188 COMMON CANADIAN WILD PLANTS. 



3. A. albus, L. Flowers greenish, in small close axillary 

 clusters. Stem low and spreading. Roadsides. 



9. MOM K MA, Moquln. 



M. tamaris'clna, Gray. (Acnida ruscocarpa, Gray.) A 

 tall smooth herb, with lanceolate or oblong-ovate alternate 

 leaves on long petioles, and small clusters of greenish flow- 

 ers in interrupted spikes. "Wet places. 



Var. eoneatena'ta, Gray, (Acnida tuberculata, Moq.) has 

 the flowers in the lower part of the stem in close clusters in 

 the axils of the leaves. 



ORDER LXXVIII. POLYGONA'CE^. (BUCKWHEAT F.) 



Herbs, well marked by the stipules of the alternate leaves 

 being in the form, of membranous sheaths above the usually 

 swollen joints of the stem (these obsolete in one Genus). 

 Flowers usually perfect. Calyx 4-6-parted. Stamens 4-9, 

 inserted on the base of the calyx. Stigmas 2 or 3. Ovary 

 1-celled, with a single ovule rising from the base, forming 

 a little nutlet. 



Synopsis of the Genera. 



* Flowers involucrate. Stamens 9. Stipules obsolete. 



1. Eriog'oiuim. Involucre 4-8-toothed, the flowers exsgrted. Calyx 



6-parted, coloured (yellow in ours), enclosing the achene. N.W. 

 only. 



* * Flowers not involucrate. Stamens 4-8. 



2. Polyg-'onnm. Sepals 5 (occasionally 4), often coloured and petal- 



like, persistent, embracing the 3-angled (or sometimes flattish) 

 nutlet or achene. Flowers in racemes or spikes, or sometimes in 

 the axils. 



3. Kuiiic.Y. Sepals 6, the 3 outer ones herbaceous and spreading in 



fruit, the Sinner (called valves) somewhat petal-like and, after 

 flowering, convergent over the 3-angled achene, often with a 

 grain-like projection on the back. Stamens 6. Styles 3. Flowers 

 usually in crowded whorls, the latter in panicled racemes. 



4. Fagopy'rnm. Calyx 5-parted, petal-like. Stamens 8, with 8 yellow 



glands between them. Styles 3. Achenes 3-angled. Flowers wnite, 

 In panicles. Leaves triangular heart-shaped or halberd-shaped. 



