Oemleria cerasiformis aka Osoberry

Oemleria cerasiformis is a deciduous shrub in the rose family. Common names include Indian plum, oso berry, and Oregon plum. Its native range runs from southwestern British Columbia to California. It grows west of the Cascade and Sierra Nevada ranges. Wild plants occur in woods, stream banks, and rocky canyons. They also grow on slopes, coastal scrub, and roadsides. These sites range from moist to fairly dry.

The plant forms an upright shrub or small tree. Root suckers can turn a single plant into a thicket. North American sources give heights of 8–20 feet [2.4–6.1 metres]. Spread can reach 15 feet [4.57 metres]. RHS gives a smaller height and spread of 5–8 feet [1.5–2.5 metres]. Its loose branches carry smooth, reddish-brown to dark gray bark. Young green stems turn reddish brown and bear orange lenticels. The simple leaves grow in an alternate pattern. They are pale green, oblong, and lighter beneath. Leaf edges are smooth or wavy. New leaves appear early in spring, and fall foliage adds interest.

Greenish-white flowers hang in clusters near the branch tips. Their scent recalls almonds. Missouri Botanical Garden gives a February to April bloom period. Virginia Tech reports April to May. Male and female flowers grow on separate plants. Female plants need a nearby male to bear fruit. The small drupes resemble plums and grow on red stalks. Young fruit is yellow, orange, or orange-red. It darkens to purple or blue-black as it ripens. Birds eat the fruit and spread the seeds.

Grow this shrub in sun or partial shade. It prefers fertile, humus-rich soil that drains well. Keep the soil moist, but avoid wet ground. Plants can also cope with somewhat dry soil. Missouri Botanical Garden lists USDA zones 6–10; RHS rates it H7. Use it as a specimen, large hedge, or woodland planting. Allow room for suckers, or remove extras to limit spread. Sources report few serious pests or diseases. Shallow, chalky soil can cause chlorosis.

The fruit has little flesh and can taste bitter. Fully ripe fruit loses much of that bitterness. PFAF lists fruit as edible raw, cooked, or dried. It also urges caution about eating large amounts. Its cyanide warning rests on family traits, not confirmed species-specific findings. The evidence does not establish a firm toxicity classification.