438 DICOTYLEDONES. 



flowers, a gamosepalous, dentate calyx, free petals, one whorl of 

 stamens which are split irregularly into several bundles (Fig. 470). 

 The fruit is a multilocular berry provided with a thick, tough, outer 

 layer. The juicy pulp, which fills up the loculi and envelopes 

 the seeds, is formed from many large-celled, juicy hair-structures 

 which arise on the inner side of the walls of the loculi and by 

 degrees entirely fill them up ; the dissepiments remain thin, and 

 form the partitions so easily separating from each other (Fig. 

 469). The seeds in many instances are remarkable for containing 

 several embryos. The blade of the leaf is separated from the 

 frequently winged stalk by a node (and hence is a compound leaf 

 with only the terminal leaflet developed ?) (Fig. 468) ; in other 

 genera, as Triphasia, there is a fully developed trifoliate leaf. 

 Thorns are frequently developed. The species of this genus, which is 

 a native of the warmer parts of S. E. Asia, are very hard to separate. The 

 differences are found in the forms of the fruit, the leaves and the leaf-stalks, 

 and in the number of stamens. Citrus medica, " Cedrat " (Ind.) ; C. Liinonum, 

 "Citron," "Lemon" (introduced into Italy in the 3rd to 4th century). 

 OFFICINAL : the fruits and essential oil of Lemon. C. aurantium from E. Asia, 

 the Orange (introduced into Italy in the 14th century). C. vulgaris (Fig. 468), 

 Bitter Orange (introduced into Europe at the time of the Crusades) ; the unripe 

 Bitter Oranges, and peel of the Bitter Orange is officinal ; it is from the flowers 

 of this species especially that the essence of Neroli is made. C. limetta, 

 C. bergamia, Bergamot ; essence of Bergamot is officinal. C. decumana, Pomalo, 

 a native of the Islands of the Pacific. About 780 species ; chiefly tropical. 



Order 4. Burseraceae. Fruit a drupe ; 1-5 stones. The bark, as well as 

 the other parts, contain strong aromatic resins and balsams, and hence 

 several species are used : the Myrrh tree, Commiphora (Balsamodendron) from 

 Arabia and Africa; OFFICINAL: Myrrha (Commipliora my rrha). Mecca-balsam 

 from C. opobalsamum, Arabia ; E. Africa. The Incense-tree (Boswellia) from the 

 same parts of the globe and E.India. The incense of B. carteri is medicinal 

 (Frankincense). The resin (Elemi) of Protium-species is officinal, and is used 

 technically for varnish (S. Am.). Takamahaka- resin from Elaphrium (S. Am.) 

 Protium (Idea) ; Amyris (1 carpel). 270 species ; tropical. 



Order 5. Zygophyllaceae. The majority have opposite, pinnate leaves with 

 stipules. Leava: without pellucid dots. The filaments have a scale on the 

 inner side. 1'ht most important is Guaiacum qfficinale (West India), the wood 

 {Lignum Vitae) of which is very hard and beavy, this wood and Gum-guaiacum 

 are officinal. Others have a peculiar repulsive smell and taste : the Creosote 

 shrub (Larrea mexicana) and Zygoplnjllum simplex. Tribulus teirester is a 

 common weed in S. Europe. Fagonia. Peganum harmala (South of Russia) 

 yields a red dye. 110 species ; especially in the Tropics ; several species in 

 sandy deserts. Nitraria. 



Order 6. Simarubaceae. This order is distinguished by the abundance of 

 Utter substances which it contains (Quassine) especially in the bark and the 

 wood. The wood of Quassia amara (Guiana, Antilles) is officinal ; Picracna 



