Plants erect, to 2.5 m, glabrous. Leaves sessile or petiolate; blade to 35 × 12 mm, broadest distal to middle; petiole ± 1 mm. Flowers yellow-green; tepals 4, 2.5 × 2 mm. Berries gray-translucent to white, tinged with green, borne on peduncle 0.5-2 × 4-5 mm diam. Seed black, 1-2 mm, granular and rugose, visible through fruit wall.

Flowering summer-fall; fruiting fall-winter. Sandy to clayey soils in thickets, wooded areas; 0-200 m; Tex.; Mexico (Baja California, Nuevo León, Sonora, Tamaulipas).

Phaulothamnus spinescens is very infrequent, scattered in the lower south Texas plains and adjacent Mexico. Because the seeds are black and easily seen within the translucent fruits, the fruits give the appearance of a small eye, hence the common name snake-eyes.