Calendula suffruticosa subsp. dersana A.C. Gonç. & P. Silveira, 2023

11b. Calendula suffruticosa subsp. dersana A.C. Gonç. & P. Silveira , subsp . nov. Type:— MOROCCO: Tetouan ,

Jbel Dersa, 468 m [ 35°35’26’’ N, 5°22’45’’ W], 7 June 2012, P GoogleMaps . Silveira & A.C.R.S. Gonçalves 3262 ( holotype RAB!;

isotypes AVE!, MARK!).

Diagnosis:— Calendula suffruticosa subsp. dersana differs from C. suffruticosa subsp. suffruticosa by the predominantly white-arachnoid indumentum, instead of predominantly ± glabrous to glandulose, and cymbiform achenes length (5.5) 5.8–6.6 mm, instead of (8.8)

10.3–11.5 (14.5) mm. It differs from subsp. hosmarensis by having smaller rostrate achenes ( 8–10 mm long instead of 11–17 mm)

with dorsal spines, and its middle achenes being exclusively cymbiform (while subsp. hosmarensis has other types of achenes).

Description:––Perennial herbs. Stems (11) 17–32.5 (65) cm long, prostrate to decumbent, with white–arachnoid pubescence. Basal leaves (3.2) 3.5–7 (7.8) × (0.7) 1.1–2 (2.4) cm, (0.3) 0.4–0.4 (0.6) mm thick, oblanceolate to spatulate, apex obtuse, or sometimes ± acute, margins sub-entire to sinuate-dentate, with white–arachnoid pubescence. Capitula solitary, (1.8) 2.8–3.2 (3.6) cm diameter. Outer achenes rostrate (5) 6–10.2 (13.5) × (1.2) 1.3–1.5 (1.7) mm, straight or slightly curved, without dorsal spines, sometimes with 1–2 teeth, at the base or at the apex; middle achenes cymbiform (5.5) 5.8–6.6 × (3.6) 3.8–5.6 mm; inner achenes vermiculate-exalate (3) 3.3–3.5 (3.7) × (1.3) 1.5–1.7 mm, falcate to hemicyclic. Figure 17 View FIGURE 17 .

Habitat and distribution:—The species occurs on limestone rocks/cliffs, at an elevation of ± 500 m, and it is found in perhumid Mediterranean bio-climate. Endemic to Jbel Dersa in Tetouan ( Morocco).

Conservation status:—Critically Endangered (CR). This taxon is under numerous threats, especially due to agricultural intensification (grazing), climate change (extreme weather), and human intervention. The subspecies is rare and local with a narrowly restricted range; only one population is known close to abandoned pastures/fields. The number of mature individuals is estimated to be <50 based on field observations. The AOO is 8 km 2, which qualifies the taxon for CR. Therefore, we propose its conservation status as CR B2ab (ii, iii).

Chromosome number:—2 n = 32.

Genome size:—3.00 ± 0.07 pg.

Eponymy:—For Jbel Dersa in Morocco where it occurs.

Additional collections:— MOROCCO. Tanger-Tetouan-Al Hoceïma : Tetouan Jbel Dersa, [ 35°35’38” N, 5°23’06” W], 10 May 1921, C GoogleMaps . Pau s.n. ( MA, BC!); Tetouan Dersa, [ 35°35’38” N, 5°23’06” W], 13 April 1929, J GoogleMaps . Mas y Guindal s.n. ( MA!); Tetouan Jbel Dersa , [ 35°35’38” N, 5°23’06” W], 15 May 1930, P GoogleMaps . Font Quer ( BC!); Tetouan Jbel Dersa, 468 m [ 35°35’26” N, 5°22’45” W], 7 June 2012, P GoogleMaps . Silveira & A. C. R. S . Gonçalves 3262 ( AVE!); Tetouan , Jbel Dersa supra Semsa, [ 35°35’38” N, 5°23’06” W], 5 April 1911, C. J GoogleMaps . Pitard 1029 ( G!); Tetouan, Jbel Dersa, [ 35°35’38” N, 5°23’06” W], 30 March 1911, C. J GoogleMaps . Pitard 1027 ( G!); Tanger, Semsa, [ 35°35’37” N, 5°24’25” W], March 1930, J GoogleMaps . Mas y Guindal s.n. ( MA!); Tanger , Tetouan, Semsa, [ 35°35’37” N, 5°24’25” W], 5 April 1911, C. J GoogleMaps . Pitard 1028 ( G!) .