HITCHCOCK — PLANTS OF AMES, IOWA. 505 



C. ALTissiMUS, (L.) Willd. Spec. iii. — Carduus altissii/ms, L. Spec. 

 Open woods and roadsides; abundant. 

 Var. DISCOT.OB, (Muhl.) Gray, Proc. Amer. Acad. xix. 1SS3. — 

 C. discolor, Muhl. in Willd. Spec. iii. 

 Borders of fields, along fences, etc.; common. 



Seems to pass into C. altissimus. The white-flowered form occurs along Skunk 

 river. 



€. odoratus, Muhl. Cat. 1st ed..— Carduus odoratus, Muhl, Cat. 2d 

 ed. — C. pnmilus, Torr. Compend. 1S26. 

 Pastures; not uncommon. 



[Of this, Mr. Watson writes : — The Cnuiis sent is not true C. pumilus. While 

 the loliage and shape of the involucral scales agree well enough, the latter have x, 

 black, glutinous thickening above, which I do not find on eastern specimens. Of 

 more importance are the more acuminate anthers, like those of the other western spe^ 

 cies of the group. It will not go into C. Drummondii, and I suspect that it is a 

 fairly good undescribed species. — T.] 



C. arveusis, (L.) Hoffm. FI. Germ, \\.\%Q\.—S(:rratida ciz-vcnsis, 

 L, Spec. 



Introduced in a few places but not established. 

 HlKEiACIUBI SCABRUM, Michx. FI. 



Upland woods ; a few specimens collected on Onion creek, north- 

 west of stone arch, in 18S6. 

 H. LONGIPII.UM, Torr, in Hook. FI. i. (note under H. Scoukri). 

 Prairie; infrequent. 



Campus south of Prof. Osborn's house; abundant a few rods south of the veter- 

 inary barn. 



Prenanthes racemosa, Michx, FI. 



Low prairie; not uncommon, 

 P. aspera, Michx. FI, 



Prairie; infrequent, 

 P. ALBA, L, Spec. 



L'pland woods ; frequent. 

 Troxi^ion cuspidatum, Pursh, FI. 



Prairie ; scarce. 



Along railroad 3 miles east of Ames, and elsewhere. 



Taraxacum officinale, (With.) Weber in Prim. FI. Holsat. 1780. 

 — Leofifodon officinale^ With. Bot. Arrang. 1776, 



Grassland; common. 

 Lactuca Scariola, L. Spec. 2d ed. 



Waste places ; becoming frequent. 



This was first described under L. Serriola (Amoen. Acad. iv. p. 32S), which is 

 probably a typographical error, for in the Species, 2d edition, the description is the 

 same as in the Amcenitates, to which reference is made without comment. 



L, Canadensis, L. Spec. 



Moist places; common. 

 L. LuDOViciANA, (Nutt.) DC Prod. vii. — Sonchns Ludovirkmus, 



Nutt. Gen. 



