The Collaborative International Dictionary of English v.0.48:

Capitellate \Cap`i*tel"late\ (k[a^]p`[i^]*t[e^]l"l[asl]t), a.
   [L. capitellum, dim. of caput head.] (Bot.)
   Having a very small knoblike termination, or collected into
   minute capitula.
   [1913 Webster]