Genus ioo.] THISTLE FAMILY. 493 



5. Centaurea Calcitrapa L. Star Thistle (Fig. 4080. ) 



Ceiiiaurea Calcitrapa L. Sp. PI. 917. 1753. 



Annual, pubescent or glabrous, green; stem 

 much branched, l°-i>i° high. Leaves 1-2- 

 pinnatifid into oblong-lanceolate to linear, ser- 

 rulatespinulose, dentate or entire mostly acute 

 lobes, the upper sessile and sliglitly clasping, 

 the lower and basal short-petioled, 4'-"' long, 

 the uppermost somewhat involucrate at the 

 bases of the sessile heads which are about l' 

 broad; involucre ovoid, its outer bracts ovate- 

 oblong, tipped with stout spreading spines 

 which are simple, or conmionly with 2-6 bristles 

 at the base; flowers purple, none of them radi- 

 ant; achenes compressed or obscurely 4-sided; 

 pappus none. 



In waste places and ballast, southern New York 

 and New Jersey to Virginia. Also in British Co- 

 lumbia. Adventive or naturalized from Europe. 

 Called also Caltrops, Maize Thorn. June-Oct. 



loi. CNICUS L. Sp. PI. 826. 1753. 



An annual herb, with alternate pinnatifid or sinuate-dentate leaves, the lobes or teeth 

 spiny, and large sessile heads of yellow tubular flowers, solitary at the ends of the branches, 

 subtended by the upper leaves. Bracts of the involucre imbricated in several series, the 

 outer ovate, the inner lanceolate, tipped by long pinnately branched spines. Receptacle 

 flat, bristly. .Achenes terete, striate, laterally attached, the horny margin lo-toothed at the 

 summit; pappus of 2 series of awns, the inner fimbriate, the outer longer, naked; anther-ap- 

 pendages elongated, united to their tips. [Latin name of Safflower, early applied to thistles. ] 



A monotypic genus of the Old World. 



I. Cnicus benedictus L. Blessed 



Thistle. Our Lady's Thistle. 



(Fig. 4081.) 



Cnicus benedictus L. Sp. PI. 826. 1753. 

 Centaurea benedicla L. Sp. PI. Ed. 2, 1296. 

 1763- 



Hirsute or pubescent, much branched, 

 seldom over 2|<° high. Leaves oblong- 

 lanceolate in outline, rather thin, reticu- 

 late-veined, 3'-6' long, the upper clasping, 

 the basal and lower ones narrowed at the 

 base and petioled; heads about 2' broad, 

 subtended by several large lanceolate to 

 ovate-lanceolate leaves; bristles of the re- 

 ceptacle soft, long; outer awns of the 

 pappus alternating with the inner. 



In waste places. Nova Scotia to Maryland, 

 Pennsylvania and Alabama, and on the Paci- 

 fic Coast. Adventive from southern Europe. 

 Called also St. Benedict's Thistle. May-Aug. 



