530 



PART III. THE CLASSIFICATION OF PLANTS. 



rupture, but encloses the seed until germination ; the testa is usually tliiu, and 

 frequent'y coalescent with the pericarp. 

 (1) One-seeded fruits : 



(a) The nut {glans), e.g. Acorn, Hazel-Nut (but not the Walnut); the 

 dry pericarp is hard and sclerenchymatous : it is inferior and sju- 

 carpous. 

 (b) The achene is superior and monomerous : the pericarp is thin and 

 coriaceous; e.g. the Eose and the Buttercup. The similar fruit 

 of the Composite is a cypsela ; it is inferior and dimerous. 



The fiuit of Grasses, termed a caryopsis, is very similar to the 

 achene ; it differs from it in that the testa and the pericarp closely 

 adhere, whereas in the achene they are not adherent. 



Fig. 342.— Dry dehiscent fruits. A The pod (legume) of the Pea: r the dorsal suture ; h 

 the ventral ; c calyx; 8 seeds. B Septicidal capsule of Colchicum auturmnale : /// the three 

 separating carpels. C Siliqua of Brassica; fc the valves; w the dissepiment and placenta; 

 (replum); « seeds ; g style ; n stigma. D Capsule, opening by pores, of Papaver somviferum, 

 the Poppy ; n stigma ; j the pores which open by the removal of the valves (a). E Pyxidium 

 ot Hyoscyamus ; d the lid; w the dissepiment; s seeds. 



(2) Many-seeded fruits : these {scliizocarps) commonly split into one-seeded 

 fruits, whic'i usually enclose the solitary seeds until germination : e.g. the 

 Umbelliferae (Fig. 341) and Maple, with two mericarps ; the Geraniaceae, with 

 five mericarps ; and most Malvaceae, where the fruit is termed a carcerulc, and 

 splits into many mericarps (see p. 532). 



