Taraxacum officinale
Taraxacum latilobum
common dandelion, dandelion, pissenlit officinal, red seed dandelion
large-lobed dandelion, pissenlit à lobes larges
1–10+, erect or ascending, sometimes ± purplish (usually equaling or surpassing leaves), glabrous or sparsely villous, slightly more so distally.
1–7+, erect to ascending, ± purplish, glabrate, sometimes ± sparsely villous distally.
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+, erect to patent;
petioles ± narrowly winged;
blades broadly oblanceolate to narrowly obovate (often runcinate), 15–47.5 × 2.5–9 cm, bases attenuate, margins usually shallowly lobed to sometimes lacerate (mostly proximally), lobes retrorse or straight, broadly deltate to triangular, sometimes antrorsely curved apically, acute to acuminate, teeth 5–7 on lobes and in sinuses, irregular, triangular or sometimes lanceolate, terminals broader than laterals, apices obtuse to bluntly short-caudate or -acuminate (rarely acute), faces glabrous or glabrate to sparsely pilose or villous.
green to dark green or brownish green, tips dark gray or purplish, campanulate, 14–25 mm.
dark green, often purplish-tinged, campanulate, (13–)15–23 mm.
40–100+;
corollas yellow (orange-yellow), 15–22 × 1.7–2 mm (outer).
ca. 150;
corollas yellow (outer dark gray striped abaxially, also purplish), 13–17 × 1–1.3 mm.
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.
14–18 in 2 series, lanceolate to linear (outer) or ovate to lance-ovate (inner), 1.2–4 mm wide, scarious, narrowly (outer, distal part of inner) or widely (proximal part of inner), apices long-acuminate, hornless, scarious, erose, hyaline, purplish-grayish.
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.
of ca. 18, reflexed to recurved, ovate to broadly lanceolate bractlets in 3 series, 8–11 × 2–5 mm, margins narrowly scarious, sometimes proximally more widely so, apices acuminate, hornless, ± scarious-erose, tips often purplish and blackish.
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.
olive-tan to tan, bodies oblanceoloid, 2.8–3.8 mm, cones terete, 0.9–1 mm, beaks slender, 8–12 mm, ribs 5, wide (with 2–3 rows of tubercles or spines), faces proximally tuberculate, muricate in distal 1/3–1/2, distalmost spines sometimes very sharp, fused in pairs and flattened;
pappi white to creamy, 6.5–7 mm.
= 24, 40, [16, 32].
Taraxacum officinale
Taraxacum latilobum
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 latilobum is known only from the Gulf of St. Lawrence and adjacent areas.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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