Euphorbia bivonae Steud., Nomencl. Botan.

Mokni, Ridha El, Barone, Giulio & Domina, Gianniantonio, 2024, The Euphorbia bivonae aggregate (Euphorbiaceae) in the Central Mediterranean area: First report of Euphorbia papillaris from Tunisia, Phytotaxa 669 (1), pp. 57-66 : 58

Euphorbia bivonae Steud., Nomencl. Botan. : 610 (1840)

Type (lectotype designated by Raffaelli & Ricceri 1988: 4):— ITALY. “Aprile, Euphorbia fruticosa Biv., M. Pellegrino ” ( PAL).

Phenology:—Flowering and fruiting plants were observed from the end of February to late April(-May).

Distribution:—This species, described from Sicily, occurs also in Algeria and Tunisia ( Figure 1 ). The records from Greece ( Dimopoulos et al. 2013) need confirmation. The records from Egypt and Sinai need to be verified, probably they refer to E. ramanensis . The reports from Kriti are to be referred to E. sultan-hassei ( Strid et al. 1989) .

Habitat and ecology in Tunisia:— Euphorbia bivonae is a chasmophytic suffrutex or shrub that in Tunisia grows on calcareous rocky slopes ( Figure 2 ) mainly with Clematis cirrhosa L., Euphorbia dendroides L., Hyoseris radiata L., Ceratonia siliqua L., Cytisus laniger DC. , Jasminum fruticans L., Olea europaea L., Ferula communis L., Festuca coerulescens Desf. , Lamarckia aurea (L.) Moench, Melica magnolii Gren. & Godr. , Teucrium marum L. subsp. marum , Parietaria lusitanica L., Pistacia atlantica Desf. , P. lentiscus L., P. terebinthus L., Phillyrea latifolia L., Periploca angustifolia Labill. , Phagnalon saxatile (L.) Cass., Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire, Ruscus hypophyllum L., Scrophularia laevigata subsp. simplicifolia (Batt.) Maire (Moroccan-Algerian-Tunisian endemic), Sedum stellatum L., Simethis mattiazzii (L.) Sacc., Smilax aspera L., Stachys major (L.) Bartolucci & Peruzzi, Theligonum cynocrambe L., Tripodion tetraphyllum (L.) Fourr., and Umbilicus horizontalis (Guss.) DC.

Figures

FIGURE 1. Revised localities of Euphorbia bivonae (green dots), E. tunetana (yellow dots), E. melitensis (light blue dots), and E. papillaris (red dots).

FIGURE 2. Euphorbia bivonae in Tunisia. A–B. Habit and habitat within calcareous rocky slopes in Djebel Ichkeul and Dj. Zaghouan; C–D. Details of umbels with verrucose capsules. Photographs by R. El Mokni.