brassica sinapistrum

from The Collaborative International Dictionary of English v.0.48
Mustard \Mus"tard\, n. [OF. moustarde, F. moutarde, fr. L.
   mustum must, -- mustard was prepared for use by being mixed
   with must. See {Must}, n.]
   1. (Bot.) The name of several cruciferous plants of the genus
      {Brassica} (formerly {Sinapis}), as {white mustard}
      ({Brassica alba}), {black mustard} ({Brassica Nigra}),
      {wild mustard} or {charlock} ({Brassica Sinapistrum}).
      [1913 Webster]

   Note: There are also many herbs of the same family which are
         called mustard, and have more or less of the flavor of
         the true mustard; as, bowyer's mustard ({Lepidium
         ruderale}); hedge mustard ({Sisymbrium officinale});
         Mithridate mustard ({Thlaspi arvense}); tower mustard
         ({Arabis perfoliata}); treacle mustard ({Erysimum
         cheiranthoides}).
         [1913 Webster]

   2. A powder or a paste made from the seeds of black or white
      mustard, used as a condiment and a rubefacient. Taken
      internally it is stimulant and diuretic, and in large
      doses is emetic.
      [1913 Webster]

   {Mustard oil} (Chem.), a substance obtained from mustard, as
      a transparent, volatile and intensely pungent oil. The
      name is also extended to a number of analogous compounds
      produced either naturally or artificially.
      [1913 Webster]
    
from The Collaborative International Dictionary of English v.0.48
Charlock \Char"lock\, n. [AS. cerlic; the latter part perh. fr.
   AS. le['a]c leek. Cf. {Hemlock}.] (Bot.)
   A cruciferous plant ({Brassica sinapistrum}) with yellow
   flowers; wild mustard. It is troublesome in grain fields.
   Called also {chardock}, {chardlock}, {chedlock}, and
   {kedlock}.
   [1913 Webster]

   {Jointed charlock}, {White charlock}, a troublesome weed
      ({Raphanus Raphanistrum}) with straw-colored, whitish, or
      purplish flowers, and jointed pods: wild radish.
      [1913 Webster]
    

[email protected]