Ceanothus cordulatus aka Mountain Whitethorn

Ceanothus cordulatus has the common name snow bush. It belongs to the Rhamnaceae family. Its native range runs from Oregon to northern Baja California, Mexico. It grows in a temperate climate. It is not native to Britain or Ireland. This shrub lives for years and keeps its leaves. Its spiny stems and spreading form are key traits. The sources give more detail on its form than its care.

The shrub has a spread of 3–6 feet [0.9–1.8 metres]. Its branches form a complex pattern. Thin branchlets spread apart at the ends of branches. The twigs are stiff and end in sharp points. These spiny tips contrast with the smooth bark. Older bark is whitish. The small branches are yellow-green. The pale bark helps give the shrub its look. The branching pattern helps define its look as well. The sources give no separate size for its full-grown height.

The leaves grow one at a time along the stems. They alternate rather than grow in pairs. Each leaf is simple, with no separate leaflets. The leaf blades range from egg-shaped to oval. They measure about 0.08 feet [0.025 metres] long. Three main veins mark each blade. Each leaf has a round base and an edge with no teeth. Tips may be pointed or blunt. The tops range from light green to gray-green. The leaf undersides are a paler gray-green. They may have no hairs or a light coat. The hairs show most along the veins when present. The leaves stay on the shrub rather than fall each year.

Small white flowers bloom in spring and early summer. They have a scent and grow in dense groups. These groups look like panicles, or branched flower clusters. Each cluster measures about 0.08–0.17 feet [0.025–0.05 metres] across. The fruit is a small capsule with three lobes. It measures about 0.014 feet [0.004 metres] across. Its skin feels rough. Young fruit is somewhat sticky. These fruit traits help tell this species from others.

The sources do not state soil, light, or watering needs. They give no hardiness rating or guide to garden placement. No account of this species here sets out landscape uses. None sets out its pests or diseases. Nor do they name edible parts or uses as medicine. The sources do not address toxicity to people or pets. These gaps do not prove that the plant is safe.