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.

ROSA

Barbara Ertter

Shrub to vine, often thicket-forming, generally prickly
Leaves generally odd-pinnately compound; stipules generally attached to petiole, generally gland-margined
Inflorescence: generally ± cyme or flowers solitary
Flower: hypanthium urn-shaped; bractlets 0; sepals 5, often with long expanded tip; petals generally 5 (except cultivars), generally pink in CA (white to red or yellow); stamens generally > 20; pistils generally many, ovaries superior, jointed to generally hairy styles
Fruit: bony achenes enclosed in fleshy, generally reddish hypanthium (hip)
Species in genus: 100+ species: generally n temp
Etymology: (Latin: ancient name)
Spp. hybridize freely; other non-natives established locally.

Native

R. spithamea S. Watson

GROUND ROSE

Dwarf shrub, generally < 5 dm, rhizomed
Stem gray-brown; prickles few–many, both slender and thick-based, ± straight
Leaf: leaflets 2–4 per side, (sub) glabrous; terminal leaflet ± 10–30 mm, ± widely elliptic (obovate), tip ± obtuse to ± truncate, margins ± double-toothed, glandular
Inflorescence 1–10-flowered; pedicels generally 5–15 mm, generally ± glandular
Flower: hypanthium generally 4–5 mm wide at flower, glandular, neck ± 3–4 mm wide; sepals generally glandular, entire, tip generally ± = body, entire; petals ± 10–15 mm; pistils ± 10–20
Fruit ± 7–10 mm wide
Ecology: Open forest, chaparral, especially after fire
Elevation: generally 150–1550 m.
Bioregional distribution: Northwestern California, Central Western California
Distribution outside California: Oregon
Synonyms: var. sonomensis (Greene) Jeps
s CW plants possibly varietally distinct
Horticultural information: DRN, IRR: 7, 14 &SUN: 4, 5, 6, 15, 16, 17; also STBL; GRCVR.