Chenopodium erosum R.Br.
jagged fathen
Annual, prostrate or decumbent, non-aromatic, eglandular, mat-forming, ± farinose herb, sometimes purplish, sometimes with central branch erect. Stems ribbed. Lamina usually 1.5-2× petiole, 2-10 × 1.5-7 cm, oblong-ovate or triangular, sometimes as wide as long, often dark purple below and sometimes above, lobulate and coarsely and very irregularly acutely or obtusely dentate, undulate; base shallowly cordate to broad-cuneate; apex acute or obtuse; lvs below infl. similar but smaller. Infls sub-paniculate or spike-like, often dark reddish, axillary and terminal, ± farinose, at least when young; branches often short and ± fasciculate, usually < subtending lvs; glomerules distant. Perianth segments 0.7-1.3 mm long at anthesis, incurved, slightly imbricate, green or purple-tinged, except for hyaline margin; keel shallow, obtuse, accrescent. Fr. loosely invested by perianth, except at free apical area; pericarp tightly adherent to testa. Seed horizontal, 1.2-1.5 mm diam., circular, compressed; margin subacute; testa black, prominently radially furrowed.
N.: occasional south of Opotiki (Bay of Plenty); S.: Canterbury, C. Otago, also collected from Molesworth Station (Marlborough), and occasional in N. Otago.
Origin unknown 1953
Waste places, roadsides, dry stony river terraces, cultivated land.
FL Dec-Apr.
In N.Z. C. erosum is fairly uniform in lf shape, infl. appearance, and floral and fruiting characters; the main variation is in plant colour and size. Although the type of C. erosum is Australian, the sp. is probably not indigenous there (P. G. Wilson, pers. comm.). It is apparently unknown in Europe and W. Asia, although it appears to have affinities with the Eurasian C. urbicum L.. C. urbicum has been recorded for N.Z., but records are either unsubstantiated by a specimen or referable to C. erosum.
