Calendula officinalis Linnaeus (1753: 921)

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 : 140-141

2. Calendula officinalis Linnaeus (1753: 921) ; Hansen & Sunding (1985: 20); Acebes-Genovés et al. (2001: 104; 2004: 131; 2010: 158); Beierkuhnlein et al. (2021: 21). Lectotype (designated by Alavi (1983: 195)):—EUROPE. ‘In Europae arvis’, Löfling s.n. (LINN! 1035.4).

Description:—Annual or perennial herbs, sometimes woody at the base. Stems (25) 33–41 (50) cm long, occasionally longer, erect, branched at the base, covered with glandular and non-glandular hairs. Basal leaves usually (6.5) 8.8–10.6 (13.5) × (1.9) 2.3–2.7 (4.7) cm, (0.1) 0.2–0.3 (0.4) mm thick, oblanceolate to spatulate, with a ± long petiole, acute or obtuse, margins sub-entire to repand, higher leaves usually smaller, oblanceolate to lanceolate, sessile and auriculate, possessing both glandular and non-glandular hairs.

Capitula concolorous or discolorous, with (4) 4.6–5.7 (6.7) cm diameter, solitary. Involucre (9) 9.45–12.2 (14.3) mm, composed of one to two rows of bracts, linear-lanceolate, acute, green with a hyaline margin, glandular pubescent. Ray florets 30–45, (18.2) 20.8–25.2 (29.4) × (4.6) 5.5–6.4 (7.2) mm, arranged in one row, yellow or orange and tri-lobed. Disc florets over 50, (3.8) 4–4.4 (4.7) × (1.4) 1.5–1.9 (2) mm, five-lobed, yellow, orange, or purple. Anthers 1.9–2.4 mm long, styles 3.2–4.3 mm, bifid.

Outer achenes rostrate (7.7) 11.8–13.2 (13.7) × (2.3) 2.6–3 (3.9) mm, most of the times only slightly curved with a long rostrum, sometimes with an 90º angle, small dorsal spines, and one to two ventral teeth, one at the apex and one at the base, many times both; middle achenes cymbiform (7.7) 8.1–9.3 (10) × (5.8) 6.7–8.1 (8.9) mm, slightly curved with a developed ventral wing, one or two ventral teeth; inner achenes vermiform-alate (4.9) 5.4–6.7 (7) × (1.8) 3.1–4.3 (4.7) mm, circular to hook-shaped, sometimes falcate, with two lateral wings and ventral teeth; vermiform-exalate (4.2) 4.6–5.4 (6.1) × (1.8) 1.9–2.1 (2.4) mm.

Habitat and Distribution:—Cultivated as an ornamental plant, sometimes escaping into ruderal grounds. Present in all major islands.

Elevation:— 350–1500 m.

Illustrations:— Figures 7 , 10E and 11D .

Chromosome number:— 2n =32.

Genome size:—3.2 pg ± 0.06.

Figures

FIGURE 7. Calendula officinalis (Silveira, P., Simão, I. and Reyes-Bet. 3388, 3409).A, B. diversity of flowering capitula capitula (3388 and 3409, respectively); C. fruiting capitulum (3409).

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).