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IOWA ACADEMY OF SCIENCES. 
there is a difference with reference to the character of the 
bristles. In some species the outer flowers are merely bar- 
bellate as in C. muticus and C. discolor. The branches of 
the pappus are usually clavate. The pappus is so arranged 
that it forms a neat contrivance for the wind to carry the 
fruit for a considerable distance from where it was pro- 
duced. One often can see hundreds of these little downy 
affairs floating in the air. For this reason so many of the 
plants make their appearance in clearings, as in pastures 
and burnt timber. The Cnicus lanceolatus frequently occurs 
in such abundance in pastures as to seriously injure the 
value of the same for pasture purposes. One sees the 
same thing in a forest burned over in the course of a year 
or so in this state The Cnicus lanceolatus comes up in 
abundance. In the Rocky mountain country the Cnicus 
drunimondii becomes abundant; in the course of a few 
years the open woods become covered with these plants, 
and not inappropriately are sometimes called fire weeds. 
CNICUS. 
Cnicus, L. Gen. 6 Ed. 1764. Tourn Inst. 447. t 255. 
Linn. Sp. PI. 1768. 2 Ed. 
Willd. Sp. 8; 1662. 
— _ Bentham & Hooker Gen. PI. 2: 468, 1286. 1878. 
Cirsium, D.C. FI. Fr. 4: 110. 1805. 8 Ed. 
Prodr. 6: 684. 1887. 
— Hoffmann in Engler and Prantl. Die Nat. 
Pflanzenfamilien. Theil IY. 5 Abt. 822. 1898. 
Carduus, L. Sp. PI. 820. 1758. 
— Greene. Proc. Acad. Nat. Sci. !892: 
Britton and Brown Illustr. FI. N. St. 8: 484 in 
part. 1898. 
Erect branching or simple caulescent or a few acaul- 
escent herbs, with alternate sessile, or decurrent, decum- 
bent sinuate dentate or pinnatifid spiny leaves, involucre 
ovoid or globose, bracts of two series, the outer armed 
with a prickle or without, with a glutinous ridge or none, 
the inner long acuminate, frequently with a scarious 
appendage. Large many-flowered, solitary or clustered 
