Calendula ricardoi I.Simão, Reyes-Bet. & P.Silveira, 2024

Simão, Inês, Reyes-Betancort, J. Alfredo, Talhinhas, Pedro, Morais-Cecílio, Leonor & Silveira, Paulo, 2024, Taxonomic revision of the genus Calendula (Asteraceae) in the Canary Islands, Phytotaxa 640 (2), pp. 125-160 : 142-159

3. Calendula ricardoi I.Simão, Reyes-Bet. & P.Silveira , sp. nov. Holotype:— CANARY ISLANDS. Fuerteventura: Road from Betancuria to Pájara , 30 March 1975, P. L. Perez & J. R. Acebes 4802 (TFC! 4802).

Diagnosis:—This species is distinguishable from C. tripterocarpa by the well-developed rostrate achenes, usually with a long rostrum, and the larger size of the plants and leaves, and also by the flowering capitula with purple/reddish spots under the ligules. It is distinguishable from C. arvensis by the trialate achenes with entire to sub-entire lateral wings.

Description:—Annual herbs. Stems (32) 33–42 (50) cm long, occasionally longer, erect, branched at the base, with dispersed glandular and non-glandular hairs. Basal leaves usually (4.1) 4.9–6.9 (7.6) × (0.5) 0.95–1.3 (1.6) cm, (0.2) 0.3–0.4 (0.5) mm thick, ovate to oblong, less frequently oblanceolate, acute, margins entire to sub-entire, sometimes dentate, higher leaves similar to the basal ones but smaller, sessile, auriculate, possessing both glandular and non-glandular hairs. Capitula concolorous, (1.4) 1.7–2.7 (3) cm in diameter, solitary. Involucre (5.3) 6.1–8.1 (8.5) mm long, bracts in 1–2 rows, lanceolate, acute, green with a defined purple apex, glandular pubescent. Ray florets 13–21, (8.1) 9.6–14.9 (16.7) × (1) 1.9–2.3 (2.5) mm, arranged in one row, yellow or orange, sometimes with purple spots, tri-lobed. Disc florets 39–50, (2.5) 2.7–2.9 (3.7) × (0.6) 0.8–1 (1.2) mm, five-lobed, yellow to orange. Anthers 1.4–1.5 mm long, styles 1.9–2.3 mm, bifid. Achenes rostrate (10.4) 13.7–22 (25) × (1.8) 2.6–3.6 (5.1) mm, most of the times forming a ± 90º angle, sometimes only slightly curved, with a long rostrum and poorly developed dorsal spines, and one to two ventral teeth, one at the base or one at the apex, many times both; achenes trialate, (8) 8.6–10.5 (11.5) × (7.1) 8.1–9.5 (11.1) mm, lateral and ventral wings sub-entire, rarely dentate, flat in the back; achenes cymbiform (4.6) 5.1–6.1 (7) × (2.8) 3.5–4 (4.4) mm, strongly curved without ventral or dorsal wings but with ventral teeth, sometimes muricate in the back; achenes vermiform-alate (3.7) 3.9–4.5 (6) × (1.9) 2.3–2.7 (3.2) mm, circular to hook-shaped, with two lateral wings and ventral teeth; vermiform-exalate (3) 3.4–3.7 (5.1) × (1.1) 1.2–1.3 (1.5) mm.

Habitat and Distribution:—Limited to the central-western part of Fuerteventura, between Betancuria and Pájara, growing along the margins being part of ruderal nitrophilous and subnitrophilous weed communities. These annual communities are found in a degraded landscape characterized by shrubby Chenopodiaceae species or by betterpreserved shrub communities dominated by succulent Euphorbia species.

Elevation:— 250– 400 m.

Illustrations:— Figures 8 , 10D and 11C .

Conservation status:—Vulnerable (VU).

Chromosome number:— 2n =54.

Genome size:—5.1 pg ± 0.7.

Etymology:—Named after Spanish botanist Ricardo Mesa Coello (b. 1954), who worked on the monitoring of the endangered flora of the Canary Islands, contributing to its conservation and better knowledge.

