530 



PART III. THE CLASSIFICATION OF PLANTS. 



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

 frequently 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 syn- 

 carpous. 



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

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

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



The fruit 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. 



D 



PIG. 342. Dry dehiscent fruits. A The pod (legume) of the Pea: r the dorsal suture ; b 

 the ventral ; c calyx; s seeds. B Septicidal capsule of ColcMcum autumnale : fff the three 

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

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

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

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



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

 fruits, whicti usually enclose the solitary seeds until germination : e.g. the 

 Umbelliferse (Fig. 341) and Maple, with two mericarps ; the Geraniacese, with 

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

 splits into many mericarps (see p. 532, and Fig. 413). 



