The Collaborative International Dictionary of English v.0.48:

Squarrose \Squar*rose"\ (skw[o^]r*r[o^]s" or skw[o^]r"r[=o]s`;
   277), a. [L. squarrosus (perhaps) scurfy, scabby.]
   Ragged or full of loose scales or projecting parts; rough;
   jagged; as:
   (a) (Bot. & Zool.) Consisting of scales widely divaricating;
       having scales, small leaves, or other bodies, spreading
       widely from the axis on which they are crowded; -- said
       of a calyx or stem.
   (b) (Bot.) Divided into shreds or jags, raised above the
       plane of the leaf, and not parallel to it; -- said of a
       leaf.
   (c) (Zool.) Having scales spreading every way, or standing
       upright, or at right angles to the surface; -- said of a
       shell.
       [1913 Webster]

   Squarrose-slashed (Bot.), doubly slashed, with the smaller
      divisions at right angles to the others, as a leaf.
      --Lindley.
      [1913 Webster]