COMPOSITES 435 



3. CICHORIUM. Chicory. 



Tall, branching perennials, with deep, hard roots: florets perfect and 

 strap-shaped: fruit lightly grooved, with sessile pappus of many small, 

 chaffy scales. 



C. Intybus, Linn. Common chicory. Runs wild along roadsides (from 

 Europe); 2-3 ft.: leaves oblong or lanceolate, the lowest pinnatifid: flowers 

 bright blue or pink, 2-3 together in the axils on long nearly naked branches. 



4. LACTtTCA. Lettuce. 



Coarse weedy plants: stems tall and leafy, simple or branching, car- 

 rying small panicled heads of insignificant flowers: juice milky: stem-leaves 

 alternate, entire, or pinnately divided with lobes and margins and under 

 midrib often spine-tipped: involucre cylindrical, with bracts in 2 or more 

 unequal rows; flowers all ligulate and perfect, with the ligules truncate and 

 5-toothed: achenes oval to linear, flattened, 3-5-ribbed on each face, 

 smooth, abruptly narrowed into a beak: pappus abundant, white or brown- 

 ish and soft. 



L. canadensis, Linn. Common in rich soil, 3-9 ft. tall: leaves smooth, 

 lanceolate to spatulate, sessile or clasping, margins entire, sinuate, or 

 runcinately pinnatifid, the radical leaves petiolate — all smooth and glaucous; 

 flowers pale yellow, in small heads (K~M m - long), the heads more or less 

 diffusely panicled. Biennial or annual. 



L. villosa, Jacq. Three to 8 ft. : leaves ovate to lanceolate, pointed and 

 serrate, teeth mucronate, sometimes hairy on under midrib, the petioles 

 winged, more or less sinuate or clasping and arrow-shaped: inflorescence a 

 panicle of numerous small heads; rays bluish: achenes short-beaked or 

 beakless: pappus brownish. Biennial or annual. 



L. Scariola, Linn. Prickly lettuce. Fig. 86. Glabrous and rather glaucous- 

 green, with tall, stiff, erect stem, branching, usually somewhat prickly: 

 leaves oblong or spatulate, dentate or pinnatifid, sessile, or auricled and 

 clasping, with margins and under midrib spiny: heads small, 6-12-flowered, 

 but numerous, the rays yellow; involucre narrow, cylindric: achenes flat, 

 ovate-oblong, with long filiform beak. Europe. A common coarse biennial 

 weed. 



L. sativa, Linn. Garden lettuce. Cultivated for the tender root-leaves 

 as a salad: flowers yellow on tall small-leaved stems. 



5. SONCHUS. Sow Thistle. Milk Thistle. 



Coarse, succulent weeds, smooth and glaucous or spiny, with leafy stem, 

 resembling wild lettuce, but achenes truncate, not beaked, and the flowers 

 always yellow: involucre bell-shape in several unequal series; rays truncate, 

 5-toothed. All from Europe. 



S. oleraceus, Linn. Annual, from fibrous roots, 1-5 ft., with pale yellow 

 flowers in heads %-l in. in diameter: leaves various, mostly on lower part 

 of stem, petiolate or clasping by an auricled base, the lobes acute; in shape 

 lanceolate to lyrate-pinnatifid, margins spinulous. 



S. arvensis, Linn. Perennial with creeping rootstocks: flowers bright 



