Taraxia subacaulis

(Pursh) Rydberg

Mem. New York Bot. Gard. 1: 281. 1900.

Basionym: Jussiaea subacaulis Pursh Fl. Amer. Sept. 1: 304. 1813
Synonyms: Camissonia subacaulis (Pursh) P. H. Raven Oenothera heterantha Nuttall O. heterantha var. taraxacifolia S. Watson O. subacaulis (Pursh) Garrett O. subacaulis var. taraxacifolia (S. Watson) Jepson Taraxia heterantha (Nuttall) Small T. taraxacifolia (S. Watson) A. Heller
Treatment appears in FNA Volume 10.
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Herbs usually glabrate, rarely sparsely strigillose, especially on leaf blade veins and margins; taproot thick, deep, sometimes branched in age, producing new rosettes. Leaves 2–22 × 0.7–4.2 cm; petiole narrowly winged, 1–12 cm; blade lanceolate to narrowly elliptic, base attenuate, margins usually subentire to sinuate, sometimes deeply and irregularly pinnatifid, apex acuminate. Flowers opening near sunrise; floral tube 1.5–3 mm, with short, matted hairs inside near base; sepals 4–15 mm, mostly glabrous, sometimes very minutely strigillose; petals yellow, 5–16 mm, often apiculate; episepalous staminal filaments 1.8–6.5 mm, epipetalous ones 0.5–2.5 mm, anthers 0.9–2 mm; sterile prolongation of ovary 15–80 mm, style 4–8.5(–11) mm, glabrous or sparsely pubescent near base, stigma usually surrounded by longer anthers at anthesis, rarely exserted beyond anthers. Capsules 4-angled, oblong-ellipsoid, 11–28 × 5–8 mm, walls thick, scarcely distended by seeds, becoming blackened and persistent on plants for 1+ years after shedding seeds; rarely with pedicel to 10 mm. Seeds uniformly tan to light brown, ellipsoid-oblanceoloid, 1.3–1.9 × 0.6–1 mm, coarsely pitted. 2n = 14.


Phenology: Flowering late Mar–Jul.
Habitat: Meadows, seasonally moist open places, from foothills to mountains.
Elevation: 400–2900 m.

Distribution

Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.

Discussion

Taraxia subacaulis occurs well inland from Pacific coastal areas. Its only occurrence in Colorado is in Moffat and Routt counties. P. H. Raven (1969) determined Taraxia subacaulis to be self-compatible and, usually, facultatively autogamous. The species is distinctive, but is sister to T. tanacetifolia in molecular analyses (R. A. Levin et al. 2004; W. L. Wagner et al. 2007).

Selected References

None.

Lower Taxa

None.
... more about "Taraxia subacaulis"
Warren L. Wagner +
(Pursh) Rydberg +
Jussiaea subacaulis +
Calif. +, Colo. +, Idaho +, Mont. +, Nev. +, Oreg. +, Utah +, Wash. +  and Wyo. +
400–2900 m. +
Meadows, seasonally moist open places, from foothills to mountains. +
Flowering late Mar–Jul. +
Mem. New York Bot. Gard. +
Camissonia subacaulis +, Oenothera heterantha +, O. heterantha var. taraxacifolia +, O. subacaulis +, O. subacaulis var. taraxacifolia +, Taraxia heterantha +  and T. taraxacifolia +
Taraxia subacaulis +
species +