I have this species from the dry, wooded bank of the St. Mary River south of Fort Wayne, from along the Wabash River east of Bluffton, and from the roadside on the south side of Half Moon Pond about 10 miles southwest of Mount Vernon, Posey County. Madge McKee collected it in Newton County. It was collected in Tippecanoe County by Young and the specimen is in the herbarium of Indiana University.
Duration: Annual
Nativity: Native
Lifeform: Forb/Herb
General: Glabrous annual to 45 cm tall, simply branching to just below the inflorescence, stems deep red to green.
Leaves: Alternate, oblong to spatulate, to 4 cm long, margins serrulate, sometimes red-tinged, especially near the tips, sessile or borne on short petioles, leaves which subtend the inflorescence opposite, elliptic to ovate, sessile, with crenulate margins, forming a cup around the inflorescence, these sometimes lighter in color than the surrounding leaves.
Flowers: Inflorescences borne in forked rays, 3-rayed or born on several short branches with 1 or more cyathia, involucres campanulate, to 1 mm long, glands yellow, oval, without appendages, not concealed.
Fruits: Globose capsules to 3 mm long, warty, with warty brown or black seeds to 1.5 mm long.
Ecology: Found on plains and hills from 3,500-7,500 ft (1067-2286 m); flowers March-April.
Notes: Distinguishing characters for this species are the yellow involucre glands without appendages and the warty capsules.
Ethnobotany: Specific use of the species is unknown, but the genus was used as an infusion to treat diabetes, mouth, and skin sores, and as a bath to treat fevers, chickenpox, smallpox, and gonorrhea. In infusion of the roots was taken to invoke diarrhea.
Etymology: Euphorbia is named for Euphorbus, Greek physician of Juba II, King of Mauretania, while spathulata means shaped like a spatula.
Synonyms: Many, see Tropicos
Editor: LCrumbacher, 2011
Glabrous annual, 1-6 dm, often branched from the base; cauline lvs oblong-spatulate, 1-4 cm, obtuse, finely serrulate, the upper truncate or even subcordate at the sessile base; lvs subtending the umbel similar; lvs of the umbel shorter and relatively wider, broadly oblong to ovate or deltoid- ovate; rays of the primary umbel commonly 3, repeatedly dichotomous; involucre delicate, 0.8 mm; ovary and fr beset with numerous conic to cylindric processes, the fr 2.5 mm; seeds thick-lenticular, 1.5-1.8 mm, marked with a reticulum of fine, sharp, low ridges. Prairies, barrens, and rocky hills; Minn. and Mo. to Mont. and Tex., w. to the Pacific. May, June. (E. dictyosperma; Tithymalus arkansanus; T. missouriensis; Galarhoeus a.; G. m.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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