6.Sonchus (fourn,)L. Sow-Thistle, 
Coarse herbs with leafy stems and abundant milky juice, Heads cymo 
rbs t Fs se 
umbellate, their involucres deeply campanulate, the bracts unequal her basered 
recevtacle naked. Flowers yellowish. Achenes strongly flattened, ribbed on j 
the faces, blunt, not beaked; pappus of soit white bristles, 
, 
o Involucral bracts 15-16 mu. long$ marginal teeth Lunar 
4 rarely 2mm. long; perennial /. Se arvensis: 
o Involucral bracts 10-15 ma. long; marginal teeth 
4 mostly 2-4 mm. longs or more; annuals 
Basal leaves mostly unlobed, oblanceolate, 
& spatulate or obovate; herbage very prickly 4a. S. asper 
Basal leaves lyrate, the terminal lobe much 
larger than the laterals, the rachis nearl ) 
( nase below the laterals; herbage n markedly 
prickly . Se oleraceus 
‘ —. 
1. Se arvensis Le —————~ ‘Jeedy perennial herbs 40-100 cm. tall or more, 
glabrous and somewhat glaucous, the lower leaves mostly oblanceolate, narrowed 
to indefinite petioles, Somewhat sinuate but mostly unlobed and finely denti- 
culate with very sharp teeth, the stem leaves oblanceolate or narrowly 
elliptical in outline, sessile, clasping at the pase, irregularly pinnatifid 
into subdeltoid svreading lobes the margins very sharply toothed but hardly 
spinose, the teeth rarely 2 mm. tall, tipped with a weak prickle; heads sub- 
umbellate, but few and panicled, inflorescence usually glandular with conspic- 
uous capitate glands; bracts 15-18 mm. long, lanceolate, acute, glandular; 
corollas yellow, 20-22 mu. lons; achenes 2 mn. long, ribbed longitudinally 
and transversely wrinkled. 
Occasional as a weed in waste places. 