Calendula ricardoi I.Simão, Reyes-Bet. & P.Silveira

SPAIN. Canary Islands

Fuerteventura: Betancuria (28°26’24” N, 14°03’15” W), 29-3-2014, Silveira, P., Gonçalves, A.C.R.S. 3327.g ( AVE); (28°25’42” N, 14°03’29” W) , 446m, 28-3-2014, Silveira, P., Gonçalves, A.C.R.S. 3327.i.1/.4 ( AVE) ; FC-30 towards Pájara , near Sra. De La Peña (28°23’46” N, 14°04’02” W), 308m, 28-3-2014, Silveira, P., Gonçalves, A.C.R.S. 3327.j ( AVE) ; Pájara (28°21’25” N, 14°04’51” W), 262m, 28-3-2014, Silveira, P., Gonçalves, A.C.R.S. 3327.l.1 ( AVE) .

Calendula ricardoi I.Simão, Reyes-Bet. & P.Silveira

SPAIN. Canary Islands

Fuerteventura: Betancuria (28°25’ N, 14°03’ W), 15-3-1974, Leskinen, M. s.n. (C); (28°26’24” N, 14°03’15” W), 29-3-2014, Silveira, P., Gonçalves , A.C.R.S. 3327.g ( AVE); (28°25’42” N, 14°03’29” W), 446m, 28-3-2014, Silveira, P., Gonçalves, A.C.R.S. 3327.i.1/.4 ( AVE) ; FC-30 towards Pájara , near Sra. de La Peña (28°23’46” N, 14°04’02” W), 308m, 28-3-2014, Silveira, P., Gonçalves, A.C.R.S. 3327.j ( AVE) ; Pájara (28°21’25” N, 14°04’51” W), 262m, 28-3- 2014, Silveira, P., Gonçalves, A.C.R.S. 3327.l.1/.2 ( AVE) .

Figures

FIGURE 8. Calendula ricardoi (Silveira, P., Simão, I. and Reyes-Bet. 3327.j, 3327.l). A. habit (observation on site); B. flowering and fruiting capitula (3327.j); C. fruiting capitulum (3327.l).

FIGURE 10. Variability of achene morphology of Calendula. A. C. arvensis form arvensis (Silveira, P. and Gonçalves, A.C.R.S. 3327.e); B. C. arvensis form macroptera (Silveira, P. and Gonçalves, A.C.R.S. 3327.c); C. C. sventenii (Silveira, P. and Gonçalves, A.C.R.S. 3327. a); D. C. ricardoi (Silveira, P. and Gonçalves, A.C.R.S. 3327.g); E. C. officinalis (Silveira, P. 2986).

FIGURE 11. Variability of leaf morphology of Calendula. A. C. arvensis (1. Reyes-Bet. in P. Silveira 3426.3; 2. Reyes-Bet. in P. Silveira 3426.5; 3. Reyes-Bet.in P. Silveira 3119.1; 4. Silveira, Simão and Reyes-Bet.3413.2; 5. Silveira, Simão and Reyes-Bet. 3413.3; 6. Silveira, Simão and Reyes-Bet. 3412.2; 7, 8. Silveira, Simão and Reyes-Bet. 3397.7); B. C. sventenii (1. Silveira, Simão and Reyes-Bet. 3383.2; 2, 3. Silveira, Simão and Reyes-Bet. 3380; 4–6. Silveira, P. and Gonçalves, A.C.R.S. 3327.a; 7–9. Silveira, P. and Gonçalves,A.C.R.S. 3327. b); C. C. ricardoi (1, 2. Silveira, P. and Gonçalves, A.C.R.S. 3377; 3. Silveira, P. and Gonçalves, A.C.R.S. 3327.i.4; 4, 5. Silveira, P. and Gonçalves, A.C.R.S. 3327.l); D. C. officinalis (1. Silveira, Simão and Reyes-Bet. 3421.1; 2. Silveira, Simão and Reyes-Bet. 3409).