Euphorbia exserta |
Euphorbia rosescens |
|
---|---|---|
coastal sand spurge, maroon or purple sand spurge |
rosy-pink spurge, scrub spurge |
|
Habit | Herbs, perennial, with spreading rootstock. | Herbs, perennial, with thickened rootstock. |
Stems | erect or ascending, unbranched or branched, solitary, few, or occasionally densely clumped, previous year's dead stems not persistent, 20–33 cm, usually glabrous, rarely sparsely villous, glaucescent. |
erect or ascending, 15–45 cm. |
Leaves | alternate; stipules less than 0.1 mm; petiole (0–)1–3 mm, glabrous; blade linear or linear-elliptic to obovate or orbiculate, proximal greatly reduced, scalelike, 15–30 × 1–20 mm, base cuneate to rounded, margins entire, apex rounded, broadly acute, or emarginate, surfaces glabrous, glaucescent; venation often obscure on narrow leaves, midvein conspicuous. |
petiole indistinct, blade narrowly elliptic, elliptic, narrowly oblong, or obovate, 25–55 × 5–21 mm, thick and fleshy, base attenuate, apex acute or mucronulate; only midvein evident. |
Involucre | usually dark red, campanulate, 1.3–1.6 × 1.4–2.1 mm, glabrous; glands 5, usually dark red, rarely greenish red, elliptic reniform, thickened, 0.3–0.5 × 0.8 mm; appendages white or green, often forming narrow rim around distal margin of gland, 0–0.2 mm, entire. |
obconic to campanulate, 2.4–3.6 × 2.5–3.6 mm, lobes ovate to oblong, 0.7–1 mm, ciliate; glands green to yellow, oblong or trapezoidal, 0.9–1.7 × 1.9–2.5 mm, distal margins crenulate-erose. |
Staminate flowers | 20–25. |
25. |
Pistillate flowers | ovary glabrous; styles 0.4–0.8 mm, 2-fid at apex. |
mature gynophore not seen, styles connate 1/2 length, 3.3–3.6 mm. |
Capsules | depressed-globose, 1.8–2.5 × 3.6–4.4 mm, glabrous; columella 1.9–2.4 mm. |
|
Seeds | ashy white, ovoid, 2.1 × 1.3 mm, angled with 5 blunt longitudinal ridges, with shallow and irregular pits; caruncle absent. |
not seen. |
Cyathia | usually in terminal dichasia, sometimes pleiochasia; peduncle 6–33 mm, filiform, glabrous. |
peduncle 3.9–6.8 mm. |
Cyathial | arrangement: terminal pleiochasial branches 3, 7–16 cm, 4–7 times 2-branched; pleiochasial bracts ovate to oblong, 17–31 × 13–14 mm, margins entire, apex acute, often also mucronulate; dichasial bracts ovate or lanceolate, 6–18 × 8–12 mm, margins entire, apex acute, often also mucronate; axillary cymose branches 1–2. |
|
Mature | capsules not seen. |
|
Euphorbia exserta |
Euphorbia rosescens |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting spring–summer, rarely fall. |
Habitat | Xeric to dry pine-oak scrub of sand hills, pine-oak woodlands, pine-oak savannas. | Xeric oak and pine scrub, mostly on white sands, disturbed habitats. |
Elevation | 0–150 m. (0–500 ft.) | 20–50 m. (100–200 ft.) |
Distribution |
FL; GA; NC; SC; VA
|
FL |
Discussion | K. R. Park (1998) recognized both Euphorbia exserta and E. gracilior as distinct species, with the former known only from the holotype. However, this treatment follows M. J. Huft (1997) and treats E. gracilior as a synonym of E. exserta. Although the type of E. exserta is unusual in having greenish red (versus dark red) cyathia and glands, as well as small gland appendages, it is otherwise typical of the species as a whole, including features such as the upright habit, reddish coloration, scalelike proximal leaves, and filiform peduncles to 30 mm that are also common to plants formerly treated as E. gracilior. Euphorbia gracilis Elliott, which has sometimes been applied to E. exserta, is an illegitimate name (a later homonym of E. gracilis Loiseleur-Deslongchamps) and pertains here. The upright habit and usually dark red cyathia and glands distinguish Euphorbia exserta from the otherwise similar E. ipecacuanhae, while the glaucescent vegetative parts and smaller gland appendages readily separate E. exserta from the similar E. curtisii. Euphorbia exserta is found on the Gulf and Atlantic coastal plains. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia rosescens is a narrow-endemic, gap-specialist known only from the southern portion of the Lake Wales Ridge in Highlands County. Based on leaf characteristics, it appears to be most similar to E. telephioides. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 246. | FNA vol. 12, p. 316. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Nummulariopsis |
Sibling taxa | ||
Synonyms | Tithymalopsis exserta, E. gracilior, T. gracilis | |
Name authority | (Small) Coker: Pl. Life Hartsville, 88. (1912) | E. L. Bridges & Orzell: Lundellia 5: 71, fig. 4. (2002) |
Web links |