414 POLTGONACE-s:. (buckwheat family.) 



1- I. celosioldes, L. Nearly glabrous annual, erect, slender (2° -4° 

 high) ; leaves ovate-lanceolate ; panicles narrow, naked ; bracts and calyx sil- 

 very-white, the latter woolly at the base. — Dry banks, Ohio to Illinois and 

 southward. Sept. 



6. FRCELtCHIA, Mcench. (OpLOTHioA, iV««.) 



Flowers perfect, 3-bracted. Calyx tubular, 5-cleft at the summit, below 2-5- 

 crested lengthwise, or tubercled and indurated in fruit, enclosing the indehiscent 

 thin utricle. Filaments united into a tube, bearing 5 oblong 1-celled anthers, 

 and as many sterile strap-shaped appendages. — Hairy or woolly herbs, wi th 

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

 Frolich, a German botanist of the last century.) 



1. r. Florid&na, Moquin. Boot annual; stem leafless above {l°-2° 

 high) ; leaves lanceolate, silky-downy beneath ; spikclets crowded into an inter- 

 rupted spike ; calyx very woolly. — Illinois, and southward. Aug. 



Okdek 87. POliYGOlVACEiE. (Buckwheat FA^vnty.) 



Herbs, with alternate leaves, and stipules in the form of sheaths (ochrese, 

 these sometimes obsolete) above the swollen joints of the stem ; the flowers 

 mostly perfect, with a more or less persistent calyx, a 1-celled ovary bearing 

 2 or S styles or stigmas, and a single erect orthotropous seed. Embryo 

 curved or straightish, 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. Stamens 4-12, inserted on the base of the 3 - 6-clefl calyx. Leaves 

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

 as in Sorrel ; the roots, as in Rhubarb, sometimes cathartic.) — West of tho 

 Mississippi are a great number of Eriogone^, having their flowers sur- 

 rounded by an involucre. Our few genera are all of the true Polygona- 

 cete, except the anomalous Brunnichia. 



• Stipalar eheatha (ocAtccb) manifest. Ovule erect from the base of the cell. 

 •*- Sepals 5, sometimea 4, somewhat equal and erect in fruit. 



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



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



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



3. Oxyrla. Sepals 4. Stigmas 2. Fruit 2-winged, samara-like. 



4. Rumex. Sepals 6. Styles 3. Fruit 3-angled, enclosed by the inner sepals. 



» « Stipules obsolete. Ovule hanging from the apex of a slender stalk. 

 6. Brunnichia. Calyx 6-parted, in fruit with a wing decurrent on the pedicel. Tendril- 

 climber. 



1. POLYGONUM, L. Knotweed. 



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

 ering or persistent and surrounding the lenticular or 3-angular achcnium. Sta- 

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

 of the albumen and curved half-way aroiind it ; the radicle and usually the cotyl- 



