Euphorbia serpens
Kunth Matted SandmatProstrate annual or perennial herb, glabrous, with slender taproot; stems to 15–50 cm long, much-branched, rooting at nodes and/or brownish root buds present on the undersurface of the node. Leaves opposite, ovate or ovate-oblong, suborbicular to orbicular, 2–7(–9) mm long, 2–6 mm wide, 1–1.2 times longer than wide, adaxial and abaxial surfaces green to glaucous, without red blotch, apex retuse, base asymmetric, margins entire; petioles 0.3–0.6 mm long; stipules united between petioles, broad-triangular, margin lacerate distally, 0.5–0.6 mm long. Cyathia solitary at distal nodes; peduncles 0.5–2 mm long; involucres turbinate, 0.5–0.6 mm long; glands patelliform, planar or shallowly concave, transverse-oblong in outline, c. 0.15 mm long, 0.15–0.3 mm wide, purple; gland appendages conspicuous, 0.1–0.2 mm long, 0.3–0.6 mm wide; female flowers with styles bifid for c. ¼ to ½ of their length. Capsule broad ovoid, oblate, or subglobose, 1.2–1.4 mm long, 1.3–1.7 diam., keeled, smooth, glabrous; seeds quadrangular-oblong, 0.7–1.2 mm long, 0.6–0.7 mm tangentially, 0.6–0.7 mm radially, bluntly tetraquetrous in cross-section, smooth, white to grey, caruncle absent. Flowers and fruit has been reported in Nov-Jan., and Apr., but possibly throughout the year.
OtP. Also naturalised SA, Qld, NSW. Native to the Americas. It grows in disturbed sites, including footpaths, urban parklands, botanic gardens, and garden beds.
Euphorbia serpens was first noted as present in Victoria in 2019, but was first collected in 2021 from Baylang Sanctuary in Geelong.
Euphorbia serpens is somewhat similar to and easily confused with E. dallachyana and E. multifaria. It differs in the stems rooting at the nodes, and in generally having smaller capsules and seeds, but see key for additional differences.
Halford, D.A.; Harris, W.K. (2012). A taxonomic revision of Euphorbia section Anisophyllum Roeper (Euphorbiaceae) in Australia. Austrobaileya 8(4): 481-484. Austrobaileya 8(4): 441–600.
Steinmann, V.W.; Morawetz, J.J.; Berry, P.E.; Peirson, J.A.; and Yang, Y. (2016). Euphorbia Linnaeus sect. Anisophyllum Roeper in J.E. Duby, Bot. Gal. 1:412. 1828. In: Flora of North America Editorial Committee, Flora of North America North of Mexico, Volume 4: Magnoliophyta: Vitaceae to Garryaceae, pp. 251–293. Oxford University Press, New York, and Oxford.
Wolf, M. and Király, G. (2014). Euphorbia serpens (Euphorbiaceae), A new alien species in Hungary. Acta Botanica Hungarica 56(1–2): 1–8.