•white (Mr. Oakes).—Muhlenberg’s name is the most appropriate, and should
have been preserved.—Pasture Thistle.
* * * Scales of the involucre rather loosely imbricated in few series, tapering to a
subulate point: heads conspicuously invohtcrate with a whorl of very spinose bracts!
13. C. horridulum (Michx.): arachnoid-woolly when young, at length
somewhat glabrous; stem simple or sparingly branched; leaves partly
clasping, lanceolate, pinnatifid, the short lobes toothed or incised, strongly
spinose; heads (large) surrounded by a whorl or dense cluster of pectinate-
spinose bracts about the length of the involucre, the prickles often fascicled ;
scales of the subglobose involucre linear-lanceolate minutely scabrous and
ciliate, tapering to a very sharp point, unarmed; flowers pale yellow.—
Michx.! Jl. 2. p. 90 ; PC. ! prodr. 6. p. 651. C. megacanthum, Nutt.! in
trans. Amer. phil. soc. 1. c. Carduus horridulus, Pers. syn. 2. p. 390. C.
spinosissimus, Walt. Cnicus horridulus, Pursh, Jl. 2. p. 507 ; Bigel. ! fl.
Bost. ed. 2. p. 291 ; Hook.! compan. to hot. mag. 1 . p. 48. C. spinosissimus,
Parlingt. ! jl. Cest. p. 438.—Varies, with the anthers and styles reddish
or purple (Bigel. 1. c. Oakes, mss.), or with the corolla sometimes
changing to purple in drying (Barratt, mss.), or
p. EUiottii : flowers purple.—Cnicus horridulus, Ell. sk. 2. p. 272.
Hills and poor soils, from the coast of Massachusetts! and Connecticut! to
Florida ! and Louisiana ! fl. Southern States, Elliott. Florida, Pr. Chapman!
(Corolla in dried specimen light purple, the anthers yellowish.)
Lincoln County, N. Carolina, Mr. Curtis! Pr. Hunter! (Corolla, anthers,
and style deeply purple.) June-Aug. in the Northern, March-May in the
Southern States.— 11 or@? Plant 1-3 feet high; the large heads subtended
by 12-30 very spinose bracts; the exterior often pinnatifid.—A somewhat
variable, but well-marked species, with the corolla and pappus much
larger than in C. spinosissimum, the heads not clustered, and the lobes of
the leaves rather distant. From the characters given, we suspect it is equally
distinct from C. glabrum, PC., of which we possess no specimen.— Yellow
Thistle.
* * * * Scales of the involucre loosely imbricated in few series, somewhat unequal in
length; the exterior with subulate-spinescent tips: heads not involucrale with bracts.
14. C. remotifolium (DC. 1. c .) : stem tall, erect, striate, branching and
nearly naked above, somewhat arachnoid and hairy; leaves remote, lanceolate,
sparsely hairy above, arachnoid-tomentose beneath, partly clasping
by an auriculate very spinose base, pinnately parted; the segments deeply
2- 3-cleft; the lobes lanceolate, tipped with a spine, the margins somewhat
spinulose ; heads large, paniculate; the panicle nearly leafless; scales of the
involucre somewhat arachnoid, nearly equal, straight, lanceolate-subulate,
loose, cuspidate; the innermost membranaceous, much acuminated, unarmed
; “ flowers purplish.”—Carduus remotifolius, Hook. jl. Bor.-Am. 1. p.
302. Cirsium stenolepidum, Nutt.! in trans. Amer. phil. soc. 1. c. p. 419.
Plains of Oregon, Douglas, Nuttall!—Stem purple above, 3-5 feet high.
Leaves somewhat resembling those of C. discolor. Heads as large as in C.
lanceolatum.
§ 3. Heads by abortion dioecious: exterior scales of the involucre oppressed,
unarmed, err the outermost tipped with a short prickle or bristle; the innermost
with scarious tips : filaments nearly glabrous: roots creeping. (Cephano-
plos, PC.)
