434 



DICOTYLEDONES. 



etc.) properties in the latex or the seeds. OFFICINAL : " Cascarilla-bark " of 

 Croton eluteria\ the fatty oil of the seeds of Croton tiglium (Trop. Asia) ; " Cas- 

 tor oil " from Ricinus communis (Africa, and cultivated in all warm climates 

 throughout the world); the glandular hairs of Mallotus philippinensis (" Kamala ") ; 

 this also yields a red dye. Gum "Euphorbium" is the hardened (resinous) 

 latex of the Cactus-like Euphorbia resinifera (Morocco). NUTRITIVE plants: 

 Manihot utilissima and other species (Maniok, Am.). Their large, farinaceous 

 roots form a very important article of food in the Tropics (Cassava-flour, 

 Tapioca or Brazilian arrow-root). The fresh latex of the root in some species 

 is a powerful poison ; but the poisonous properties are diminished by roasting 

 or cooking. Caoutchouc is obtained from Siphonia elastica (Trop. S. Am.). 

 The vegetable tallow of the Chinese tallow-tree (Stillingia sebifera) is used in 

 large qantities in soap factories. AD indigo-like dye is obtained from Crozo- 

 phora tinctoria, and is also found in Mercurialis perennis. Shellac is obtained 

 from Aleurites laccifera. ORNAMENTAL plants : Acalypha, Croton, Dalechampia.. 

 Hippomane is poisonous. 



Order 2. Buxaceae. This order differs from the Euphorbiacete in having 

 the micropyle turned inwards ; the $ -flower has a 4-partite perianth and 4 

 stamens ; the ? -flower a 6-partite perianth and 3 carpels. Capsule with, 

 loculicidal debiscence, the inner layer being detached elastically from the outer. 

 30 species. Shrubs without latex and with evergreen leaves. Buxus semper - 

 virens (Box) is an ornamental shrub (poisonous) ; it has a very hard and valuable: 

 wood which is used for wood engraving and carving. 



463. 4' ; 4 



FIGS. 462-164. Caliitrich} stagnates. 



FIG. 462. <J -flower with the 2 bracteoles and the solitary stamen. FIG. 4G3. ? -flower.. 

 FIG. 464. Longitudinal section of the ripe fruit. 



Order 3. Callitrichaceae. Aquatic plants, growing at the bottom of shallow 

 water, with opposite, simple, undivided, entire, exstipulate leaves, which are 

 generally crowded and form a rosette in the apex of the branches. The flowers 

 are unisexual (monoecious) and borne singly in the leaf-axils; they have no 

 perianth, but are provided with two delicate bracteoles ; the $ -flowers consist . 

 of only 1 terminal stamen (Fig. 462) ; the $ -flowers of a bicarpellate gynoeceum 

 (Fig. 463) which is originally 2-locular, but later on becomes 4-locular, as in the 

 case of the gynoeceum of the Labiata?, by the formation of a false partition- 

 wall ; in each loculus there is 1 pendulous ovule with the micropyle turned 

 outwards. Fruit a ^-partite schizocarp (Fig. 464). 25 species. Callitriche. 



Order 4 (?). Empetraceae. 4 species. Empetrum; E. nigrum (Crowberry)/ 



