Taraxacum officinale
Taraxacum californicum
common dandelion, dandelion, pissenlit officinal, red seed dandelion
California dandelion
1–10+, erect or ascending, sometimes ± purplish (usually equaling or surpassing leaves), glabrous or sparsely villous, slightly more so distally.
1–10+, ascending to decumbent (at and after flowering) (occasionally erect), usually purplish, (mostly at or below foliage before fruiting) glabrous, often cobwebby-villous basally.
20+, horizontal to erect;
petioles ± narrowly winged;
blades oblanceolate, oblong, or obovate (often runcinate), (4–)5–45 × (0.7–)1–10 cm, bases attenuate to narrowly cuneate, margins usually shallowly to deeply lobed to lacerate or toothed, lobes retrorse, broadly to narrowly triangular to nearly lanceolate, acute to long-acuminate, terminals ± as large as distal laterals, ultimate margins toothed or entire (secondary lobules irregular, perpendicular to retrorse), teeth minute to pronounced apices acute to acuminate or obtuse, faces glabrous or sparsely villous (commonly on midveins).
10–20, horizontal to patent;
petioles usually broadly, sometimes narrowly winged;
blades oblanceolate to narrowly oblong, sometimes linear-oblanceolate, 5–12 × 1–2(–3) cm, bases cuneate, margins toothed or denticulate, occasionally with basal lobes, rarely some entire, lobes straight or slightly retrorse, lanceolate to triangular-long-acuminate, teeth narrowly to broadly triangular, straight to retrorse, apices obtuse to rounded or ± acute, faces glabrate or glabrous.
green to dark green or brownish green, tips dark gray or purplish, campanulate, 14–25 mm.
green, tips purplish gray, broadly campanulate, 11–16 mm.
40–100+;
corollas yellow (orange-yellow), 15–22 × 1.7–2 mm (outer).
corollas pale yellow, outer abaxially striped pale purplish, 9–10 × 1.5–2.
13–18 in 2 series, lanceolate, 2–2.8 mm wide, margins scarious (proximal 2/3) to narrowly scarious, apices acuminate, erose-scarious, usually hornless (seldom appendaged), callous.
12–16 in 2 series, lanceolate to lanceolate-linear, 2–3.5 mm wide, margins not or narrowly scarious, sometimes broadly so basally, hyaline, apices rounded, erose, scarious.
of 12–18, reflexed, sometimes ± glaucous, lanceolate bractlets in 2 series, 6–12 × 2.8–3.5 mm, margins very narrowly white-scarious, sometimes villous-ciliate distally, apices acuminate, hornless.
9–12, appressed, green, sometimes ± hyaline, often purplish, ovate-lanceolate to broadly ovate bractlets in 2 series, 5–7 × 1.7–4.3 mm, margins hyaline, purplish (at least distally) or white, scarious, apices acuminate to long-acuminate or widely caudate, tips ± rounded, erose, hornless.
olivaceous or olive-brown, or straw-colored to grayish, bodies oblanceoloid, (2–)2.5–2.8(–4) mm, cones shortly terete, 0.5–0.9 mm, beaks slender, 7–9 mm, ribs 4–12, sharp, faces proximally smooth to ± tuberculate, muricate in distal 1/3;
pappi white to sordid, 5–6(–8) mm.
pale brown, bodies obovoid, flattened, 2.2–2.7 mm, cones narrowly conic, 0.5–0.7 mm, beaks slender, 6–9.5, ribs 15–16, narrow, faces muricate distal 2/3–3/4;
pappi creamy, 4.5–5.5 mm.
= 24, 40, [16, 32].
= 16.
Taraxacum officinale
Taraxacum californicum
Taraxacum officinale is the most widespread dandelion in temperate North America, though its abundance decreases in the arid south. It is a familiar weed of lawns and roadsides. It is also the species most commonly used for medicinal and culinary purposes (e.g., E. Small and P. M. Catling 1999).
Phenotypic and genotypic variation of this species have been studied in North America (L. M. King 1993; King and B. A. Schaal 1990; J. C. Lyman and N. C. Ellstrand 1998; O. T. Solbrig 1971; R. J. Taylor 1987), but results of those studies did not lead to the recognition of microspecies.
Specimens of Taraxacum officinale with deeply lobed leaves are sometimes difficult to distinguish from those of T. erythrospermum when fruits are missing (see also R. J. Taylor 1987). Usually, however, early leaves of the former are much less deeply lobed than those of the latter, which are more consistently lacerate throughout development, though broadly winged initially. The two taxa are easily distinguished in fruit, the red cypselae of T. erythrospermum standing out from the dull olive ones of T. officinale.
In northeastern North America, Taraxacum officinale and T. lapponicum often are confused, which has led to reports of the common dandelion farther north than I have been able to verify (it has yet to be collected from the Nunavik region of Quebec, for instance). The characters in the key above help separate the two taxa.
The typification by A. J. Richards (1985) would leave the common dandelion of both Europe and North America without a valid name (J. Kirschner and J. Štepánek 1987). For the time being, with the nomenclatural situation still not resolved, I am following traditional usage of the name Taraxacum officinale.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Taraxacum californicum is known only from the San Bernardino Range. It is easily distinguished from T. ceratophorum by the lack of horns on the phyllaries and bractlets of calyculi.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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