The Collaborative International Dictionary of English v.0.48:

Amylaceous \Am`y*la"ceous\, a. [L. amylum starch, Gr. ?. See
   Amidin.]
   Pertaining to starch; of the nature of starch; starchy.
   [1913 Webster]

WordNet (r) 3.0 (2006):

amylaceous
    adj 1: resembling starch [syn: starchlike, amylaceous,
           amyloid, amyloidal, farinaceous]