CHAMBERS'S INFORMATION FOR THE PEOPLE. 



but ako in their general properties. They are 

 much simplified by subdivision into two orders 

 namely, Urticacece and Artocarpacea the former 

 including the herbaceous species as the nettle, 

 hemp, and hop, with watery juice ; and the latter 

 the ligneous species as the bread-fruit, mulberry, 

 and fig, which have their juice milky. Bearing 

 this distinction in mind, the following may be 

 stated as the characteristics common to both : 

 Trees, shrubs, or herbs, with alternate leaves, 

 sometimes covered with asperities or stinging 

 hairs, and furnished with membranous stipules, 

 which are deciduous or convolute in vernation ; 

 flowers, usually monoecious, sometimes dioecious ; 

 perianth, membranous, lobed, and persistent ; 

 stamens, definite, distinct, inserted into the base 

 of the perianth, and opposite its lobes ; anthers, 

 turned backwards with elasticity when bursting; 

 ovary, superior, simple ; ovule, solitary, erect, or 

 pendulous ; stigma, simple ; fruit, a simple inde- 

 hiscent nut, as in the nettle and hemp or con- 

 sisting of achenes immersed in a fleshy recep- 

 tacle, or the persistent fleshy perianths, as in the 

 bread-fruit, or inclosing them within its cavity, as 

 in the fig. 'The unisexual flowers,' says Dr 

 Lindley, 'simple lenticular fruit, and superior 

 radicle and stipules, afford the essential char- 

 acteristics of this order, which cannot well be 

 mistaken for any except Chenopodiacea; and the 

 plants of that order never have stipules, or rough 

 or stinging leaves.' 



The chief genera in the order URTlCACEjE are 

 Urtica, of which U. dioica is the common 

 stinging-nettle ; U. urens, the smaller stinging- 

 nettle ; and 17. pilulifera, the Roman nettle ; 

 Humulus lupulus, the cultivated hop ; Cannabis 

 sativa, the fibrous hemp of commerce ; and Pari- 

 etaria erecta, the pellitory of the wall. The 

 members of this order are widely scattered over 

 the world, and increase apparently with the pro- 

 gress of civilisation ; some of them as, for 

 example, the nettles following in the footsteps 

 of man. The chief genera of the order ARTO- 

 CARPACEvE are Artocarpus, of which A. incisa is 

 the bread-fruit of the South Sea Islands ; and 

 A. integrifolia, the jack-tree of the East India 

 Islands ; Galactodendron utile, the cow-tree or 

 palo de vaca of South America ; Antiaris toxi- 

 caria, the upas-tree of Java, about which so many 

 fabulous stories have been told ; Morus, of which 

 M. nigra is the common black mulberry, M. 

 rubra, the red, and M. alba, the white mulberry, 

 the leaves of which are so much esteemed for 

 feeding silkworms ; Ficus, of which F. Carica is 

 the common edible fig, F. Sycamorus, the syca- 

 more fig, the wood of which is very durable, and 

 is supposed to have been used in the construction 

 of mummy-cases ; Urostigma, of which U. Indica 

 is the spreading banyan, U. elasticum the India- 

 rubber tree, and U. religiosum the sacred fig or 

 pippul-tree of India. Baehmeria (Urtica) nivea, 

 the China nettle, is the source of that beautiful 

 fabric for handkerchiefs, &c. which has of late 

 years come into use under the name of China- 

 grass and China nettle-fibre. Large quantities 

 of the fibre are produced in the East, and find a 

 ready sale in European markets, and especially 

 among European residents in hot countries, for 

 whose clothing this extremely fine fibre is peculi- 

 arly adapted. 

 The Urticaceae have watery juice, which is 



106 



acrid and astringent, and the fibres of their stems 

 are all less or more tenacious. The leaves of the 

 hemp are narcotic ; the hop (fig.) has bitter, aro- 



Hop. 



matic, and stomachic properties, and its effluvia 

 are said to be narcotic. The stinging property of 

 the common nettle is well known. In the Artocar- 

 paceae, the juice is milky, and on exposure to the 

 air, becomes tough and elastic. Their fruit is 

 edible, but their juice is generally acrid and 

 poisonous ; except in that of the Galactodendron, 

 which is wholesome and nutritious. The elabor- 

 ation of a tough elastic product seems to be char- 

 acteristic of the whole order making its appear- 

 ance in the stem of the hemp, in the inspissated 

 juice of the India-rubber tree, or in silk, the best 

 of which is derived from silkworms which feed 

 on the leaves of the mulberry. 



BETULACE^E. A small order of trees and shrubs, 

 abounding in the temperate and colder regions of 

 the globe. They have alternate simple leaves, 

 with the primary veins often running straight from 

 the midrib to the margin, and deciduous stipules. 

 The flowers are in catkins, unisexual, and monoe- 

 cious ; the males having small scales in place 

 of a perianth, or, in Alnus, a four-leaved mem- 

 branous perianth. Stamens distinct, opposite the 

 scales, scarcely ever monadelphous ; anthers, two- 

 celled ; ovary, two-celled ; ovules, definite, pen- 

 dulous ; style, single or none ; stigmas, two ; fruit, 

 membranous, indehiscent, by abortion one-celled ; 

 seeds, pendulous, naked. 



The chief genera are Bettila, the birch, and 

 Alnus, the alder, the species of which abound in 

 every northern country. The common white birch 

 (B. alba) is an elegant tree, thriving in almost any 

 sort of soil, and becoming stunted and dwarfish 

 only in the arctic regions, or at great elevations. 

 The weeping-birch is a still more graceful tree, 

 grown in lawns and parks for its fine drooping 

 branches and neat foliage. B. nana is the dwarf 

 birch of high and exposed situations, being found 

 on the Scottish mountains and in some countries 

 approaching to the very limits of perpetual snow. 

 B. nigra is the black birch of North America, 

 the timber of which is used by cabinet-makers ; 

 and B. papyracea is the paper birch, whose b 



