The Collaborative International Dictionary of English v.0.48:

Monostichous \Mo*nos"ti*chous\ (m[-o]*n[o^]s"t[i^]*k[u^]s), a.
   [See Monostich.] (Bot.)
   Arranged in a single row on one side of an axis, as the
   flowers in grasses of the tribe Chloridae.
   [1913 Webster]