POLYGONACEa:. 325 POLYGONUM. 



***Flowers in terminal,so]ilary spikes. Stamens 9. Stigmas 3. Bistorta. 



12. P. VIVl'PARUM. 



Slciii simple ; leaves linear-lanceolate, revolute at the margin ; spike linear, 

 solitary. Stem erect, leafy, ^ foot high, bearing a smgle spike of white 

 flowers which are often transformed into bulblets while on tiie stem. Leaves 



] li inch long, 2 — 3 lines wide, with entire, obtuse, smooth stipules. 



While Mts. July. Mpirie Bistvrt. 



^*** Flowers in panicled spikes. Polygonella. 



13. P. ARTICULA.'TUM. 



Stem erect ; haves linear ; spikes panicled, filiform ; flowers solitary, pedun- 

 culated, with imbricate, truncated bracts; stamens 8; styles 3. Found in 

 dry, hilly pastures. Stem slender, branching, straight, with numerous, 

 racemed spiUt's. and imbricate, sheathing bracts. Leaves ^ — 1 inch long and 

 i — 2 Imes wide, obtuse. Flowers flesh-colored, on nodding, hair-like 

 peduncles issuing from above the bracts. Achenia acutely triangular. 

 Auff. Ann. Joiiittd PoLygunum. 



***** Flowers in racemose panicles. Leaves subcordate or sagittate. 

 Fagopykum. 



14. P. sagitta'tum. 



Stem prostrate, rough-angled ; leaves sagittate ; floincrs capitate ; stamens 

 8 ; stifes 3. Wet grounds. A rough, climbing species, often several feet in 

 leno-th. Stem square, the angles very rough with prickles pointing down- 

 wards. Leaves acute, 1 — 3 inches long, ^ as wide, on petioles \ — J inch 

 long, with smooth stipules. Flowers in small, terminal heads, whitish. 

 Jui^e. Ann. Scratch-grass. 



15. P. ARIFO'LIUM. 



Stem aculeate willi reversed prickles ; Icarcs hastate ; spikes few-flowered ; 

 y?07/-cr.9 distinct; stamens (J; styles 2. Wet grounds. Distinguished trom tlie 

 last cliieflv by its larger, halbert-shaped leaves, which are 2 — 4 inches long 

 and ^ as wide. Petioles ^ — 1 inch long. Clusters racemose, slender, loose, 

 few-Bowered, at the ends'of the branches. Jn.,Jl. Ann. Hastate Knot-grass. 



16. P. convo'lvulus. 



Stem, tv/ining, angular ; haves cordate-hastate ; segments of the calyx obtuscl}' 

 keeled ; stamens 8° sti/lcs 3. A common climbing species, in fields and waste 

 grounds. Stem 2— C "feet long, roughish, angled, with axillary branches. 

 Leaves 1—2 inches long, i as wide, on petioles A— f inch long, with some- 

 what spreading and acute' lobes at base. Flowers whitish, in terminal, 

 interrupted spikes. June — Sept. Ann. Knot Biud-icccd. 



fi. cilirwdc (P. cilinode. .Mx) ; phuit minutely pubescent; stipules fringed 

 with reflexed hairs at base. 



17. P. SCANDENS. 



Ste.m. twining, smooth; haves cordate, acuminate; segments of the calyx 

 winged; stamens 8; styles '.i. Stem 3— 7 feet long, cliuibing, often colored 

 and' with axillary branches. Leaves heart-shaped, with distinct, rounded 

 lobes. Flowers in long, interrupted racemes. Calyx and fruit conspicuously 

 3-winged, the wings decurrent on the slender, jointed pedicels. Aug. Per. 



Climbing Knot-grass. 



18. P. fagopy'rum. 



Stem erect, smooth ; leaves cordate-sagittate ; racemes panicled ; stamens 

 8 J styles 'i; angles of the ackenium equal. The name from the La.t. fagus, 

 CC 



