United States, Texas, Presidio, Ca. 4.3-4.5 airmiles N to NNW of jct. US Rt. 90 and St. Rt. 17 in downtown Marfa. Northern part of Mimms Ranch (Dixon Water Foundation). Marfa Quadrangle.
In sandy to clayey alluvial soil on high bank of wet-weather creek draining very gently rolling landscape underlain by a mix of Perdiz Conglomerate (a fanglomerate of variable composition) and Quaternary alluvium. Associates included Cyperus 31901, Datura quercifolium, Echinochloa sp., Eriochloa acuminata, Gaura 31902, Marsilea vestita, Paspalum distichum, Rumex altissimus, Vernonia marginata, Xanthium strumarium.