131. Argyranthemum Webb ex Schultz-Bipontinus in P. B. Webb and S. Berthelot, Hist. Nat. Îles Canaries. 3(2,75): 245, 258. 1844.
Marguerite [Greek argyros, silver, and anthemon, flower; allusion unclear]
John L. Strother
Subshrubs or shrubs, 10–80+[–150] cm. Stems usually 1, procumbent to erect, usually branched, glabrous [hairy]. Leaves mostly cauline; alternate; petiolate or sessile; blades ± obovate [oblong to lanceolate or linear] (bases sometimes ± clasping), [0](1–)2–3-pinnately lobed (lobes cuneate to linear), ultimate margins dentate [entire], faces glabrous [hairy]. Heads radiate [discoid], borne singly or in open, corymbiform arrays. Involucres hemispheric or broader, [6–]10–18[–22+] mm diam. Phyllaries persistent, 28–45+ in 3–4 series, distinct, oblanceolate or ovate to lance-deltate or lanceolate (not keeled abaxially), unequal, margins and apices (stramineous to brown) scarious (tips of inner often ± dilated). Receptacles convex to conic, epaleate. Ray florets 12–35+, pistillate, fertile; corollas usually white, sometimes yellow or pink, laminae ± ovate to linear. Disc florets [50–]80–150+, bisexual, fertile; corollas yellow [red, purple], tubes ± cylindric (not basally dilated, ± gland-dotted), throats campanulate, lobes 5, deltate (without resin sacs). Cypselae dimorphic: outer (ray) 3-angled, each angle usually ± winged (wings not spine-tipped); inner (disc) compressed-prismatic (± quadrate, sometimes 2 angles winged, wings not spine-tipped); all ± ribbed or nerved, faces usually glabrous, sometimes gland-dotted between ribs (pericarps without myxogenic cells or resin sacs; embryo sac development bisporic); pappi 0 (cypselar wall tissue sometimes produced as teeth, crowns, or oblique tubes similar in texture to cypselar wings). x = 9.
Species 24 (1 in the flora): introduced; Atlantic Ocean Islands (Macaronesia).
SELECTED REFERENCE
Humphries, C. J. 1976. A revision of the Macaronesian genus Argyranthemum Webb ex Schultz Bip. (Compositae–Anthemideae). Bull. Brit. Mus. (Nat. Hist.), Bot. 5: 147–240.
