Calendula, Linnaeus, 1753

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 : 128

publication ID	https://doi.org/ 10.11646/phytotaxa.640.2.3
DOI	https://doi.org/10.5281/zenodo.13375946
persistent identifier	https://treatment.plazi.org/id/03E8878D-FFEF-FF9A-FF3F-FD4AFACC77DD
treatment provided by	Felipe
scientific name	Calendula
status

Treatment

Variability of Calendula View in CoL species in the Canary Islands

Twenty-one quantitative characters from Table 1 View TABLE 1 were selected considering their importance in the distinction between taxa and submitted to analysis of variance to test for significant differences. The results of these tests are summarized in Table 4 View TABLE 4 and showed significant differences between groups (P<0.0001) in the 21 characters analyzed, except for the length of spines in rostrate and sub-rostrate achenes and the length and width of sub-rostrate achenes. Boxplots representing the variability of 27 quantitative characters for the Calendula species are presented in Figures 1 View FIGURE 1 , 2 View FIGURE 2 , and 3. Appendix I contains a table with the results of the morphometric analysis, used for the elaboration of the boxplots. Some of the characters are only present in one or two groups, such as the trialate achenes length and width ( Figure 3 View FIGURE 3 ).

The morphometric analysis allowed to distinguish four groups of specimens in the Canary Islands. Two of these groups corresponded to already established species, C. arvensis and C. officinalis . However, the other two corresponded to new taxa, since their morphology was not consistent with any other species known in the genus, for the Canary Islands or any other territory of the distribution of Calendula , especially concerning the presence or absence of certain morphological characters of the achenes and floral morphology. The specimens from these groups were named C. sventenii ( Figures 9 View FIGURE 9 , 10c View FIGURE 10 , and 11b View FIGURE 11 ) and C. ricardoi ( Figures 8 View FIGURE 8 , 10d View FIGURE 10 , and 11c View FIGURE 11 ). These differences were further confirmed with the multiple comparison tests done on the morphometric analysis which showed significant differences between the two taxa in several characters, such as HD, LL, IL, R1, RL, RW, TL, and TW. The main morphological differences between these two taxa and the most similar species, C. tripterocarpa and C. arvensis , are presented in Table 2 View TABLE 2 .