COMPOSITAE (COMPOSITE FAMILY) 859 



chiefly plane and uncut, or the lowest slightly pinnatifid. Local, Que., N. E., 

 andN. Y. (Nat. from Eu. ) 



*- -i- At least the lower leaves strongly decurrent. 



14. C. PALTJSTRE (L.) Scop. Tall, not stoloniferous ; stem armed throughout 

 by the prickly decurrent wings which extend down from the very long linear or 

 linear-lanceolate more or less pinnatifid spinose-ciliate leaves heads resembling 

 those of no. 13, but in denser glomerulate clusters, hermaphrodite. Thoroughly 

 naturalized in woods, East Andover, N. H. (G. W. Holt). (Nat. from Eu.) 



15. C. CANUM (L.) Bieb. Boots fusiform ; lower leaves very long, lanceo- 

 late, toothed or slightly pinnatifid, green on both sides, their bases decurrent as 

 ciliate wings along the stem ; upper leaves sessile ; heads comparatively large, 

 hemispherical, on long peduncles. Established at Kendal Green, Mass. ( Miss 

 Parsons). (Adv. from Eu.) 



84. ONOP6RDUM [Vaill.] L. COTTON or SCOTCH THISTLE 



Receptacle deeply honey-combed, not setose. Pappus not plumose. Other- 

 wise as Cirsium. Coarse branching annuals or biennials, with the stems 

 winged by the decurrent bases of the lobed and toothed somewhat prickly leaves. 

 Heads large ; flowers purple. (Latinized from the ancient Greek name of the 

 plant. ) 



1. 0. AcANTHiuM L. Stem (1-3 m. high) and leaves cotton-woolly; scales 

 linear-awl-shaped. Roadsides and waste places, N. B. and N. S. to Ont., s. to 

 N. J. and Mich., rather rare. July-Sept. (Nat. from Eu.) 



85. SILYBUM [Vaill.] Adans. MILK THISTLE 



Heads many-flowered ; flowers all alike, tubular, perfect, fertile. Involucre 

 large, depressed-globose ; the bracts large, prickly, the broadly ovate base 

 gradually or rather abruptly contracted to a straightish rigid spreading or 

 reflexed herbaceous but indurated and pungent tip. Receptacle flattish, densely 

 bristly. Achenes glabrous ; pappus of numerous flattish barbellate bristles 

 united into a ring at the base and deciduous together. Thistle-like tall stout 

 prickly herbs with sinuate-lobed or pinnatifid mottled leaves and large solitary 

 heads of purple flowers. (Derived from <rf\vos, the ancient Greek name of an 

 edible-stemmed thistle.) 



1. S. MARI\NUM (L.) Gaertn. (LADY'S THISTLE.) Stout and nearly gla- 

 brous annual or biennial, with large mottled amplexicaul leaves variously lobed 

 and prickly on the margin. (Mariana Hill.) An occasional escape from gar- 

 dens, or weed on ballast and waste grounds. (In trod, from s. Eu.) 



86. 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 bracts margined or appendaged. Achenes obovoid or oblong, 

 compressed or 4-angled, attached obliquely at or near the base ; pappus setose 

 or partly chaffy, or none. Herbs with alternate leaves ; the single heads rarely 

 yellow. (Kevravply, an ancient Greek plant-name, poetically associated with 

 Chiron, the Centaur, but without wholly satisfactory explanation.) 



Bracts of the Involucre (or at least the outer ones) terminated by a definite 

 elongate rigid spine; annuals. 



Sterns not winged 1. (7. Calcitrapa. 



Steins winged. 



Spines of the involucre stout, straw-colored, 12-18 mm. long ... 2. C. solattitialis. 

 Spines of the involucre slender, purplish, 6-9 mm. long .... 8. C. melitensis. 

 Bracts not spinose-tipped, or merely with short firm tip hardly longer than 



the lateral teeth, cilia, or fringe. 



Bracts entire or merely with irregularly denticulate or lacerated (not regu- 

 larly toothed or pectinate) margin 4. C. Jac*a. 



