336 
Polygonacese. 
4. Pedicels jointed near to the perianth; outer divisions 
of the perianth obtusely keeled. Stem 5—15 dm .—Fields 
after mowing, market-gardens; distrib 7 
Convolvulus L. 1909. 
— Pedicels jointed below the middle. Outer divisions of 
the perianth with a winged-membranous keel (wings 
2 — 8 mm broad). Stem 10 — 20 dm. — Hedges, damp thickets; 
distrib. but not common. 7 . . dumetorum L. 1910. 
5 (1). FI.-clusters separate in the axils of ordinary leaves 
(sometimes rather reduced towards the top). Stem gen. 
very branchy with prostrate, rarely (v. erectum Roth.) 
erect ramifications. P. microspermum Jord. (a delicate 
narrow-leafed sand form: Geneva!).—Road-sides, rubbish- 
heaps: everywhere. 6 aviculare L. 1911. 
— FI.-clusters crowded in the axils of (reduced) bracts, 
forming a false spike or a raceme, or only the lower 
ones rather distant in the axils of ordinary small Is 6* 
6. FIs yellowish white in paniculate false racemes.—Meadows; 
G. T. W. 0. U. (in immense quantities in the trans¬ 
alpine valleys). 7 . alpinum L. 1912. 
— FIs in false spikes ....... 7 
7. Stems lateral, terminated by a single (rarely 2 in P. 
Bistorta) spike. Styles 3, separate; stigs small . S 
— Stems terminal, bearing several spikes (in P. amphibium 
only 3—1). Styles 2—3, slightly united; stigs large .9 
8. Lower Is oblong-oval, cordate at the base, with a winged 
petiole. FIs flesh-coloured. — Damp meadows, in patches, 
especially in the valleys of the mount. 5 Bistorta L. 1913. 
— Ls all elliptic-lanceolate, contracted to the petiole, rolled 
at the edges. Petioles not winged. FIs white, gen. inter¬ 
mixed with little bulbs.—Alp., subalp. and Jura. 6 
viviparum L. 1914. 
9. Perenn. pis with creeping rt-stock Ls with long petioles, 
floating, in the land form (v. terrestre) with shorter 
petioles, narrower and rough, with short hairs.—Ponds, 
ditches; the variety at the edges of ditches and fields; 
distrib. 7 ..... amphibium L. 1915. 
— Ann. pis, with a fusiform-fibrous rt. Ls shortly petioled 
or sessile ........ lO 
10. Spikes oblong-cylindric, compact, erect, or, the lateral 
especially, rather laxer and slightly drooping . 11 
— Spikes linear-filiform, slender, lax, interrupted at the 
base, drooping, rarely (in 1920) almost erect . 12 
11. Common peduncles more or less glandular. Sheaths lying 
looser on the stem, with short fine cilise.. Ls spotted 
(often glandular) underneath. P. tomentosum Schrank. — 
Var.: with fls of a greenish white, and rose (as in P. 
Persicaria), the ls gray-tomentose underneath (v. incanum), 
