Euphorbia chamaesyce, 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 : 158

Euphorbia chamaesyce [ Fig.1B ]

Euphorbia massiliensis DC. in Candolle & Lamarck (1815: 357); Tithymalus nummularius Lamarck (101: 1779)

Origin: Native to the south and central Europe and the entire Mediterranean region ( Smith & Tutin 1968, Euro+Med 2006–2017).

Occurrences in Europe and the Mediterranean area: Native throughout the Mediterranean-Macaronesian region and south east Europe, but regarded as an introduced species in central Europe namely in Ukraine, Czeck Republic, Slovakia, the Netherlands, Germany, Austria, Switzerland, Belgium, Portugal and Baleares according to DAISIE (2008) and Euro+Med (2006–2017).

Habitat: Rocky ground at valley sides and dry exposed valley beds.

First record: Recorded in historical Maltese literature since Zerapha (1827) from urban areas, but it must have been confused with E. serpens (see discussion above). The first substantiated record of E. chamaesyce in natural habitats from Malta is reported in this account from a small valley side near Salini on the 6 th September 2014.

Flowering: June–October.

Morphological observations: Two varieties are described and mentioned in some local floras (e.g., Haslam et al. 1977): var. chamaesyce and var. massiliensis (DC.) Thellung (1917: 457) . They differ in the shape of the nectary glands (see key below) and only var. chamaesyce has been identified from the material examined. Many authors treat these two taxa as synonyms.

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.