WEEDS OF THE TEASEL FAMILY. 139 



Its seeds are readily told by the cross-groove on the rounded side. 

 Remedies : hand digging in late fall or early spring ; cutting before 

 the seeds ripen; thorough cultivation. 



The dwarf white plantain (P. virginica L.), leaves ovate or 

 spoon-shaped, white hairy, stamens 4, corolla lobes erect and closed 

 over the tops of the capsules, occurs frequently in dry or sandy 

 soil, but does not promise to spread enough to do much harm. 



THE TEASEL FAMILY. DIPSACACE^E. 



Herbs with opposite leaves, mostly prickly stems, and perfect 

 flowers in dense oblong heads surrounded by an involucre. Calyx 

 cup-shaped, the tube attached to the ovary; corolla oblique or 2- 

 lipped, 4-lobed; stamens 4, inserted on the tube of the corolla and 

 alternate with its lobes; ovary 1-celled. Fruit an achene, its tip 

 crowned with the persistent calyx-lobes. 



In the Old World this family is represented by 140 species, four 

 of which have been introduced and now grow wild in the eastern 

 United States. Of these only one occurs in Indiana. The sweet 

 scabious is a cultivated member. 



104. DIPSACUS SYLVESTBIS Huds. Wild or Common Teasel. English Thistle. 

 (B. I. 2.) 



Stem stout, 3-6 feet high, with numerous short prickles on the 

 branches, midribs of the leaves and involucre; leaves sessile, lanceolate or 

 oblong, the upper pointed, entire, often united at base, the lower blunt- 

 toothed or somewhat divided, often 1 foot long. Flowers purplish, \ inch 

 long, in dense cylindric heads 3-4 inches long, each flower with a bract 

 or scale beneath it which ends in an awl-shaped barbed awn longer than 

 the flower itself; leaves of the involucre linear, curved upward, as long 

 as the head. (Fig. 101.) 



Common in dry soil in southern 

 Indiana along roadsides, waste places 

 and barren slopes of old abandoned 

 fields. July-Sept. The flowers be- 

 gin to blossom in a ring about the 

 middle of the head and gradually 

 open towards both base and apex. 

 The large heads, spiny involucre and 

 prickly leaves make the teasel a strik- 

 ing and rather handsome roadside 

 plant when in blossom but an un- 

 sightly weed when dead. Remedies: 

 Fig. 101. (After Miiispaugh.) mowing as often as the heads are 



