The Collaborative International Dictionary of English v.0.48:

Gentianella \Gen`tian*el"la\, n. [See Gentian.]
   A kind of blue color. --Johnson.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Gentianella
    n 1: genus of herbs with flowers that resemble gentian; in some
         classifications included in genus Gentiana [syn:
         Gentianella, genus Gentianella]
    2: low-growing alpine plant cultivated for its dark glossy green
       leaves in basal rosettes and showy solitary bell-shaped blue
       flowers [syn: gentianella, Gentiana acaulis]