1. Taraxacum erythrospermum Andrz. ex Besser (red-seeded dandelion)
T. laevigatum (Willd.) DC.
T. laevigatum f. scapifolium F.C. Gates &
S.F. Prince
Pl. 263 a; Map
1099
Stems 2–25 cm
long. Leaves (3–)6–25 cm long, almost always very deeply lobed (nearly
compound), except on small plants. Involucre 10–20(–25) mm long, the inner
series of bracts mostly 11–18, the outer series usually less than half to about
half as long as the inner series. Fruits with the body 2.5–4.0 mm long, dull
brick red to reddish or purplish brown at maturity. 2n=16, 22, 24, 26,
32. January–December.
Introduced,
scattered nearly throughout the state (native of Europe, introduced nearly
throughout temperate North America). Banks of streams and rivers, openings of
dry upland forests, margins of glades, and disturbed sand prairies; also lawns,
gardens, crop fields, fallow fields, pastures, roadsides, railroads, and open,
disturbed areas.
There is widespread
disagreement on the correct name for this taxon. Many authors have continued to
call these plants T. laevigatum (Barkley, 1986), but Shinners (1949)
suggested that the original description of that name did not describe the plant
that has been naturalized in North America. He suggested instead the epithet T.
erythrospermum, which has also been adopted in most of the recent
literature on dandelions in Europe. However, both of these names are of
uncertain application, as type specimens still have not been designated for
them. The nomenclatural situation merits further research. Gates and Prince
(1938) studied an unusual mutant ascribed to this species from Stone County
that they named f. scapifolium, which was characterized by leafy stems
as well as leaflike bracts subtending the heads. This odd form has not been
seen since their initial discovery, and to avoid confusion it has not been
included in the descriptions of the genus and species above.
This species is
somewhat less commonly encountered in Missouri than is T. officinale.
Steyermark (1963) suggested the existence of hybrids between the two species of
dandelion in Missouri, but this could not be confirmed during the present
study. In the absence of mature fruits, Missouri plants of the two dandelions
are nearly impossible to distinguish. Individuals of T. erythrospermum
tend to be slightly smaller plants than those of T. officinale and are
more likely to have all of the leaves deeply lobed all the way to the rachis.
They also are more likely to occur in sandy soils. However, T. officinale
is so variable in its morphology and habitats that there is almost total
overlap between the species.