The Collaborative International Dictionary of English v.0.48:

Poinciana \Poin`ci*a"na\, n. [NL. Named after M. de Poinci, a
   governor of the French West Indies.] (Bot.)
   A prickly tropical shrub (C[ae]salpinia, formerly Poinciana,
   pulcherrima), with bipinnate leaves, and racemes of showy
   orange-red flowers with long crimson filaments.
   [1913 Webster]

   Note: The genus Poinciana is kept up for three trees of
         Eastern Africa, the Mascarene Islands, and India.
         [1913 Webster]

WordNet (r) 3.0 (2006):

Poinciana
    n 1: small subgenus of ornamental tropical shrubs or trees; not
         recognized in some classifications [syn: Poinciana,
         subgenus Poinciana]
    2: a tropical flowering shrub having bright orange or red
       flowers; sometimes placed in genus Poinciana [syn: bird of
       paradise, poinciana, Caesalpinia gilliesii, Poinciana
       gilliesii]