JULY. 315 
TETRADYNAMIA, SILICULOSA. 
THALAMIFLORA. CRUCIFER&. 
THLASPI. (PEnny-crEss.) 
Generic Character. See page 103. 
THLASPI ARVENSE. Iithridate mustard, or Penny-cress. 
Not common everywhere ; but found occasionally in fields. 
In the sandy soil of Sussex it is tolerably frequent, and 
attracts notice by its curiously winged seed-pouches, which 
are nearly round, and having a flat broad wing on each side 
not united at the top. The flowers are very small and 
white. Leaves smooth, oblong, arrow-shaped, and toothed. 
Stem about a foot high, and branched. 
TETRADYNAMIA. SILIQUOSA. 
THALAMIFLORA. CRUCIFER2. 
NASTURTIUM. (Cruss.) 
Generic Character. Pod nearly cylindrical, sometimes long, at 
others short, seeds in two irregular rows. Calyx spreading. 
NasTURTIUM OFFICINALE. Water-cress. This well-known 
plant, and wholesome salad, is frequent in brooks and rivu- 
