CASUAEINACE^ — BETULACEjE — PLATANACE^. 593 



Order 178.^ — Oasuaeinace^, the Beef- wood Family. (Apet. 

 Dielin.) Flowers moncBcious or dioecious, bracteated. Males in spikes : 

 stamen 1 ; filament lengthening ; anther dehiscing longitudinally. 

 Females in capitula : ovary 1-celled, ovules 2 ; fruit consisting of 

 winged achsenia, collected into a cone ; seed erect ; radicle superior. 

 — Australian trees or shrubs, with filiform branches, bearing mem- 

 branous toothed sheaths in place of leaves. They are found also in 

 India, the Indian Archipelago, and Madagascar. Genus, 1 ; species, 

 about 20. Example — Oasuarina. 



The species of Oasuarina (Oassowary-tree) yield excellent timber, 

 called Beef-wood, from its having some resemblance to raw beef. 

 What is called the She-oak in Australia is G. quadrivalms. In the 

 integument of the seeds of Gasuarinas there are numerous spiral cells. 



Order 179. — BETULACE.ffi!, the Birch Family. {Apet. Dielin.) 

 Flowers monoecious, in catkins. Male flowers borne on scales, which 

 are sometimes vertioillate, so as to form a perianth : stamens 4 or 2 ; 

 anthers innate (basifixed). Female spikes pendulous : ovary 2-eelled ; 

 ovules solitary, pendulous, anatropal ; fruit membranous, indehiscent, 

 forming a sort of cone ; seeds pendulous, exalbuminous ; embryo with 

 a supeior radicle. — Amentiferous trees with alternate stipulate leaves, 

 stipules deciduous. Natives of temperate and cold regions in Europe, 

 Asia, and America, and extending to the Arctic and Antarctic regions. 

 Genera, 2 ; species, about 35. Examples — Betula, Alnus. 



The species of Betula, Birch, have astringent and resinous barks. 

 The oil from the bark of the common Birch {Betula alba and glutinosa) 

 gives the peculiar odour to Kussia leather. In North America the 

 bark of the Oanoe Birch {Betula papyracea) is used for making boats. 

 A saccharine matter exists in the sap of the Birch. Betula lenta is 

 the Black Birch of America, and is called Mountain Mahogany on 

 account of the beauty and hardness of its timber. The bark of B. 

 Bhaja/paltra is used in India to form paper. Alnus glutinosa, common 

 Alder, grows well in muddy ground on the banks of rivers. Its 

 charcoal is used in the manufacture of gunpowder. In Kamtschatka 

 the bark of Alnus incana is used in the preparation of a kind of 

 bread. 



Order 180. — Platan ACE.ffl, the Plane Family. {Apet. Dielin.) 

 Flowers in unisexual globose catkins or capitula. Male flowers covered 

 by scale-like bracts; stamen 1, with scales. Female flowers with a 

 1-celled ovary: style thick and subulate; ovules solitary or in pairs* 

 suspended, orthotropal. Fruit consisting of compressed clavate nuts, 

 terminated by recurved styles ; seeds 1-2, pendulous, albuminous ; 

 embryo with an inferior radicle. ^Trees with alternate, palmate, and 

 stipulate leaves. Natives chiefly of temperate regions, as the 

 Levant and North America. Genus, 1 ; species, about 6. Example 

 — Platanus. 



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