CICHORIACEAE 1317 
7. Lactuca pulchélla (Pursh) DC. Perennial, glabrous, more or less glaucous. 
Stems erect, 3-7 dm. tall, corymbosely paniculate above : leaves 5-20 cm. long, numer- 
ous ; blades linear to lanceolate, entire, toothed or pinnatifid, acute or obtuse, those of basal 
and lower stem-leaves sometimes with winged petioles, those of upper stem-leaves sessile 
and partly clasping : peduncles often copiously scaly : involucres 16-20 mm. long; inner 
bracts linear-lanceolate, acute or obtusish : ligules blue or violet: achenes black, the body 
rather elliptic, ribbed, 4 mm. long; beak shorter than the body. 
In moist places, Ontario to the Northwest Territory and British Columbia, south to the Indian Ter- 
ritory, New Mexico and California. Spring to fall. 
8. Lactuca villósa Jacq. Annual or biennial, rather slender. Stems erect, 1-2 m. 
tall, panieulately branched above, glabrous : leaf-blades elliptic, oval or oblong-lanceolate, 
8-20 em. long, acuminate, irregularly dentate, narrowed into winged petioles or nearly 
sessile : peduncles commonly with few scales: involucres 10-13 mm. high; bracts linear- 
lanceolate to lanceolate, often purple: ligules blue: achenes elliptic, 4 mm. long, with 
thick margins and 3 ribs on each face, beakless, not narrowed into a slender neck. 
On banks or in thickets, New York to Illinois, south to Florida and Kentucky. Summer and fall. 
9. Lactuca Floridàna (L.) Gaertn. Annual or biennial, stout or stoutish. Stems 
1-3 m. tall, paniculately branched above, often mottled : leaf-blades thin, commonly ample, 
36-45 cm. long, lyrate-pinnatifid ; segments irregularly toothed, the terminal one usually 
triangular: involucres 10-12 mm. high; bracts linear-lanceolate to linear, deep green or 
purplish : ligules blue: achenes curved, 6-7 mm. long, each narrowed into a neck. 
On hillsides and open grounds, New York to Nebraska, Florida and Louisiana. Summer and fall. 
10. Lactuca spicata (Lam.) A. S. Hitchcock. Biennial, glabrous. Stems erect, 1- 
3.5 m. tall, paniculately branched above: leaf-blades 1-4.5 dm. long, merely toothed or 
sinuately or uncinately pinnatifid ; segments coarsely and irregularly dentate : peduncles 
often sparingly scaly: involucres 9-11 mm. high; bracts lanceolate to linear-lanceolate, 
pale or scarious-margined : ligules white, bluish or yellowish : achenes 5 mm. long, each 
with a wing-like margin and thinly ribbed faces, narrowed into a very short neck. [L. 
leucophaea A. Gray. ] 
In dry or moist soil, Newfoundland to Manitoba, North Carolina, Tennessee and Iowa. Summer 
and fall.—The variety with merely toothed leaf-blades, is L. spicata integrifolia (A. Gray) Britton. 
7. SONCHUS L. 
Annual or perennial caulescent weedy herbs, with succulent tissues. Leaves alternate ; 
blades entire, toothed or pinnatifid, often clasping, the edges and midnerve beneath often 
prickly. Heads yellow, peduncled, disposed in corymbose panicles. Involucres various, 
glabrous or pubescent: bracts herbaceous or membranous, in several rows of gradually 
differing lengths. Receptacle flat, naked. Ligules yellow, often numerous, truncate and 
toothed at the apex. Anthers sagittate at the base. Stigmas slender. Achenes more or 
less flattened, linear to oval, truncate, beakless, 10-20-ribbed, the ribs often undulate or 
toothed. Pappus conspicuous, of numerous white hair-like bristles, deciduous. Sow 
THISTLE. 
Stem-leaves with rounded auricles: achenes ribbed, or the base smooth. 1. S. asper. 
Stem-leaves with acute auricles: achenes striate and transverse-wrinkled. 2. S. oleraceus. 
1l. Sonchus ásper (L.) All. Annual, nearly glabrous. Stem erect, 2-15 dm. tall, 
simple or somewhat branched: leaf-blades tender, spatulate to oblong, 5-25 cm. long, 
with copiously spine-tipped teeth, the upper ones clasping by rounded bases: peduncles 
often glabrous : involucres about 1 em. high ; bracts linear to linear-lanceolate : heads pale 
Im 2.5 cm. broad or smaller: achenes about 2 mm. long, margined, 3-ribbed on each 
side. 
In waste places, throughout most parts of North America and,the civilized world. Naturalized 
from Europe. Spring to fall. 
2. Sonchus oleraceus L. Annual, nearly glabrous. Stems erect, 1-18 dm. tall, 
more or less widely branched : leaf-blades various, those of basal or lower stem-leave, 
lyrately-pinnatifid, with a triangular terminal segment; those of upper leaves shorters 
runcinately or lyrately-pinnatifid, the teeth tipped with soft spine-like teeth, the basal lobes 
acute : peduncles often glandular-hirsute : involucres about 1 cm. high; bracts lanceolate- 
subulate to lanceolate: heads pale yellow, 3 mm. broad or smaller: achenes 2.5-3 mm. 
long, striate, finely transverse-wrinkled. 
In waste places and fields, throughout North America, except the extreme north, and the civilized 
world. Naturalized from Europe. Spring to fall. 
