Source : Webster's Revised Unabridged Dictionary (1913)

Water torch \Wa"ter torch`\ (Bot.)
   The common cat-tail ({Typha latifolia}), the spike of which
   makes a good torch soaked in oil. --Dr. Prior.

Bulrush \Bul"rush`\, n. [OE. bulrysche, bolroysche; of uncertain
   origin, perh. fr. bole stem + rush.] (Bot.)
   A kind of large rush, growing in wet land or in water.

   Note: The name bulrush is applied in England especially to
         the cat-tail ({Typha latifolia} and {T. angustifolia})
         and to the lake club-rush ({Scirpus lacustris}); in
         America, to the {Juncus effusus}, and also to species
         of {Scirpus} or club-rush.

Flag \Flag\, n. [From {Flag} to hang loose, to bend down.]
   (Bot.)
   An aquatic plant, with long, ensiform leaves, belonging to
   either of the genera {Iris} and {Acorus}.

   {Cooper's flag}, the cat-tail ({Typha latifolia}), the long
      leaves of which are placed between the staves of barrels
      to make the latter water-tight.

   {Corn flag}. See under 2d {Corn}.

   {Flag broom}, a coarse of broom, originally made of flags or
      rushes.

   {Flag root}, the root of the sweet flag.

   {Sweet flag}. See {Calamus}, n., 2.

Cat-tail \Cat"-tail\, n. (Bot.)
   A tall rush or flag ({Typha latifolia}) growing in marshes,
   with long, flat leaves, and having its flowers in a close
   cylindrical spike at the top of the stem. The leaves are
   frequently used for seating chairs, making mats, etc. See
   {Catkin}.

   Note: The {lesser cat-tail} is {Typha angustifolia}.

Source : WordNet®

Typha latifolia
     n : tall marsh plant with cylindrical seed heads that explode
         when mature shedding large quantities of down; its long
         flat leaves are used for making mats and chair seats; of
         North America, Europe, Asia and North Africa [syn: {cat's-tail},
          {bullrush}, {bulrush}, {nailrod}, {reed mace}, {reedmace}]