ANGIOSPERMA:, DICOTYLEDONES. 777 



Alliance LVI. Disciflorae. 



Families: Linacece, Erythroxylacece, Oxalidacece, Humiriacece, Malpighiacece, Zygo- 

 phyllacece, Geraniacece, Balsaminece, Tropceolaccce, Rutacece, Aurantiaccce, 

 Diosmacece, Zanthoxylacece, Simarubacece, Ochnacece, Burseracece, Meliacece, 

 Ilicinece, Celastrinece, Rhamnacece, Ampelidece, Sapindacece, Acerinece, 

 Hippocastanece, Sabiacece, Terebinthacece. 



Annual and perennial herbs, shrubs, and trees, with simple and compound 

 foliage-leaves. Flowers actinomorphic and zygoinorphic, hermaphrodite, pseudo- 

 hermaphrodite, monoecious and dioecious; arranged in varying types of inflores- 

 cence. Floral-leaves in two 4-5-merous whorls; the lower whorl a calyx, the upper 

 a, corolla. The gynseceum is composed of a whorl of carpels borne on a swollen 

 disc. Ovary superior. Each carpel has a separate loculus. In Aurantiaceae and 

 Ampelideae the carpels are completely united so as to form a single pistil; in 

 Rutaceae and Zygophyllaceae they are united at the base and form a lobed ovary, 

 whilst in Zanthoxylaceae, Ochnaceae, and Simarubaceae, they are quite separate (see 

 fig. 438 6 ). In Terebinthaceae only one carpel is developed, but there are usually 

 traces of suppressed carpels close to it. The ovules are in the inner angles of the 

 loculi; in Aurantiaceae, Rutaceae, and Zygophyllaceae their number exceeds two in 

 -each loculus, in the other families it is only 1-2. The stamens are arranged in 1-2 

 whorls, and number 4-5 in each whorl; they spring from the edge or from the 

 surface of the floral receptacle, which is swollen and forms a ring round the ovary; 

 their place of origin is always lower than the base of the ovary (see figs. 438 2 - 6 - 7 ). 

 The pollen is adhesive. The fruit contains either few seeds or a single compara- 

 tively large seed. 



The Disciflorae are in most instances woody plants, containing etherial oils and 

 .aromatic, resinous substances like turpentine. Amongst the Malpighiaceae, Celas- 

 trineae, and Ampelideae are many lianes. The foliage-leaves are undivided in 

 Erythroxylaceae and Celastrinese (see fig. 438 x ), lobed in most Aceraceae and 

 Ampelideae, and variously segmented and compounded in the other families (see 

 -fig. 438 3 ). The petals are usually small, and of a greenish-yellow colour. The 

 filaments in Melianthaceae and Aurantiaceae are connate all together, or in groups. 

 The fruits are extremely various. In Staphyleaceae and Diosmaceae they are 

 follicles; in Celastraceae and Rutaceae, capsules (see fig. 325 6 , p. 431); in Zygo- 

 phyllaceae, Aceraceae, and Malpighiaceae, schizocarps; in the Tree of Heaven, of the 

 family Simarubaceae, winged achenes (samaras, see fig. 323 7 , p. 428); and in 

 Ampelideae and Aurantiaceae, berries. The Disciflorae are distributed over the 

 whole earth. The majority belong to the tropics, and several, e.g. Burseraceae, 

 Ochnaceae, and Malpighiaceae are exclusively tropical. The Diosmaceae are confined 

 to South Africa, the Rutaceae to the districts of the Mediterranean and the Black 

 Sea Comparatively few species occur in the Northern Temperate Zone, or in 

 corresponding situations on mountains. The Mountain Maple covers about the 



