64 Flora of the Palouse Region 



P. bistortoides Pursh. Perennial, from a thick oblong tuber, glabrous 

 throughout or sparsely puberulent: stem erect, simple, 30-60 cm. tall: radical 

 leaves oblong, acute or acuminate, 5-20 cm. long, 3-5 cm. broad, on slender 

 usually shorter petioles; cauline 3-4, sessile, the uppermost much reduced, 

 lanceolate: spikes oblong, 3-6 cm. long, dense: calyx white, deeply 5-cleft: 

 akene chestnut-brown, 3-angled, smooth, shiny. Moist meadows near Mos- 

 cow. 



P. muhlenbergii Wats. Perennial, sparsely scabrous throughout: stems 

 erect or decumbent, 1-2 m. long, rooting at the nodes: leaves oblong-lanceo- 

 late, acuminate, cuneate or rounded at base, 8-16 cm. long, short-petioled; 

 ocreae cylindric, loose, entire: spikes dense, 3-7 cm. long, short- peduncled: 

 calyx rose-red, 5-parted: akenes lenticular, black, shiny, slightly roughened. 

 Common in wet meadows and on pond and river banks. 



P. aniphibillm L. Yen- much like the above, but strictly aquatic: leaves- 

 oblong, obtuse or somewhat acute, smooth and shiny above. In ponds, near 

 Moscow. 



Family 25. CHENOPODIACEAE. 



Annual or perennial herbs, rarely shrubs: stems angled, striate 

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

 toothed or lobed, mostly petioled, without stipules: flowers perfect, 

 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 superior and free from the calyx, 

 i-celled; ovule 1: fruit a utricle: endosperm mealy, fleshy or want- 

 ing. 



Endosperm little or none. 9S. sai,sola. 



Endosperm copious. 



Fruit much exserted beyond the calyx. 97. corisi'ERMim. 



Fruit enclosed by or not longer than the calyx or bractlets. 



Calyx 2-5-lobed or parted: stamens 1-5. 95. chenopodium. 



Calyx of 1 sepal: stamen 1. 96. monolepis. 



95. CHENOPODIUM. 



Annual or perennial, green and glabrous, white-mealy or gland- 

 ular-pubescent herbs: leaves alternate, petioled, entire, sinuate- 

 dentate or pinnately-lobed: flowers very small, green, per- 

 fect, sessile, bractless, clustered in axillary or terminal, often 

 panicled or compound spikes: calyx 2-5-parted or lobed: stamens 

 1-5: utricle embraced or enclosed by the calyx, the segments of 

 which are herbaceous or slightly fleshy in fruit: endosperm mealy, 

 farinaceous. 



Leaves whitish, somewhat mealy. C. ALBUM. 



Leaves glandular, not mealy. • C. botrys. 



Leaves green, neither mealy nor glandular. C. capiTaTum. 



