Taraxacum officinale F. H. Wigg., common dandelion. Perennial herb, taprooted with short root crown, rosetted, acaulous, scapose with 1—10+ inflorescences, 5—60 cm tall; shoots with several—20+ basal leaves, rosette 10—80 cm across with horizontal or ascending, leaves thin and easily wilted, latex milky, copious; taproot long, ± thick, sometimes with branched caudices, tan to brown, white–fleshed.
Leaves helically alternate, deeply lobed, petiolate, without stipules; petiole 10—40 mm long, not sharply distinct from blade, white to rose with tawny, soft long hairs at flaring winglike base; blade oblanceolate or oblong to spatulate, 30—450 × 7—100 mm, long–tapered to broadly tapered at base, lobed to irregularly cut, the lobes alternate to subopposite, broadly to narrowly triangular or lanceolate and sometimes backward–pointing (runcinate), the sinuses from midblade nearly to midrib, terminal segment ± deltate to arrow–shaped, toothed and sometimes wavy on margins, acute to acuminate or obtuse at tip, pinnately veined with midrib raised on both surfaces, dull green, initially villous often becoming almost glabrate.
Inflorescence heads solitary, ligulate, hemispheric with sunken center, 20—50 mm across, of 40—100+ flowers, bracteate; peduncle (scape) hollow–cylindric, 50—400+ × 1.5—7 mm, light green to rose and faintly striped, smooth, thin–walled, with scattered hairs along axis and long hairs at base and approaching head, with bracts at top (calyculus), calyculus bracts 13—19 in 2—3 series, reflexed, lanceolate, 5—10 × 1.2—2 mm, with membranous margins; involucre bell–shaped, 14—25 mm wide, phyllaries 13—19 in 2 series, at anthesis erect, linear to narrowly lanceolate, 8—18 × 1.3—2.8 mm, green or brownish and often purplish to gray at tip, glaucous, membranous on 1 or both margins, sometimes with a subterminal projection on midvein on outer surface, papillate or puberulent at tongue–shaped tip; receptacle slightly concave aging convex in fruit, without bractlets (paleae), not pitted, glabrous.
Flower bisexual, bilateral, ± 2 mm across, lightly scented; calyx (pappus) of 80+ capillary bristles in 1 series, at anthesis 3.7—5 mm long increasing in fruit, silky white, on a cylindric beak, the beak at anthesis 0.3—0.8 mm long increasing in fruit; corolla shallowly 5–toothed, 9—17 mm long; tube 1.5—3.5 mm long, pale yellow to white; limb strap–shaped, 7—12.5 × 1.5—2.2 mm, bright yellow but on the outermost flowers throat and lower surface of limb red–brown to olive brown or light red, outer throat and lower surface of limb base ± tomentose; stamens 5, fused to corolla tube at base of throat; filaments 1.5—2 mm long, yellow; anthers fused into cylinder surrounding style, exserted, basifixed, dithecal, 2.7—4 mm long, yellow and faintly red–striped, with linear appendages at base ± 0.3 mm long, longitudinally dehiscent; pollen bright yellow; nectary cupped at base of style, weakly 4–lobed, ca. 0.2 mm long and wide, greenish yellow, producing thin nectar; pistil 1; ovary inferior, inversely conic with truncate base, ± 1.2 mm long, white, with short, light green beak, with bumps and minute scales at top forming a transverse pattern, 1–chambered with 1 ovule; style exserted 2—4 mm beyond anthers, 9—13 mm long, 2–branched, yellowish below fork, with radiating to ascending short hairs, the branches spreading and recurved, 1.5—2 mm long, orangish with faintly reddish spots, glabrous on flat upper side.
Fruits cypselae with long beak and silky pappus, fruit body oblanceoloid and several–angled, 2.8—3 × 0.6—0.8 mm, olive brown, often with 5 deep, narrow longitudinal grooves, with bumps (tubercles), above midpoint having ascending, acute, short scales arranged in 12—16 columns, upper fruit body tapered 0.5—0.9 mm; fruit beak 7—9 mm long, slender but wider where attached to fruit body; pappus in spheric array of 80—110 capillary bristles, 5—7 mm long, grayish white.
A. C. Gibson & B. A. Prigge