316 



CICHORIACEAE. 



VOL. III. 



3. Leontodon erythrospermum (Andrz.) Britton. 



Fig. 4064. 



Red-seeded Dandelion. 



Taraxacum erythrospermum Andrz. in Bess. Enum. 

 PI. Vilh. 75. 1821. 



Similar to the two preceding species, the leaves 

 glabrous, very deeply runcinate-pinnatifid or pin- 

 nately divided into narrower triangular-lanceolate 

 usually long-pointed segments ; scapes glabrous, 

 or pubescent above; heads rarely more than i' 

 broad, 7o-9O-flowered ; bracts of the involucre 

 glaucous, the outer lanceolate, spreading or as- 

 cending, the inner linear, longer, each usually 

 with an appendage just below the tip; flowers 

 sulphur-yellow, the outer rays purplish without; 

 achenes narrower, bright red, or red-brown, spin- 

 ulose above, the filiform beak not more than twice 

 their length; pappus dirty white. 



In fields and woods, Maine and Vermont to New 

 York, Pennsylvania, Ontario, Alberta, Illinois and 

 Wyoming. Naturalized from Europe. April-June. 

 April-June. 



16. SONCHUS [Tourn.] L. Sp. PI. 793. 1753. 



Annual or perennial succulent herbs, with alternate, mostly auriculate-clasping, entire 

 dentate lobed or pinnatifid, prickly-margined leaves, and large or middle-sized, peduncled 

 corymbose or paniculate heads of yellow flowers. Involucre ovoid or campanulate, usually 

 becoming thickened and more or less conic at the base when old, its bracts herbaceous or 

 membranous, imbricated in several series, the outer successively smaller. Receptacle flat, 

 naked. Rays truncate and 5-toothed at the apex. Anthers sagittate at the base. Style- 

 branches slender. Achenes oval, oblong, or linear, more or less flattened, io-2O-ribbed, 

 somewhat narrowed at the base, truncate. Pappus of very copious soft white simple capillary 

 bristles, usually falling away connected, sometimes with i or 2 stouter ones which fall sepa- 

 rately. [The Greek name of the Sow-thistle.] 



About 45 species, natives of the Old World. Besides the following, another occurs on the 

 Pacific Coast. Type species : Sonchus oleraceus L. 



Involucre glandular-pubescent; heads nearly i' high. i. 5. arvensis. 

 Involucre glabrous ; heads 6"-8" high. 



Auricles of the leaves acute ; achenes striate and transversely wrinkled. 2. S. oleraceus. 



Auricles rounded ; achenes ribbed, not transversely wrinkled. 3. S. asper. 



i. Sonchus arvensis L. Corn Sow-Thistle. 

 Milk Thistle. Fig. 4065. 



Sonchus arvensis L. Sp. PI. 793. 1753. 



Perennial by deep roots and creeping rootstocks, 

 glabrous; stem leafy below, paniculately branched 

 and nearly naked above, 2-4 high. Lower and 

 basal leaves runcinate-pinnatifid, often 12' long, 

 spinulose-dentate, narrowed into short petioles, the 

 upper pinnatifid or entire, lanceolate, clasping; heads 

 several or numerous, corymbose-paniculate, i'-2 f 

 broad, bright yellow, very showy; involucre nearly 

 i' high, its bracts as also the peduncles glandular- 

 bristly; achenes oblong, compressed, with about 10 

 rugose longitudinal ribs. 



In low grounds, fields and waste places. New Jersey 

 to Quebec, Newfoundland, Minnesota, Colorado and 

 British Columbia. Naturalized from Europe. Native 

 also of Asia. July-Oct. Dindle. Gutweed. Swine-thistle. 

 Tree sow-thistle. 



