(Jepson) W. A. Weber

Phytologia 85: 19. 1999

Etymology: Possibly Greek agnostos, unknown, and rhiza, root, alluding to the initially unknown roots in protologue of basionym of type species, Greene stated, “Root unknown.”
Basionyms: Balsamorhiza sect. Agnorhiza Jepson
Treatment appears in FNA Volume 21. Treatment on page 104. Mentioned on page 65, 66, 100.
Perennials, 5–60(–100) cm (taproots relatively massive; caudices sometimes branched). Stems erect and branched (mostly distally), or decumbent (and seldom branched distally). Leaves basal and cauline (basal usually scalelike on flowering stems, well-formed on non-flowering shoots); alternate; petiolate; blades (3-or 5-nerved or pinnately nerved), cordate-ovate, deltate, deltate-triangular, ovate, ovate-lanceolate, or suborbiculate, bases broadly cuneate, subcordate, or truncate, margins entire or dentate to crenate, faces glabrous or hairy (often gland-dotted). Heads radiate or discoid, borne singly (terminal) or in ± racemiform arrays. Involucres campanulate to ± hemispheric, 12–40 mm diam. Phyllaries persistent, (8–)12–26+ in 2–3+ series (subequal to unequal, outer usually surpassing inner). Receptacles flat to convex, paleate (paleae persistent, conduplicate, chartaceous). Ray florets 0 or (1–)5–21+, pistillate, fertile; corollas yellow. Disc florets 50–150+, bisexual, fertile; corollas yellow, tubes shorter than cylindric throats, lobes 5, lance-deltate (style branches stigmatic in 2, barely distinct lines, appendages filiform). Cypselae ± prismatic, 3–4-angled (faces glabrous or strigillose); pappi usually persistent, coroniform (± lacerate, sometimes with 1–4 teeth or scales), sometimes 0. x = 19.


Calif., nw Mexico.


Species 5 (5 in the flora).


1 Plants (5–)15–30(–45+) cm; stems decumbent, seldom distally branched; cauline leaves: blades ovate, suborbiculate, elliptic, rounded-deltate, or oblong; involucres ± campanulate, 12–25(–30+) mm diam > 2
1 Plants (20–)40–100 cm; stems erect, usually distally branched; cauline leaves: blades deltate, ovate, or ovate-lanceolate; involucres ± hemispheric, (15–)20–40 mm diam > 3
2 Leaves glabrous (shining, finely gland-dotted, glutinous); heads held among or beyond leaves; ray florets (7–)8–12, laminae (12–)20–30(–35) mm; cypselae 7–9 mm; pappi 0 or coroniform, 0.1–0.3 mm Agnorhiza bolanderi
2 Leaves silky-villous to strigillose, glabrescent; heads in axils of (and overtopped by) leaves; ray florets 5–8(–9), laminae 8–18 mm; cypselae 9–10 mm; pappi coroniform, 1–1.5+ mm Agnorhiza ovata
3 Ray florets 0 or 2–3 Agnorhiza invenusta
3 Ray florets 10–23 > 4
4 Leaf blades: faces tomentulose to pilosulous (and gland-dotted); cypselae 8–12 mm; pappi (0.5–)1–2(–3) mm Agnorhiza elata
4 Leaf blades: faces sparsely hispid or scabrous (and finely gland-dotted, green, shin-ing, often vernicose); cypselae ca. 6 mm; pappi 0.1–1 mm Agnorhiza reticulata