COMPOSITAE. Vor. III. 
4. Cirsium virginianum (L.) Michx. Vir- 
ginia Thistle. Fig. 4639. 
Carduus virginianus L. Sp. Pl. 824. 1753. 
Cirsium virginianum Michx. Fl. Bor. Am.2:90. 1803. 
Cnicus virginianus Pursh, Fl. Am. Sept. 506. 1814. 
Biennial; stem slender, naked or scaly above, 
pubescent or somewhat tomentose, simple or 
branched, 2°-33° high. Leaves oblong, oblong- 
lanceolate, or the lowest slightly spatulate, ses- 
sile, or somewhat clasping, not decurrent, acute 
or acutish, spinulose-margined, entire, lobed or 
pinnatifid into triangular-lanceolate lobes, the 
lower sometimes 8 long and 2’ wide, narrowed 
into margined petioles, all pubescent or glabrate 
above, and densely white-tomentose beneath; 
heads long-peduncled, 1’-14’ broad, about 1’ high; 
outer bracts of the involucre not coriaceous, lan- 
ceolate or ovate-lanceolate, tipped with weak short 
bristles, the inner ones very narrow and merely 
acuminate; flowers purple. 
In dry woods and thickets, Virginia to Kentucky, 
Ohio, Florida and Texas. April-Sept. 
Ws 
{ y) 
5. Cirsium Pitcheri (Torr.) T. & G. Pitcher’s Thistle. Fig. 4640. 
Cnicus Pitcheri Torr.; Eaton, Man. Ed. 5, 180. 1829. ~~ 
Cirsium Pitcheri T. & G. Fl. N. A. 2: 456. 1843. 
Carduus Pitcheri Porter, Mem. Torr. Club 5: 345. 1894. 
Biennial, persistently white-tomentose throughout ; 
stem stout, leafy up to the heads, usually branched, 
1°-2° high. Leaves sessile, partly clasping or slightly 
decurrent, pinnately divided into narrowly linear, 
entire lobed or pinnatifid, acute sparingly prickly seg- 
ments, 2-3” wide, with revolute margins; basal 
leaves often 12’ long; heads solitary or several and 
racemose-spicate at the ends of the branches, about 
1’ broad; outer bracts of the involucre ovate-lan- 
ceolate, sparingly pubescent and tomentose-ciliate, 
glutinous on the back, tipped with short spreading 
bristles, the inner narrowly lanceolate, acuminate or 
a tipped with weak prickles; flowers cream 
color. 
Wy 
" Shores of Lakes Michigan, Huron and Superior. June— 
ug. 
QUA) hy / 6. Cirsium undulatum (Nutt.) Spreng. 
ile Wy If Wavy-leaved Thistle. Fig. 4641. 
yy K UZ aS CC Carduus undulatus Nutt. Gen. 2: 130. 1818. 
SN 
Zh i IN 
SSS 
SS 
= 
—<—sS 
Cnicus undulatus var. megacephalus A. Gray, Proc. Am. 
Acad. 10: 42. 1874. 
Carduus undulatus megacephalus Porter, Mem. Torr. 
Club 5: 345. 18094. 
Biennial, persistently and densely white-tomentose 
throughout, or the upper surfaces of the leaves at 
length green and glabrous; stem stout, leafy, usually 
branched, 1°-3° high. Leaves lanceolate or oblong- 
lanceolate in outline, acute, sessile or decurrent, or 
the lowest petioled, undulate, lobed or pinnatifid, the 
lobes dentate, triangular, often very prickly; basal 
leaves often 8’ long; heads 14’-3’ broad, and nearly 
as high, solitary at the ends of the branches; outer 
bracts of the involucre ovate or ovate-lanceolate, 
firm, glutinous on the back, tipped with short spread- 
ing prickles, the inner ones lanceolate, acuminate; 
flowers purple or pink. 
— 
V Cirsium undulatum Spreng. Syst. 3: 374. 1826. 
CAN Cnicus undulatus A. Gray, Proc. Am. Acad. 10: 42. 1874. 
Nie 
Ni BAIN 
WS 
= 
On plains and prairies, Lake Huron to Assiniboia, Alberta, Kansas, New Mexico and Arizona. 
June-Sept. 
