CHENOPODIACEAE (GOOSEFOOT FAMILY) 161 



keeled or crested, becoming dry and inclosing the utricle, at least in part. 

 Stamens 5. Styles 2-3. Pericarp membranous, closely investing the lenticular 

 seed. Many are introduced weeds. 



Pericarp firmly attached to the smooth seed; stamens 5. 

 Leaves more or less white-mealy. 



At least the lower ones angulate-toothed 1. C. albmn. 



Nearly entire; plant heavy-scented 2. C. Watsonii. 



Leaves not mealy. 



Glabrous and coarsely toothed . . , . , . , 3, C. hybridum. 

 Glandular- or viscid-puberulent. 



Finnatelylobed; calyx glandular-pubescent .... 4. C. Botrys. 

 Sinuate-pinnatifid; calyx resinousrdotted . . . . 5, C. comutum. 

 Tericarp easily separable from the seed. 

 Stamens 5. 



Leaves lanceolate or broader, undulate-toothed or lobed. 

 Alore or less mealy. 



Plant low, divaricately branched or spreading. 



Leaves green, at least above 6. C. glaucum. 



Leaves white-farinose . . , . . , . 7. C. incanum. 

 Plant erect, green, sparsely mealy. 



Leaves triangular-hastate 8. C. Fremontii. 



Leaves ovate to oblong . . , , , . , 9. C. aridum. 



Not mealy, glabrous and succulent 10. C. succosum. 



Leaves oblong or narrower, entire. 

 Decidedly mealy. 



Leaves lance-linear 11. C. leptophyllimi. 



Leaves oblong, small 12. C. desiccatum. 



Hardly at all mealy, bright green 13. C. subglabrum. 



Stamens 1-2 14. C. rubrum. 



1. Chenopodiiun album L. Sp. PI. 219. 1753. Stem erect, branched above, 

 3-10 dm. high, Ught green: leaves generally pale green above, white-mealjr 

 beneath, rhombic-ovate to narrowly lanceolate, at least some of them angulate- 

 toothed: flowers in terminal and axillary spikes: perianth wholly inclosing the 

 utricle, the black shining seed adherent to the pericarp.— An introduced weed 

 common in waste places; commonly known as Lamb's Quarters. 



2. Chenopodium Watsonii A. Nelson, Bot. Gaz. 34: 362. 1902. Moderately 

 mealy throughout, heavy-scented, more or less branched, 2-5 dm. high: 

 leaves dull green, rather thick, oblong to ovate, often subhastate, margin en- 

 tire or nearly so, 15-20 mm. long, on slender petioles: flowers in close clusters 

 arranged in open panicles: pericarp mealy and adherent to the large seed. 

 C. olidum Wats. Proc. Am. Acad. 9: 96. 1874. — Indigenous from New Mexico 

 to Utah and Wyoming. 



3. Chenopodium hybridum L. Sp. PI. 219. 1753. Glabrous throughout 

 or only the inflorescence mealy, erect, 4-8 dm. high: leaves thin, bright green, 

 rhombic-cordate, acuminate at apex, with 1—4 large acute teeth on each side, 

 3^5 cm. long, the uppermost smaller and entire: flowers large, in large spread- 

 ing panicles: perianth-segments somewhat keeled, not wholly inclosing the 

 utricle: seed with acutish margin, firmly united to the pericarp. — A widely 

 distributed weed but probably indigenous in our range. 



4. Cbenopoditmi Botrys L. Sp. PI. 219. 1753. Glandular-pubescent or 

 even viscid, strong-scented: stem leafy below, branching above into the dense 

 naked inflorescence,, 2-5 dm. high: leaves ovate or narrower, deeply pinnately- 

 toothed or -lobed, obtuse, truncate or cuneate at base, reduced upward: 

 flowers very small in numerous axillary panicles: calyx-lobes acute, loosely 

 inclosing the fruit. — Generally introduced; from Europe. 



5. Chenopodium cornutum Benth. & Hook. Gen. PI. 3: 51. 1880. More 

 or less gland ular-puberulent, aromatic, not mealy, diffusely branched: leaves 

 thin, lanceolate, repand-dentate or coarsely sinuate-pinnatifid: flowers minute 

 and solitary, axillary and terminal upon the repeatedly dichotomous nearly 

 naked branches: calyx resinous-dotted. {Tehxys cornuta Torr. Pac. R. R. 

 Rept. 4: 129. 1856.) — ^Through the southern part of our range to California. 



6. Chenopodium glaucum L. Sp. PI. 220. 1753. A succulent, low spread- 

 ing or often prostrate annual, glaucous-mealy, the upper surface of the leaves 

 smooth and green: leaves Ovate to ovate-lanceolate, sinuate-dentate, 10-20 

 mm. long, on slender petioles: flowers clustered in axillary spikes shorter 



