§ 2. Scales o f the ovoid-globose involucre appendiculate ; the appendages cili-
ale-Jimbriate, or those o f thoinnermost somewhat lacerate-scarious and roundish
: ray-flowers often none: pappus wanting or nearly so! (corolla purplish
or rarely white).—J a c e a , Cass.
2. C. nigra (Lina.): stem erect, branching ; radical leaves petioled; the
cauline sessile, lanceolate, entire, denticulate, or sparingly angulate-incised
towards the base, scabrous; flowers all equal and perfect; pappus much
shorter than the achenium.—FI. Dan. t. 906 ; Engl. bot. t. 278; HooJc.l fl.
Bor.-Am. 1. p. 301 ; D C .! prodr. 6. p. 571; Bigel.! fl. Bost. ed. 3.
p . 339.
Newfoundland! (perhaps indigenous.) Naturalized in the eastern parts
of Massachusetts! July-Aug.— 21 Flowers purple. Scales of the involucre
black, with a stiff pectinate fringe.
§ 3. Scales of the ovoid or subglobose involucre surrounded by a membranaceous
serrate and ciliate margin: rays larger than the d is k : pappus
double, often short: heads not bracteate.—C y a n u s , Cass.
3. C. Cyanus (Linn.): floccose-tomentose ; stem erect, branching; leaves
linear, sessile, entire ; the lower broader, tapering into a kind of petiole, and
toothed or pinnatifid at the base; pappus shorter than the achenium.
DC. prodr. 6. p. 578; Darlingt. fl. Cest. p. 435.
Old fields and roadsides, having escaped from gardens; sparingly naturalized
in the Northern and Middle States. July-Aug.— (T) Flowers blue
(varying to purplish or white), or those of the disk violet.—Blue Bottle.
§ 4. Scales of the ovoid involucre coriaceous, imbricated; the middle ones
ovate, and produced into a long spine, which is naked above but sparingly
pectinate-spinulose at its base ; the inner oblong and with a simple spine ;
the outermost spineless: rays 3-5-cleft, shorter than the d isk : pappus
double ; the exterior rigid in several series ; the inner short, regular, con-
nivent (corolla yellow).—M e s o c e n t r o n , DC.
4. C. Melitensis (Linn.): stem erect, branched; radical leaves pinnately
parted, tapering into a petiole ; the cauline decurrent, broadly linear, toothed ;
heads solitary, ovate-globose, somewhat tomentose ; innermost scales of the
involucre acuminate-spinescent. DC. ! prodr. 5. p , 593; Hook. A m .!
bot. Beechey, suppl. p. 360. C. Partibilcensis, DC. 1. c., fide Hook.
8f Am.
California, Douglas ! Probably introduced (as also into South America)
with grain from Europe.
§ 5. Involucre ovoid; the middle scales produced into a spine, which is pin nately
spinulose at the base; the innermost scarious at the apex: rays
equalling or exceeding the disk: pappus short or none (corolla purple).—
C a l c i t r a f a , Cass.
5. C. Calcitrapa (Linn.): stem diffusely much branched, ha iry ; leaves
sessile, pinnately lobed ; the lobes linear, acute, toothed ; „heads sessile among
the uppermost mostly entire leaves ; spines of the involucre strong, spreading,
grooved above, with 2 or 3 small spinulas on each side at the base ; the
lowest involucral scales scarious and obtuse : pappus none. DC. prodr.
6. p. 597.
Naturalized in Virginia near Norfolk!— (1) @
C. Caroliniana, Walt, is doubtless Stokesia cyanea, L'Her.
170. CNICUS. Vaill. ; Geertn. fr . t. 162; DC. diss. 8f prodr. 1. c.
Heads many-flowered ; the ray-flowers sterile, slender, nearly equal to the
disk. Scales of the ovoid involucre coriaceous, appressed, produced into a
long and rigid pinnated spinose appendage. Receptacle densely clothed with
capillary bristles. Achenia terete, smooth, strongly striate, with a large lateral
basilar areola. Pappus triple; the exterior, or rather margin of the
fruit, of 10 very short corneous teeth ; the intermediate of 10 elongated subulate
filiform rigid bristles; the inner of 10 short bristles; the three series
regularly alternating with each other.—An annual slightly woolly or
villous branching herb (of uncertain nativity); with clasping and somewhat
decurrent undivided subpinnatifid leaves, and bracteate heads.
Corolla yellow.
C. benedictus (Linn.)—Centaurea benedicta, Linn. spec. ed. 2. p. 1296.
Sparingly introduced, but scarcely naturalized in New York, &c. Louisiana,
Mr. Leavenworth! It has also been found in Mexico and Chili, to
which it was probably brought from Southern Europe.
Subtribe 3. Carduineje, Less., DC.—Heads discoid, homogamous,
many-flowered; the flowers all similar, perfect or dioecious. Scales of the
involucre imbricated in several series, often spinosfc at the apex. Corolla
usually curved outwards, the exterior lobe often deeper cleft than the others.
Anthers slightly or not at all caudate. Achenia glabrous, with a terminal
areola. Pappus composed of slender scabrous or plumose bristles, which
are often united into a ring at the base.
171. CIRSIUM. Tourn.; DC. fl. Fran. ed. 3, Sf prodr. 6. p. 643.
Heads many-flowered ; the flowers perfect and similar, rarely subdioe-
cious. Scales of the involucre imbricated in numerous series, mostly cuspidate
or tipped with a prickle. Receptacle bristly. Corolla regularly or
often unequally 5-cleft. Anthers more or less produced and lacerate at the
base : filaments often hairy. Branches of the style concreted nearly to the
apex. Achenia oblong, compressed, glabrous, not ribbed. Bristles of the
pappus numerous and somewhat unequal, united into a ring at the base,
plumose, merely denticulate (and the stronger ones often slightly clavellate) at
the apex.—Herbs, with sessile or decurrent alternate leaves, which are often
pinnatifid ; the margins and teeth usually spinose. Heads subglobose.
Corolla purple, reddish, or ocbroleucous.— Thistle.