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.

PURSHIA

ANTELOPE BUSH

Thomas J. Rosatti

Shrub or small tree
Leaves ± clustered on short lateral branches, mostly deciduous, generally deeply lobed, ± strongly rolled under, generally with ± sunken glands above; bases persistent, overlapping, sheathing stem
Inflorescence: flowers solitary on side-branch tips
Flower: hypanthium ± funnel-shaped, sometimes partly glandular, bractlets 0; stamens ± 25; pistils 1–5(12), simple, styles persistent, ± hairy
Fruit: achene, ± fusiform to oblong
Species in genus: ± 5 species: w North America
Etymology: (Frederick T. Pursh, North America flora author, 1774–1820)
Reference: [Koehler & Smith 1981 Madroño 28:13–25; Henrickson 1986 Phytologia 60:468]

Native

P. mexicana (D. Don) Welsh var. stansburyana (Torr.) Welsh

Shrub 3–30 dm
Leaf: lobes (3)5–9, from just below middle, entire to again lobed
Flower: hypanthium ± 5 mm; sepals 4–6 mm, ± ovate; petals 6–8 mm, widely ovate, white to cream; pistils 4–5(12)
Fruit glabrous to becoming so; styles 2–6 cm, plumose
Chromosomes: n=9
Ecology: Dry Joshua-tree or pinyon/juniper woodland
Elevation: 1100–2500 m.
Bioregional distribution: White and Inyo Mountains, Desert Mountains
Distribution outside California: to Colorado, New Mexico, n Mexico
Flowering time: May–Jul
Synonyms: Cowania m. D. Don var. stansburyana (Torr.) Jeps
Hybridizes with P. tridentata var. glandulosa.
Horticultural information: DRN, SUN: 1, 2, 3, 7, 9, 10, 11, 14, 18, 19, 20, 21 &DRY: 15, 16, 22, 23.