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Osmorhiza occidentalis

Higher Taxonomy
Family: Apiaceae (Umbelliferae)View DescriptionDichotomous Key

Habit: Annual to perennial herb [shrub, tree], generally from taproot. Stem: generally +- scapose, generally ribbed, hollow. Leaf: basal and generally cauline, generally alternate; stipules generally 0; petiole base generally sheathing stem; blade generally much dissected, occasionally compound. Inflorescence: umbel or head, simple or compound, generally peduncled; bracts present in involucres or 0; bractlets generally present in "involucels". Flower: many, small, generally bisexual (or some staminate), generally radial (or outer bilateral); calyx 0 or lobes 5, small; petals 5, free, generally ovate or spoon-shaped, generally incurved at tips, generally +- ephemeral; stamens 5; pistil 1, ovary inferior, 2-chambered, generally with a +- conic, persistent projection or platform at tip subtending 2 free styles. Fruit: 2 dry, 1-seeded halves (= mericarps), separating from each other but generally +- persistent to central axis; ribs on halves 5, 2 marginal, 3 to back; oil tubes 1--several per interval between ribs.
Genera In Family: 300 genera, 3000 species: +- worldwide, especially temperate; many cultivated for food or spice (e.g., Carum, caraway; Daucus; Petroselinum); Bupleurum lancifolium Hornem. is historical garden weed; some toxic (e.g., Conium). Note: Mature fruit generally critical in identification, shape given in outline. Hydrocotyle moved to Araliaceae. Petroselinum crispum (Mill.) A.W. Hill is a waif.
eFlora Treatment Author: Lincoln Constance & Margriet Wetherwax, except as noted
Scientific Editor: Douglas H. Goldman, Bruce G. Baldwin.
Genus: OsmorhizaView DescriptionDichotomous Key

Habit: Perennial herb, +- glabrous to hairy; roots thick, clustered, licorice-scented. Stem: branched, leafy. Leaf: blade oblong to triangular-ovate, 2-pinnate or ternate-pinnate or 2--3-ternate, leaflets lanceolate to round. Inflorescence: umbels compound; bracts 0; bractlets 0--several, conspicuous; rays, pedicels few, spreading-ascending to spreading. Flower: calyx lobes 0; petals obovate, white, purple, or +- green-yellow (+- green-white), tips narrowed; disk occasionally present. Fruit: linear to oblong, cylindric to club-shaped, +- compressed side-to-side, bristly to glabrous; base obtuse or long-tapered into tail, tip tapered into beak or obtuse; ribs thread-like; oil tubes obscure; fruit axis divided in distal 1/2. Seed: face concave or grooved.
Species In Genus: +- 10 species: America, eastern and southern Asia. Etymology: (Greek: sweet root)

Osmorhiza occidentalis (Nutt.) Torr.
Habit: Plant 4--12 dm, glabrous to sparsely fine-hairy. Leaf: petiole 5--25 cm; blade 1--2 dm, oblong to ovate, 2-pinnate, leaflets 2--10 cm, lance-oblong to ovate, serrate and generally irregularly cut or lobed. Inflorescence: peduncle 6--20 cm; bractlets generally 0; rays 5--12, generally 3--8 cm, ascending to spreading-ascending; pedicels 3--8 mm. Flower: corolla yellow; styles 0.8--1.4 mm; disk conspicuous. Fruit: 12--22 mm, linear-fusiform, not long-tapered at base; tail 0; tip narrowed proximal to beak; ribs (and intervals) glabrous. Chromosomes: 2n=22.
Ecology: Conifer forest, oak woodland; Elevation: 200--3200 m. Bioregional Distribution: KR, NCoR, CaRH, n&c SNH, MP, n SNE; Distribution Outside California: to western Canada, Colorado. Flowering Time: May--Jul
eFlora Treatment Author: Lincoln Constance & Margriet Wetherwax
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botanical illustration including Osmorhiza occidentalis


Citation for this treatment: Lincoln Constance & Margriet Wetherwax 2016. Osmorhiza occidentalis, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on February 13, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora,, accessed on February 13, 2016.

Osmorhiza occidentalis
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© 2015 Barry Breckling
Osmorhiza occidentalis
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© 2003 Steve Matson
Osmorhiza occidentalis
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© 2008 Keir Morse
Osmorhiza occidentalis
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© 2006 Steve Matson
Osmorhiza occidentalis
click for enlargement
© 2006 Steve Matson
Osmorhiza occidentalis
click for enlargement
© 2003 Steve Matson

More photos of Osmorhiza occidentalis in CalPhotos

Geographic subdivisions for Osmorhiza occidentalis:
KR, NCoR, CaRH, n&c SNH, MP, n SNE;
Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

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Data provided by the participants of the Consortium of California Herbaria.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.