Cichorium intybus L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Perennial 3–17 dm from a long taproot; lower lvs oblanceolate, petiolate, toothed or more often pinnatifid, 8–25 × 1–7 cm, becoming reduced, sessile, and entire or merely toothed upwards; heads to 4 cm wide in fl, mainly matutinal, sessile or short-pedunculate, borne 1–3 together in the axils of the much reduced upper lvs, the long branches thus racemiform; invol 9–15 mm, its outer bracts loose, fewer than the inner and at least half as long, becoming callous-thickened at base; achenes 2–3 mm, pappus-scales numerous, minute, narrow; 2n=18. Roadsides, fields, and waste places; native of Europe, now a cosmopolitan weed. June–Oct.