SECT. II 



THANEROGAMIA 



573 



there is more or less marked heteropliylly. Flowers hermaphrodite, with calyx 

 and corolla. The whorls consist of three (rarely), four or more numerous 

 members. Carpels sometimes free. Parts of the flower often spirally arranged 

 (Figs. 553-555). Latex. 



Nymphaca alha, the White Water Lily (Fig. 553), has large floating leaves and 

 white flowers, protected by firm green sepals. Within the corolla comes the zone 



Fio. 554. — Nymphaea. 

 Floral diagram. 



A 



Fig. 555. — A, Floral diagram. B, Fruit of Cahumld aquatica 

 showing two carpels developed as partial fruits. (After 

 Baillon. X 4.) 



of numerous stamens and the inferior ovary composed of numerous, coherent 

 carpels. The spiral arrangement of the members of the perianth and androecium 

 is seen by the scars of their insertion when they are removed from the inferior 

 ovary (Fig. 553), and in the floral diagram (Fig. 554). In Nuphar the ovary is 

 superior and tlie small petals bear nectaries ; the conspicuous calyx renders the 

 flower attractive. In the American geniis Cabomha the flowers are trimerous and 

 the pistil is apocarpous. The finely divided, submerged leaves differ in appearance 



B 



D 



E 



*»}> 



Fig. 556. — Floral diagrams of Ranunculaceae. A, Anemone nemorosa. B, Adonis autnmnulis. 

 C, Aconituvinuptllus. I), AquUe(jia vulgaris. E, Cimicifuga racemosa. (After Eichlee.) 



from the entire, floating leaves. The car})els are also free in Nelumhium, both the 

 leaves and flowers of which are raised above the surface of the water. Victoria 

 regia from the Amazon, and Euryale ferox from tropical Asia, have gigantic 

 floating leaves ; they are often cultivated in Botanic Gardens. 



The family of the Ceratophyllaceae (•'-) with the single genus Ccrafophyllum may 

 be placed here. The plants, which often occur in masses, are submerged aquatics. 



Family 2. Ranunculaceae (■^^). — Herbs or rarely woody plants 



