Sphaeromeria

Nuttall

Trans. Amer. Philos. Soc., n. s. 7: 401. 1841

Common names: False sagebrush chickensage
Etymology: Greek sphaira, sphere, and meros, a part, alluding to the capitate arrays of heads in S. capitata
Treatment appears in FNA Volume 19. Treatment on page 499. Mentioned on page 52, 68, 486, 531.
Perennials or subshrubs, (1–)5–60(–70) cm (usually aromatic). Stems 1–5+ (with interxylary cork), lax to erect, branched from bases or throughout, glabrous or sericeous to tomentose (hairs medifixed), usually gland-dotted as well. Leaves mostly basal (sometimes in rosettes) or basal and cauline; alternate; petiolate or sessile; blades obovate to cuneate or linear, usually 1–2-pinnately or -palmately lobed (ultimate lobes oblanceolate to linear) or apically 3-toothed or -lobed, ultimate margins entire, faces glabrous or ± sericeous to tomentose and usually gland-dotted. Heads disciform, borne singly or (2–60+) in usually corymbiform, rarely paniculiform, arrays or in subcapitate clusters. Involucres hemispheric to campanulate, 3–5(–12) mm diam. Phyllaries persistent, (8–)12–20+ in 2–3+ series, mostly obovate, unequal to subequal, margins and apices (colorless, pinkish, or brownish) scarious. Receptacles conic to nearly flat (villous in S. potentilloides), epaleate. Ray florets 0 (peripheral pistillate florets 4–15+; corollas ± filiform, lobes usually 3). Disc florets 30–50+, bisexual, fertile; corollas usually bright yellow (ochroleucous in S. cana), tubes ± cylindric, throats ± campanulate, lobes 5, ± deltate (tips glabrous or hairy). Cypselae columnar or obovoid to obconic, ribs 2–3 or 5–10, faces glabrous or gland-dotted (pericarps with myxogenic cells only in S. potentilloides, without resin sacs); pappi usually 0 (of 3–5 subulate scales in S. compacta). x = 9.

Distribution

w United States, nw Mexico.

Discussion

Species 9 (8 in the flora).

Key

1 Receptacles villous; cypselae becoming mucilaginous when wet Sphaeromeria potentilloides
1 Receptacles glabrous; cypselae not mucilaginous when wet > 2
2 Subshrubs, 20–70 cm; leaves mostly cauline (not forming basal clusters) > 3
2 Perennials, 1–20 cm (often cespitose); leaves mostly basal (commonly forming clusters) > 5
3 Corollas ochroleucous, lobes villous Sphaeromeria cana
3 Corollas yellow, lobes glabrous or gland-dotted > 4
4 Leaves glabrous; heads 5–20 in corymbiform or subumbelliform arrays (as wide as or wider than long) Sphaeromeria diversifolia
4 Leaves tomentose; heads (8–)10–30(–60) in paniculiform arrays (longer than wide) Sphaeromeria ruthiae
5 Heads 1–7 (S. argentea) or 8–20 > 6
5 Heads 1–3(–5) > 7
6 Leaf blades (± cuneate, 7–15 mm) entire or apices 3(–5)-toothed or -lobed, faces silvery-canescent; heads usually in subcapitate to corymbiform arrays (1–1.5 cm across), sometimes borne singly Sphaeromeria argentea
6 Leaf blades (± cuneate, 8–20 mm) usually 1–2-pinnati-palmately lobed (ultimate lobes ± linear), faces ± tomentose; heads in tight, capitate arrays (1–1.3 cm across) Sphaeromeria capitata
7 Leaves: blades (10–25 mm) pinnati-palmately lobed (lobes 3–6+, ± oblanceolate to linear) or linear, faces sericeous (pappi of 3–5, subulate scales) Sphaeromeria compacta
7 Leaves: blades (15–30 × 1.5–8 mm) pinnati-palmately lobed (lobes 2–3, linear, 1–2 mm wide) or linear, faces silvery-canescent Sphaeromeria simplex