The Collaborative International Dictionary of English v.0.48:

Castanea \Cas*ta"ne*a\, n. [L., a chestnut, fr. Gr. ?.] (Bot.)
   A genus of nut-bearing trees or shrubs including the chestnut
   and chinquapin.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Castanea
    n 1: chestnuts; chinkapins [syn: Castanea, genus Castanea]