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.

ACAENA

Barbara Ertter

Perennial, nonglandular
Leaves generally ± basal, odd-1-pinnate; leaflets ± evenly toothed to lobed
Inflorescence: dense spike or head
Flower: hypanthium ± conic; bractlets 0; sepals generally 4; petals 0; stamens 2 or 4, opposite sepals; pistils 1(2), ovaries superior, continuous to style at top, stigma many-branched, exserted from hypanthium
Fruit: hypanthium ± hardened, encasing elliptic achenes; prickles generally 4–many, barbed
Species in genus: 50–150 species: especially s hemisphere
Etymology: (Greek: thorn, from fruit)
Reference: [Yeo 1973 Bot Soc British Isles Conf Rep 13:193–221]

Native

A. pinnatifida Ruiz & Pav. var. californica (Bitter) Jeps.

Stem: flower-stem 10–60 cm
Leaf 3–12 cm; stipules 0; leaflets 5–8 per side, 4–15 mm, ± oblanceolate-ovate, lobed nearly to midvein into 3–8 linear-lanceolate segments
Inflorescence: spike 10–20 mm diam, ± oblong
Flower: sepals 2.5–3.5 mm, elliptic-lanceolate; stamens generally 4, purple-black
Fruit: hypanthium body 4–7 mm, obovate, ± ridged; prickles > 4, scattered, generally 1–3 mm
Ecology: Coastal grassland, open, rocky slopes
Elevation: 50–400 m.
Bioregional distribution: s North Coast, Central Coast, w San Francisco Bay Area
Synonyms: A. c. Bitter
South America plants (var. p.) variable
Horticultural information: DRN: 4, 5, 15, 16, 17 &IRR: 14, 19, 20, 21, 22, 23, 24.