Perideridia bolanderi
Perideridia montana
Bolander's Yampah, olasi
common Yampah, common yampeh, mountain 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-pinnate, primary leaflets 7–11;
petiole (3–)8–15(–18) cm;
blade oblong-lanceolate, (6–)20–35 cm, primary leaflets undivided, proximal sometimes deeply lobed, ultimate divisions monomorphic, linear or lanceolate, rarely ovate, 30–150 × 2–10 mm, margins entire, rarely toothed;
cauline leaves 1–2-pinnate or 1–2-ternate.
2–20 cm.
3–20 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 1–2, bristle-shaped, rarely 6–8, linear-lanceolate;
rays (3–)11–16(–20), 1.5–7 cm, unequal, spreading-ascending;
involucel bractlets 8–12, linear-lanceolate, 1–4 mm;
umbellets flat-topped or convex, 11–33-flowered.
2–5 mm.
4–8 mm.
petals 1-veined;
styles 2 mm, spreading and usually recurved.
petals 1–1.2 mm, 5–7-veined;
styles 2 mm, spreading and usually recurved.
oblong;
mericarps 4–6 mm;
ribs threadlike;
oil ducts 2–3 in intervals, 4 on commissure.
globose or subglobose;
mericarps 3–3.5 mm;
ribs threadlike;
oil ducts 1 in intervals, 2 on commissure.
= 40, 80, 120.
Perideridia bolanderi
Perideridia montana
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 montana has dorsiventral leaf anatomy. It is the most widely distributed of all species in the genus, extending from coastal northern California and the Warner Mountains northward to Oregon, Washington, and British Columbia, and eastward across the Great Basin to the Rocky Mountains, from Saskatchewan to South Dakota and Colorado. Plants are usually distinguishable from other Perideridia species by their 1-pinnate leaves with 7–11 leaflets and globose or subglobose mericarps with solitary oil ducts in the intervals.
Although T. I. Chuang and L. Constance (1969) treated Perideridia montana as P. gairdneri subsp. borealis, D. E. Giannasi and Chuang (1976) suggested that it should be treated as a distinct species based on differences between it and P. gairdneri in flavonoid chemistry, morphology, leaf anatomy, and haploid chromosome number. This suggestion is also supported by the phylogenetic analysis of morphological data (S. R. Downie et al. 2004), but this result has not yet been tested with molecular data.
Carum montanum Blankenship (1905) is an illegitimate name that pertains here, not C. montanum (Cosson & Durieu ex Battandier) Bentham & Hooker f. ex Arcangeli (1882).
(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 |
- Local floras:
BC, 
OR, 
WA - Local Web sites:
CalFlora, CalPhotos, 
Flora NW, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
