The Collaborative International Dictionary of English v.0.48:

Coelospermous \C[oe]l`o*sper"mous\ (? or ?), a. [Gr. koi^los
   hollow + ? seed.] (Bot.)
   Hollow-seeded; having the ventral face of the seedlike
   carpels incurved at the ends, as in coriander seed.
   [1913 Webster]