Calendula oualidii 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 : 34

8. Calendula oualidii A.C. Gonç. & P. Silveira , sp. nov. Type:— MOROCCO. Bokkoya , 33 km from Imzouren, 740 m

[34°54’46” N, 3°47’59” W], 13 May 2014, P . Silveira & A.C.R.S. Gonçalves 3339 (holotype RAB!; isotypes AVE!,

MARK!).

Diagnosis:— Calendula oualidii differs from C. eckerleinii by the presence of a white-arachnoid indumentum (in C. eckerleinii whitearachnoid hairs are restricted to the leaf margin) and by the trialate achenes with subentire margins (instead of sinuate-dentate on lateral wings).

Description:––Perennial herbs, ± woody at the base. Stems (16) 30.3–44 (48) cm long, erect to ascending, with a mixture of glandular and white-arachnoid non-glandular hairs. Basal leaves (3.5) 4.5–7.1 (9.5) × (0.8) 0.9–1.3 (1.5) cm, with 0.3–0.4 (0.5) mm thick, oblanceolate to spatulate, apex acute, margins sinuate-dentate, with some glandular hairs, but predominantly white-arachnoid pubescent. Capitula solitary, (2.2) 2.6–3.6 (3.8) cm diameter, concolorous, yellow. Achenes heteromorphic: outer achenes rostrate (5.8) 6.5–8.1 (8.7) × 1.5–1.7 (1.8) mm (brevirostrate), ± straight or slightly curved, without dorsal spines; middle achenes trialate (5) 5.6–6.7 (7) × (3) 3.3–4.4 (5.8) mm, lateral and ventral wings sub-equal and sub-entire; inner achenes vermiculate-exalate (3.7) 3.8–4.8 (5) × (1.3) 1.5–1.7 mm, falcate, without ventral wing. Figure 16 .

Habitat and distribution:— Limestone rocks, at an elevation of ± 740 m. It grows under semi-arid Mediterranean bio-climate. Endemic to Bokkoya Mountains in Al Hoceïma ( Morocco). Figure 13 .

Conservation status:—Critically Endangered (CR). Calendula oualidii is under numerous threats, especially grazing and effects of climate change such as drought. The species is rare and local with a small-restricted range; only one subpopulation is known, intersected by a road. The number of mature individuals is estimated to be <50 based on field observations. The AOO is 8 km 2, which qualifies for CR. The existence of other populations is unlikely. Therefore, we propose its conservation status as CR B1ab(iii, v)+2ab(iii, v); C2a(I, II), D.

Chromosome number:— 2n = 18.

Genome size:—1.69 ± 0.10 pg.

Eponymy:— Calendula oualidii commemorates the Moroccan botanist Dr Jalal El Oualidi (1958–) who is a prolific botanist and curator of RAB herbarium.

Figures

FIGURE 13. Geographic distribution of the species included in the Calendula maroccana group.

FIGURE 16. Variability of achene morphology of Calendula. A. C. meuselii (Silveira 3063, AVE); B. C. eckerleinii (Silveira 3064,AVE); C. C. oualidii (Silveira & Gonçalves 3339,AVE); D. C. davisii (Silveira & Gonçalves 3263,AVE); E. C. maroccana (Silveira 3144,AVE); F. C. maroccana (Silveira, Gonçalves, & Ouhammou 3295, AVE); G. C. murbeckii (Silveira, Gonçalves, & Ouhammou 3280, AVE); H. C. lanzae (Silveira, Gonçalves, & Ouhammou 3293, AVE); I. C. pinnatiloba (Silveira 3137, AVE); J. C. stellata (Silveira 3137, AVE); K. C. stellata (Silveira 3062, AVE); L. C. tripterocarpa (Silveira 3068, AVE). Rostrate achenes: A1, 2; B1, 2; C1, 2; D1, 2; E1-3; F1, 2; G1-4; H1-2; I1, 2; J1, 2; K1. Bialate achenes:A3, 4; B3, 4; E4, H4-6; K2. Cymbiform achenes: E7, 8; G7; H7, 8; I6; J3, 4; K4, 5; L2, 3. Trialate achenes: B5, 6; C3, 4; D4, 5; E5, 6; F3, 4; G5, 6; I3, 4; L1. Vermiculate-alate achenes: H9; J5; K6; L4. Vermiculate-exalate achenes:A5; B7; B8; C5, 6; D6, 7; E9, 10; F5, 6; G8; H10, I7, J6, K7; L5. All achenes in side view, except:A3, B4, B5, C3, D3, D5, E4, E5, F3, G5, H4, H5, H7, I3, I5, I6, J3, K2, K4, L1 and L2 in ventral face view, and A4, B3, B6, C4, D4, E6, F4, G6, H6, H8, I4, J4, K3, K5 and L3 in ± dorsal face view. Scale bars = 1 cm.