132 POLYGONACEAE. 



Polygonum amphibium L. Perennial, aquatic, glabrous or nearly so; 

 leaves floating, elliptic or oblong, obtuse or acutish, smooth and shiny above, 

 5-12 cm. long, long-petioled; spikes dense, 2-3 cm. long. 



In ponds and lakes, common. 



Polygonum hartwrightii Gray. Perennial, on muddy banks, more or less 

 strigose-pubescent especially on the sheaths and bracts. 



On the borders of ponds and lakes, not uncommon. Many botanists 

 consider this only a hairy terrestrial state of P. amphibium. 



Family 34. CHENOPODIACEAE. GOOSEFOOT FAMILY. 



Mostly annual or perennial herbs; stems angled, striate or 

 terete; leaves alternate or sometimes opposite, simple, entire, 

 toothed or lobed, mostly petioled, without stipules; flowers per- 

 fect, polygamous, monoecious or dioecious, small, greenish, 

 regular or slightly irregular, commonly in panicled spikes, with 

 or without bracts; calyx persistent, 2-5-lobed or parted, or 

 rarely reduced to a single sepal or in some pistillate flowers 

 wanting; petals none; stamens as many as the calyx lobes or 

 fewer and opposite them; disk usually none; ovary mostly free 

 from the calyx, 1-celled; ovule 1; fruit a utricle; endosperm 

 mealy, fleshy or wanting. 



Leaves nearly terete, fleshy. 161. DONDIA, 132. 



Leaves flat, scale-like or subulate, not fleshy. 



Leaves scale-like; flowers embedded in the 



fleshy axis. 162. SALICORNIA, 132. 



Leaves not scale-like; flowers not embedded in 



the axis. 

 Flowers unisexual; fruit enclosed by two 



bracts. 163. ATRIPLEX, 133. 



Flowers perfect; fruit bractless. 



Leaves becoming spiny. 164. SALSOLA, 133. 



Leaves not spiny. 165. CHENOPODIUM, 133. 



161. DONDIA. 



Fleshy plants growing in salty places; leaves alternate, fleshy, 

 linear, nearly terete; flowers sessile in the axils of leafy bracts; 

 calyx 5-parted, fleshy, enclosing the fruit; stamens 5; stigmas 

 2 or 3; embryo spirally coiled; endosperm scanty or none. 



Dondia maritima (L.) Druce. Sea-blite. Stems 5-40 cm. high, with 

 ascending or sometimes procumbent branches; leaves linear, plane above, 

 convex beneath, glaucous, 3-5 cm. long, those on the flowering branches 

 reduced; flowers 1-4, axillary, shorter than the subtending leaf; sepals convex 

 or obscurely keeled; seed brown to black, 2 mm. broad. 



Salt marshes, rare in our limits. Coupeville, Gardner. 



162. SALICORNIA. 



Low plants growing in salty places; stems succulent, jointed; 

 leaves reduced to opposite scales or teeth; flowers perfect, em- 



