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.

POTENTILLA

CINQUEFOIL

Barbara Ertter

Annual to shrub; odor resinous or 0
Leaves generally basal, odd-1-pinnate to 1-palmate or 1-ternate; leaflets ± toothed or lobed, terminal generally ± = lateral
Inflorescence: cyme, generally ± open; pedicels generally ± straight
Flower: hypanthium ± shallow; bractlets 5; sepals generally 5, ± triangular; petals generally 5, generally = or > sepals, generally ± widely obcordate, generally yellow; stamens generally 20; pistils generally many, styles generally jointed near tip
Fruit: achene
Species in genus: 200–500 species: n temp
Etymology: (Latin: diminutive of powerful, for reputed medicinal value)
Reference: [Clausen, Keck, & Hiesey 1940 Carn Inst Wash Pub 520:26–195]
P. anglica Laicharding is a waif from cultivated: stem trailing; pedicels 2–8 cm, slender; sepals and petals generally 4; leaflets 3–5.

Introduced

P. recta L.

Plant generally ± tufted from taproot or branched caudex, sparsely glandular
Stem ± ascending, 20–60 cm, spreading-hairy; base with short and long hairs
Leaves palmate; basal generally fallen or withered in flower; cauline 8–15 cm, leaflets generally 6–7, central leaflet 30–80 mm, oblanceolate, toothed ± 1/2 to midvein, sparsely hairy
Inflorescence many-flowered
Flower: hypanthium 3–6 mm wide; petals 6–9 mm; stamens ± 25, filaments 1–2 mm, anthers ± 1 mm; styles ± 1 mm, stubby
Fruit 1–1.5 mm, prominently veined, brown
Chromosomes: 2n=28,42
Ecology: Generally disturbed areas
Elevation: 150–1500 m.
Bioregional distribution: High Cascade Range, Sacramento Valley, San Francisco Bay Area
Distribution outside California: N.America; native to Eurasia
Probably closer to Eurasian P. norvegica than to P. gracilis , with which it is most often confused.