FAMILIES OF FLOWERING PLANTS 95 
give a good idea of the floral structure in this family, and of the curved 
embryo shown in the cross-section of the fruit. 
_ With the exception of Chenopodium, the species of which are mostly 
distributed over the country as weeds, the American Chenopodiaceae 
are largely natives of the western States, where they form the predom- 
inant vegetation of the so-called “alkali” plains, and are known as 
saltbushes (Atriplex and Suaeda). Farther south one meets the shrubs 
known as “greasewoods” (Sarcobatus), which are abundant in the des- 
ert regions of the lower Colorado watershed. When growing in saline 
soils, either in the interior, or along the coast, the plants are usually 
extremely fleshy and succulent, like other halophytes. (See Fig. 78.) 
As potherbs many of the mem- 
bers of this family are highly es- 
teemed. The leaves of spinach (Sp- 
nacia), of the beet (Beta), and of the \' 
common lamb’s quarters (Chenopo- \ 
dium album) are used for this pur- 
pose. The beet, moreover, is of com- 
mercial importance, aside from its 
value as a vegetable, on account of 
the sugar extracted from it. The 
sugar-beet industry, particularly in 
France, has assumed large propor- 
tions in recent years, and the product 
is in many respects superior to cane 
sugar. Soda and potash are obtain- 
ed from some species of Salsola, while 
many of the genera yield essential 
oils valuable in medicine as antispas- 
a Fig. 78. ‘The common saltwort (Salicornia 
modics. herbacea), showing the fleshy cylindrical 
Family Amaranthaceae. Ama- leaf. After Britton & Brown, Ill. Fl. North- 
ranth family. Contains about 40 ae 
genera and 450 species, widely distributed, but most abundant in the 
tropics. They are herbs or undershrubs, with simple leaves and small 
perfect monoecious or dioecious flowers, usually borne in dense clus- 
ters. The perianth may be in one or two series, but there are no true 
petals. Like other families in the order Centrospermae, the Amaranth 
fruit is utricular, but it splits in a transverse ring at about the middle ; 
this is called by botanists a circumscissile dehiscence. The flower and 
fruit are shown in the middle line of Fig. 77. 
The genus Amaranthus, which shares with Chenopodium the name 
of “pig-weed,” is one of the largest representatives of the family, and 
includes a number of familiar weeds of the eastern United States. The 
