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-ales

American  
Botany.
  1. a suffix of names of orders.

    Cycadales.


-ales British  

suffix

  1. denoting plants belonging to an order

    Rosales

    Filicales

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of -ales

< Latin plural of -ālis -al 1