Calendula

Annuals, perennials [subshrubs], 5–50(–70+) cm. Stems procumbent to erect, glabrous or arachnose and/or stipitate-glandular. Leaves sessile or petiolate; blades elliptic, obovate, or oblong to oblanceolate, spatulate, or linear (bases sometimes clasping), margins entire or denticulate, faces sparsely arachnose and/or stipitate-glandular. Heads borne singly. Involucres campanulate to hemispheric or broader, 10–30+ mm diam. Phyllaries 13–40+ in 2+ series, lanceolate to lance-linear. Receptacles flat. Ray florets 13–50(–100+) in 1–3+ series; corollas yellow to orange, laminae linear to oblanceolate. Disc florets 20–60(–150+), functionally staminate; corollas yellow, reddish, or purplish, tubes shorter than ± campanulate throats. Cypselae arcuate to ± coiled (usually some beaked, some 2–3-winged, some both beaked and winged), abaxial faces usually tuberculate and/or transversely ridged. x = 11.

Distribution

Introduced; Macaronesia, Mediterranean Europe, Near East, North Africa, widely cultivated, sometimes escaping and/or persisting.

Discussion

Species 15 or fewer (2 in the flora).

Selected References

Heyn, C. C., O. Dagan, and B. Nachman. 1974. The annual Calendula species: Taxonomy and relationships. Israel J. Bot. 23: 169–201.

Lower Taxa

Calendula arvensis, Calendula officinalis

Key

1	Phyllaries 13–21+, 6–10+ mm; ray florets 13–18+, corolla laminae 5–8(–12+) mm	Calendula arvensis
1	Phyllaries 12–40+, (8–)10–12+ mm; ray florets 30–50(–100+), corolla laminae 12–20+ mm.	Calendula officinalis