Ontario Weeds: Prostrate
pigweed
Table of Contents
- Name
- Other Names
- Family
- General Description
- Stems and Leaves
- Flowers and Fruit
- Habitat
- Similar Species
- Related Links
Name: Prostrate pigweed, Amaranthus
blitoides S. Wats.,
Other Names: amarante fausse-blite,
Prostrate amaranth, Spreading amaranth, Tumbleweed, amarante étalée,
amarante basse, amarante charnue, Amaranthus graecizans L.
Family: Amaranth Family (Amaranthaceae)
General Description: Annual, reproducing
only by seed.
Photos and Pictures
Prostrate pigweed. A. Portion of a prostrate branch. B.
Short branch with several clusters of flowers.
Stems & Leaves: Stems and leaves
prostrate or with tips of some branches raised 2-5cm (1-2in.) above
the ground surface, 10-120cm (4in.-4ft) long, much-branched and
often forming thick, circular mats, usually not rooting from the
nodes, green or purplish-red, somewhat fleshy; leaves alternate
(1 per node), numerous along the branches, 1-5cm (2/5-2in.) long,
the blade paddle-shaped, light green or sometimes a bit reddish,
rounded or slightly indented at the end and usually ending in a
short, very soft spine, not succulent.
Flowers & Fruit: Flowers very small
(3mm, 1/8in. long), greenish, without petals; sepals narrow, bract-like;
2 or more flowers plus several narrow bracts in clusters on short
lateral branches in the axils of small leaves; each flower unisexual,
either female (seed-producing) with only a pistil or male (pollen-producing)
with only stamens; seeds black, disk-shaped, about 1.5mm (1/16in.)
in diameter. Flowers from June to September.
Habitat: Prostrate pigweed occurs
throughout southern Ontario in waste areas, roadsides, gardens and
in some row crops, usually on coarse or sandy soils.
Similar Species: It is distinguished from
Tumble pigweed by its prostrate habit, its narrow bracts about the
same length as the sepals and its larger seed; from Redroot, Smooth
and Green pigweed by its prostrate habit, its flowers in small clusters
on very short branches in the axils of leaves, the absence of large,
terminal inflorescences and by its larger seeds; from Purslane by
its thinner leaves with pointed tips, its clusters of narrow-bracted
flowers and its relatively non-succulent nature.
Related Links
... on general Weed
topics
... on weed identification, order OMAFRA
Publication 505: Ontario Weeds
... on weed control, order OMAFRA
Publication 75: Guide To Weed Control
| Back
to the Ontario Weeds Gallery |
