512 COMPOSITAE (COMPOSITE FAMILY) 
if cut above the surface of the ground, they will stool and require 
attention a second time. Cultivation of the ground at once de- 
stroys these plants. 
TALL THISTLE 
Circium altissimum, Spreng. 
(Cdérduus altissimus, L.) 
Other English names: Roadside Thistle, Horse Thistle. 
Native. Biennial. Propagates by seeds. 
Time of bloom: Late July to September. 
Seed-time: August to October. 
Range: Massachusetts to Minnesota and Nebraska, southward to 
Florida and Texas. 
Habitat: Roadsides, borders of.fields, waste places. 
Root thickened, deep-boring, and winter rosettes very large. 
Stem three to ten feet in height, branching, downy-hairy. Leaves’ 
oblong lance-shaped, the lowermost sometimes pinnatifid into 
triangular lobes, with short, margined petioles, but those above 
wavy-edged and prickly-toothed, sessile or somewhat clasping but 
not decurrent, dark green and rough-hairy above, white-woolly 
beneath. Heads solitary, terminal, about two inches broad, 
light purple, the outer bracts of the involucre with a dark, glandu- 
lar spot on the back and tipped with spreading spines; the inner 
scales without prickles. Achenes dark brown, numerous, with 
copious, white, plumose pappus. 
Means of control the same as for the Spear Thistle. 
PASTURE, OR FRAGRANT, THISTLE 
Circium pumilum, Spreng. 
(Cdérduus odordtus, Porter) 
Native. Biennial. Propagates by seeds. 
Time of bloom: July to September. 
Seed-time: August to October. 
Range: Maine to Penpsylvania and Delaware. 
Habitat: Pastures, and borders of fields. 
Root round, thick, solid, often branching, the autumn tufts of 
leaves large and spreading. Stem one to three feet tall, stout, 
hairy, with few branches, very leafy. Leaves oblong lance-shaped, 
