388 DICOTYLEDONES. 



tached from its stalk, and d-hiscing from the base upwards so that the seeds are 

 set free; while in Nymphcea albai\\e spirally-twisted stalk draws the fruit under 

 water, and it dehisces by its upper part being thrown off as a hood, and the 

 seeds which are enclosed in air-tight sacs rise to the surface of the water. In 

 this condition they are able to float and can only sink to the bottom when the 

 air has disappeared. 



53 species ; in fresh water in all parts of the world, but especially in the 

 Tropics. The rhizomes and seeds of some may be used as food ; Euryaleferox 

 is even cultivated. Xymphcea ccerulea and Lotus were sacred among the 

 Egyptians. 



Order 3. Ceratophyllacese. About 3 species. Aquatic 

 plants, submerged, rootless ; leaves cartilaginous, verticillate, dis- 

 sected into repeatedly dichotomous branches which are finely 

 toothed ; only one of the leaves in a whorl supports a vegetative 

 branch. The flowers are monoecious, axillary. Inside ths 6-12 

 perianth-leaves is situated in the ^-flower 10-20 stamens with 

 thick connective, and in the ? -flower a gynceceum formed by 

 one carpel, with one orthotropous and pendulous ovule, which has 

 only one integument. Fruit a nut, which, in some species, bears 

 on each side a pointed horn, and at the apex a similar one, formed 

 by the persistent style. The embryo has an unusually well de- 

 veloped plumule with several whorls of leaves. The plant is root- 

 less throughout its whole life. Ceratophyllum (Horn- wort). 



Order 4. Anonacese. Sf-pals 3; petals 3 + 3 (most frequently valvate) ; 

 succeeding these (as in the Ranunculacece) are numerous acyclic stamens and an 

 apocarpous gynceceum ; the flowers are' hypogynous, regular and $ , generally 

 very large (2-3 cm. in diameter), and the leaves of the perianth are more or less 

 fleshy or leathery. The majority have syncarps with berry-like fruitlets, but 

 in Anona and some others the carpels fuse together into a large, head-like fruit 

 a kind of composite berry. The seeds have ruminate endosperm as in 

 Myristica. Trees or shrubs with alternate, simple, entire, penninerved leaves 

 without stipules. 450 (700 ?) species ; especially tropical. The best known are 

 Anona cherimolia, squamosa and reticulata (all from America) cultivated on 

 account of their large, delicious fruits. Some have acrid and aromatic pro- 

 perties (Xylopia, C anew go. the flowers of t"he latter yield Ylaug-ylang) ; 

 Artabotrys odoratissima ; Asimina (N. Am.). 



Order 5. Magnoliaceae. Trees or shrubs with scattered, often leathery, 

 entire leaves, generally with stipules, which (as in Ficus) are rolled together and 

 form a hood round the younger internodes above them, and are cast off by the 

 unfolding of the next leaf, leaving a ring-like scar. The endosperm is not 

 ruminate. Corolla imbricate. Fruit a syncarp. 



A. MAGNOLIEJE. The flowers are borne singly, and before opening are en- 

 veloped in an ochrea-like spathe which corresponds to the stipules of the foliage- 

 leaves. The perianth generally consists of 3 trimerous whorls, the external one 

 of which is sometimes sepaloid (Liriodcndron, and the majority of Magnolia- 



