costate

from WordNet (r) 3.0 (2006)

costate
    adj 1: (of the surface) having a rough, riblike texture [syn:
           {costate}, {ribbed}]
    2: having ribs

from The Collaborative International Dictionary of English v.0.48

Costate \Cos"tate\ (k?s"t?t), Costated \Cos"ta*ted\ (-t?-t?d),
   a. [L. costatus, fr. costa rib.]
   Having ribs, or the appearance of ribs; (Bot.) having one or
   more longitudinal ribs.
   [1913 Webster]