CHE NOP OD I A CEA E. 369 



Pericarp readily detached from the seed ; stem low. 



6. C. Fremontii incanum. 

 Sepals not keeled in fruit ; stem decumbent. 2. C. glaucum. 



Leaves mostly entire, narrowly linear or oblong. 3. C. leptophyllum. 



Leaves green and glabrous or nearly so on both surfaces when mature. 



Leaves oblong or ovate-oblong, entire. 4. C. polyspermum. 



Leaves, at least the lower, sinuate, toothed or incised. 

 Stamens 5 ; calyx not fleshy. 



Pericarp readily separable from the seed. 



Leaves oblong or lanceolate ; calyx-lobes scarcely keeled. 



5. C. Boscianum. 

 Leaves triangular-hastate ; calyx-lobes keeled. 6. C. Fremontii. 

 Pericarp firmly attached to the seed. 



Flower-clusters, at least the upper, longer than the leaves. 



Leaves oblong, rhombic-ovate or lanceolate, narrowed at the base. 

 Leaves obtuse or merely acute. 1. C. album viride. 



Leaves or some of them cuspidate or brittle-tipped. 



7. C. Berlandieri. 

 Leaves triangular-ovate, truncate or subcordate at base. 



8. C. urbicum. 

 Spikes loosely panicled in the axils, the panicles shorter than the leaves. 



9. C. murale. 

 Stamens only 1 or 2 ; calyx slightly fleshy, red. 11. C. rubrum. 



Leaves very coarsely toothed. 10. C. hybridum. 



Leaves broadly triangular-hastate, entire or merely undulate. 12. C. Bonus-Henricus. 



** Embryo an incomplete ring. 

 Leaves ovate or oblong, pinnately lobed ; flowers id long loose panicles. 



13. C. Botrys. 

 Leaves lanceolate ; flowers in continuous or interrupted spikes. 



Spikes borne in the axils of the numerous small upper leaves. 14. C. ambrosioides. 

 Spikes in large commonly leafless terminal panicles. 15. C. a?ithelminticum. 



i. Chenopodium album L. Lamb's Quarters. White Goosefoot. Pig 

 weed. (I. F. f. 1359.) Annual; stem usually slender, erect, commonly mud 

 branched, 0.3-3 m - ta ^- Leaves rhombic-ovate or the upper lanceolate, narrowed 

 at the base. 3-nerved, dentate, sinuate or lobed, or the upper entire, 2-10 cm. long; 

 spikes terminal and axillary, simple or compound, often panicled ; calyx about 1 mm. 

 broad in fruit, its segments usually completely enclosing the utricle ; seed hori- 

 zontal, black, shining, firmly attached to the pericarp. In waste places. A com- 

 mon weed throughout N. Am. except the extreme north. Nat. from Europe. 

 Native also of Asia. June-Sept. 



Chenopodium album viride (L.) Moq. Plant brighter green; leaves green on both 

 sides or but slightly mealy beneath. Range of the type. 



2. Chenopodium glaucum L. Oak-leaved Goosefoot. (I. F. f. 1360.) 

 Annual, succulent; stem usually much branched, decumbent or prostrate. Leaves 

 oblong, lanceolate or ovate-lanceolate, mostly narrowed at the base, dark green 

 above. 2-5 cm. long, the lower or all of them sinuate-dentate or lobed ; flowers in 

 axillary- often branched spikes, or the upper panicled ; calyx about 1 mm. broad, 

 its segments obtuse, neither fleshy nor keeled in fruit; utricle brown, depressed, its 

 summit not completely covered by the calyx; seed of lateral flowers vertical, that 

 of terminal flowers commonly horizontal. A weed in waste places throughout 

 N. Am. except the extreme north. Nat. from Europe. June-Sept. 



3. Chenopodium leptophyllum (Moq.) Nutt Narrow-leaved Goosefoot. 

 (I. F. f. 1 361.) Annual, scarcely succulent; stem slender, usually erect, striate or 

 grooved, at least when dry, branched. 1.5-8 dm. tall, mealy above. Leaves 

 linear to oblong, acute or acuminate, or the lower obtuse, entire or the lower rarely 

 toothed, short-petioled, 2-6 mm. wide, 1-3-nerved; flowers axillary and terminal 

 simple or branched spikes; calyx about 1 mm. broad, its segments strongly keeled 

 and nearly covering the fruit; seed horizontal, readily detached from the pericarp. 

 In dry soil. Manitoba and the N. W. Terr, to Mo.. N. Mex. and Ariz. Also on the 

 shores of Lake Erie and on sands of the seashore, Conn, to N. J. July-Sept. 



Chenopodium leptophyllum subglabrum S. Wats. Leaves scarcely mealy or quite 

 green; flowers loosely clustered. W. Neb. and Colo. 



