Melocactus deinacanthus

{{Short description|Species of cactus}}

{{Speciesbox

|image = Melocactus deinacanthus.jpg

|status = EN

|status_system = IUCN3.1

|status_ref = {{cite iucn |author=Braun, P. |author2=Machado, M. |author3=Taylor, N.P. |author4=Zappi, D. |date=2013 |title=Melocactus deinacanthus |volume=2013 |page=e.T40915A2943388 |doi=10.2305/IUCN.UK.2013-1.RLTS.T40915A2943388.en |access-date=14 November 2021}}

| status2 = CITES_A1

| status2_system = CITES

| status2_ref =

|genus = Melocactus

|species = deinacanthus

|authority = Buining & Brederoo

}}

Melocactus deinacanthus, also known as the Wonderfully Bristled Turk's-Cap Cactus{{cite web |title=Melocactus deinacanthus |url=https://eol.org/pages/5175756 |website=Encyclopedia of Life |access-date=19 January 2022}} is a species of plant in the family Cactaceae. It is endemic to Brazil. Its natural habitat is rocky areas. It is threatened by habitat loss.