Echinocereeae

The tribe includes large treelike species, as well as shorter shrubby species.[1] Some species can grow to be over 15 m (50 ft) tall, like the saguaro (Carnegiea gigantea)[2] and Neobuxbaumia macrocephala.[3] Their stems are ribbed and columnar, not divided into segments. Most have flowers that open at night.[1]

In 1958, Franz Buxbaum published a division into tribes of what is now the subfamily Cactoideae, then Cereoideae. Two of these tribes were Pachycereeae (which he spelt "Pachycereae") and Echinocereeae (which he spelt "Echinocereae"). Pachycereeae was a newly published taxon; Echinocereeae was an elevation of the subtribe Echinocereinae ("Echinocereanae") established by Britton and Rose in 1922.[4][5] Studies based on chloroplast DNA showed that Echinocereus, the type genus of the Echinocereeae, was nested within the Pachycereeae, as then circumscribed, and Pachycereeae was expanded to include Echinocereeae.[6][1] In 2006, David Hunt and the International Cactaceae Systematics Group used the name Echinocereeae rather than Pachycereeae for the tribe.[7] This has been followed in much subsequent work, including a major 2011 molecular phylogenetic analysis of the family Cactaceae.[8] However, some authors continue to use the name Pachycereeae for the tribe.[9]

Genera

"Core Echinocereeae" recovered in molecular phylogenetic analyses in 2005 and 2011 contains the following genera, often only in part compared to earlier generic circumscriptions.[8][13] Some genera were further placed in two subtribes, Pachycereinae and Echinocereinae.[14] The position of some genera remained unclear, as of October 2023. Brachycereus was not included in many studies, but has been placed with Armatocereus and Jasminocereus, both included in Echinocereeae.[15][16]

Image	Genus	Subtribe
	Armatocereus Backeb.	-
	Bergerocactus Britton & Rose	Pachycereinae
	Brachycereus Britton & Rose 1920	-
	Carnegiea Britton & Rose	–
	Cephalocereus Pfeiff.	Pachycereinae
	Echinocereus Engelm.	Echinocereinae
	Escontria Rose	–
	Jasminocereus Britton & Rose	-
	Myrtillocactus Console	Echinocereinae
	Neoraimondia Britton & Rose
	Pachycereus (A.Berger) Britton & Rose	Pachycereinae
	Peniocereus (A.Berger) Britton & Rose	Pachycereinae
	Polaskia Backeb.	Echinocereinae
	Stenocereus (A.Berger) Riccob. (including Isolatocereus)	Echinocereinae
	Corryocactus Britton & Rose ("outside of a well-supported larger clade")[8]	–
	Deamia Britton & Rose[11][12]	–
	Leptocereus (A.Berger) Britton & Rose[17]	–
	Lophocereus Britton & Rose, when it is separated from Pachycereus[9]	Pachycereinae
	Strophocactus Britton & Rose[11][12]	–
	Morangaya G.D.Rowley	-

The 2011 study found the tribe Hylocereeae to be embedded within a wider Echinocereeae, but studies in 2017 and 2020 asserted the independence of the Hylocereeae, including within it two genera placed within Pachycereeae in earlier classifications: Acanthocereus and Pseudoacanthocereus (sunk into Strophocactus).[11][12]

Members of the Echinocereeae are native from the southwestern United States, through Mexico, Central America and the Caribbean to northern South America.[1] Many are classic columnar desert cacti of Mexico and the southwestern US, like the saguaro (Carnegiea gigantea).[2] A few have a wider distribution: Stenocereus griseus is found from northeastern Mexico to Colombia.[18]