leaves opposite below, subsessile or petioled above, 2-5 cm. long; blades 

 triangular-ovate to rounded-ovate, the margins smooth or sparsely tuberculate or 

 cristate, gray-furfuraceous but sometimes glabrate, the upper surface greener; 

 flowers of both sexes on same plant, the staminate ones in the upper axils or in 

 short dense spikes or the staminate and pistillate flowers mixed in axillary clusters 

 at least at the middle of the plant; fruiting bracts 4—8 mm. long and as wide, 

 united to the middle or above, obovate to cuneate-orbicular, the margins green, 

 subentire to laciniate, the faces smooth or appendaged; seed brown, 1.5 mm. long; 

 radicle superior. 



Alkaline grounds, floodplains and valleys, in w. Tex., w. Okla. (Waterfall), 

 N.M. (San Juan and Valencia cos.) and Ariz. (Apache, Coconino and Navajo 

 COS.); Sask. to Ore., s. to N.M., Ariz., Tex. and Calif.; introd. in e. U.S.; also in 

 w. Minn, and w. Mo. 



Subsp. expansa (Wats.) Hall & Clem. Annual herb or perennial; stems erect, 

 3-12 dm. tall, much-branched, forming clumps 3-10 dm. broad, finely mealy- 

 scurfy; leaves alternate, with petioles 2-21 mm. long on the lower leaves; blades 

 3-nerved at the base, ovate to lanceolate-ovate or deltoid-ovate, irregularly dentate 

 or entire, 25-75 mm. long and often as broad, the upper leaves reduced to sessile 

 and more or less cordate floral bracts as broad as long or broader than long; 

 spikes elongated, slender; flowers in small axillary glomerules or the glomerules 

 in short naked terminal spikes; perianth 5-cleft; fruiting bracts sessile to sub- 

 sessile, roundish, mostly 3-nerved, 5-7 mm. long, 2-4 mm. broad, the margins 

 sharply dentate, the sides smooth or with a few irregular green projections or 

 crests, or unappendaged; seed brown, 2 mm. long; radicle superior. 



Low alkaline valleys and bottomlands, Colo., Ut. and Nev., s. to w. Tex., 

 Calif, and Mex. 



11. Chenopodium L. Goosefoot. Pigweed 



Annual or perennial weedy herbs, rarely suffrutescent, often strongly scented, 

 usually with mealy-coated or glandular foliage but sometimes glabrate; stems 

 sometimes quite rough and nearly woody; leaves alternate, usually petiolate, 

 flat, varying from linear to ovate or hastate to lanceolate, the blade entire, 

 toothed or lobed, quite variable; flowers perfect or rarely unisexual, in axillary 

 or terminal spikes or glomerules; perianth usually 5-parted, calyxlike, the per- 

 sistent segments flat or keeled; stamens 1 to 5; ovary superior, usually depressed, 

 1-celled; styles 2 to 5; utricle containing one horizontal or vertical seed; pericarp 

 usually adherent to the seed, sometimes fleshy; embryo curved or annular, 

 surrounding the mealy endosperm; radicle inferior or centrifugal. 



A large genus of weedy plants, consisting of nearly 100 species, cosmopolitan 

 but mainly Eurasian. 



Some species, such as C. album, are used as potherbs while C. quinoa Willd. 

 is a valuable cereal plant in South America. Various songbirds, upland game 

 birds and small mammals utilize seeds of most species as a part of their diet. 

 The plants are especially valuable since the seeds persist on most species until 

 late in the year. 



1. Plants more or less resinous with sessile or stalked glands, usually strongly 

 aromatic (2) 



1. Plants without glands, often glabrous, never strongly aromatic (3) 



2(1). Perianth glabrous or only lightly puberulent, only slightly if at all glandu- 

 lar; flowers sessile and more or less glomerate in large panicles or 

 short spikes 1. C. ambrosioides. 



2. Perianth conspicuously glandular, usually also pubescent; flowers in numerous 



small axillary dichotomously branched cymes 2. C. Botrys. 



853 



