Abstract
A new species, Puya cahuachensis, is described and illustrated. It can be distinguished from its closely related species P. weberbaueri by the longer leaves with retrorse brown spines, erect peduncles, a lax inflorescence with long subcylindrical spirally arranged branches exceeding primary bracts, an inflorescence with a soft white woolly pubescence that does not fully mask the greyish colour of the rachis, and greenish bracts and sepals at anthesis.