Calendula eckerleinii Ohle (1975a: 8)

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 : 27

3. Calendula eckerleinii Ohle (1975a: 8) ; Valdés et al. (2002: 671); Ibn Tattou & Fennane (2009: 27); Dobignard & Chatelain (2011: 186); Gonçalves et al. (2014: 273). Type:— MOROCCO. Middle Atlas, Ifrane, 15 May 1955, Meusel s.n. (holotype HAL! [29895]).

Description:––Perennial herbs, ± woody at the base. Stems (15) 33–45.5 (56) cm long, ascending to decumbent, with glandular hairs. Basal leaves (3.8) 4.6–7.0 (9.7) × (0.4) 0.6–1.1 (1.5) cm, with (0.2) 0.3–0.4 (0.5) mm thick, linear to oblanceolate, apex obtuse, margins sinuate-dentate, with glandular hairs predominating in the lamina and white-arachnoid non-glandular hairs in the margin. Capitula solitary, (2.7) 3.1–3.8 (5.2) cm diameter, concolorous, yellow. Achenes heteromorphic: outer achenes rostrate (7) 9.3–10.3 (12.2) × (1.3) 1.7–1.8 (2.2) mm, ± straight or slightly curved, without dorsal spines and ventral tooth; middle achenes trialate (5.7) 6.3–7 (7.8) × (2.5) 4.2–6.7 (7.8) mm, slightly curved, lateral wings sinuate-dentate, with a narrow ventral wing, without dorsal wings or spines; inner achenes vermiculate-exalate (3.3) 4.5–5.2 (5.8) × (1.3) 1.7–1.8 (2) mm, falcate or hook-shaped, sometimes with a small ventral wing. Figures 16 and 21 C-F.

Habitat and distribution:—Limestone rocks, slopes or gravel of low and medium mountains, at elevations of 895 – 1950 m. It is found in humid to sub-humid cold Mediterranean bio-climate. Endemic to Middle Atlas (Ifrane, Ain Leuh near Oued Oum-er-Rbia; Timahdite; Massif du Kandar; and Jbel Zalagh); with one population in Kef - el - Ghar. Figure 13 .

Conservation status:—Endangered (EN). Some populations of this species are threatened by climate change, due to reduced habitat range and lack of connection between populations. The species is known from six subpopulations (6 locations) in the Middle Atlas Mountains. It is rare and local with a small-restricted range. Both the EOO of 17 871.722 km 2 and the AOO of 52 km 2, qualify the species as EN. Therefore, we propose its conservation status as EN Bab (iii, v) +2ab (iii, v).

Chromosome number:—2 n = 18.

Genome size:—1.74 ± 0.08 pg.

Notes:— Calendula eckerleinii is widely distributed in the moist region of Ifrane, occurring near C. meuselii in the Middle Atlas Mountains. According to Ohle (1975a: 8), the limits of the distribution of this taxon may extend towards Tlemcen ( Algeria), however, we did not find specimens of C. eckerleinii beyond the above mentioned area. Ohle (1975b: 537) described C. suffruticosa subsp. tlemcensis from Tlemcen, but he did not mention the occurrence of C. eckerleinii in this region. Ibn Tattou & Fennane (2009: 27) and Valdés et al. (2002: 671) also recorded C. eckerleinii for Jbel Tazzeka. However, a different plant morphology was found in this region (see C. davisii described from Jbel Tazzeka). Calendula eckerleinii was initially identified as C. suffruticosa due to some similar morphologies (e.g. habit, basal leaves). It has been postulated that, by crossing with C. stellata (2n = 14), C. echerleinii (2n = 18) has originated the C. suffruticosa group (2n = 32) ( Heyn & Joel 1983: 326, Ohle 1975a: 7).

The basal leaves of the populations of C. eckerleinii occurring near Ifrane have the narrowest leaves, with margins sinuate-dentate, while those from Jbel Zalagh and Oued Oum-er-Rbia have oblanceolate leaves, with margins subentire. This variation may be linked to environmental conditions (temperature, humidity, shade). According to the description provided by Ohle (1975a: 8), sometimes they present trialate achenes with a narrow or reduced ventral wing, resembling a bialate achene.

Additional collections:— MOROCCO. Casablanca-Settat: Ain Leuh , estrada P7311 , perto de l’Oued Oum-er-Rbia, 1505 m [33°16’48” N, 5°20’23” W], 8 May 2014, P . Silveira & A. C. R. S . Gonçalves 3330 ( AVE!) . Fès-Meknès: Timahdite, rocas de Foung Kheneg, 1920–1980 m, [33°14’12” N, 5°03’34” W], 8 May 2014, P . Silveira & A. C. R. S . Gonçalves 3331 ( AVE!); 31 km from Ifrane, 48 km from Sefrou, 25 km of Boulemane, at junction of Ifrane road, 1572 m [33°27’18” N, 4°51’25” W], 8 May 2014, P . Silveira & A. C. R. S . Gonçalves 3332 ( AVE!); Fes Jbel Zalagh, 895 m [34°06’19” N, 4°58’11” W], 9 May 2014, P . Silveira & A. C. R. S . Gonçalves 3333 ( AVE!) .

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.

FIGURE 21. A–B. Calendula meuselii (Silveira 3063, AVE). A. Habit and habitat; B. fruiting capitulum. C–F. C. eckerleinii (Silveira 3064, AVE). C. Habit; D. flowering capitulum; E. fruiting capitulum; F. detail of leaves.