The Collaborative International Dictionary of English v.0.48:

Xyla'riaceae \Xy*la'ri*a"ce*ae\ pr. n.
   A natural family of fungi characterized by dark brown to back
   spores.

   Syn: family Xylariaceae.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Xylariaceae
    n 1: family of fungi characterized by dark brown to black spores
         [syn: Xylariaceae, family Xylariaceae]