redseeded dandelion (Taraxacum laevigatum)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COMMON NAMES:
rock dandelion
redseeded dandelion
red-seeded dandelion

 

SCIENTIFIC NAMES:
Leontodon erythrospermum (Andrz. ex Besser) Britton
Taraxacum disseminatum G.E. Haglund
Taraxacum erythrospermum Andrz. ex Besser
Taraxacum lacistophyllum (Dahlst.) Raunk.
Taraxacum scanicum Dahlst.

 

CONFIRMATION STATUS: Pending confirmation.

 

TAXONOMY: The currently accepted scientific name for redseeded
dandelion is Taraxacum laevigatum (Willd.) DC. There are two gener-

ally accepted species of the Taraxacum genus - Taraxacum laevigatum
(common danelion) and Taraxacum officinale (redseeded dandelion)
- although even this distinction is not universally accepted. The United
States Depeartment of Agriculture's Natural Resources Conservation
Service PLANTS Database lists each species separately; however, the
1993 Jepson Manual Treament from the Jepson Herbarium, University
of California, Berkeley and the International Plants Names Index list
Taraxacum laevigatum as a synonym for Taraxacum officinale. For the
Nature Guide, Taraxacum laevigatum and Taraxacum officinale are
treated as two separate species.

 

There are two generally accepted means of differentiating common dan-
delion from redseeded dandelion - 1) the common dandelion seed head
is larger, is much denser (more achenes) and the seeds are yellowish
brown rather than brownish red, and 2) the leaves of redseeded dandelion
are very slender, deeply pinnatifid, the backward-turning lobes very
narrow and acute. Both of these characteristics work best with older
plants.

 

The name Taraxacum laevigatum has been used for Leontodon erythro-

spermum in North America, following H. Handel-Mazzetti (1907). L. H.

Shinners (1949) questioned that usage. The name is listed in the index of

Flora Europaea (A. J. Richards and P. D. Sell 1973) as an unassigned syn-

onym; however, the PLANTS Database lists Taraxacum erythrospermum

as a synonym for Taraxacum laevigatum.

 

NATIVE STATUS: Introduced, United States and Canada.

 

GENERAL BOTANICAL CHARACTERISTICS: Reseeded dande-

lion is often difficult to differentiate from the very ubiquitous Taraxacum

officinale, or common danelion. Particularly when redseeded dandelion is

young, there is little overt evidence for distinguishing the two species.

Early leaves of redseeded dandelion sometimes may be broadly winged

along the midvein, making distinction from common dandelion difficult;

usually, its later leaves become more deeply lobed with time. Much of the

following general botanical characteristics for redseeded dandelion is con-

sistent in many ways with that of common dandelion.

 

Habit: Redseeded dandelion is a naturalized, perennial forb with mostly

erect stems, 2 inches to 12 inches tall (containing a milky juice) with

strong tap-roots that seldom branch. The stems pinkish to reddish in color,

(more or less consistent with the color of the foliage), hairless to having

fine, long, unmatted hairs, usually more densely hairy farther from the

stem.

 

Leaves: There may be twenty or more horizontal to erect leaves with

slightly winged petioles. The leaf blades are obovate to oblanceolate,

harply incised or pinnatifid with the segments facing backwards. The

base of the leaf gradually narrows to a tip. The leaf margins irregular-

ly cut or cleft, with lobes bent backward or downward, reflexed. The

lobes are triangular to nearly lanceolate, tapering to a sharp-pointed

apex with more or less straight sides along the tip or tapering gradual-

ly to a pointed apex with more or less concave sides along the tip. Few

if any teeth, irregular in spacing, straight to bent backward or down-

ward. Leaf usually tapering to a sharp-pointed apex with more or less

straight sides, sometimes concave, along the tip. Leaf faces generally

hairless but may have sparsely fine, long, unmatted hairs (mainly near

the midveins).

 

Flowers: The inflorescence is a single head on a long, hollow stalk from

the base of the plant. Flower-heads about an inch broad, sulfur yellow,

the outer row of rays purple on the under side. There may be 70 to 75 or

more florets per flower. Flower bracts of the involucre hairless, the outer

ones lance-shaped, spreading or ascending, the inner row linear and usual-

ly with a small horny appendage just below the tips.

 

Fruit/Seeds: Achenes bright brownish red, the upper part bearing many

very small spines, the beak less than twice the length of the achene. The

fruit is a reddish, dry seed on a grayish white, very fine, fluffy pappus.

 

Roots: The root system consists of a stout taproot.

 

REGENERATION PROCESS: Redseeded dandelion propogates
itself by reseeding.

 

HABITAT TYPES: Like its more numerous relative, common dan-
delion, almost any disturbed area is potentially a habitat for redseed-

ed dandelion. Pastures, yards, walkways, construction sites, playing

and sports fields, open meadows, abandoned home sites - any area

which has mostly full sun and has been disturbed.

 

SITE CHARACTERISTICS: Site characteristics for redseeded

dan-delion are similar to those of common dandelion - redseeded

dandelion generally prefers full sun, mesic conditions, and a soil

that consists of loam or clay-loam.

 

SEASONAL DEVELOPMENT: Blooming time is generally April

to November, although members of the Taraxacum genus, given the

right conditions, can be found blooming nearly year round.

 

GENERAL DISTRIBUTION: Redseeded dandelion is found through-

out most of continental North America - with the exceptions of Mississ-

ippi, Louisiana, and Nevada in the United States, and Newfoundland and

the northern territories of Canada. It is often confused with its even more

widely distributed relative - the common dandelion.

 

SKY MEADOWS DISTRIBUTION: To be determined.

 

IMPORTANCE AND USES: See discussion of Taraxacum or common
dandelion (Taraxacum officinale).

 

 

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