126. Cotula Linnaeus, Sp. Pl. 2: 891. 1753; Gen. Pl. ed. 5, 380. 1754.
[Greek kotule, small cup]
Linda E. Watson
Annuals or perennials, 2–25[–50+] cm (sometimes aromatic). Stems usually 1, erect or prostrate to decumbent or ascending (sometimes rooting at nodes), usually branched, glabrous or ± strigillose to villous (hairs mostly basifixed). Leaves usually mostly cauline [basal]; alternate [opposite]; petiolate or sessile; blades obovate or spatulate to lanceolate or linear, sometimes 1–3-pinnately [palmati-pinnately] lobed, ultimate margins entire or irregularly toothed, faces glabrous or ± strigillose to villous [lanate] (hairs mostly basifixed). Heads disciform [discoid or radiate], borne singly (peduncles sometimes dilated). Involucres broadly hemispheric to saucer-shaped, 3–12+[–15+] mm diam. Phyllaries persistent, 13–30+ in 2–3+ series, margins and apices (colorless, light to dark brown, or purplish) scarious. Receptacles flat to convex [conic], epaleate (sometimes ± covered with persistent stalks of florets). Ray florets 0 [5–8+, pistillate, fertile; corollas white] (peripheral pistillate florets 8–80+ in 1–3+ series; corollas usually none). Disc florets 12–200+[–600+], bisexual, fertile [functionally staminate]; corollas ochroleucous or yellow, tubes ± cylindric (bases sometimes adaxially saccate), throats abruptly ampliate, lobes (3–)4, ± deltate (sometimes one larger than others, usually each with central resin canal). Cypselae obovoid to oblong, ob-compressed or -flattened, ribs 2, lateral, sometimes becoming wings, faces ± papillate (pericarps relatively thin, sometimes with myxogenic cells and/or 2 lateral resin sacs); pappi 0. x = 10.
Species 55 (2 in the flora): introduced; s Old World; introduced also (perhaps some native) in Mexico, South America, s Oceanic Islands.
Some species of Cotula are widely naturalized. F. Hrusa et al. (2002) reported Cotula mexicana (de Candolle) Cabrera as established on golf courses in California; it is similar to C. australis and differs in leaf blades mostly 1-pinnate, receptacles pilose, and disc florets functionally staminate.