The Collaborative International Dictionary of English v.0.48:

Convolvulus \Con*vol"vu*lus\ (k[o^]n*v[o^]l"v[-u]*l[u^]s), n.;
   pl. L.Convolvuli, E. Convoluluses. [L., bindweed, fr.
   convolvere to roll around. So named from its twining stems.]
   (Bot.)
   A large genus of plants having monopetalous flowers,
   including the common bindweed (Convolvulus arvensis), and
   formerly the morning-glory, but this is now transferred to
   the genus Ipom[ae]a.
   [1913 Webster]

         The luster of the long convolvuluses
         That coiled around the stately stems.    --Tennyson.
   [1913 Webster]

WordNet (r) 3.0 (2006):

convolvulus
    n 1: any of numerous plants of the genus Convolvulus