Calendula meuselii Ohle (1975a: 6)

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 : 29-33

publication ID	https://doi.org/ 10.11646/phytotaxa.605.1.1
DOI	https://doi.org/10.5281/zenodo.8181540
persistent identifier	https://treatment.plazi.org/id/E82AFC0A-1552-CA4F-66ED-F9408211FC75
treatment provided by	Plazi
scientific name	Calendula meuselii Ohle (1975a: 6)
status

Treatment

6. Calendula meuselii Ohle (1975a: 6) View in CoL View at ENA ; Fennane & Ibn Tattou (1998: 23); Valdés et al. (2002: 672); Ibn Tattou & Fennane (2009: 28); Dobignard & Chatelain (2011: 187); Gonçalves et al. (2014: 271). Type:—Plate 1 in Ohle (1975a: Tafel I) (lectotype designated here).

Description:––Perennial herbs. Stems (15.5) 18.1–44.3 (57) cm long, erect to ascending, densely white-arachnoid pubescent, not viscous. Basal leaves (4.4) 4.6–8.4 (10) × (1.3) 1.4–2.3 (2.4) cm, with (0.2) 0.3–0.5 (0.6) mm thick, oblanceolate to spatulate, apex acute to slightly acuminate, margins entire to sub-entire, densely white-arachnoid pubescent. Capitula solitary, (2) 3.3–3.8 (4.5) cm diameter, concolorous, yellow to orange. Achenes heteromorphic: outer achenes rostrate (12) 14–17 × (1.8) 2–2.3 (3.3) mm, ± straight or slightly curved, without dorsal spines or muricate; middle achenes bialate (9.7) 10.2–11 (11.7) × (4.7) 5.3–7 (7.5) mm, with a rostrum (1.3) 1.7–2.2 (3.3) mm, lateral wings sinuate-dentate, sometimes with a rudimentary ventral wing; inner achenes vermiculate-exalate (5.8) 6.3–7.3 (7.8) × (1.7) 2–2.3 (2.7) mm, falcate with a small ventral wing, or with an apical and/or a basal tooth. Figure 16 View FIGURE 16 .

Habitat and distribution:— Limestone cliffs at elevations of 650–800 m. It is found in sub-humid to humid Mediterranean bio-climate. Endemic to Massif du Zerhoun, Jbel El – Rherraf near Sidi Kdat, and Jbel Takerma (distribution based on herbarium specimens and literature). Although at MGC there is a specimen collected in Zoumi, we did not find any population in that locality. Figure 13 View FIGURE 13 .

Conservation status:—Critically Endangered (CR). This species is threatened by climate change, due to its small-restricted range. Presently only one population is known but based on herbarium specimens there may be others in the Massif of Zerhoun. Nevertheless, recent searches done by others in the area have been unsuccessful. The number of mature individuals is estimated to be <50 based on field observations. Based on the only subpopulation known by the team, the AOO is 4 km 2, which qualifies the species for CR. Therefore, we propose its conservation status as CR B1ab (i, ii, iv, v) + 2ab (i, ii, iv,v).

Chromosome number:— 2n = 18.

Genome size:—1.71 ± 0.03 pg.

Notes:—Several attempts have been made to find type specimens of Calendula meuselii without success. The holotype cited by Ohle (1975a: 4) is ‘ Marokko, Djebel Zerhoun. leg. Sauvage 1932, Privatherbar Nr. 6235 (Montpellier)’, a collection of Charles Sauvage (1909–1980). Sauvage was a botanist who worked in Morocco and later moved to Montpellier where his herbarium is kept.The specimen was loaned to Ohle but was never returned to Montpellier (Caroline Loup, pers. comm.). Other collections that are cited by Ohle (1975a: 4) are ‘ Zerhoun-Moussoua, Nordnord̂stlich er Djebel Takerma, leg. Sauvage 1932 (RAB), leg. Baillier 1955 (RAB)’. These have also not been found at RAB. In the absence of any specimens, an illustration can be designated as lectotype (Art. 9.12 of the ICN, Turland et al. 2018). Two plates were published by Ohle (1975a), Plate 1 (Tafel I) consists of a photograph of the holotype and Plate 2 (Tafel II) represents closeups of an infrutescence and achenes. Plate 1 ( Ohle 1975a: Tafel I) is here designated as lectotype.

Calendula meuselii is distinguished from other species in the C. maroccana group by having leaves with very dense white-arachnoid indumentum, and by the absence of cymbiform and vermiculate-alate achenes. The vermiculate-exalate achenes are usually large and falcate.