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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California

  • Up-to-date information about California vascular plants is available from the Jepson eFlora.



Annual to tree
Leaves simple to pinnately to palmately compound, generally alternate; stipules free to fused, persistent to deciduous
Inflorescence: cyme, raceme, panicle, or flowers solitary
Flower generally bisexual, radial; hypanthium free or fused to ovary, saucer- to funnel-shaped, often with bractlets alternate with sepals; sepals generally 5; petals generally 5, free; stamens (0)5–many, pistils (0)1–many, simple or compound; ovary superior to inferior, styles 1–5
Fruit: achene, follicle, drupe, pome, or blackberry- to raspberry-like
Seeds generally 1–5
Genera in family: 110 genera, ± 3000 species: worldwide, especially temp. Many cultivated for ornamental and fruit, especially Cotoneaster , Fragaria , Malus , Prunus , Pyracantha, Rosa , and Rubus
Reference: [Robertson 1974 J Arnold Arbor 55:303–332,344–401,611–662]
Family description, key to genera by Barbara Ertter and Dieter H. Wilken.


Barbara Ertter

Perennial, generally ± glandular, generally resinous-smelling; caudex generally branched
Stem generally ascending to erect
Leaves generally basal, odd-1-pinnate, generally ± flat; cauline alternate, reduced upward; uppermost lateral leaflets generally ± fused with terminal
Inflorescence: cyme, open or of dense clusters; pedicels generally straight
Flower: hypanthium a ± flat-bottomed cup, width ± 2 X length; bractlets 5, generally 2/3 sepals; sepals 5, often reflexed; petals 5, generally ± = sepals, blunt, white; stamens 10, filaments flat, often forming a tube; pistils 2–many, ovaries superior, styles jointed below fruit tip, ± thicker at base
Fruit: achene
Species in genus: 19 species: w North America
Etymology: (J. Horkel, German plant physiologist, 1769–1846)
Data apply to basal leaves, pressed hypanthia.


H. tridentata Torr.

Plant rosetted or tufted, ± gray, ± odorless; caudex 0–few-branched
Stem decumbent to erect, < 45 cm, generally ± glabrous
Leaf 3–12 cm; leaflets 2–5 per side, separated, 5–30 mm, generally elliptic to oblong, ± 3-toothed < 1/4 to base (rarely entire), at least lower surface ± densely hairy
Inflorescence: clusters 1–many, ± head-like, generally 3–40-flowered; pedicels generally 1–6 mm
Flower: hypanthium width 2–5 mm, 1–2 X length; bractlets < 0.5 mm wide, linear; sepals generally 1.5–3 mm; petals 1.5–4 mm, linear to widely oblanceolate; filaments 1–2 mm, bases generally ± 0.2–0.5 mm wide, anthers 0.2–0.5 mm; pistils 5–15, styles 1–2.5 mm
Fruit 1.5–2.5 mm
Ecology: Dry, open coniferous forest
Elevation: 300–2500 m.
Bioregional distribution: Klamath Ranges, North Coast Ranges, Cascade Range, Sierra Nevada, Modoc Plateau
Distribution outside California: s Oregon
Sspp. intergrade extensively
Horticultural information: DRN, IRR, SUN: 1, 2, 3, 7, 14, 15, 16, 17, 18; DFCLT.


subsp. flavescens (Rydb.) D.D. Keck

Stem decumbent
Inflorescence: cluster generally 1
Flower 6–10 mm wide; hypanthium width 2.5–5 mm, inner wall hairy (except in NCoRH); petals often < sepals, ± widely oblanceolate; filaments 1–2 mm
Fruit 2–2.5 mm
Ecology: Often on ± serpentine
Elevation: 750–2000 m.
Bioregional distribution: Klamath Ranges, North Coast Ranges, n High Sierra Nevada (especially Plumas Co.).

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