Polygonacese. 12 



ORDKR 60. — Polygonacese. 



Calyx inferior of 3 — 6 sepals. Stamens 5 — 8 perigynous opposite the 

 sepals. Pistil syncarpous, styles I — 3, ovule solitary erect. Fruit a hard 

 triangular nut. Leaves alternate, the stipules uniting round the stem forming 

 a membranaceous ochrea. 



Sepals 5, equal, Polygonum I. 



Sepals 6, 3 large and 3 small, Rumex IT. 



\.— POLYGONUM. 



Flowers purple in dense spikes with ochreate bracts, sepals 5, stamens 

 5 — 8, anthers lightly attached, ovary compressed or triangular. 



Stem erect or climbing, 490 



Stem procumbent, 492 



490 Stem climbing, flowers racemose, 491 



490 Stem erect, flowers in spikes, 493 



491 Fruiting perianth winged, ..... P. dumetorum. 



491 Fruiting perianth without wings, .... P. convolvulus. 



492 Flowers axillary, ...... P. aviculare. 



492 Flowers in spikes, plant creeping or floating, P. amphibium. 

 493 Stem simple, spike terminal, 494 



493 Stem branched, flowers racemed or panicled, 495 



494 Leaves ovate, petiole winged, .... P. Bistorta 



494 Leaves linear-lanceolate, petiole not winged, P. viviparum. 



495 Spike dense, not leafy at the base, 496 



495 Spike lax, leafy at the base, P. Hydropiper. 



496 Leaves ovato-lanceolate, spotted, lower 



stipules not fringed, .... P. lapathifolium. 



496 Leaves lanceolate often spotted, stipules 



fringed, P. Persicaria. 



POLYG'ONUM BISTOR'TA (70). Bistort Snake-root. 6—9. Stem 



(121 7) simple erect i — \\ ft. high, leaves oblong-ovate obtuse waved, flowers 

 pink in a dense cylindric terminal spike. Moist meadows. 



Polyg^onum vivip'arum (28). Alpine Bistort. 6 — 7. Stem simple erect 



(1218) 4 — 8 in. high, leaves linear-lanceolate, spike slender few-flowered. 



[G. [Feizor, Helwith Bridge, Horton.) 



POLYG'ONUM AMPHIB'IUM (105). Amphibious Bistort. 7—8. 



(1 216) Root-stock creeping, stem erect (or floating) nearly simple, leaves 

 lanceolate smooth when aquatic, rough with very short adpressed 

 hairs when terrestrial, spike short dense not leafy at the base. IVasU 

 ■places, juarshes, and ponds. 



