The Collaborative International Dictionary of English v.0.48:

Japonica \Ja*pon"i*ca\, n. [NL., Japanese, fr. Japonia Japan.]
   (Bot.)
   A species of Camellia (Camellia Japonica), a native of
   Japan, bearing beautiful red or white flowers. Many other
   genera have species of the same name.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Camellia \Ca*mel"li*a\, n. [NL., after Georg Josef Kamel, or
   Camelli, a Jesuit who is said to have brought it from the
   East.]
   1. (Bot.) An Asiatic genus of small shrubs, often with
      shining leaves and showy flowers. Camellia Japonica is
      much cultivated for ornament, and Camellia Sassanqua and
      Camellia oleifera are grown in China for the oil which
      is pressed from their seeds. The tea plant is now referred
      to this genus under the name of Camellia Thea.
      [1913 Webster]

   2. (Hort.) An ornamental greenhouse shrub (Thea japonica)
      with glossy evergreen leaves and roselike red or white
      double flowers.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

Camellia japonica
    n 1: greenhouse shrub with glossy green leaves and showy
         fragrant rose-like flowers; cultivated in many varieties
         [syn: japonica, Camellia japonica]