28.
Chenopodium ficifolium
Smith, Fl. Brit. 1: 276. 1800.
Stems
erect, simple, 1.8-5.5 dm, glabrous to sparsely farinose.
Leaves
nonaromatic; petiole 0.3-4.5 cm, usually shorter than leaves; blade distinctly 3-lobed, narrowly ovate to elongate, (1.4-)2.7-6.2 × (0.5-)1.2-2.5 cm, base cuneate, margins toothed or nearly entire, with pair of basal lobes, apex obtuse to subacute, sparsely farinose.
Inflorescences
glomerules in terminal and lateral spikes and panicles, 11 cm; glomerules irregularly globose, in different stages of development, 1.7-1.9 mm diam.; bracts absent or leaflike.
Flowers:
perianth segments 5, connate at base into 0.3 mm tube; lobes ovate, 0.5-0.9 × 0.5-0.8 mm, apex acute, farinose, keeled, covering fruit at maturity; stamens 5; stigmas 2, 0.3 mm.
Utricles
depressed-ovoid; pericarp nonadherent, smooth.
Seeds
lenticular, 0.9-1 mm diam.; seed coat black, honeycomb-pitted.
2
n
= 18.
Fruiting early summer-fall. Disturbed nitrogen-rich habitats; 0-200 m; introduced; Que.; Fla., Mo., Oreg., Pa.; native s, se Asia, occasionally introduced in other parts of the world.
Chenopodium ficifolium
has often been called
C. serotinum
Linnaeus. P. Aellen (1929b) and P. Uotila (1979b) have shown that the type of
C. serotinum
is a sterile
Atriplex
specimen (most probably
A. tatarica
Linnaeus) based on its Kranz-type leaf structure.
Chenopodium blomianum
Aellen [=
C. ficifolium
subsp.
blomianum
(Aellen) Aellen] was described from Sweden based on alien plants of presumably East Asian origin (P. Aellen 1928). According to Aellen, that subspecies occurs in southern and southeastern Asia and differs from
C. ficifolium
subsp.
ficifolium
in having leaves with spreading basal lobes almost perpendicular to the central lobe and seeds with shallow elongate depressions. All North American plants of
C. ficifolium
belong to subsp.
ficifolium
. In Europe
C. ficifolium
occasionally hybridizes with other species, including
C. album
(producing
C.
×
zahnii
Murr) and
C. suecicum
(producing
C.
×
gruellii
Aellen). No study has been made of such hybrids in North America.
