Carduus 



COMPOSITAE 



999 



50 



Map 2192 



Arclium minus (Hill) Bernh. 



Involucre about 2.5 cm wide; outer bracts 3-5 mm long, inner bracts at least equaling 

 the flowers; heads corymbose; petioles usually solid. (See excluded species no. 

 686, p. 1103) A. Lappa. 



1. Arctium minus (Hill) Bernh. Common Burdock. Map 2192. In- 

 frequent to frequent throughout the state. Commonly found in rich soil 

 about habitations, but also found along roadsides, in waste grounds, and 

 open woodland. Since it is avoided by stock, it has little to prevent its 

 spreading. The roots are used in medicine. 



Nat. of Eu. ; throughout the U. S. and s. Canada. 



9461. CARDUUS [Tourn.] L. 



1. Carduus nutans L. Musk Thistle. Map 2193. Hansen (Proc. 

 Indiana Acad. Sci. 34: 257. 1925) reports that this species was found 

 established in a few fields east of Elkhart. Miss Edna Banta, in 1934, 

 found it in a pasture field along Lost Fork Creek near Brooksburg, Jeffer- 

 son County. She writes that it has been known in this locality for about 

 17 years and it is spreading, since no determined effort has been made to 

 exterminate it. In 1935 Kriebel found it in Posey County in a pasture be- 

 tween Hovey Lake and Half Moon Pond. 



Nat. of Eu. ; N. B. and Que. to Pa. 



9462. CIRSIUM [Tourn.] Mill. Thistle 



Upper surface of leaves copiously covered with stiff, upwardly appressed, acicular 

 bristles of unequal lengths, otherwise glabrous; involucral bracts all ending in 



prickles 1. C. vulgare. 



Upper surface of leaves glabrous or with weak, multicellular hairs (woolly in C. 

 Pitcheri) . 

 Leaves woolly on both surfaces, pinnately parted, usually into 12-20 linear or linear- 

 oblong, entire segments ending in a prickle and usually with a prickle near 

 the base; segments of leaves revolute; flowers cream color; plants found only 

 on the dunes near Lake Michigan 2. C. Pitcheri. 



