CLASS DIADELPHIA. 153 



it to be of perennial duration. You will meet with it 

 in flower from May to June, and it always prefers 

 sandy woods. In the southern states there are 2 very 

 remarkable biennial species, L. villosus, and L. diffusus, 

 with entirely simple, oblong, silky, or villous leaves ; 

 and producing long showy spikes of variegated purple 

 flowers. 



Stamens Diadelphous. 



In this section we shall commence with the Pea 

 (Pisum), which is not very readily distinguished in 

 generic character from the Lathyrus or Vetchling. 

 It differs, however, in the calyx ; having the segments 

 all equal, and leaf-like ; the vexillum has also 2 pro- 

 truding plaits. The style is compressed and carinate, 

 with the upper side villous ; the suture of the legume 

 is likewise naked. The native country of the cultivat- 

 ed pea (Pisum sativum) is said to be Alsace and other 

 parts of Europe ; yet it is now difficult to ascertain 

 whether it be really indigenous, or only naturalized in 

 such places. 



The Lathyrus, Vetchling or Sweet Pea, has a calyx 

 with the 2 upper segments shortest. A flat style, vil- 

 lous on its upper side and widening above. All the 

 species have a strong resemblance to the Pea. One 

 of the most beautiful, as well as fragrant annual spe- 

 cies, is the commonly cultivated Sweet Pea (Lathyrus 

 odoratus). The Everlasting Pea (L. latifolius) is a 

 very common denizen of old gardens, being a large and 

 diffuse perennial, attaching and supporting itself, like 

 all scandent plants, by means of the branching ten- 

 drils terminating its single pair of broad leaflets, and 

 which twining economical processes are, in fact, rea- 

 soning from strict analogy, the abortive rudiments of 

 other sets of leaves, though never developed. Indeed, 

 tendrils generally, of which there are abundance in 



