What is "thlaspi arvense"

Penny \Pen*ny\, n.; pl. Penniesor Pence. Pennies denotes the number of coins; pence the amount of pennies in value. [OE. peni, AS. penig, pening, pending; akin to D. penning, OHG. pfenning, pfenting, G. pfennig, Icel. penningr; of uncertain origin.]

1. An English coin, formerly of copper, now of bronze, the twelfth part of an English shilling in account value, and equal to four farthings, or about two cents; -- usually indicated by the abbreviation d. (the initial of denarius).

   Note: ``The chief Anglo-Saxon coin, and for a long period the only one, corresponded to the denarius of the Continent . . . [and was] called penny, denarius, or denier.''
   --R. S. Poole. The ancient silver penny was worth about three pence sterling (see Pennyweight). The old Scotch penny was only one twelfth the value of the English coin. In the United States the word penny is popularly used for cent.

2. Any small sum or coin; a groat; a stiver.
   --Shak.

3. Money, in general; as, to turn an honest penny.

   What penny hath Rome borne, What men provided, what munition sent?
   --Shak.

4. (Script.) See Denarius.

   Penny cress (Bot.), an annual herb of the Mustard family, having round, flat pods like silver pennies ( Thlaspi arvense).
   --Dr. Prior.

   Penny dog (Zo["o]l.), a kind of shark found on the South coast of Britain: the tope.

   Penny father, a penurious person; a niggard. [Obs.]
   --Robinson (More's Utopia).

   Penny grass (Bot.), pennyroyal. [R.]

   Penny post, a post carrying a letter for a penny; also, a mail carrier.

   Penny wise, wise or prudent only in small matters; saving small sums while losing larger; -- used chiefly in the phrase, penny wise and pound foolish.

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).

   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).

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.

   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.

Thlaspi arvense, known by the common name field pennycress, is a flowering plant in the cabbage family Brassicaceae.