The Collaborative International Dictionary of English v.0.48:

Dicentra \Di*cen"tra\ (d[-i]*s[e^]n"tr[.a]), Prop. n. [NL., fr.
   Gr. di- = di`s- twice + ke`ntron spur.] (Bot.)
   A genus of herbaceous plants, with racemes of two-spurred or
   heart-shaped flowers, including the Dutchman's breeches,
   and the more showy Bleeding heart (Dicentra spectabilis).
   [Corruptly written dielytra.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

bleeding heart
    n 1: garden plant having deep-pink drooping heart-shaped flowers
         [syn: bleeding heart, lyreflower, lyre-flower,
         Dicentra spectabilis]
    2: someone who is excessively sympathetic toward those who claim
       to be exploited or underprivileged