Euphorbia tunetana (Murb.) Vierh. ex Buxb.

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 : 58-59

Euphorbia tunetana (Murb.) Vierh. ex Buxb. in Verh. Zool.- Bot. Ges. Wien 76: 43 (1927) [«1926»]

≡ Euphorbia bivonae subsp. tunetana Murb. in Acta Univ. Lund. 35(3): 17 (1899), basion.

Type (lectotype designated by Simon & Vicens 1999: 586):— TUNISIA. “Université d’Alger, Herbier de l’Afrique du Nord, Euphorbia bivonae, ssp. tunetana Murbeck , Tunisie: Bou-Hedma, 26 April 1884, Doumet s.n. ” (MPU008008!). Notes:—The protologue of E. tunetana reports several localities from Tunisia and one from Algeria ( Domina & El Mokni 2019). Simon & Vicens (1999) designated as Lectotype a specimen from southern Tunisia. The large part of current contributions ( POWO 2024) considers this taxon a subspecies of E. bivonae . According to the variability observed among the other species of this group we judge more opportune to consider this taxon at species rank in accordance with the treatment reserved for the other taxa of this group. We believe, however, that further morphological and/or molecular studies are appropriate to better clarify the taxonomic relationships between those taxa.

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

Distribution:—This species occurs in Algeria, Tunisia and Libya ( Figure 1 ).

Habitat and ecology in Tunisia:— Euphorbia tunetana is a chasmophytic suffrutex that grows on calcareous rocky slopes ( Figure 3 ), mainly with Ferula vesceritensis Batt. (endemic to the same chorological area), Teucrium alopecurus de Noé (endemic to Tunisia), T. ramosissimum Desf. (Moroccan-Algerian-Tunisian endemic), Galium petraeum Coss. (Algerian-Tunisian endemic), Centaurea microcarpa Batt. (Algerian-Tunisian endemic), Oreobliton thesioides Durieu & Moq. (Algerian-Tunisian endemic), Reseda alphonsi Müll. Arg. (Algerian-Tunisian endemic), Sedum rubens L., S. sediforme (Jacq.) Pau , Senecio flavus (Decne.) Sch. Bip.

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 3. Euphorbia tunetana in Tunisia. A. Habit and habitat within rocky slopes in Djebel Bouhedma; B–C. Details of branches with umbels and typical verrucose capsules. Photographs by R. El Mokni.