Chilopsis linearis desert willow

The only member of the showy bignonia family native to California and the Southwest, this small deciduous tree bears flowers that do indeed resemble those of the jacaranda and catalpa – attractive 1½-inch trumpets ranging from white to lavender-pink, their throats streaked with purple and gold. The fuzzy calyx is two-lipped (Chilopsis means “like lips”). Slender pod-like capsules up to a foot long remain on the crown after the narrow willow-like leaves (whence the species name linearis) have fallen, the two-lipped calyx often persisting at the capsules’ base, shriveling and dropping at the lightest touch. Each capsule is divided by a septum, its twin chambers filled with elongated seeds edged at both ends by delicate fringes, much as in catalpa.

Two stunted street trees remain of several west of the entrance to 1047 Campus Drive (formerly ΣΑΕ house). Two fuller-canopied trees with substantial trunks – 16 and 9 inches across – stand east of the north tip of Pampas Lane, along the edge of the service yard. With the construction of the new building at 560 Fremont Road in 2024 came a group of ‘Bubba’, with wide dark green leaves and deep violet blossoms, scattered on both sides of the road to the left of the building.

×Chitalpa tashkentensis ‘Pink Dawn’, a pink-flowered cross of desert willow and catalpa created in the USSR in the 1960s, is widely grown in horticulture. The catalpa pollen donor has recently been shown to be a hybrid itself, Catalpa ovata × C. speciosa, not C. bignoniodes as reported when the name C. tashkentensis was first published in 1991.

The only specimens known at Stanford are a pair at 813 Cedro Way, at the corner, in front of a pineapple guava hedge. They bloom for months through the summer. In Palo Alto, more can be seen in planting beds at 201, 206, and 480 California Avenue, and as curbside trees at 2147 and 2149 Yale Street. ‘Morning Cloud’, a white-flowered hybrid of desert willow with C. speciosa, is not yet known locally.

×Chitalpa tashkentensis ‘Pink Dawn’. Sairus Patel, 19 Jun 2024

Chilopsis linearis. From An Illustrated Manual of Pacific Coast Trees, Howard E. McMinn & Evelyn Maino

Illustrations: Chilopsis linearis: silhouette from Trees of Stanford & Environs | flower.

Name derivation: see text above.