Euphorbia paralias
Common name
sea spurge
Family
Euphorbiaceae
Flora category
Vascular – Exotic
Structural class
Herbs - Dicotyledons other than Composites
Distribution
Exotic. New Zealand: North Island, North Aotea Harbour Heads, Mokau, Himatangi Beach: South Island, North Westland (2020). Indigenous to the Northern Hemisphere (Europe, Mediterranean) species now naturalised throughout South Africa and Australia (Western Australia, South Australia, Victoria, New South Wales and Tasmania)
Habitat
Coastal - on sandy beaches and sand dunes. A strand-line species.
Features
Erect, ± fleshy, tap-rooted, glabrous, glaucous (sometimes tinged red), perennial herb forming dense swards 0.3–0.7(–1.0 m) tall. Rootstock stout, crown woody, 10–20(–30) mm diam. Stems 1–8(–12), branching from rootstock apex, each divided into 3–5(–10) terminal fertile branches; these dichotomously branched 1–3× again; basal stems woody, bark dark grey to brown; otherwise ± fleshy, pliant, initially glaucous, often maturing reddish-grey to maroon. Leaves fleshy, crowded, closely to loosely imbricate, becoming ± patent with age, increasing in size toward stem apex; lamina (basal) 3.8–4.9(–6.1) × 1.03–2.3 mm, narrowly oblong to obovate-oblong, apex sharply acute, sometimes shortly acuminate, base obtuse, margins entire, adaxially concave, lamina inrolled when dry; lamina (mid stem and upper stem) (6.1–)16.0(–26.2) × (2.4–)3.8(–16.3) mm, obovate-oblong, elliptic-oblong to ovate, apex acute (rarely obtuse), often shortly apiculate, apiculus reddish 0.2–0.4 mm long, base obtuse (sometimes weakly cordate), margins entire; lamina of fertile branches 10.05–14.5(–20.1) × 9.2–13.6(–16.2) mm, suborbicular orbicular, to rhomboid or reniform, apex acute or obtuse, often minutely apiculate, apiculus 0.1-0.3 mm long, base obtuse to weakly cordate, margins entire, adaxially concave. Cyathia solitary, borne in upper forks or terminal; pedunculate, peduncles 0.3–0.5(–10.0) mm long; involucre c.1.5 mm long, yellow-green, campanulate; glands 4, 0.75–1.0 mm long, dull orange to yellow, lunate, emarginate, with 2 short, widely spreading, horns. Male flowers (1–)2–3, sessile or minutely pedicellate, pedicel, 0.01v0.1 mm long, stamen 1, filament 0.1–0.22 mm long; anther 1, 0.2–0.36 mm long, pollen dark yellow. Female flowers solitary, trilocular, each locule bearing one ovule, styles 3, 0.2–1.1 mm long, yellow, each divided into 2 short dark yellow stigmas. Capsule 3.0–5.0 ×4.5–6.0 mm, dark green maturing grey-brown, cartilaginous, depressed-globose, deeply sulcate, keels granulate. Seeds (2.3–)2.5–3.5(–3.6) mm long, pale grey, whitish grey or white, ovoid-globose, smooth, caruncle minute, reniform.
Etymology
euphorbia: After Euphorbus, a Greek physician who served King Juba of Numidia in 12BC. Juba named a cactus to honour Euphorbus and later Linnaeus named the entire genus after the physician.
Fact Sheet Prepared for NZPCN by:
P.J. de Lange 4 May 2012. Description by P.J. de Lange based on New Zealand specimens collected from Aotea Harbour Heads.