Euphorbia texana
Cent. Euphorb., 30. 1860.
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.
Phenology: Flowering and fruiting spring.
Habitat: Open ground, prairies.
Elevation: 0–200 m.
Discussion
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.
Selected References
None.