COMPOSITE 157 



2. H. scabrifisculum, Sohwein. 



Resembling the preceding, but slender, 1-2 ft. high, rather strict, often 

 hairy; leaves linear or lanceolate; heads usually few. (Sometimes included 

 in H. umbellatum, L., which is the European form.) About thickets, 

 Man.-Alta. 



38. SONCHUS. Sow Thistle. 



Heads resembling the preceding, but the bracts of the involucre 

 getting gradually smaller outward; pappus not borne on an elon- 

 gated beak. Coarse, leafy, more or less prickly herbs with rather 

 large heads of yellow flowers. 



1. S. arvensis, L. Perennial Sow Thistle. 



Perennial, from a deep-branching rootstock; stem 2-4 ft. high, rather 

 naked above; leaves runoinate to pinnatifid, spiny-toothed, clasping; 

 heads large, showy, several, on bristly peduncles; flowers bright yellow. 

 An exceedingly troublesome weed in cultivated ground. 



2. S. oleraceus, L. Common Sow Thistle. 



Annual; stem tall, 2-8 ft. high, sparingly branched and rather naked 

 above; leaves pinnatifid, with soft prickles, the lower petioled, the upper 

 clasping; heads several or many, not showy; flowers pale, yellow. An un- 

 sightly introduced weed, rather common about dwellings. 



3. S. Ssper, L. Spiny Sow Thistle. 



Resembling the preceding, but the leaves not so much divided and sharply 

 spiny. Waste places, introduced. 



39. CHICORIUM. Chicory. 



Heads 10-20-flowered; involucre consisting of an iimer row of 

 8-10, and an outer row of 5 herbaceous bracts, the outer shorter and 

 spreading; pappus 2 or 3 rows of small scales. Erect, branching, 

 perennial herbs with sessile, more or less blustered axillary heads of 

 bright blue flowers. 



1. C. Intybus,. L. Common Chicory. 



Flowering branches stiff; leaves partly clasping, getting smaller and bract- 

 like above. An introduced plant sometimes growing in clumps about towns. 



40. LACTUCA. Lettuce. 



Heads several to many-flowered; involucre of one or two rows of 

 principal bracts and several rows of shorter outer ones ; pappus of 

 numerous hairs which fall separately, and borne on a prolonged 

 beak of the-achene. Leafy herbs with heads of different colored 

 flowers. 



