The Collaborative International Dictionary of English v.0.48:

Pelargonium \Pel`ar*go"ni*um\, prop. n. [NL., fr. Gr. pelargo`s
   a stork.] (Bot.)
   A large genus of plants of the order Geraniace[ae],
   differing from Geranium in having a spurred calyx and an
   irregular corolla.
   [1913 Webster]

   Note: About one hundred and seventy species are known, nearly
         all of them natives of South Africa, and many having
         very beautiful blossoms. See the Note under Geranium.
         [1913 Webster] Pelasgian

WordNet (r) 3.0 (2006):

Pelargonium
    n 1: geraniums native chiefly to South Africa; widely cultivated
         [syn: Pelargonium, genus Pelargonium]