Pachycormus discolor is a large shrub or small tree that grows to 30 feet in height with an equal spread (1,2,3). It has grey or cream-colored bark that peels as the plant grows, revealing green photosynthetic tissue below (1,2,3,4,5). The plant’s trunk stores water and may become enlarged and swollen, reaching over 30 inches in diameter (1,2). The plant exudes a milky resinous sap when cut or damaged (1,6). Its pubescent leaves, measuring up to 2 inches in length, are alternate and pinnately-compound and emerge in response to winter rains (1,2,4,5). The oval leaflets have smooth-toothed margins, with the terminal leaflet often being trifoliate (1). Its flowers, which appear from May to September, are small, measuring about ¼ inch in diameter, and may be cream to pink in color (1,2,4). Fruit are small and bladder like (1).

Pachycormus discolor is endemic to Baja California, where it commonly grows in rocky soils and lava fields (2). There are several subspecies, generally identified by differences in flower color (2). Like other plants native to the Baja California peninsula, it is most active in the winter (5). The genus name Pachycormus is a compound of two Greek words, pachys, which means “thick,” and cormus, which means “trunk” or “log” (2,3,4). The specific epithet means “lacking color” and refers to the pale bark. Pachycormus discolor is the only plant in its genus.

Pachycormus discolor is an interesting choice for southwestern landscapes. It is a showy species with its swollen trunk and irregular branching form. It is heat tolerant and grows best in full sun, but will drop its leaves if drought-like conditions occur (3,4). It is also frost sensitive, being hardy down to about 25 °F (3). In areas that receive frost in the winter, this plant is best grown in a protected environment or in a container that can be moved indoors. It makes a good bonsai species (6).