Anthemis arvensis L.
corn chamomile
Almost scentless, annual herb. Stems prostrate, ascending, or erect, 10-20-(40) cm long, striate, moderately to densely hairy, at least above, usually much-branched from base. Basal and lower cauline lvs apetiolate, obovate to oblong, sparsely to moderately hairy and glandular, 1-pinnate with segments again 1-2-pinnatisect, up to 5 cm long; ultimate segments ovate-oblong to subulate, entire, all in one plane; cauline lvs similar to basal, small and less divided near capitula, usually oblong. Involucral bracts sparsely hairy, 2-6 mm long; margins and apex of at least inner bracts membranous. Capitula solitary, c. 2-3 cm diam.; ray florets c. 12-20; ligules white; disc florets numerous, yellow. Scales present to base of receptacle, elliptic-lanceolate, acuminate. Achenes c. 2 mm long, obpyramidal, broadest at apex, square in section, pale brown, with c. 10 thickened smooth ribs; pappus 0.
N.: 3 early collections, Penrose and Otahuhu (Auckland) and Poverty Bay; S.: Landsdowne Station (Wairau Valley, Marlborough), Windwhistle, Middleton Railway Yards, Lincoln and Darfield (Canterbury), between Oamaru and Kakanui (Otago).
Europe, N. Africa, Caucasia, Iran 1870
Casual or local in waste places, pasture and ballast.
Corn chamomile is known in N.Z. from only a few scattered localities. It superficially resembles A. cotula from which it is distinguished by the broad receptacle scales (Fig. 16) and the squared, ribbed achenes (Fig. 17). It may also be confused with Chamaemelum nobile from which it differs in having acuminate receptacle scales and again in the squared achene not narrowed to the apex. N.Z. plants can be referred to subsp. arvensis.
