Koeberlinia spinosa aka Crown Of Thorns

Koeberlinia spinosa is a thorny shrub or small tree. It belongs to the family Koeberliniaceae. Its native range runs from California to Texas. It also extends into eastern and central Mexico. This plant grows in desert and dry shrubland. Its form can range from a dense shrub to a twisted tree. As a shrub, it reaches about 10 feet [3 metres]. Occasional trees reach 20 feet [6.1 metres]. Those taller plants represent the larger end of its size range.

The plant has many stiff branches and few lasting leaves. Its twigs range from green to gray-green. Most side branches grow at right angles to the main stem. Each ends in a sharp thorn with a dark brown tip. These side branches measure 1–2 inches [2.5–5 centimetres] long. The close branching and thorns give the shrub a dense form. Green twigs remain visible when the plant has no leaves. Young bark also has a greenish cast. With age, it turns dark gray-brown and develops rough scales.

The small leaves appear for short spells after spring rain. They grow in an alternate pattern along the stems. Each leaf measures about a quarter inch [6 millimetres] long. Leaf shapes range from ovate to elliptical. Their edges lack teeth, though some tips have a notch. Their colour ranges from yellow-green to gray-green. The leaves fall rather than staying on the branches year-round. This brief leaf stage contrasts with the lasting thorny framework. For much of the time, the plant is mostly leafless.

Small flowers grow in short, close clusters along the twigs. Each flower has four pale petals with a greenish-white tint. A flower spans about a quarter inch [6 millimetres]. Blooms can appear at any time of year. The heaviest flowering follows rain in fall. Small black berries also form in clusters along the stems. Each glossy berry measures about a quarter inch [6 millimetres]. Fruit can ripen throughout the year, rather than in one short season. The supplied sources describe its dry habitat and seasonal growth. They do not establish garden hardiness, care needs, or pest problems. Nor do they establish whether people can safely eat the berries.