Euphorbia exigua

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 : 161

Euphorbia exigua

The detailed examination of the seeds of the two varieties of Euphorbia exigua ( Figure 4 ), resulted in no significant differences between the two. The shape, colour, texture and size of the seeds were found to be similar, with very subtle and non-significant variations in the density of the papillae which do not appear specifically linked to any one of the two varieties in comparison. In general, the seeds are ash-grey with a light brownish tinge, measuring (1.15–)1.27(– 1.40) × (0.72–)0.81(–0.94) mm in size, ovate-oblong with a subtruncate base and obtuse apex, having one longitudinal slit at the ventral side and a testa covered with tiny isolated rounded papillae, rarely two or three joined adjacently.

Figures

FIGURE 4. Comparison of the seeds of Euphorbia exigua var. exigua (e) and E. exigua var. pycnophylla (p) which essentially show no morphological differences in size, colour, outline shape and texture of the testa, hence no clear distinction can be made between the two forms. Collections. 1A–1D: Ġebel Ċiantar, Fawwara, Siġġiewi; 2A: Mtaħleb, Rabat; 2B: Marfa, Mellieħa; 2C: Red Tower area, Mellieħa; 2D: Binġemma, Mġarr; 3A: Pig farm area, Comino; 3B: Għallis, Baħar iċ-Ċaghaq, San Pawl il-Baħar; 3C: Agrigento, Sicily; 3D Modica; Sicily; 4A: Mġarr ix-Xini, Xewkija side, Gozo; 4B: Wied Babu, Żurrieq; 4C: Il-Wileġ, Qala Gozo; 4D: Ta’ Ċenċ, ta’ Sannat, Gozo. Seeds had the size of (0.9) 1.0–1.2 (1.3) × 0.6–0.8 mm [n=110] without any bias towards any of the two forms (mean size of var. exigua: 1.08 × 0.71 mm [n=60]; var. pycnophylla 1.08 × 0.75 mm [n=50]).