BOTANY. 93 



of them is B. papyracea, paper or canoe bircli. from whose bark the northern 

 and western Indians and hunters manufacture their canoes. The genus Alnus, 

 or Alder, is of Httle economical importance. 



Sub-order 5. Casuarinea, the Beefwood Tribe. FloAvers with bracts ; 

 stamen one ; ovar^y one-celled ; ovules one to two ; fruit consisting of winged 

 achaenia, collected into a cone ; seed erect ; radicle superior. Australian trees 

 or shrubs, with filiform branches, bearing membranous toothed sheaths in place 

 of leaves. 



Sub-order 6. Myricece, the Myrtle Tribe. Achlamydeous flowers ; stamens 

 two to eight in the axil of a scale ; ovary one-celled, with hypogynous scales ; 

 ovule solitary, erect, orthotropal ; fruit drupaceous, often with a waxy secretion, 

 and with fleshy adherent scales ; radicle superior. Natives both of temperate 

 and tropical regions, and found in North and South America, in India, and at 

 the Cape of Good Hope. North American genera, Myrica and Comptonia. 

 Examples : Myrica gale. Sweet gale or Bog-myrtle ; M. cerifera, wax myrtle ; 

 and Comptonia asplenifolia or sweet fern. 



Sub-order 7. Salicinece^ the Willow Tribe. Dioecious trees or shrubs, Avith 

 both kinds of flowers in catkins, one under each bract, entirely destitute of 

 calyx or corolla ; the fruit a one-celled and two-valved pod, containing numer- 

 ous seeds clothed with a long silky down. Ovary one-celled or imperfectl}' 

 two-celled ; styles two, very short, or more or less united, each with a two- 

 lobed stigma. Seeds ascending, anatropous, without albumen. Cotyledons 

 flattened ; leaves alternate, undivided, with scale-like and deciduous, or leaf- 

 like and persistent stipules. Wood soft and light, bark bitter. The genera 

 Salix and Populus, known respectively as Willows and Poplars, have numer- 

 ous North American species, although none of sufficient importance to require 

 special mention. They are of little value as timber trees, owing to the soft 

 and spongy texture of their wood ; the charcoal, however, is in much request by 

 gunpowder manufacturers. 



Quercus tinctoria. Black oak, is a North American tree from which the 

 yelloAV dye, Quercitron, is obtained. See pi. 12, ßg. 8 ; a, branch with fruit ; 

 b, a leaf ; c, represents a female flower of the Cork oak (Q. suber). 



Chastena vesca or Chestnut (European variety). PL 12, ßg. 1 ; a, branch 

 with male and female flowers ; b, a nut ; c, the same in the partly removed 

 hull. 



Liquidambar styraciflua. Sweet Gum. (North American). PL 12, ßg. 9 ; a, 

 branch with leaves and flowers ; b, anther ; c, pistil ; d, the fruit ; e, open pod : 

 /, ovary ; g, dissepiment with the seeds ; h, a single seed. 



Order 45. Piperace.e, the Pepper Family. FloAvers ^. Perianth 0, 

 flowers supported on a bract. Stamens two, three, or six, arranged on one 

 side or all around the ovary ; anthers one- or two-celled, with or without a 

 fleshy connective ; pollen roundish, smooth. Ovary solitary, free, one- 

 celled ; ovule solitary, erect, orthotropal ; stigma simple, sessile, rather 

 oblique. Fruit somewhat fleshy, indehiscent, unilocular. Seed erect ; 

 embryo in a fleshy vitellus outside the albumen, and at the apex of the seed. 

 Shrubs or herbs, with articulated stems, opposite (sometimes alternate by 

 abortion of one of the pair of leaves), or verticillate. exstipulate or stipulate 



93 



