Amaranthus palmeri S. Watson

Family: Amaranthaceae

Pertinent Synonyms & Notes (particularly those used in California; go to GRIN for other synonyms)


Pertinent Common Names (particularly those used in California; go to GRIN for other common names)

Palmer amaranth

Primary Disseminule Type


Description (diagnostics are in brown)

Fruit a dehiscent (circumscissile) utricle, obovoid to subglobose, 1.5–2 mm long, almost smooth to indistinctly rugose, with 5 attached tepals (tepals obovate to spoon-shaped, 1.7–3.8 mm long, apex rounded to slightly notched or mucronulate), containing 1 seed.

Seed elliptic to obovate in outline, compressed with an acute to obtuse marginal rim, cross-section lens-shaped to fusiform, with a barely protruding notch along the margin where hilum occurs and from which a shallow depression runs inward for a short distance, 1–1.4 mm diameter x 0.4–0.6 mm thick. Surface shiny, ± smooth (under magnification, looking cobblestone-like to reticulated, as well as pitted and punctate in some spots), dark reddish-brown to black.

Hilar region round to elliptic, often darker-colored, often plugged with a bit of white funicular remnant.

Embryo annular, surrounding copious perisperm.

Similar Species

Similar Species Comparison Chart

Risk Assessment (codes in yellow or red indicate cause for concern; assessments are current as of mid-2011; click AUQP, NZBORIC, or NZBPI for access to the most recent versions of these databases and possible assessment changes)