GROUP IV. — PHANEROGAMIA : ANGIOSPERM J] 489 



circular bilobed upper surface, a single long persistent foliage-leaf being borne 

 at the margin of each lobe : the inflorescences are borne in dichotomous cymes, 

 usually in the axil of each of the two leaves. Habitat, Damaraland, Western 

 South Africa. 



\ 



DIVISION B. 

 CLASS II.— ANGIOSPERM^. 



The plants of this class are to a large extent herbaceous annuals, 

 biennials, or perennials ; but it also includes a great number of 

 shrubs and trees. 



The Sporophyte. 



The General Morphology of the Vegetative Organs is so varied that 

 it cannot be dealt with in a general way. The reader is referred 

 to the treatment of the subject in Book I,, and to the descriptions 

 given in the systematic account of the class. 



The General Morphology of the Reproductive Organs. The repro- 

 ductive organs are pollen-sacs (niicrosporangia) and ovules (macro- 

 sporangia), borne generally on sporophylls, but sometimes directly 

 on the floral axis {e.g. microsporangia of Naias, Casuarina, etc. ; 

 raacrosporangia of Polygonum, Primulaceae, etc.) : they are de- 

 veloped in special shoots differentiated as flowers., and the flowers 

 are arranged in a more or less complex branch-system, the w- 

 fiorescence. 



The Inflorescence (see p. 76). It is only in comparatively few 

 cases that the primary axis of the plant terminates in a flower ; 

 such plants are said to uniaxial : it is usually not until the secon- 

 dary or tertiary branches, or even those of a higher order, are 

 developed, that a flower is formed. Such plants are said to be 

 6i-, tri-, or poly -axial. 



The floral axis of the Angiosperms frequently forms an elaborate 

 branch-system which is usually sharply defined, as a sporophore, 

 from the vegetative shoots, and which bears leaves which are 

 either sporophylls or hypsophylls (p. 59). 



In the inflorescence, as usually in all parts of the shoot of 

 Angiosperms, the branching is almost always monopodial and 

 axillary. Some apparent exceptions may be easily reduced to this 

 type : thus, in the racemes of most of the CrucifereB the bracts at 

 the bases of the individual lateral branches are abortive, and the 

 same occurs in many of the Composite. In the Solanaceee and 



