POLYGONACEJE. (BUCK^'HEAT FAMILY) 371 



opposite sessile leaves, and spiked gcarious-bracted flowers. (Named for J. A. 

 Frdlich, a German botanist of the last century.) 



1. F. Floridaiia, Moquin. Stem leafless above (l-2 high); leaves 

 lanceolate, silky-downy beneath ; spikelets crowded into an interrupted spike ; 

 calyx very woolly. (L) Illinois, in Mason and Cass Counties, Mead . Aug. 

 Perhaps of recent and casual introduction : for elsewhere it is only found much 

 farther south. 



GOMPHRENA GLOB68A, L., is the common GLOBE AMARANTH of the gar- 

 dens. 



ORDER 92. POLYGONACE^E. (BUCKWHEAT FAMILY.) 



Herbs, with alternate leaves, furnished with stipules in the form of sheaths 

 (ochreae) above the swollen joints of the stem ; the flowers mostly perfect, 

 with a more or less persistent calyx, a 1-cetted ovary bearing 2-3 styles or 

 stigmas, and a single erect orthotropous seed. Embryo curved or straight- 

 isli, on the outside of the albumen, or rarely in its centre ; the radicle 

 pointing from the hilum and to the apex of the dry seed-like fruit. Sta- 

 mens 4-12, inserted on the base of the 3 - 6-cleft calyx. Leaves usually 

 entire. (The watery juice often acrid, sometimes agreeably acid, as in 

 Sorrel ; the roots, as in Rhubarb, sometimes cathartic.) Our few genera 

 all belong to the POLYGONE^E PROPER. 



Synopsis. 



* Sepals mostly 5, somewhat equal, all erect in fruit. 



1. POLYGONUM. Embryo narrow, curved around one side of the albumen : cotyledons 



slender or flat. 



2. FAGOPYRUM. Embryo in the albumen, its very broad cotyledons twisted-plaited. 



* * Sepals 4-6, the outer row reflexed, the inner erect and enlarging. 

 8. OXYRIA. Sepals 4. Stigmas 2. Fruit 2-winged, samara-like. 



i. RUMEX. Sepals 6. Styles *8. Fruit 3-angled, wingless, enclosed in the enlarged inner 

 sepals 



1. POL,YOONtJM[, L. KNOTWEED. 



Calyx mostly 5-parted ; the divisions often petal-like, all erect in fruit, wither- 

 ing or persistent and surrounding the lenticular or 3-angular achenium. Sta- 

 mens 4 -9. Styles or stigmas 2-3. Embryo placed in a groove on the outside 

 of the albumen and curved half-way around it ; the radicle and usually the coty- 

 ledons slender. Pedicels jointed. (Name composed of iro\v, many, and yow, 

 knee, from the numerous joints.) 



1. BIST6RTA, Tourn. Calyx petal-like, deeply s-deft : stamens 8 or 9 : styles 

 3, slender: achenium 3-sided: stems low and simple from a woody creeping root- 

 stock : Jlowers in a spike-like raceme. 

 1. P. viviparum, L. (ALPINE BISTORT.) Smooth, dwarf (4' -8' 



high), bearing a linear spike of flesh-colored flowers (or often little red bulblets 



