388 DICOTTLEDOXES. 



tacbed from its stalk, and dehiscing from the base upwards so that the seeds are 

 set free ; while in Nymph aa aZ&athe 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. ]$ympha:a ccerulea and Lotus were sacred among the 

 Egyptians. 



Order 3. Ceratophyllaceae. About 3 species. Aquatic 

 plants, submerged, rootless ; leaves cartilaginous, vertieillate, 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 the 6-12 

 perianth-leaves is situated in the g -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. CeratnpJiyllum (Horn-wort). 



Order 4. Anonaceae. Sepals 3; petals 3 + 3 (most frequently r air ate) ; 

 succeeding these (as in the Ranunciilacca) 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 

 Mi/ristica. Trees or shrubs with alternate, simple, entire, penninerved leaves 

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

 Anona clirrimolia, squamosa and reticuJata (all from America) cultivated on 

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

 perties (Xylnpiti, Cananffi the flowers of the latter yield Ylang-ylang) ; 

 Artabotrys odoratissima ; Asimina (N. Am.). 



Order 5. Magnoliacese. 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 3*0 linger iuternodes 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. MAGNOLIE.E. 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- 



