COMPOSITE. (COMPOSITE FAMILY.) 297 



C. NfrrANS, 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. Other- 

 wise 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 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. CENT A UREA, 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 glo- 

 bose, 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, IQ-dentate ; pappus ofW long bristles and 10 short inner ones. 



C. BENEixf CTA, L. Low branching annual, with clasping scarcely pinnat- 

 ifid 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. Flow- 

 ers 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. CALC^TRAPA, 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. Sea- 

 ports, 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. LAMPS AN A, Tourn. NIPPLE-WORT. 



Heads 8- 12-flowered. Scales of the cylindrical involucre 8, erect, in one 

 row. Receptacle naked. Achenes oblong ; pappus none. Slender branch- 

 ing annuals, with angled or toothed leaves, and loosely panicled small heads ; 

 flowers yellow. (The \a^dvr) of Dioscorides was evidently a wild Mustard.) 



L. coMMtiNis, L. Nearly smooth, 1-2 high j lower leaves ovate, some- 

 times lyre-shaped. Roadsides, N. Eng. to N. Y. and Penn. (Nat. from Eu.) 



84. K RIG I A, Schreber. DWARF DANDELION. 



Heads several - many-flowered. Involucral scales several, in about 2 rows, 

 thin. Achenes short and truncate, top-shaped or columnar, terete or angled; 



