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Perideridia gairdneri subsp. gairdneri

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: PerideridiaView DescriptionDichotomous Key

Common Name: YAMPAH
Habit: Perennial herb, glabrous, generally glaucous; roots tuberous, single or clustered, or clustered-fibrous. Stem: erect, branched. Leaf: blade lanceolate to triangular-ovate, generally 1--2-ternate-pinnate or 1--2-pinnately or ternate-pinnately dissected, leaflets or segments generally linear to lance-linear. Inflorescence: umbels compound; bracts 0--many, conspicuous and reflexed or not; bractlets several to many, narrow, +- scarious; rays, pedicels few to many, generally spreading-ascending; 2° umbels generally convex distally. Flower: calyx lobes evident; petals generally obovate, white, tips narrowed. Fruit: linear-oblong, +- compressed side-to-side or not at all, glabrous; ribs +- equal, thread-like to prominent, not winged; oil tubes 1--several per rib-interval; fruit axis divided to base. Seed: face flat to grooved.
Species In Genus: +- 12 species: generally western America. Etymology: (Greek: around the neck, from involucre) Note: Roots, basal leaves needed for identification.
Species: Perideridia gairdneriView Description 

Habit: Plant 3--14 dm; roots 2--3-clustered or 1, 1.5--8 cm, fusiform. Leaf: basal petiole 8--15 cm; basal blade 20--35 cm, oblong to ovate, generally 1-pinnate, leaflets 2--12 cm, linear or lanceolate, basal occasionally lobed or ternately dissected; cauline leaves 1--2-pinnate or 1--2-ternate. Inflorescence: peduncle 3--20 cm; bracts generally 0; bractlets 8--13, 1--4 mm, lance-linear; rays 1.5--7 cm, unequal, spreading-ascending; pedicels 4--8 mm; 2° umbels 15--40-flowered. Flower: styles 1--2 mm. Fruit: 2.5--3.5 mm, +- round; ribs thread-like; oil tube 1 per rib-interval.
Note: Subspecies possibly distinct species.

Perideridia gairdneri (Hook. & Arn.) Mathias subsp. gairdneri
Habit: Plant generally flexible; root 1, tuberous, 10--15 mm wide. Inflorescence: rays generally 7--14. Flower: petals 1-veined. Chromosomes: 2n=38.
Ecology: Coastal flats, grassland, pine forest; Elevation: < 350 m. Bioregional Distribution: s NCo (Sonoma Co.), NCoRO, NCoRI, CCo (scarce s of Monterey Co.), SCo. Flowering Time: Jun--Jul
eFlora Treatment Author: Lincoln Constance & Margriet Wetherwax
Jepson Online Interchange
Listed on CNPS Rare Plant Inventory

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Citation for this treatment: Lincoln Constance & Margriet Wetherwax 2016. Perideridia gairdneri subsp. gairdneri, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on May 02, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora,, accessed on May 02, 2016.

Perideridia gairdneri subsp. gairdneri
click for enlargement
© 2007 Neal Kramer
Perideridia gairdneri subsp. gairdneri
click for enlargement
© 2007 Neal Kramer
Perideridia gairdneri subsp. gairdneri
click for enlargement
© 2007 Neal Kramer
Perideridia gairdneri subsp. gairdneri
click for enlargement
© 2007 Neal Kramer
Perideridia gairdneri subsp. gairdneri
click for enlargement
© 2007 Neal Kramer

More photos of Perideridia gairdneri subsp. gairdneri in CalPhotos

Geographic subdivisions for Perideridia gairdneri subsp. gairdneri:
s NCo (Sonoma Co.), NCoRO, NCoRI, CCo (scarce s of Monterey Co.), SCo.
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.