The Collaborative International Dictionary of English v.0.48:

Impatiens \Im*pa"ti*ens\ ([i^]m*p[=a]"sh[i^]*[e^]nz), prop. n.
   [L., impatient.] (Bot.)
   A genus of plants, several species of which have very
   beautiful flowers; -- so called because the elastic capsules
   burst when touched, and scatter the seeds with considerable
   force. Called also touch-me-not, jewelweed, and
   snapweed. Impatiens Balsamina (sometimes called lady's
   slipper) is the common garden balsam.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Touch-me-not \Touch"-me-not`\ (t[u^]ch"m[-e]*n[o^]t`), n. (Bot.)
   (a) See Impatiens.
   (b) Squirting cucumber. See under Cucumber.
       [1913 Webster]

WordNet (r) 3.0 (2006):

touch-me-not
    n 1: North American annual plant with usually yellow or orange
         flowers; grows chiefly on wet rather acid soil [syn:
         jewelweed, lady's earrings, orange balsam,
         celandine, touch-me-not, Impatiens capensis]
    2: Mediterranean vine having oblong fruit that when ripe expels
       its seeds and juice violently when touched [syn: squirting
       cucumber, exploding cucumber, touch-me-not, Ecballium
       elaterium]
    3: prostrate or semi-erect subshrub of tropical America, and
       Australia; heavily armed with recurved thorns and having
       sensitive soft grey-green leaflets that fold and droop at
       night or when touched or cooled [syn: sensitive plant,
       touch-me-not, shame plant, live-and-die, humble
       plant, action plant, Mimosa pudica]