Amaranthus powellii S. Watson

Family: Amaranthaceae

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

Amaranthus bracteosus Uline & W.L. Bray

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

Powell amaranth

Primary Disseminule Type


Description (diagnostics are in brown)

Fruit a dehiscent (circumscissile) utricle, compressed-ovoid, 2–3 mm long, smooth or distally slightly rugose, with 3–5 attached tepals (tepals oblong to linear-lanceolate, unequal, 1.5–3.5 mm long, apex acute to aristate), with subtending bracts 4–7 mm long and spinescent, containing 1 seed.

Seed elliptic to obovate in outline, compressed with an obtuse marginal rim, cross-section lens-shaped to barely fusiform, with a protruding notch along the margin where hilum occurs and from which a shallow depression runs inward for a short distance, 0.9–1.5 mm long x 0.5–0.7 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, consisting of a round to linear opening between two semi-circular scars, sometimes 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)