Calendula suffruticosa subsp. tunetana (Cuénod) A.C. Gonç. & P. Silveira 2023

Gonçalves, Ana Carla, Ouhammoud, Ahmed, Amirouche, Rachid, Santos, Conceição, Figueiredo, Estrela & Silveira, Paulo, 2023, A taxonomic revision of Calendula (Asteraceae) in Morocco, including some taxa from Algeria and Tunisia, Phytotaxa 605 (1), pp. 1-83 : 58-62

publication ID	https://doi.org/ 10.11646/phytotaxa.605.1.1
persistent identifier	https://treatment.plazi.org/id/E82AFC0A-1577-CA52-66ED-F9F88206FEC9
treatment provided by	Plazi
scientific name	Calendula suffruticosa subsp. tunetana (Cuénod) A.C. Gonç. & P. Silveira
status	comb. et stat. nov.

Treatment

11o. Calendula suffruticosa subsp. tunetana (Cuénod) A.C. Gonç. & P. Silveira View in CoL , comb. et stat. nov. Calendula tunetana Cuénod (1910: ci). Calendula suffruticosa var. tunetana (Cuénod) Ohle (1975b: 532) . Type:— TUNISIA. ‘Berges sablounneuses de l’Oued, entre Bir bou Rekba et Hamamet’, Cuneod s.n. (holotype G! [G00022975]).

Description:––Perennial herbs. Stems (14.3) 16.5–25.8 (40) cm long, ascending to erect, with glandular and non-glandular, slightly predominant white-arachnoid, pubescence. Basal leaves (3.2) 3.6–5.4 (6.1) × (0.3) 0.4–0.6 (0.7) cm, 0.4–0.6 mm thick, linear to narrowly oblanceolate, apex acute, margins slightly sinuate-dentate, with glandular and non-glandular, slightly predominantly white-arachnoid, pubescence, drying into a light grey-greenish colour. Capitula solitary, (3.3) 3.4–4.7 (5.0) cm diameter, concolorous, yellow. Outer achenes rostrate (16) 16.5–19 (20) × (1.8) 1.9–2.3 (2.5) mm, straight or curved up to ± 110º, with small dorsal spines or muricated, with basal, and sometimes apical, ventral teeth; middle achenes trialate (10) 10–10.5 (10.7) × (6.3) 7.1–9.7 (9.7) mm, lateral wings sub-entire; inner achenes vermiculate-alate (5.0) 5.1–5.8 (6.0) × (3.1) 3.3–4.1 (4.2); vermiculate-exalate 4.2–4.7 × 2.0– 2.2 mm, both circular and with apical and basal teeth. Figure 18 View FIGURE 18 .

Habitat and distribution:—Riverine sandy banks at elevations of 10–20 m, in semi-arid Mediterranean bio-climate. Endemic to Tunisia where it is restricted to near Bir bou Rekba and Hamamet.

Conservation status:— Data Deficient (DD) . Only one population (Hamamet) was assessed. In this population the number of mature individuals is estimated to be <50, but more filed work is needed in the region to check the real size of the population and its range. Therefore, the information is inadequate to assess its extinction risk based on distribution and/or population numbers.

Chromosome number:— 2n = 32.

Genome size:—3.39 ± 0.08 pg.

Notes:— Pottier-Alapetite (1981: 1024) has not validly published (Art. 41.5; Turland et al. 2018) the combination ‘ C. suffruticosa subsp. tunetana’. Ohle (1975b: 532) considered this taxon as a variety of C. suffruticosa subsp. suffruticosa . In our view, subsp. tunetana is a distinct subspecies, characterised by narrow basal leaves and trialate achenes. Furthermore, the different habitats and edaphic conditions of the two subspecies support their recognition as separate entities.

Additional collections:— TUNISIA. Nabeul: between Bir Bou Regba and Hammamet, [36°26’ N, 10°35’ E], 11 April 2009, P GoogleMaps . Silveira 3039 d ( AVE!) .