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.

CRATAEGUS

HAWTHORN

Thomas J. Rosatti

Shrub or tree, generally thorny
Leaves stipuled, petioled, deciduous, toothed to lobed
Inflorescence: racemes at branch tips
Flower: hypanthium cup- to urn-shaped, bractlets 0; sepals becoming reflexed; petals generally white; stamens 5–25; ovary inferior, styles 1–5, free
Fruit: pome, drupe-like, purple-black and glabrous in CA; stones 1–5, generally 1-seeded
Species in genus: ± 300 species: n temp
Etymology: (Greek: flower thorn, used by Theophrastus?; or strength, from strong wood or thorns)
Reference: [Brunsfeld & Johnson 1990 Madroño 37:274–282]
C. erythropoda may occur in e D; C. monogyna Jacq. escaped from or persistent beyond cultivated, perhaps naturalized. Many hybrids and morphologically identifiable clones.

Native

C. douglasii Lindl.

Stem: older thorns 13–18 mm
Leaf 2–9 cm; blade base wedge-shaped, entire, margin above base toothed, generally lobed, tips truncate
Flower 14–16 mm wide when dry; sepals entire to ± gland-toothed; stamens (5–)10; ovary often ± hairy, styles generally 5
Fruit generally many per inflorescence, 9–10 mm wide when fresh; stone ± 5 mm, outer face rounded, plump, sides shallowly pitted
Chromosomes: 2n=34
Ecology: Streamsides, forest, meadows, grassland, sagebrush scrub
Elevation: 700–1700 m.
Bioregional distribution: Modoc Plateau
Distribution outside California: to Alaska, east-central N.America
Some plants may = C. columbiana Howell (hairier, styles generally 2–4, older thorns 2–7 cm, sepals strongly gland-toothed)
Horticultural information: SUN: 4, 5, 6, 15, 16, 17 &IRR: 1, 2, 7, 10, 14, 18.