Balsamorhiza sericea
Gerald D. Carr

Flora of Oregon

Stems 6–38 cm, sericeous; from single taproot.

Leaves ovate-lanceolate, 1-pinnately divided almost or entirely to midribs, often more deeply divided proximally than distally, margins entire or few-toothed, occasionally some lower leaves serrate on lower margins, surfaces sericeous, more densely so abaxially than adaxially; basal leaves in 1–few rosettes, blades 3–18 × 1–7 cm, pinnae 6–16 mm wide, petioles 3–17 cm; cauline leaves in 1 pair, opposite, reduced, blades 2.5–4 × 1–1.6 cm, petioles 2.5–4 cm.

Inflorescences with 1 terminal head.

Involucres 12–15 × 15–22 mm.

Phyllaries ovate, 10–17 × 5–9 mm, tips acuminate, sericeous.

Paleae 13–14 mm.

Ray florets 13–14, yellow; rays 12–20 × 5–8 mm.

Disc florets ~9 mm.

Fruits 6–7 × 1.5 mm, glabrous.

Serpentine. Flowering Apr–May. 400–600 m. Sisk. CA. Native.

Balsamorhiza sericea is endemic to serpentine-influenced soils and is thus far known only from Josephine County, Oregon, and adjacent Siskiyou and Trinity counties, California. The specific epithet “sericea” refers to the pubescence.

Flora of North America

as described under Balsamorhiza sericea

Plants 10-30(-40) cm. Basal leaves: blades silvery, lanceolate or lance-ovate, 9-30 × 2-7 cm (1-pinnatifid, lobes oblong to oblanceolate, 5-35 × 3-17 mm), bases cuneate, ultimate margins usually entire (plane or weakly revolute, obscurely, if at all, ciliate), apices rounded to acute, faces densely sericeous. Heads borne singly. Involucres campanulate to hemispheric, 11-20+ mm diam. Outer phyllaries broadly ovate to triangular-ovate, 12-20 mm, slightly surpassing inner, apices acuminate to attenuate (margins not ciliate). Ray laminae 15-20 mm (adaxially puberulous on veins).Flowering Apr-May. Serpentine outcrops, among surface rocks, in crevices, hillsides, dry streamsides among cobbles; 400-1800 m; Calif., Oreg.Balsamorhiza sericea hybridizes with B. deltoidea.

Photo images

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Herbarium specimens

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