Accepted name
Kew cites Lophophora williamsii (Lem. ex J.F.Cels) J.M.Coult. and a native range from southwestern and southern Texas into Mexico, reaching Jalisco. Older author citations may differ; retain them when citing historical publications.
Body, root and flower
The Flora of North America describes a flat or domed crown with a depressed centre and a fleshy, carrot-shaped root. Flowers have pale margins and darker midstripes. Plants can branch into clusters. Record these characters together with provenance rather than assigning a locality from the crown alone.
A locality is not a guaranteed identity
Keep the source label and generation history for cultivated plants. A locality name, caespitose growth or a nursery form does not establish a wild collection chain. Do not give undocumented plants a locality based on appearance.
Growing without false guarantees
Give the substantial root room without surrounding a small plant in a large volume of persistently wet mix. Use the growing guide and the grafting guide; neither promises a particular flowering age.
Conservation and sourcing
Field conservation work documents pressures on wild populations. Support documented propagation and habitat conservation. Cultivation is not a replacement for conserving populations and their ecological and cultural context. Consult current local rules before acquiring plants.