams. 

 Cnicus lanceolatus, Hoffm. Thistle, p. J. % 2 — 4 ft. Road sides. 

 C. altissimus, Willd. w-p. Ju. ^ 3 — 8 ft. Damp thickets. 

 C arvensis, Hoffm. Canada Thistle, p. Ju. IJ. 2 — 3 ft. Cultivated 



fields. 

 C. odoratus, Muhl. j3. Ju. S 1 — 2 ft. Dry woods. 

 C. virginianus, Ph. p. Ju. jy 2—3 ft. Woods. 

 Cnidium atropurpureum, Sp. p. J. 2/ 2 — 3 ft. Rocky woods, 

 CocHLEARiA urmoracia, Linn, Horse Radish. «?. J. ^ 2 ft. Waste 



grounds. 

 CoLLiNsoNiA canadensis, Linn. Horse Balm, y. Ju, 2/ 2 — 4 ft. 



Woods, 

 CoMMELiNA augustifolia, Mx, Day-flower, h. Ju. J^ Rocky banks 



of Potomac. 

 CoMPTONiA asplenifolia. Ait. Sweet Fern. g. Ap. )2 1 — 3 ft. 



Woods. 

 CoNiuM maculatum, Linn. Poison Hemlock, w. Ju. J^ 2 — 4 ft. 



Meadows. Poisonous. 

 CoNVALLARiA UfoUa, Linn. w. M, 21 4 — 6 i. Shady Woods, 

 C, stellata, Linn, 10. M. 2/ 8— 18 i. Dry meadows. 

 C. racemosa, Linn. Solomon's Seal. y-io. M. 2/ 1 — 2 ft. Woods. 

 C. multiflora, Linn. m>-^. Ju. ^ 2—4 ft. Meadows. 

 C. pubescens, Willd. g-io. M. J^ 12— 18 i. Dry woods. 

 C.bijlora, Wr. g-y. M. 2/ 12—181. Rocky woods. 

 C. majalis, Linn. Lily of the valley, tv. J. 21 6 1. Mountain 

 woods. 

 9 



