Diodia teres

Rough buttonweed, poor joe, Poor Joe

Family: Rubiaceae · Type: annual · Native

Rough buttonweed is a naturalized annual found in the southeastern Imperial County desert regions on dry mesas and sandy slopes at an elevation of 50 meters. Flowering from June to October, this plant produces small white or pink flowers approximately 3 millimeters long. Growing with erect stems 7 to 25 centimeters tall that are 4-angled and sometimes branched, it has a distinctive growth habit. Its leaves are lanceolate, reaching 2.5 centimeters long, with transparent stipules at the base forming a cup-like structure that partially encloses the flower cluster. The plant has stiff, unequal calyx lobes that contribute to its characteristically rough appearance.

Habitat: dry mesas, slopes, often sandy

Bloom period: Jun-Oct

Elevation: 50 m

Bioregions: DSon (se Imperial Co.)

California counties: Imperial

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.