The Collaborative International Dictionary of English v.0.48:

Nettle \Net"tle\, n. [AS. netele; akin to D. netel, G. nessel,
   OHG. nezz["i]la, nazza, Dan. nelde, n[aum]lde, Sw.
   n[aum]ssla; cf, Lith. notere.] (Bot.)
   A plant of the genus Urtica, covered with minute sharp
   hairs containing a poison that produces a stinging sensation.
   Urtica gracilis is common in the Northern, and Urtica
   chamaedryoides in the Southern, United States. The common
   European species, Urtica urens and Urtica dioica, are
   also found in the Eastern united States. Urtica pilulifera
   is the Roman nettle of England.
   [1913 Webster]

   Note: The term nettle has been given to many plants related
         to, or to some way resembling, the true nettle; as:

   Australian nettle, a stinging tree or shrub of the genus
      Laportea (as Laportea gigas and Laportea moroides);
      -- also called nettle tree.

   Bee nettle, Hemp nettle, a species of Galeopsis. See
      under Hemp.

   Blind nettle, Dead nettle, a harmless species of
      Lamium.

   False nettle (Baehmeria cylindrica), a plant common in
      the United States, and related to the true nettles.

   Hedge nettle, a species of Stachys. See under Hedge.

   Horse nettle (Solanum Carolinense). See under Horse.

   nettle tree.
   (a) Same as Hackberry.
   (b) See Australian nettle (above).

   Spurge nettle, a stinging American herb of the Spurge
      family (Jatropha urens).

   Wood nettle, a plant (Laportea Canadensis) which stings
      severely, and is related to the true nettles.
      [1913 Webster]

   Nettle cloth, a kind of thick cotton stuff, japanned, and
      used as a substitute for leather for various purposes.

   Nettle rash (Med.), an eruptive disease resembling the
      effects of whipping with nettles.

   Sea nettle (Zool.), a medusa.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hedge \Hedge\, n. [OE. hegge, AS. hecg; akin to haga an
   inclosure, E. haw, AS. hege hedge, E. haybote, D. hegge, OHG.
   hegga, G. hecke. [root]12. See Haw a hedge.]
   A thicket of bushes, usually thorn bushes; especially, such a
   thicket planted as a fence between any two portions of land;
   and also any sort of shrubbery, as evergreens, planted in a
   line or as a fence; particularly, such a thicket planted
   round a field to fence it, or in rows to separate the parts
   of a garden.
   [1913 Webster]

         The roughest berry on the rudest hedge.  --Shak.
   [1913 Webster]

         Through the verdant maze
         Of sweetbrier hedges I pursue my walk.   --Thomson.
   [1913 Webster]

   Note: Hedge, when used adjectively or in composition, often
         means rustic, outlandish, illiterate, poor, or mean;
         as, hedge priest; hedgeborn, etc.
         [1913 Webster]

   Hedge bells, Hedge bindweed (Bot.), a climbing plant
      related to the morning-glory (Convolvulus sepium).

   Hedge bill, a long-handled billhook.

   Hedge garlic (Bot.), a plant of the genus Alliaria. See
      Garlic mustard, under Garlic.

   Hedge hyssop (Bot.), a bitter herb of the genus Gratiola,
      the leaves of which are emetic and purgative.

   Hedge marriage, a secret or clandestine marriage,
      especially one performed by a hedge priest. [Eng.]

   Hedge mustard (Bot.), a plant of the genus Sisymbrium,
      belonging to the Mustard family.

   Hedge nettle (Bot.), an herb, or under shrub, of the genus
      Stachys, belonging to the Mint family. It has a
      nettlelike appearance, though quite harmless.

   Hedge note.
   (a) The note of a hedge bird.
   (b) Low, contemptible writing. [Obs.] --Dryden.

   Hedge priest, a poor, illiterate priest. --Shak.

   Hedge school, an open-air school in the shelter of a hedge,
      in Ireland; a school for rustics.

   Hedge sparrow (Zool.), a European warbler (Accentor
      modularis) which frequents hedges. Its color is reddish
      brown, and ash; the wing coverts are tipped with white.
      Called also chanter, hedge warbler, dunnock, and
      doney.

   Hedge writer, an insignificant writer, or a writer of low,
      scurrilous stuff. [Obs.] --Swift.

   To breast up a hedge. See under Breast.

   To hang in the hedge, to be at a standstill. "While the
      business of money hangs in the hedge." --Pepys.
      [1913 Webster]

WordNet (r) 3.0 (2006):

hedge nettle
    n 1: perennial herb with an odorless rhizome widespread in moist
         places in northern hemisphere [syn: hedge nettle,
         Stachys palustris]
    2: foul-smelling perennial Eurasiatic herb with a green creeping
       rhizome [syn: hedge nettle, dead nettle, Stachys
       sylvatica]