BOTANY. 93 
of them is B. papyracea, paper or canoe birch, from whose bark the northern 
and western Indians and hunters manufacture their canoes. The genus Alnus, 
or Alder, is of little economical importance. 
Sub-order 5. Casuarinee, the Beefwood Tribe. Flowers with bracts ; 
stamen one ; ovary one-celled ; ovules one to two; fruit consisting of winged 
achzenia, 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. Myricee, 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 T. Salicinee, the Willow Tribe. Dicecious trees or shrubs, with 
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 imperfectly 
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 
yellow dye, Quercitron, is obtained. See pl. 72, fig. 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. 72, fig. 7; a, branch 
with male and female flowers; 6, a nut; c, the same in the partly removed 
hull. 
Liquidambar styraciflua, Sweet Gum (North American). Pl. 72, fig. 9; a, 
branch with leaves and flowers ; b, anther; c¢, pistil; d, the fruit ; e, open pod; 
f, ovary ; g, dissepiment with the seeds ; h, a single seed. 
Orver 45. Pireraces, the Pepper Family. Flowers ¥. 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 
