Calendula davisii A.C. Gonç. & P. Silveira, 2023
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publication ID |
https://doi.org/ 10.11646/phytotaxa.605.1.1 |
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persistent identifier |
https://treatment.plazi.org/id/E82AFC0A-1557-CA75-66ED-FB4884BBFDC6 |
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treatment provided by |
Plazi |
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scientific name |
Calendula davisii A.C. Gonç. & P. Silveira |
| status |
sp. nov. |
2. Calendula davisii A.C. Gonç. & P. Silveira View in CoL , sp. nov. Type:— MOROCCO. NW foot of Jbel Tazzeka (W of Taza),
350 – 400 m, [34°09’ N, 4°19’ W], 14 April 1971, Davis 51 257 (holotype BM! [000813587]; isotypes RNG!, E! GoogleMaps
[00245753]).
Diagnosis:— Calendula davisii differs from C. eckerleinii by having entire leaves (instead of sinuate-dentate) and trialate or bialate achenes with lateral wings deeply incised (instead of trialate achenes with lateral wings sinuate-dentate). It differs from C. maroccana by having entire leaves (instead of slightly sinuate-dentate) and lacking cymbiform achenes.
Description:––Perennial herbs, ± woody at the base. Stems (44) 45–57 (65) cm, erect to ascending, with glandular hairs. Basal leaves (3.5) 4.1–8 (10) × (0.5) 0.7–1.2 (2) cm, with (0.2) 0.3–0.4 mm thick, oblanceolate to spatulate, apex acute, margin entire to sub-entire, attenuated in a ± large petiole, with glandular hairs predominating in the lamina and white-arachnoid non-glandular hairs in the margin. Capitula solitary, ± 3.4 cm diameter, concolorous, yellow. Outer achenes rostrate (15) 18–22 (23) × (1.7) 1.9–2.3 (3) mm, ± straight or slightly curved, without dorsal spines, or with them very small; middle achenes bialate (11.7) 12.5–15.4 (16.2) × (6.7) 9–10.8 (12.2) mm, with a rostrum (2.5) 3–3.8 (4.5) mm, lateral wings incised, without dorsal wings but, sometimes, with small dorsal spines; or, less frequently, trialate 8.1–12.5 (12.7) × 6.9–11.7 (12.2) mm, with lateral and ventral wings incised, without dorsal wings but, sometimes, with small dorsal spines; inner achenes vermiculate-exalate (4.5) 4.9–6.0 (6.7) × (1.3) 1.5–1.7 (1.8) mm, hemicyclic to hook-shaped, with a small basal ventral tooth. Figures 16 View FIGURE 16 and 20 View FIGURE 20 .
Habitat and distribution:—Limestone cliffs with some intrusion of granites, at elevations of 350–530 m and is found growing in a semi-arid to sub-humid Mediterranean bio-climate. Endemic to Morocco restricted to the eastern slope of Jbel Tazzeka in Taza.
Conservation status:—Critically Endangered (CR). This species is under numerous threats, especially those resulting from climate change (extreme weather and drought). It is rare and has a small-restricted range. Only one subpopulation is known (the two points on the map belong to the same subpopulation). The few herbarium specimens known originated from the same locality. The species occurs in a Natural Park, which might imply some protection. However, the number of mature individuals is estimated to be <50 based on field observations. The AOO is 8 km 2, which qualifies for CR. Therefore, we propose its conservation status as CR B1ab(iii, v)+2ab(iii, v); C2a(i, ii); D due to the reduced size of the population and of its habitat, which puts it under a high risk of extinction due to climate changes, or other unexpected threats.
Chromosome number:— 2n = 18.
Genome size:—1.76 ± 0.05 pg.
Eponymy:— Calendula davisii commemorates the British botanist Peter Hadland Davis (1918–1992), who was the first to collect material of the species.
Additional collections:— MOROCCO. Fès-Meknès: c. 6 km SE of Sidi Abdallah around Jbel Tazzeka, 340 m, [34°07’50” N, 4°18’09” W], 15 June 1992, Optima Inter V 1014 ( RNG!, PAL!); Taza, road S GoogleMaps from Taza around Jbel Tazzeka, Gorge de Sidi Abdallah , 530 m, [34°07’50” N, 4°18’09” W], 29 May 2002, S. L GoogleMaps . Jury , M. A . Lafkih , R . Brown , M . Carine , F. J . Rumsey 19431 ( BM!, RNG!); Massif du Jbel Tazzeka, entre amont des Gorge de l’Oued Zireg , 520 m, [34°07’50” N, 4°18’09” W], 1 June 2008, A GoogleMaps . Dobignard AD 15006 ( G!); Taza, Jbel Tazzeka, 500 m [34°07’50” N, 4°18’09” W], 9 June 2012, P GoogleMaps . Silveira & A. C. R. S . Gonçalves 3263 ( AVE!, MARK!, RAB!) .
| BM |
Bristol Museum |
| RNG |
University of Reading, Centre for Plant Diversity and Systematics |
| E |
Royal Botanic Garden Edinburgh |
| PAL |
Herbarium Mediterraneum Panormitanum |
| S |
Department of Botany, Swedish Museum of Natural History |
| L |
Nationaal Herbarium Nederland, Leiden University branch |
| M |
Botanische Staatssammlung München |
| A |
Harvard University - Arnold Arboretum |
| R |
Departamento de Geologia, Universidad de Chile |
| F |
Field Museum of Natural History, Botany Department |
| J |
University of the Witwatersrand |
| G |
Conservatoire et Jardin botaniques de la Ville de Genève |
| P |
Museum National d' Histoire Naturelle, Paris (MNHN) - Vascular Plants |
| C |
University of Copenhagen |
| AVE |
Universidade de Aveiro |
| MARK |
Cadi Ayyad University |
| RAB |
Institut Scientifique |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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