Euphorbia crenulata |
Euphorbia hexagona |
|
---|---|---|
Chinese caps, western wood spurge |
six-angle spurge |
|
Habit | Herbs, usually biennial, occasionally annual, with taproot. | Herbs, annual, with taproot. |
Stems | erect, sometimes decumbent at base, unbranched or branched, 12–40 cm, glabrous. |
erect, unbranched or branched, 30–70(–100) cm, sparsely hispid, occasionally densely so at distal nodes. |
Leaves | petiole 0–2 mm; blade obovate-spatulate to oblanceolate, 8–22 × 3–10 mm, base broadly attenuate, margins entire or slightly crisped, apex obtuse to ± rounded, minutely apiculate, surfaces glabrous; venation pinnate, midvein prominent. |
opposite; stipules (0–)0.1 mm; petiole 1–4 mm, pilose; blade linear-filiform, linear, or elliptic, 21–40 × 0.9–7.5 mm, base attenuate, margins entire, apex acute, abaxial surface sparsely hispidulous to strigillose, adaxial surface glabrous; venation obscure, only midvein conspicuous. |
Involucre | campanulate, 1.8–2.1 × 1.6–1.8 mm, glabrous; glands 4, crescent-shaped, 0.6–1.2 × 1.5–2.3 mm; horns slightly divergent to slightly convergent, 0.4–0.6 mm. |
campanulate, 1–1.5 × (1–)1.5–1.8 mm, hispid; glands 5, green to deep red, elliptic to reniform, 0.5 × 0.8–1 mm; appendages white to green, tinged red, deltate to ovate, 0.7–1.7 × (0.9–)1.3–1.5 mm, entire. |
Staminate flowers | 11–18. |
15–30(–40). |
Pistillate flowers | ovary glabrous; styles 0.9–1.4 mm, 2-fid. |
ovary glabrous; styles 0.7–1.1 mm, 2-fid nearly entire length. |
Capsules | subovoid, 2.5–3 × 3.5–4 mm, 3-lobed; cocci rounded, smooth or puncticulate, glabrous; columella 1.9–2.3 mm. |
subglobose to broadly ovoid, 4.7–6.5 × 4.9–6.5(–7.1) mm, glabrous; columella 3.5–4.5 mm. |
Seeds | cream and brown mottled, oblong-ovoid to nearly globose, 2–2.5 × 1.4–1.7 mm, usually irregularly vermiculate-ridged and large-pitted, occasionally tuberculate or nearly smooth; caruncle reniform, conic, 0.5–0.6 × 0.5–0.7 mm. |
dark brown or dark gray, ovoid, 3.4 × 2.7 mm, rugose, whitish glaucous; caruncle absent. |
Cyathial | arrangement: terminal pleiochasial branches 3, each 2-branched; pleiochasial bracts obovate to orbiculate-reniform, wider than distal leaves; dichasial bracts usually connate 1/3–1/2 length (often only on one side), rarely only connate basally, triangular ovate to reniform, base truncate to perfoliate, margins erose-denticulate to subentire, apex rounded to obtuse, rarely apiculate; axillary cymose branches 0–5. |
|
Cyathia | peduncle 0–0.5 mm. |
solitary in leaf axils or in terminal cymes or dichasia; peduncle 1–2.1 mm, strigillose. |
Euphorbia crenulata |
Euphorbia hexagona |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting late summer–fall. |
Habitat | Conifer, oak, and mixed forests, coastal scrub, grasslands, barrens and outcrops, roadsides. | Sand prairies, other sandy soil habitats, stream banks, sand bars, damp places. |
Elevation | 30–1800 m. (100–5900 ft.) | 200–1300 m. (700–4300 ft.) |
Distribution |
CA; CO; NM; OR
|
AR; CO; IA; IL; KS; MN; MO; MT; NE; NM; OK; SD; TX; WI; WY
|
Discussion | Euphorbia crenulata is most common in the central valleys of California and southern Oregon; it occurs disjunctly in southwestern Colorado and northwestern New Mexico. Previous reports from Arizona are based on misidentified specimens. Euphorbia crenulata is closely related to E. commutata. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia hexagona is native to the central United States and is most common from southern South Dakota to Oklahoma and northern Texas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 301. | FNA vol. 12, p. 247. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Synonyms | Tithymalus crenulatus | |
Name authority | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 192. (1859) | Nuttall ex Sprengel: Syst. Veg. 3: 791. (1826) |
Web links |