Euphorbia maculata, Linnaeus, 1753

Mifsud, Stephen, 2018, Contribution to the flora of the Maltese Islands: Euphorbia subg. Chamaesyce and Euphorbia exigua s. l. (Euphorbiaceae), Phytotaxa 372 (2), pp. 153-166 : 159

Euphorbia maculata [ Fig.1C ]

Origin: eastern and northern America, but introduced in south America, Europe, Asia and north Africa ( Smith & Tutin 1968, Euro+Med 2006–2017, Steinmann et al. 2016, Tropicos 2017).

Occurrences in Europe and the Mediterranean area:An alien species occurring throughout entire Europe according to DAISIE (2008) but according to Euro+Med (2006–2017) it occurs only in Crete, Ukraine (including Crimea), France, Spain, and Portugal.

Introduction in Malta: Imported from horticulture products, namely potted trees and large plants. Given that it has been first recorded by Borg in 1913 ( Sommier & Caruana Gatto 1915), it can be assumed that it had been introduced in Malta sometime close to that date.

Habitat: Paved curbs and between flagstones in city squares, roadsides, less frequent in public gardens, parks or planters. Naturalised in urban and suburban areas, locally frequent but generally not common.

Invasiveness: Spreading readily in urban areas but not alarming - not observed in natural habitats.

First record: 1913 by John Borg cited by Sommier & Caruana Gatto (1915)

Flowering period: June–November.

Morphological observations: The species is well known and distinct by its deep red markings on the leaf, hence the epithet maculata . However this marking gradually disappears in late-growing individuals, typically from October onwards, and is less prominent in plants which are in the shade.

Chromosome number: 2n = 42 ( Benedì & Orell 1992).

Figures

FIGURE 1. Photos of stipules (left), fruit capsules (centre) and seeds (right) of:A: Euphorbia serpens (EUP03); B: Euphorbia chamaesyce (EUP05); C: Euphorbia maculata (EUP15), D: Euphorbia prostrata (EUP 11); E. Euphorbia hypericifolia (EUP 20). Scale bar = 2mm.