438 PART IV. CLASSIFICATION. 



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. 



GROUP V. ANGIOSPERALE. 



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

 triennials, 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 group. 



The General Morphology of the Reproductive Organs. 

 The reproductive organs are pollen-sacs (microsporangia) and ovules 

 (macrosporangia), borne generally on sporophylls, but sometimes 

 directly on the floral axis (e.g. microsporangia of Naias, etc. ; 

 macrosporangia of Polygonum, Primulacese, etc.) : they are de- 

 veloped on special shoots differentiated as flowers, and the flowers 

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

 florescence. 



The Inflorescence (see p. 54). It is only in comparatively few 

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

 such plants are said to uniaxiol : 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 

 bi-j tri- 1 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. 55). 



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

 Augiosperms, 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 Craciferse the bracts at 

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

 same occurs in many of the Compositae. In the Solanaceae and 

 Boraginaceae the bract often undergoes displacement, so that it 



