Ceanothus spinosus aka Greenbark Ceanothus

Ceanothus spinosus is a shrub in the buckthorn family, Rhamnaceae. Common names include greenbark ceanothus and red heart ceanothus. Its native range runs from southern California into northern Baja California, Mexico. Kew puts it in a subtropical climate region. It is not native to Britain or Ireland. It is evergreen: it keeps its leaves rather than shedding them each year. Green bark, pale blooms, and shoots with thorn tips mark its looks.

It grows as an upright shrub or a small tree. Its branches form a loose shape, not a dense one. Virginia Tech notes a height of 20 feet (6.1 metres). This is a height it can reach, not a stated garden range. The source gives no width to go with that height. Young bark is bright green, which fits the name greenbark. As bark ages, it turns gray and grows rough. Young green stems thus contrast with the older gray bark.

Leaves grow one at a time along stems, not in pairs. This leaf pattern is called alternate. Each leaf is simple, with just one oval blade. The thick blades are one to three inches long. Their tops are glossy green, with no hairs. The lower sides are paler than the tops. Most leaves have smooth edges with no teeth. Shoots that grow strongly may have leaves with teeth instead. Leaf edges can thus vary within this species. The thin twigs are smooth, stiff, and angled. They range in shade from bright green to tan-green. Their tips often end in thorns, but some do not.

Small blooms open from February through May. They range from white to pale lilac in colour. Long groups of blooms grow at the shoot tips. They also grow in leaf axils, where leaves meet stems. Each bloom has both male and female parts. Virginia Tech also calls the blooms botanically complete. These pale groups of blooms contrast with the glossy green leaves.

The fruit is a small, sticky capsule. Its shape ranges from round to a rough triangle. Each lobe has a raised ridge. The capsules reach about three-sixteenths of an inch across. The supplied records for this species do not state its garden hardiness. Nor do they state how much water it needs. They give no guidance on edible uses for this species. They also give no guidance on whether it is toxic.