Frangula californica aka California Buckthorn

Frangula californica is a shrub that stays green year-round. It belongs to the buckthorn family, Rhamnaceae. Common names include coffeeberry and California buckthorn. Its older name is Rhamnus californica. Its native range spans the western United States to northern Mexico. It grows in chaparral, woodland, and forest. Oregon State notes plants along the coast. These grow from southwestern Oregon south into California.

Some plants grow low and spread; others stand upright. They often form round clumps with several stems. The usual height is 4–8 feet [1.2–2.4 metres]. Some reach small-tree size, near 20 feet [6 metres]. The bark starts smooth and reddish gray. It has many small pores called lenticels. As bark ages, it turns paler and forms shallow cracks. Young twigs have some fuzz, which they lose with age. Brown buds lack the scales that many woody plants have.

Each leaf has one blade, a form called simple. Leaves grow in an alternate pattern along the stems. They are oval to oblong, with dark green upper sides. Their undersides look paler and may have fine hairs. Raised veins stand out on the underside of each leaf. These form a pinnate pattern, branching from the main vein. Leaf edges may be smooth or have fine teeth. Some edges roll under toward the leaf's lower side. Leaves at dry sites tend to be smaller and thicker. They range from about one-and-a-half to three inches long. They stay on the plant through the year.

Small greenish flowers grow in groups where leaves meet stems. They bloom in late spring, each with five yellow-green petals. Round fruits called drupes look like berries. They follow the flowers and ripen in fall. The fruit turns from green to red, then purple-black. Each fruit holds two seeds that look like coffee beans. This does not mean the seeds are safe to eat. The supplied sources give no clear guidance on food use. They also give no clear guidance on toxicity.

In gardens, coffeeberry grows in sun or shade and varied soils. It needs little added water, and may need none. Oregon State lists it as hardy to USDA Zone 7. Gardeners can prune and shape it to fit a space. Its range of forms suits both spreading and upright plantings. The leaves give cover throughout the year. The supplied species accounts name no specific pests or diseases. They give no firm growth rate or mature width.