Participant Info

Species

Amaranthus retroflexus

Family

Amaranthaceae

CommonName

redroot pigweed

Presence

Yes

Status

native

EarliestDate

1930

LatestDate

2022

Ecosystem

basin, shrubland, foothill, montane, urban, sanddunes

Geobotanical

Garitas, SSanjuans, NCristos, UBasin, LBasin

Counties

Alamosa, Conejos, Mineral, Rio Grande, Saguache

Passes

Stunner

WildlifePreserves

Baca, Great Sand Dunes

Other Localities

Del Norte

PhotoRecords

YES Rich Haswell: Rio Grande Co, CR 13, 1 mile S of San Francisco Creek trailhead 3 Sept 2021; Del Norte street side 30 Sept 2022

Comments

Amaranthus retroflexus is the most commonly collected pigweed in the Watershed, although its presence may be over-represented because of the difficulty in distinguished it from A. hybridus and A. powellii. Locations for A. retroflexus are scattered throughout the Watershed from Basin to shrubland and occasionally higher. In Rio Grande Co, for instance, it is common in late summer along road sides and street sides. This pigweed is present in every USA state, and from almost all New Mexico counties. It continues down the Rio Grande drainage to the Big Bend country of Texas, with one observation at the Gulf. Note that authorities differ as to whether it is native or exotic.

Annotation