Perideridia bolanderi
Perideridia erythrorhiza
Bolander's Yampah, olasi
red-root Yampah, western Yampah
basal 2–4 pinnate;
petiole 2–15 cm;
blade deltate, ovate, or ovate-lanceolate, 10–20 cm, most primary leaflets dissected, ultimate divisions monomorphic or dimorphic (terminal more elongate than laterals), oblong to filiform, 5–60 mm (terminal sometimes to 80 mm), margins usually toothed or lobed;
cauline leaves usually 1-ternate or 1-ternate-pinnate.
basal 1–2-pinnate, primary leaflets 7–15;
petiole 4–13 cm;
blade ovate or ovate-lanceolate, 10–20 cm, most primary leaflets dissected or only proximal deeply lobed or dissected, ultimate divisions monomorphic, filiform, 30–120 × 0.5–1 mm, margins entire;
cauline leaves 1-ternate or 1-pinnate.
2–20 cm.
4–12 cm.
involucral bracts 8–12, linear to narrowly lanceolate;
rays 9–23, 1–2 cm, subequal, ascending or spreading-ascending;
involucel bractlets 4–10, obovate or lanceolate to linear-lanceolate, 3–9 mm, widely scarious-margined or entirely scarious, apex acuminate;
umbellets convex, 18–30-flowered.
involucral bracts 0 or 1, bristle-shaped;
rays 6–11, 1–5 cm, unequal, spreading-ascending;
involucel bractlets 4–6, linear-lanceolate, 2–3 mm;
umbellets convex, 22–33-flowered.
2–5 mm.
3.5–6 mm.
petals 1-veined;
styles 2 mm, spreading and usually recurved.
petals mostly 1.8 mm, 3–5-veined;
styles 2 mm, spreading and usually recurved.
oblong;
mericarps 4–6 mm;
ribs threadlike;
oil ducts 2–3 in intervals, 4 on commissure.
ellipsoid;
mericarps 4–7 × 3.5 mm;
ribs threadlike;
oil ducts 2–3 in intervals, 4 on commissure.
= 38.
Perideridia bolanderi
Perideridia erythrorhiza
Subspecies 2 (2 in the flora).
Perideridia bolanderi is distinguishable from all other species in the genus by the following combination of characters: ultimate divisions of the basal leaves dimorphic, or if homomorphic, less than 1 mm wide; bracts and bractlets broad, conspicuously scarious, and cuspidate or acuminate, or if only broadly scarious-margined and acuminate, the bracts persistent at maturity; and mericarps oblong with 2–3 oil ducts in the intervals. Although the two subspecies share this combination of characters, phylogenetic analysis of DNA sequence data shows that they do not form a monophyletic group, though this separation is only weakly supported (S. R. Downie et al. 2004).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Perideridia erythrorhiza is unique in its combination of usually numerous fusiform roots, narrow and multiveined petals, and ellipsoid mericarps with numerous oil ducts. It is restricted to three areas in southwestern Oregon (Douglas County, Jackson and Klamath counties, and Josephine County) (V. D. Hipkins and B. L. Wilson 2001; https://explorer.natureserve.org). On the basis of morphological, phenological, physiological, and genetic studies, R. J. Meinke (unpubl.) suggested that plants in each area may represent different species. However, limited sampling of DNA sequence data does not support the recognition of different species (S. R. Downie et al. 2004).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Plants not glaucous; ultimate divisions of basal leaf blades 1–4 mm wide, dimorphic (terminal more elongate than laterals); involucral bracts and involucel bractlets entirely scarious, deciduous. | subsp. bolanderi |
1. Plants glaucous; ultimate divisions of basal leaf blades 0.3–0.7 mm wide, monomorphic; involucral bracts and involucel bractlets widely scarious-margined, persistent. | subsp. involucrata |
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
