The Collaborative International Dictionary of English v.0.48:

Morning-glory \Morn"ing-glo`ry\, n. (Bot.)
   A climbing plant (Ipomoea purpurea) having handsome,
   funnel-shaped flowers, usually red, pink, purple, white, or
   variegated, sometimes pale blue. See Dextrorsal.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Ipomoea purpurea
    n 1: pantropical annual climbing herb with funnel-shaped blue,
         purple, pink or white flowers [syn: common morning glory,
         Ipomoea purpurea]