P6Vtao^sAC■kM. 191 



slender, erect, pale rose-ooloured. Sepals glandidar-dotted. 

 Stamens 8. Aohene 3-angled, shining. — Muddy soil or 

 shallow water. 



13. P. Hydrop'lpeP, L. (Common Smaetwbbd or "Water- 

 PEPPEB.) Sheaths and leaves as in the last, the leaves, how- 

 ever, larger. Spikes slender, nodding, greenish. Sepals 

 glandular-dotted. Stamens 6. Achene dull, — Wet places. 



14. P. Virginla'num, L. Calyx greenish, unequally 4- 

 parted. Stamens 5. Styles 2, persistent on the flat aohene. 

 Flowers in long and slender naked spikes. Stem upright, 

 nearly smooth. Leaves ovate or ovate-lanoeolate, taper- 

 pointed, rough-oiUate. Sheaths hairy and fringed. — Thick- 

 ets, in rich soil. 



*- ■*- Leaves heart-shaped or sagittate. Sheaths much longer on one 

 side than on the other. 



15. P. arifo'lium, L., (Haiberd-leavbd Tear-thumb; 

 with grooved stem, halberd-shaped long-petioled leaves, 

 flowers in short loose racemes, 6 stamens, and a flattish 

 achene, is not uncommon on the Lower St. Lawrence ; rare 

 in Ontario. 



16. P. sagltta'tum, L. (Arrow-Leaved Tear-thumb.) 

 Stem, 4-angled, the angles heset with refiexed m,inute prickles, 

 by which the plant is enabled to climb. Leaves arrow- 

 shaped. Stamens 8. Achenes 3-angled. — Common in low 

 grounds, especially beaver- meadows. 



17. P. Convol'vulus, L. (Black BiNi)wia)D.) Stem tunn- 

 ing, not prickly but roughish ; the joints naked. Flowers 

 in loose panicled racemes, 3 of the calyx-lobes rigid in fruit. 

 Leaves heart-shaped and partly halberd-shaped. Not climb- 

 ing so high as the next. — Cultivated grounds and waste 

 places. 



18. P. dumeto'rum, L., var. seandens. Gray. (Cumb- 

 Tsa False Buckwheat.) Stem twining high, smooth ; sheaths 

 naked, 3 of the calyx-lobes winged in fruit. — Moist thickets. 



19. P. eillno'de, Michx. Stem twining, minutely downy. 

 Sheaths fringed at the base with refleoced bristles. — Sandy pine 

 woods and rocky hills. 



