156 POPULAR FIELD BOTANY. 
TETRADYNAMIA, SILIQUOSA. 
THALAMIFLOR®. CRUCIFER. 
BRASSICA. (Canpages and Turnip.) 
Generic Character. Calyx erect and closed. Petals ovate. 
Seed-vessel long, round, opening by two valves; seeds in one row. 
There are five species of this useful genus of plants, all in 
flower in this month, or early in the next. 
Brassica RAPA. Wild Navew, Rape, or Coleseed. This 
species is found in cornfields and waste places; it is cultivated 
for the oil produced by its seeds, and the refuse is formed 
into cakes, and used as manure, and for feeding and fat- 
tening cattle; it is, however, inferior for the latter purpose 
to that made from flax, which is called linseed cake. Its 
flowers are yellow and small. Leaves smooth, upper ones 
having no stalk, and rather long and heart-shaped. Lower 
ones lyrate, that is divided into four or six parts, the 
terminal one being large and round. 
Brassica NAPus. Common Turnip. Borders of fields 
and waste places produce this species. It varies in height 
according to soil. ‘The root-leaves are shaped like the last 
species, but rough; those of the stem nearly smooth, and 
not stalked. Flowers rather large and yellow. 
Td 