15. C. arvense (Scop.): rhizoma creeping; stem striate-angled, paniculate
; the branches somewhat woolly: leaves oblong or lanceolate, sessile,
glabrous, sometimes a little woolly beneath, sinuate-pinnatifid, undulate,
spinose; heads small and numerous; scales of the involucre ovate-lanceolate,
mucronate, a few of the exterior cuspidate-spinose ; flowers pale purple,
or rarely whitish.—P C .! prodr. 6. p. 643. Serratula arvensis, Lin n .; Fl.
Pan. t. 644. Carduus arvensis, Smith, Engl. bot. t. 975 ; Hook.! jl. Bor.-
Am. 1 . p. 301 ; Parlingt. ! jl. Cest. p. 439. Cnicus arvensis, Pursh, jl. 2.
p . 506 ; Bigel. jl. Bost. ed. 2. p. 291. Breea arvensis, Less. syn. p. 9.
Cultivated fields of the Northern and Middle States ! introduced with grain
from Europe, and in many places becoming an extremely troublesome weed.
Also Canada! to Saskatchawan and Newfoundland; probably indigenous.
July-Aug.— U Too well known to our farmers, under the name of Canada
Thistle, or Cursed Thistle.
} Little-known species.
16. C.foliosum (DC. 1. c .): stem erect (simple ?), robust, striate, somewhat
woolly; leaves erect, the upper very numerous and exceeding the
heads, flaccid, irregularly sinuate-toothed, unequally ciliate with rather rigid
spines, sparingly hairy above, pale and arachnoid-tomentose beneath ; heads
large, glomerate in the axils of the uppermost leaves ; scales of the involucre
linear, appressed ; pappus very copious. Hook.—Carduus foliosus, Hook. fl.
Bor.-Am. 1 . p. 303.
Prairies of the [Northern] Rocky Mountains, Drummond.—“ The stems
are singularly erect and straight; the leaves also erect, 6-8 inches long, the
uppermost very numerous, considerably exceeding and almost concealing the
flowers.” Hook.
17. C. edule (Nutt.) : annual or biennial, nearly smooth; leaves lanceolate,
clasping, moderately pinnatifid ; the segments obtuse, almost equally 2-
lobed, spiiiescent and spinulose-ciliate ; heads terminal, glomerate, sessile,
3-5 together; involucre subglobose, arachnoid-tomentose ; the scales linear-
lanceolate, tipped with short erect spines. Nutt, in trans. Amer. phil. soc.
(n. ser.) 7. p. 420.
Common in the plains of the Oregon and the Blue Mountains, Nuttall._A
robust plant 3-4 feet high, somewhat succulent, with purple flowers, nearly
as large as in C. lanceolatum. Filaments hairy. The young stems are
eaten raw by the aborigines. Nutt.—Probably the same as the C. foliosum,
Hook. An edible thistle is mentioned by Lewis and Clarke.
18. C. bremfolium (Nutt.): stem slender, nearly terete, and as well as the
lower surface of the leaves canescently tomentose, bearing 2-3 heads; leaves
oblong-lanceolate, clasping, green and nearly glabrous above, sinuate-pinnatifid,
with shallow simple or 2-cleft lobes, tipped with spines, and with
spinose serratures ; involucre ovate, naked ; the scales lanceolate, glutinous,
smooth, terminating in small erect spines; flowers ochroleucous. Nutt, in
trans. Amer. phil. soc. 1. c. p. 421.
Plains of the Rocky Mountains, Nuttall.—Leaves about half an inch wide,
2-3 inches long. Allied to C. Virginianum. Nutt.
19. C. canescens (Nutt.): perennial, dwarf, slender, canescently tomentose;
leaves lanceolate, decurrent, pinnatifid; the undulate segments oblong,'
2-cleft, spinescent, and with spiny serratures; heads few (3- 5), conglomerate,
sessile; involucre slightly pubescent; the scales lanceolate, with rigid
erect spines. Nutt, in trans. Amer. phil. soc. 1. c. p. 420.
Arid deserts of the Platte, Nuttall.—Root creeping as in C. arvense. Stem
8-10 inches high. Leaves 3-4 inches long, about an inch wide, nearly
white on both sides, but most so beneath, decurrent with narrow spiny