80 CHENOPODIACEAE 



Plants notglandnlar nor aromatic. 

 Pericarp easily separated from the'seed. 

 Calyx lobes barely keeled. 2. C. Boadanum. 



Calyx lobes stro^ngly keeled. 

 Leaves lioear to oblong. 3. C. leptophyUum. 



Leaves triangular-hastate. 4. C. Fremonlii iiicanum. 



Pericarp separated from seed with difficulty. 

 Leaves coarsely 2-8-toothed. 8. C. hybridum. 



Leaves sinuate to incised, j 

 Sepals strongly keeled. 1. C. album. 



Sepals not keeled in fruit. 



Leaves vfhite-glaucous beneath. 7. C. glaucum. 



Leaves green on both sides. 

 Seeds with rounded margins. 5. C. urUcum. 



Seeds with acute margins. 6. C. murale. 



Plants glandular or aromatic. 



Leaves sinuate-pinnatifid. 9. C. Botrys. 



Leaves repand-dentate to incised. 

 Flowers in leafy spikes. 10. C. ambroaioides. 



Flowers in leafless spikes. 11. C. anthelminticum. 



• 



1. C. album L. Pigweed. Erect annual, e'-lO" high, mealy : 



leaves rhombic-ovate to linear-lanceolate, at least the lower usually angu- 

 late-toothed, acuminate to obtuse : spikes in terminal clusters. — Abun- 

 dant in waste places. May-November. A form with linear entire leaves 

 occurring in the southern part and apparently native may be distinct. 



Var. viiide (L. ) Moq. Plant not mealy: leaves obtuse or acute. — 

 Infrequent in waste places. 



Var. Berlandieri (Moq.) Mackenzie & Bush, n. comb. Plant not 

 mealy : leaves cuspidate or bristle-tipped. — Abundant in waste places. 

 (C Berlandieri Moq.) 



2. C. BoBcianum Moq. Wood Pigweed. 1°-4° high, not mealy : 

 leaves oblong-lanceolate, slender-petioled, nearly entire : flowers in 

 slender, terminal spikes on widely diverging branches. — Common in 

 woods and thickets. July-October. 



3. C. leptophyllum (Moq.) Nutt. Narrow-leaved Pigweed. 

 Annual, S'-SO' high, more or less mealy : leaves linear to oblong-linear, 

 entire : branches erect : flowers densely clustered. — Infrequent along rail- 

 roads and in sandy soil throughout. May-October. 



Var. oblongifolium S. Wats. Leaves oblong. — With the type but 

 much more common. 



4. C. FremontU incanum S. Wats. Prairie Pigweed. Annual, 

 about 6' high, erect, mealy : leaves broadly triangular-hastate, sinuate- 

 dentate, densely mealy on both sides : spikes slender, axillary and ter- 

 minal. — Has been found as a waif at Courtney; also at Armstrong, 

 Kansas. July-September. 



5. C. urbloum L. City Pigweed. Dull green annual, l°-3° high, 

 not mealy, erect : leaves triangular-ovate, irregularly dentate : spikes 

 terminal and axillary, the upper longer than the leaves. — Waste places in 

 Kansas City and Sheffield. Not common. June-September. 



