Crepis acuminata

Nuttall
Trans. Amer. Philos. Soc., n. s. 7: 437. 1841.
Common names: Longleaf or tapertip hawksbeard
IllustratedEndemic
Synonyms: Crepis acuminata subsp. pluriflora Babcock & Stebbins Crepis angustata Rydberg Crepis seselifolia
Treatment appears in FNA Volume 19. Treatment on page 225. Mentioned on page 224, 227, 229, 234.

Perennials, 20–65 cm (taproots deep, woody, caudices swollen, branched, often covered by old leaf bases). Stems 1–5, erect, stout, branched near or beyond middles, tomentulose (at least proximally). Leaves basal and cauline; petiolate; blades elliptic to lanceolate, 8–40 × 0.5–6(–11) cm, margins deeply pinnately lobed, lobes 5–10 pairs, usually lobed (± halfway to midveins, lobes entire), apices long-acuminate, faces ± tomentulose. Heads 30–70(–100+), in compound, corymbiform arrays. Calyculi of 5–7, triangular, tomentulose bractlets 1–2 mm. Involucres cylindro-campanulate, 8–16 × 2–3 mm. Phyllaries 5–8, (medially green) lanceolate, 8–12 mm, (margins yellowish, often scarious), apices acute (ciliate), abaxial faces usually glabrous, sometimes sparsely tomentulose, adaxial glabrous. Florets 5–10(–15); corollas yellow, 10–18 mm. Cypselae pale yellowish brown, subcylindric, 6–9 mm, apices ± narrowed (not beaked), ribs 12; pappi white, 6–9 mm. 2n = 22, 33, 44, 55, 88.


Phenology: Flowering May–Aug.
Habitat: Dry rocky hillsides, ridges, grassy flats, open pine woods
Elevation: 1000–3300 m

Distribution

V19-275-distribution-map.gif

Ariz., Calif., Colo., Idaho, Iowa, Mont., Nebr., Nev., N.Mex., Oreg., Utah, Wash., Wyo.

Discussion

Crepis acuminata is identified by the narrow, pinnately lobed leaves cleft about half way to the midrib and with long-acuminate apices, heads with relatively few florets, relatively small involucres, and glabrous phyllaries. The fertile diploid form of this species is most widespread (E. B. Babcock 1947). In addition, there are apomictic, polyploid populations. The latter often are more variable in leaf size, shape, and indument, and can be difficult to distinguish from C. pleurocarpa and C. intermedia.

Selected References

None.

Lower Taxa

None.

... more about "Crepis acuminata"
David J. Bogler +
Nuttall +
Longleaf or tapertip hawksbeard +
Ariz. +, Calif. +, Colo. +, Idaho +, Iowa +, Mont. +, Nebr. +, Nev. +, N.Mex. +, Oreg. +, Utah +, Wash. +  and Wyo. +
1000–3300 m +
Dry rocky hillsides, ridges, grassy flats, open pine woods +
Flowering May–Aug. +
Trans. Amer. Philos. Soc., n. s. +
Illustrated +  and Endemic +
Crepis acuminata subsp. pluriflora +, Crepis angustata +  and Crepis seselifolia +
Crepis acuminata +
species +