618 CICHORIACEAE 
11. LACTUCA, L. 
Leafy herbs, with diffuse clusters of yellow, blue or white flowers, and 
alternate narrow leaves, which are lobed or not, the margins spiny, wavy 
or toothed. Heads several or many flowered, the involucre cylindric, of 
overlapping scales in 2 or more series. Receptacle flat, naked. Fruit 
flattened, oval to linear, with 1 to 5 ribs on each face, contracted into a 
column from the somewhat expanded summit of which spring the nearly 
simple soft hairs of the white or brown pappus. 
Flowers Yellow 
Margins of leaves spiny. 
1b 
obed eee a RE oe out AMC M cm goo. SRI AE 
Not Yobed’ . <2 hs She. red | on Wate) cahensall “Pao. Je iye Wet Mist UC See act oR ra 
Margins not spiny. 
Whole plant hairy. 
Rays’ reddish yellow) < “.) is 2.0 o. «© ©! te we), ba, sey eicameaee 
Rays blue . « o 8 «© se dogeiloreess 
Plant Tote hairy or only the stem below hairy. 
Lower leaves not lobed or only pees. so . .« . “L. sagstiifolha 
Lower leaves conspicuously lobed . . 2 Nr 3 6S canadensts 
Flowers Blue 
Leaves egg-shaped to broad sonee: Sueboe 
Not deeply lobed . acer Aste hee Sol Ste! (a. ew meee 
Deeply lobed. 
Margins with low teeth . Ssh NE. Alay We wax bee eet elo eer On etna 
Margins with high pointed ‘teeth eo  ¢ «Se ep we, nga = oeRG aaron 
1. L. Scariola, L. (Fig. 5, pl. 162.) Prickty Lerruce. Biennial. 
Stem stiff, 2 to 7 ft. high, smooth above and smooth or hairy below. 
Leaves oblong or lance-shaped, the lower deeply lobed, the margins spiny, 
the base with an angular auricle each side of stem; upper leaves entire, 
clasping the stem. Heads numerous, 6- to 12-flowered. Waste grounds, 
New York, Penna. Aug.-Sept. 
2. L. virosa, L. (Fig. 4, pl. 162.) Srrone-scentep Lettuce. (L. 
scariola, var. integrata, Gren. and Gedr.) Plant erect, 2 to 7 ft. high, 
smooth. Leaves long pear-shaped, 2 to 10 in. long, 4 to 3 in. broad, clasp- 
ing the stem, margins finely and irregularly toothed, the longer teeth 
somewhat prickly. Under surface of mid-vein prickly, the prickles turning 
backward. Heads of flowers pale yellow, several on a single slender stem, 
the whole forming a loose pyramidal cluster. Fruit black, ribbed. Juice 
foetid, said to be an acrid narcotic. Waste places, our area and westward. 
3. L. canadensis, L. (Fig. 1, pl. 165.) Witp Lerruce. Stem 3 to 
10 ft. high, leafy, branching above into the diffuse flower cluster. Whole 
plant smooth. Leaves, the lower on leaf stems, 6 to 12 in. long, deeply 
lobed, margins wavy or with low teeth, covered with a whitish bloom. 
Heads about 20-flowered. Damp soil, in most of our area. June-Nov. 
4. L. hirsuta, Muhl. (Fig. 2, pl. 164.) Harry Woop Lerruce. 
Plant hairy, 2 to 3 ft. high. Leaves lobed. Heads numerous. Flowers 
yellow-purple to whitish. Dry soil, most of our area. July-Sept. 
5. L. Morssii, Robinson. Morsr’s Witp Lerruce. Similar to No. 
3; involucre shorter and rays blue, Along salt meadows, Maine and 
eastern Mass, to New York, 
