01 December 1982.
Sonora, Mexico
Locality: Suvuk, Pinacate Desert National Park.
Coordinates: 31.7500, -113.5000
(Map it)
Elevation: 120m.
Comment: This quick growing ephemeral (July-October) was found in the same habitat but is less frequent than Amaranthus palmeri. Less than 5 inches of rain per year. Lava-cinder and sand wash, where air temperatures reach 121 F and soil 155 F.