Asteraceae tribe Calenduleae
Annuals, perennials, shrubs, or trees. Leaves cauline [rosulate]; usually alternate, sometimes opposite; petiolate or sessile; margins usually entire or dentate, sometimes lobed to dissected. Heads heterogamous (radiate), borne singly or in ± corymbiform arrays. Calyculi 0 (peduncular bractlets sometimes intergrade with phyllaries). Phyllaries persistent, in (1–)2(–3) series, distinct [connate], usually ± equal, usually herbaceous (sometimes fleshy), margins and/or apices ± scarious. Receptacles flat to conic, epaleate (sometimes bristly-setose). Ray florets in 1–2+ series (more in horticultural “doubles”), pistillate, fertile [styliferous and sterile or neuter]; corollas usually yellow to orange and/or cyanic to white (abaxial and adaxial faces often different colors). Disc florets usually functionally staminate, sometimes bisexual and fertile; corollas yellow, orange, or cyanic (sometimes combinations within corollas), lobes 5, ± deltate (tips sometimes terete or dilated); anther bases ± tailed, apical appendages ovate to deltate; styles abaxially papillate (at least near tips), branches sometimes barely discernible (0.5–1 mm), adaxially stigmatic in 2 lines from bases to apices, apices rounded to truncate, appendages penicillate or essentially none. Cypselae usually polymorphic within heads (straight, arcuate, contorted, or ± coiled), ± columnar to prismatic, sometimes obcompressed, compressed, or flattened, sometimes ± beaked, bodies usually tuberculate, ridged, and/or winged (usually glabrous; blue-black and drupelike in Chrysanthemoides); pappi 0 [bristles].
Introduced; most in Africa, also Atlantic Islands, Europe, and sw Asia, some are widely cultivated and become ± established in local floras.
Genera ca. 8, species 100+ (4 genera, 7 species in the flora).
Plants of Dimorphotheca cuneata (Thunberg) Lessing, a native of southern Africa, have been collected outside cultivation in Arizona (Gila County, ca. 1000 m): subshrubs or shrubs to 100 cm, leaves cuneate to obovate, 1–2(–3)cm, margins dentate to denticulate, faces ± glutinous, phyllaries usually 13, 6–9 mm, ray corollas abaxially bluish to violet, adaxially white, disc cypselae obovate to nearly orbiculate, 10 mm.
|1||Shrubs or trees; cypselae fleshy (drupelike)||Chrysanthemoides|
|1||Annuals, perennials, or shrubs; cypselae not fleshy (often tuberculate or ridged and/or winged)||> 2|
|2||Disc florets bisexual (some or all fertile)||Dimorphotheca|
|2||Disc florets all functionally staminate||> 3|
|3||Cypselae arcuate to ± coiled, abaxially tuberculate, sometimes winged||Calendula|
|3||Cypselae triquetrous-prismatic to clavate, ± tuberculate and/or winged||Osteospermum|