ROSACEAE

ROSE FAMILY

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.

HORKELIA

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.

Native

H. californica Cham. & Schldl.

Plant clumped, green
Stem 10–120 cm
Leaf 5–40 cm; leaflets 3–9 per side, generally ± separated, 5–60 mm, ± ovate to round, unevenly toothed and lobed (teeth generally > 20), ± hairy
Inflorescence open, of few–many separate flowers and few-flowered clusters; pedicels generally 1–20 mm
Flower: hypanthium width 4–10 mm, 1–2 X length; bractlets ± 4–6 mm, generally ± 2 mm wide, ovate, often toothed; sepals generally 4–6 mm; petals 3–8 mm, generally ± oblanceolate to elliptic; filaments 0.5–3 mm, bases 0.2–1.5 mm wide, anthers 0.8–1.8 mm; pistils generally > 50, styles 2–4 mm
Fruit ± 1 mm
Ecology: Open scrub, n slopes, streambanks
Elevation: < 1600 m.
Bioregional distribution: North Coast, North Coast Ranges, Sierra Nevada Foothills, Central Western California, San Bernardino Mountains.Often confused with Potentilla glandulosa (terminal leaflets distinct). Sspp. intergrade
Reference: [Ertter 1992 Phytologia 71:420–422]

Native

subsp. dissita (Crum) Ertter

Leaf generally 5–25 cm; sheathing bases generally glabrous; leaflets generally 7–9 per side, 5–25 mm, unevenly toothed, lobed 1/2–3/4 to base; terminal leaflet 10–40 mm
Flower: hypanthium inner wall glabrous; bractlets often entire; sepals not red-mottled inside; filaments generally 0.5–1.5 mm, bases generally < 0.5 mm wide; styles generally 2–3 mm
Chromosomes: 2n=28
Ecology: Shady meadow edges, seasonal streams, open chaparral
Elevation: 50–1600 m.
Bioregional distribution: North Coast Ranges, Sierra Nevada Foothills, San Francisco Bay Area, San Bernardino Mountains
Synonyms: H. elata (Greene) Rydb
Horticultural information: IRR: 5, 7, 15, 16, 17 &SHD: 1, 14, 19, 20, 21, 22, 23, 24; GRCVR.