DIPSACACE.^— TEASEL FAMILY 



WILD TEASEL 



Dipsacus sylvestris 



Name from Greek, dipsao, to thirst, probably because 

 the united bases of the opposite leaves frequently form a 

 little cup which will hold water. 



Biennial. Naturalized from Europe. A tall, stiff, 

 angular and prickly plant standing by the roadside 

 in rows or in colonies; bearing in summer large, oblong, 

 prickly heads with many small, lavender florets. At all 

 other seasons of the year the brown stalks crowned with 

 the brown heads stand erect, stiff, and forbidding. Maine 

 to Minnesota and south to Virginia. July-September. 



Stem. — Three to six feet high, stout, bristly, leafy; 

 sending out a flowering stem from the axil of each upper 

 leaf. 



Leaves. — Opposite, lance-oblong, six to twelve inches 

 long, sessile, entire, acuminate, prickly along the stout 

 midrib; frequently a pair of leaves unite at the base and 

 so form a cup. The seedlings form a full rosette, a foot 

 or more in diameter. 



Flower-heads. — Oblong-cylindric, three to four inches 

 long, solitary at the summit of a long, stout peduncle, 

 borne in the axil of a leaf. Pale lilac florets are densely 

 packed upon these heads; each floret protected by a sharp, 

 slender, stiff-pointed bract. Usually the florets open first 

 at the middle of the oblong heads and the bloom con- 

 tinues both up and down. An involucre of several 

 narrow, stiff, bristly leaflets curves upward as high 

 or higher than the flower-head. Each flower sits in an 

 enclosing, spiny scale longer than the flower. 



214 



