Polygonaceae. Buckwheat Family. 
Herbs with alternate, entire leaves which in some genera are provided with 
scarious stipules (ocreae, which are tubular and sheath thestem for a short 
distance. Nodes swollen. Flowers perfect, the perianth a single petal-like 
whorl, 5-6 cleft, more or less persistent. Stamens 4-12. Ovary superior, 
l-chambered, l-seeded, bearing 2-3 styles. Fruit an achene, commonly 5-angled 
or winged. 
o Stipules none; flowers borne within a more or less cup-shaped calyx-like 
4 involucre; stamens 9; leaves woolly t Eriogonum 7 
© Stipules present; flowers without involucre; stamens 4-8; 
4 leaves glabrous or at most wae pubescent, not woolly 
2 Perianth segments 4 or 6, the inner whorl enclosing 
L the fruit, usually enlarging, the outer whorl 
\wery small 
A Perianth segments 4; stignas 2; achene flat, 
@ winged; leaves kidney-shaped 2 ria 
aa / 
4 Perianth segments 6; stigmas 5; achene 3-angled ; 
8 leaves mostly lanceolate 3, Bumex 
z Perianth seements 5, equal and erect}, persistent but not 
4A. Polygonum 
(enlarging in fruit 
si A ae ee BE RIBRIS S ee ee ee 
