554 COMPOSITAE. Vo. III. 
16. Cirsium palistre (L.) Scop. Marsh Thistle. 
Fig. 4651. 
Carduus palustris L. Sp. Pl. 822. 1753. 
Cirsium palustre Scop. Fl. Carn. Ed. 2,2: 128, 1772, 
Annual or biennial; stem little branched, 4°-5° high, 
loosely floccose or glabrate and covered by the decur- 
rent prickly margins of the leaves. Leaves pinnatifid, 
the lower often 6’-8’ long, linear-oblong in outline, the 
segments lobed, loosely floccose beneath, spinulose; 
heads usually many, rather less than 1’ broad, densely 
clustered, short-peduncled, the involucre ovoid, its bracts 
with very short, prickly tips. 
Woodlands, East, Andover, New Hampshire, recorded as 
thoroughly naturalized. Native of Europe and northern 
Asia. Summer. 
Cirsium canum (L.) Bieb., with larger, long-peduncled 
heads, the decurrent leaf-bases merely ciliate, is recorded as 
established in Massachusetts. Adventive from Europe. 
105. CARDUUS [Vaill.] L. Sp. Pl. 820. 1753. 
Herbs resembling Cirsium in habit, usually annual or biennial, the leaves decurrent on 
the stem and branches as spiny wings, the heads often nodding. Involucre ovoid to globose, 
many-flowered, its bracts narrow, in many series. Receptacle copiously bristly, flat or convex. 
Corolla-tube slender, the limb deeply 5-cleft. Filaments papillose-pubescent. Anthers sagit- 
tate at the base and with slender auricular appendages. Style-branches obtuse. Achenes 
mostly obovoid, sometimes angled or ribbed, glabrous. Pappus of many naked or merely 
roughened bristles. [Ancient Latin name of these plants.] 
About 80 species, natives of the Old World. Type species: Carduus nutans L. 
Heads solitary at end of stem or branches, nodding. 1. C. nutans. 
Heads usually several, crowded at ends of winged branches. 2. C.crispus. 
1. Carduus nitansL. Musk Thistle. Plumeless Thistle. Fig. 4652. 
Carduus nutans L. Sp. Pl. 821. 1753. 
Biennial, branched, sparingly tomentose, 2°-3° 
high. Leaves lanceolate in outline, deeply pinnatifid, 
acuminate, 3’-6’ long, the lobes triangular, very 
prickly; heads long-peduncled, solitary at the end 
of the stem or branches, 14’-24’ broad, nodding, pur- 
ple, rarely white, fragrant; involucre hemispheric, its 
bracts in many series, lanceolate, long-acuminate, the . 
prominent mid-nerve prolonged into a prickle, or the 
inner nerveless and awned; pappus bristles 10’—1’ 
long, white, very minutely barbed. 
In waste places, District of Columbia, Pennsylvania 
and New Jersey to New Brunswick, and in ballast about 
the seaports. Naturalized or adventive from Europe. 
Native also of Asia. Bank- or buck-thistle. Queen Ann’s- 
thistle. July—Oct. 
