THE DICOTYLEDONES 1607 



RANALES 



The Ranales are Archichlamydeae in which the number of the floral 

 parts is generally indefinite and the carpels are free and either superior or 

 rarely immersed in the receptacle. The embryo is minute and embedded 

 in a fleshy endosperm. The flowers are usually hypogynous or rarely 

 perigynous, hermaphrodite, and with the parts arranged spirally, cyclically 

 or spiro-cyclically. 



The leaves are often large, are usually arranged alternately, rarely 

 opposite, and very rarely possess stipules. The vascular bundles in the 

 stem are sometimes scattered, as in Monocotyledons. 



The systematic position of the Ranales has been a subject of much 

 controversy. That they are relatively primitive is generally accepted but 

 whether they are to be considered as the most primitive group of the 

 Dicotyledons depends upon the attitude adopted regarding the systematic 

 position of those Monochlamydeae which are devoid of petals and whose 

 flowers are pollinated by wind. This latter group was considered by 

 Bentham and Hooker to be a reduced series derived from more elaborate 

 ancestral types. On the other hand Engler and Prantl placed them first, as 

 the most primitive Dicotyledons, on a supposed similarity between their 

 floral structure and that of the Gymnosperms. 



In the arrangement adopted here the Ranales are represented as the 

 most primitive group. This is supported by the free carpels, the indefinite 

 number of the floral parts and the fact that they may be spirally inserted 

 on the receptacle. It has been decided however not to follow Hutchinson 

 who splits the order into two distinct parts, retaining the Ranales for the 

 herbaceous types and making a new order, the Magnoliales, for the arbor- 

 escent forms. 



The Ranales as treated here include a number of important and well- 

 known families of which we may mention the following: Nymphaeaceae, 

 Ranunculaceae, Berberidaceae, Magnoliaceae, Annonaceae, Myristicaceae, 

 Lauraceae, Calycanthaceae and Ceratophyllaceae. Of these we shall 

 consider only the Ranunculaceae in detail (page 1619). The order as a whole 

 is well represented as fossils in Tertiary Rocks and appears to have been 

 very widely distributed at an early period. 



The Nymphaeaceae, or Water Lily Family, include a number of 

 aquatic herbaceous plants which are widely distributed in tropical and north 

 temperate regions, and many are cultivated in this country. The family 

 includes eight genera and about sixty species. In Nymphaea the flowers 

 are variously interpreted but most authors consider that the four outermost 

 segments represent a calyx. There are four outer and four inner petals, 

 within which are eight series of spirally arranged segments, which show a 

 gradual transition from petals to stamens. These segments and the very 

 numerous stamens are inserted on the side of the gynoecium, which has 

 from ten to twenty loculi, each containing many ovules scattered over the 

 carpellary surface. The fruit ripens under water and there dehisces and 



