About the Plant

Texas rue grows on limestone soils. In our area this native perennial is found in washes, usually in light shade. Only a foot tall with small pink flowers and leaves that appear to be evergreen, it can go unnoticed. Never showy, it would make a carefree addition to a garden.

In Texas this plant has yellow flowers and is known as rue of the mountains or Dutchman's breeches (from the shape of the fruit). There it is listed as a host plant for the eastern black swallowtail butterfly.

Note: The scientific name of this plant is often misspelled on the web and in literature as Thamnosma texana.

More Information:

Weekly Plant on Texas rue

Information from Jim Conrad's Naturalist Newsletter (Texas)

Map of distribution in US

Technical botanical description from SEINet

ID Characteristics

This plant is in the Rutaceae - the rue family.

Texas rue is a small woody plant with a vase-like form. It is only about a foot high.

Texas rue has alternate linear leaves about half an inch long. If you hold a leaf to the light, you'll see tiny yellow scent glands. Rub the leaf and break the glands open to release a citrus smell. There are even some glands at the edge of the leaf that look like tiny indentations.

In Arizona, the flowers of Texas rue are pink and white; eastward, in the Chihuahuan Desert region, the flowers are yellow. The flowers are one-fourth inch long, shaped like a bell, with 4 petals.

The fruit has two lobes, reminiscent of the shape of Dutchman's breeches and giving rise to a common name for this plant. Click on the photo to enlarge and look for the tiny dots on the fruit. This may remind you of the freckling you see on the skin of citrus fruit. Texas rue is in the rue family (Rutaceae), the family of citrus, the herb rue, and Sichuan peppers.