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.

IVESIA

Barbara Ertter

Perennial, glandular; odor resinous
Leaves generally basal, odd-1-pinnate, generally ± cylindric; cauline reduced; leaflets generally overlapped, generally divided ± to base
Inflorescence: cyme
Flower: hypanthium shallow or deep; bractlets (0)5, generally < sepals; sepals generally 5; petals generally 5, acute to rounded; stamens generally < or = 20; pistils 1–many, ovaries superior, style jointed below fruit tip, base ± rough-thickened
Fruit: achene
Species in genus: 30 species: w North America
Etymology: (E. Ives, Yale Univ. pharmacologist, 1779–1861)
Reference: [Ertter 1989 Syst Bot 14:231–244]
Lf and leaflet data are for basal leaves.

Native

I. paniculata T. Nelson & J. Nelson

ASH CREEK IVESIA

Plant matted, grayish green; caudex much-branched
Stem prostrate in fruit, generally 5–15 cm
Leaf generally 2–5 cm; sheathing bases densely strigose; leaflets generally 8–15 per side, lobes generally > 5, < 2 mm, obovate; cauline leaf 1
Inflorescence ± open; clusters 1–many, 10–20 mm wide, ± loose, ± 10–20-flowered; pedicels 2–6 mm, ± S-shaped in fruit
Flower ± 5 mm wide; hypanthium length ± 1/2 width; petals ± 1 mm, linear, white to pale yellowish, < sepals; stamens 5; pistils 1–3
Fruit 1–1.5 mm, smooth, brown
Ecology: Shallow, rocky soil, open sagebrush
Elevation: 1500–1700 m.
Bioregional distribution: Modoc Plateau (Ash Valley, north-central Lassen Co.).Related to I. rhypara Ertter & Reveal of OR, NV (leaflet lobes 2–4, generally > 2 mm)
Horticultural information: In cultivation.