POLYGONACE.E. 121 



id slender naked spikes. Stem upright, nearly smooth. 

 Leaves ovate or ovate-lanceolate, taper-pointed, rough eiliate. 

 Sheaths hairy and fringed. Thickets, in rich soil. 



1- +- Leaven /marl-shaped or sagittate. Sheatte much longer on one side than 

 on the other. 



13. P. arifolium, L., (HALBERD-LEAVED TEAR-THUMB) with 

 grooved stem, halberd-shaped long-petioled leaves, flowers in 

 short loose racemes, 6 stamens, and a flattish achene, is not 

 uncommon oil the Lower St. Lawrence; rare in Ontario. 



14. P. sagitta'tum, L. (ARROW-LEAVED TEAR-THUMB.) Stem 

 4-angled, the angles beset with reflexed minute prickles, by which 

 the plant is enabled to climb. Leaves arrow-shaped. Stamens 

 8. Achene 3-angled. Common in low grounds, especially beaver- 

 meadows. 



15. P. Convol'vulus, L. (BLACK BINDWEED.) Stem twining, 

 not prickly but roughish; the joints naked. Flowers in loose 

 panieled racemes, 3 of the calyx-lobes ridged in fruit. Leaves 

 heart-shaped and partly halberd-shaped Not climbing so high 

 as the next. Cultivated grounds and waste places. 



16. P. dumeto'rum, L., var. scandens, Gray. (CLIMBING 

 FALSE BUCKWHEAT. ) Stem twining high, smooth; sheaths naked, 

 3 of the calyx-lobes ivinged in fruit. Moist thickets. 



17. P. cilino'de, Michx. Stem twining, minutely downy. 

 Sheaths fringed at the base with reflexed bristles. Sandy pine 

 woods and rocky hills. 



3. RUMEX, L. DOCK. SOBREL. 

 * Herbage not sour, nor tlie leaves halberd-shaped. 



1. R. orbicula'tus, Gray. (GREAT WATER DOCK.) Growing 

 in marshes. Stem erect, stout, 5-6 feet high. Leaves lanceolate^ 

 not wavy-margined or heart-shaped, often over a foot long. 

 Flowers nodding on thread-like pedicels. Valves nearly orbicular, 

 finely net- veined, each with a grain on the back. Wet places. 



2. E. salicifo'lius, Weinmann, (WHITE DOCK) may be looked 

 for in marshes on the sea-coast and far northward. The whorls 

 of flowers are dense and form a very conspicuous spike, owing to 

 the great size of the grains on the back of the valves. 



