Chapter C: NUTANS, L. (MUSK THISTLE.) Biennial; leaves decurrent, sinuate,

spiny; heads solitary, drooping; flowers purple.--Fields near Harrisburg, Pa., _Prof. Porter_. (Adv. from Eu.)

81. ONOPORDON, Vaill. COTTON or SCOTCH THISTLE.

Receptacle deeply honeycombed, not setose. Pappus not plumose. Otherwise as Cnicus.--Coarse, branching annuals, or biennials, with the stems winged by the decurrent base of the lobed and toothed somewhat prickly leaves. Heads large; flowers purple. (The ancient Greek name of the plant.)

O. ACANTHIUM, L. Stem (2--4 deg. high) and leaves cotton-woolly; scales linear-awl-shaped.--Roadsides and waste places in the Atlantic States; rather rare. July--Sept. (Adv. from Eu.)

82. CENTAUREA, L. STAR-THISTLE.

Heads many-flowered; flowers all tubular, the marginal often much larger (as it were radiate) and sterile. Receptacle bristly. Involucre ovoid or globose, imbricated, the scales margined or appendaged. Achenes obovoid or oblong, attached obliquely at or near the base; pappus setose or partly chaffy or none.--Herbs with alternate leaves and single heads. (Named from the _Centaur_, Chiron, famous for his skill in healing.)

[*] _Achenes terete, 10-dentate; pappus of 10 long bristles and 10 short inner ones._

C. BENEDICTA, L. Low branching annual, with clasping scarcely pinnatifid cut leaves, and large sessile leafy-bracted heads; flowers yellow. (Cnicus benedictus, _L._)--Roadsides and waste grounds, S. Atlantic States; rare. (Adv. from Eu.)

[*][*] _Achenes compressed or 4-angled; pappus very short or none._

C. CYANUS, L. (BLUEBOTTLE.) Scales of the globular involucre fringe-margined; _false rays large_; pappus very short; _leaves linear, entire_, or toothed at the base; root annual.--Roadsides, escaped from gardens. July.--Flowers blue, varying to purplish or white. (Adv. from Eu.)

C. NIGRA, L. (KNAPWEED.) Scales of the globular involucre appendaged, and with a black pectinately ciliate fringe; _rays wanting_; pappus very short; _leaves lanceolate_, entire, or the lower lyrate-toothed, rough; root perennial.--Waste places, E. New Eng. Aug.--Flowers purple. (Adv. from Eu.)

C. CALCITRAPA, L. (STAR-THISTLE.) Stem diffusely much branched; _leaves pinnately lobed_ or spinulose-toothed; heads sessile, the middle _scales of the ovoid involucre spiny_; pappus none; flowers purple; root annual.--Seaports, N. Y., and southward. (Adv. from Eu.)

C. JACEA, L. Like the last; heads rather larger, the brownish scale-appendages lacerate; rays conspicuous, palmate.--Charlotte, Vt. (_Pringle_); near N. Y., etc., on ballast. (Nat. from Eu.)

83. LAMPSANA, Tourn. NIPPLE-WORT.

Heads 8--12-flowered. Scales of the cylindrical involucre 8, erect, in one row. Receptacle naked. Achenes oblong; pappus none.--Slender branching annuals, with angled or toothed leaves, and loosely panicled small heads; flowers yellow. (The [Greek: lampsa/ne] of Dioscorides was evidently a wild Mustard.)