GENUS 105. 



THISTLE FAMILY 



2. Carduus crispus L. Curled Thistle. Welted 

 Thistle. Fig. 4653. 



Carduus crispus L. Sp. PI. 821. 1753. 



Biennial, somewhat tomentose; stem much branch- 

 ed, densely prickly, 2-4 high. Leaves lanceolate 

 in outline, with undulate and ciliate-spiny margins, 

 all sinuate-pinnatifid into broad, 3-lobed, toothed 

 segments, the teeth prickle-pointed ; heads several, 

 usually crowded at the ends of the winged branches, 

 i' broad or less, purple or white, sessile or short- 

 peduncled, or some of them rarely solitary and 

 slender-peduncled ; involucre ovoid, its bracts very 

 numerous, linear, the outer prickle-tipped and rigid, 

 the inner thinner and merely acuminate. 



In fields and waste places. New Brunswick, Quebec, 

 Nova Scotia and Pennsylvania, and in ballast about the 

 seaports. Adventive from Europe. Native also of Asia. 

 July-Sept. 



Carduus acanthoides L., which resembles this species, 

 but has larger hemispheric involucres, their outer bracts 

 not rigid, has been collected in ballast on waste grounds 

 about Atlantic seaports, and several other species of 

 Carduus have been found in ballast deposits. 



106. MARIANA Hill, Veg. Syst. 4: 19. 1762. 

 [SILYBUM Vaill. ; Adans. Fam. PI. 2: 116. 1763.] 



Annual or biennial, simple or branched, nearly glabrous herbs, with large alternate clasp- 

 ing, sinuate-lobed or pinnatifid, white-blotched leaves, and large discoid heads of purple 

 tubular flowers, solitary at the end of the stem or branches. Involucre broad, subglobose, 

 its bracts rigid, imbricated in many series, the lower ones fimbriate-spinulose at the broad 

 triangular summit, the middle ones similar but armed with huge spreading or recurved spines, 

 the inner lanceolate, acuminate. Receptacle flat, densely bristly. Corolla-tube, slender, the 

 limb expanded and deeply 5-cleft. Filaments monadelphous below, glabrous. Anthers sag- 

 ittate at the base. Style nearly entire. Achenes obovate-oblong, compressed, glabrous, sur- 

 mounted by a papillose ring. Pappus bristles in several series, flattish, barbellate or scabrous. 



[St. Mary's thistle.] 



A montypic genus of the Mediterranean region. 



i. Mariana mariana (L.) Hill. Milk 

 Thistle. Fig. 4654. 



Carduus marianus L. Sp. PI. 823. 1753. 

 Mariana mariana Hill, Hort. Kew. 61. 1769. 

 Silybum marianum Gaertn. Fruct. & Sem. 2: 378. 

 1802. 



Stem striate, glabrous or slightly woolly, little 

 branched, 2-4 high. Leaves oblong-lanceolate, 

 prickly, strongly clasping, the lower often 12' 

 long and 6' wide, the upper much smaller, scarce- 

 ly lobed, acute; heads about 2*' broad; spines of 

 the middle involucral bracts often I*' long; pap- 

 pus bristles white, barbellate. 



Escaped from gardens near Kensington, Ontario 

 (T. Walker, according to Macoun), in ballast and 

 waste grounds about the eastern seaports, south to 

 Alabama, and on the Pacific Coast from British Co- 

 lumbia to southern California, where it is naturalized. 

 Virgin Mary's-thistle, lady's-milk, holy thistle. June- 

 Aug. 



107. ONOPORDON [Vaill.] L. Sp. PI. 827. 1753. 



Coarse, branching or rarely acaulescent, tomentose herbs, with stout stems winged by 

 the decurrent bases of the alternate dentate or pinnatifid, prickly leaves, and large discoid 

 heads of purple violet or white flowers, mostly solitary at the ends of the branches. Invo- 

 lucre nearly globular, its bracts imbricated in many series, all tipped with long spines in our 

 species, the inner narrower than the outer. Receptacle flat, fleshy, honeycombed, not bristly. 



