Ermakova A., Whiting C. V., Trout K., Clubbe C., Terry M. K., Fowler N., Densities, plant sizes, and spatial distributions of six wild populations of Lophophora williamsii (Cactaceae) in Texas, U.S.A., Journal of the Botanical Research Institute of Texas, 2021, 15(1):149-160, doi: 10.17348/jbrit.v15.i1.1057
Measurements taken in May and July 2019 cover six known populations, 121 random transects and 294 plants. The authors analyse clustered distribution, density, crown number and above-ground volume. They compare southern and western Texas, examine slope aspect and discuss the extent to which the data can support conservation assessment.