T. officinàle, Weber. (Common Dandelion.) Smooth, or at first pubescent; outer involucre reflexed. (T. Dens-leonis, Desf.)—Pastures and fields everywhere. Indigenous forms occur northward and in the Rocky Mountains. April–Sept.—After blossoming, the inner involucre closes, and the slender beak elongates and raises up the pappus while the fruit is forming; the whole involucre is then reflexed, exposing to the wind the naked fruits, with the pappus displayed in an open globular head. (Eu.)
95. PYRRHOPÁPPUS, DC. False Dandelion.
Heads, etc., nearly as in Taraxacum, but the soft pappus reddish or rusty-color, and surrounded at base by a soft-villous ring.—Mostly annual or biennial herbs, scapose or often branching and leafy below. Heads solitary, terminating the naked summit of the stem or branches. Flowers deep yellow. (Name composed of πυῤῥός, flame-colored, and παππός, pappus.)
1. P. Caroliniànus, DC. Annual or biennial, stem branching (1–2° high); leaves oblong or lanceolate, entire, cut, or pinnatifid, the stem-leaves partly clasping.—Sandy fields, from Maryland southward. April–July.
2. P. scapòsus, DC. Low, scapose, perennial by roundish tubers; leaves all radical, pinnatifid.—Prairies; Kan. to Tex.
96. CHONDRÍLLA, Tourn.
Heads few-flowered. Involucre cylindrical, of several narrow linear equal scales, and a row of small bractlets at base. Achenes terete, several-ribbed, smooth below, roughened at the summit by little scaly projections, from among which springs an abrupt slender beak; pappus of copious very fine and soft capillary bristles, bright white.—Herbs of the Old World, with wand-like branching stems, and small heads of yellow flowers. (A name of Dioscorides for some plant which exudes a gum.)
C. júncea, L. Biennial, bristly-hairy below, smooth above (1–3° high); root-leaves runcinate; stem-leaves few and small, linear; heads scattered on nearly leafless branches, 6–8´´ long.—Fields and roadsides, abundant in Md. and northern Va. Aug. (Adv. from Eu.)
97. LACTÙCA, Tourn. Lettuce.
Heads several–many-flowered. Involucre cylindrical or in fruit conical; scales imbricated in 2 or more sets of unequal lengths. Achenes flat (obcompressed, parallel to the scales), abruptly contracted into a beak, which is dilated at the apex, bearing a copious and fugacious very soft and white capillary pappus, its bristles falling separately.—Leafy-stemmed herbs, with panicled heads; flowers of variable color, produced in summer and autumn. (The ancient name of the Lettuce, L. sativa; from lac, milk, in allusion to the milky juice.)