DICOTYLEDONKS : POLYPETALJS : CALYCIFLOR^. 



625 



(Fig. 426 B, C, o), and sometimes other secondary ridges, 

 (juga secund'iria) (tig. 426, E, F, n), which do not enclose vascular 

 bundles. The mericarp when ripe is filled by the seed, which 

 consists of the abundant endosperm (Fig. 426 (7, D, jP, e) en- 

 closing a small embryo. According to the form assumed by the 

 endosperm, the following groups may be distinguished : the OrtTio- 

 spermece, in which the surface of the endosperm, which is directed 

 towards the plane of junction of the two mericarps, is flat or con- 

 vex, as in Carum (Fig. 426 0) : the Campylnspermew, in which the 

 endosperm is concave towards the same plane, as in Conium (Fig. 

 426 I)\ and the Coelospermece, in which the whole endosperm is 

 curved, so that it is seen to be concave 

 towards this plane both in longitudinal 

 and in transverse section, as in Coriander 

 (Fig. 426 F). 



The flowers, with few exceptions (Hy- 

 drocotyle, Astrantia, Eryngium), are in 

 compound umbels ; in some few cases, as 

 in Caucus, the umbel has a distinct ter- 

 minal flower which is black in colour : an 

 involucre and involucels are largely de- 

 veloped in some species, in others they 

 are wholly wanting. The hollow stem 

 bears large leaves with generally well- 

 developed sheathing bases and much 

 divided lamina? : rarely the leaves are 

 simple, as in Hydrocotyle and Bupleurum. 



The British genera are arranged as follows : 

 Sub-order I. ORTHOSPERMK^E. 



A. Umbels simple. 



Tribe 1. Hydrocotylece. Fruit laterally com- 

 pressed. The genus Hydrocotyle consists of 

 marsh -plants with peltate leaves (Fig. 31). 



Tribe 2. Saniculea. Fruit nearly cylindrical. This group includes the 

 genera Astrantia, Eryugium, and Sanicula. 



B. Umbels compound. 



Tribe 3. Amminece. Fruit without secondary ridges, laterally compressed: 

 Ammi, Bupleurum, Petroselinum, Apiutu, ^gopodiurn, Carum (Figs. 426 G, 

 and 427), Cicuta, Slum, Pimpinella, Trinia, Conopodium, Sison. 



Tribe 4. Seselinece. Secondary ridges absent, or if present (Siler) not so 

 prominent as the primary : fruit not compressed: ^Ethusa,Foeniculum,(Enautbe, 

 Seseli, Meum, Ligusticum, Silaus, Crithmum, Siler. 



Tribe 5. Angelicece. Fruit without secondary ridges, dorsally compressed, 



FIG. 427. Fruit of Carum 

 Carui. A Ovary of the tlower 

 (/). B Ripe Fruit. The two 

 carpels have separated so as 

 to form two mericarps (m). 

 Part of the septum consti- 

 tutes the carpophore (a). 



