capitalized : a large genus of usually low-growing roundish or cylindrical cacti that often grow in clumps, have round, angular, or cone-shaped tubercles tipped with few to many straight or hooked spines, and usually small pink, red, yellow, or white flowers

Note: Cacti of the genus Mammillaria are found from the southwestern U.S. to South America and the West Indies, with most species native to Mexico. The key identifying characteristics of this genus are that the surface of the tubercle does not possess any grooves and that flowers arise from the base of the tubercle.

plural -s : any cactus of the genus Mammillaria

Word History


New Latin, from Latin mammilla + New Latin -aria

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Dictionary Entries Near mammillaria

Cite this Entry

“Mammillaria.” Dictionary, Merriam-Webster, Accessed 20 Apr. 2024.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!