Stenocactus lloydii has, at times, been included under Stenocactus multicostatus but is here separated as its own species. The outstanding feature of these plants is the extra long, flat, papery central spine. Stenocactus erectocentrus also has long papery spines and is sometimes included as a synonym of S. lloydii. The whole genus really needs some taxonomic work as there are many interesting forms and you should collect as many as you can! The flowers are typically whitish with a purplish central stripe.