POLTGONACE^. (bOCKWHEAT FAMILr.) 371 



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

 Fr/llich, a German botanist of the last century.) 



I. F. Floridana, Moquin. Stem Iea6es8 above (1°- 2° high); leaves 

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

 calyx very woolly. (£^ — Illinois, in Mason and Cass Counties, ilfearf. Aug. — 

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

 farther south. 



GoMFHiiiiNA OLOBbsA, L., is the common Globe Amarakth of the gar- 

 dens. 



Oeder 92. POLYGONAcE^. (Buckwheat Family.) 



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

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

 with a more or less persistent calyx, a l-ceUed ovary bearing 2-3 styles or 

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

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

 pointing from the hilimi 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 

 Son-el ; the roots, as in Rhubarb, sometimes cathartic.) — Our few genera 

 all belong to the Polygonbje Pkopkk. 



Synopsis. 



« Sepals mostly 6, somewhat equal, all erect in fruit. 



1. POLYGONUM. Embryo narrow, curved around j>ne side of the albumen : cotyledons 



slender or flat. 



2. FA60PYRU1V1. Embryo in the albumen, its very broad cotyledons twisted-plaited. 



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

 8. OXYRLA. Sepals 4. Stigmas 2 Fruit 2-wlnged, samara-like. 



4. KUMEX. Sepals 6. Styles 8. Fruit S-angied, wingless, enclosed in the enlarged inner 

 sepals 



1. POLiVGONUM, 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 noKi, many, and yovv, 

 knee, from the numerous joints.) 



5 1 . BIST6RTA, Toui-n. — Calyx petal-like, deeply 5-cleft : stamens 8 or 9 : styles 

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

 stock •■ fmvers in a spike-like raceme, 

 1. P. viVtpai'HHi, L. (Alpine Bistort.) Smooth, dwarf (4' -8' 



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



