122. Euphorbia texana Boissier, Cent. Euphorb. 30. 1860.
Texas spurge Texas spurge
Euphorbia dictyosperma Fischer & C. A. Meyer var. leiococca Engelmann; E. leiococca (Engelmann) Norton
Herbs, annual, with taproot. Stems erect or ascending, unbranched or branched, sometimes extensively at crown, 7–20 cm, glabrous. Leaves: petiole 0–0.2 mm; blade oblanceolate to oblong-oblanceolate, 8–15 × 2–5 mm, base usually attenuate, occasionally cuneate, margins crenulate distally, apex rounded to obtuse, bluntly mucronate, surfaces glabrous; venation pinnate, midvein prominent. Cyathial arrangement: terminal pleiochasial branches 3, each 1–3 times 2-branched; pleiochasial bracts similar in shape and size to distal leaves; dichasial bracts distinct, elliptic to ovate, base acute to ± truncate, margins crenate distally, apex obtuse to rounded and mucronate; axillary cymose branches 1–3. Cyathia: peduncle 0.3–0.6 mm. Involucre hemispheric, 0.5–0.9 × 0.6–1 mm, glabrous; glands (4–)5, elongate reniform, 0.1–0.3 × 0.3–0.5 mm; horns absent. Staminate flowers 5. Pistillate flowers: ovary glabrous; styles 0.8–1 mm, 2-fid. Capsules depressed-globose, 1.6–2 × 2.5–3 mm, 3-lobed; cocci rounded, smooth, glabrous; columella 1.2–1.5 mm. Seeds brownish black, globose-lenticular, 1.4–1.5 × 1.3–1.4 mm, finely reticulate or areolate with distinct line on back; caruncle low conic, 0.4 × 0.5 mm.
Flowering and fruiting spring. Open ground, prairies; 0–200 m; La., Tex.
Euphorbia texana is related to E. alta and E. spathulata, but differs from both of those species in its smooth capsules. It is endemic to southeastern Texas and adjacent Louisiana.