124 
POLYGONUM 
15. POLYGONUM RAIL Plate 131 
Polygonum marinum Ray Syn. ed. 3 > J 47 ( I 7 2 4 ) partim. 
Polygonum raii 1 Babington in Trans. Linn. Soc. xvii, 458 (1834)!; Syme Eng. Bot. viii, 68 (1868); 
Rouy FI. France xii, 109 (1910); P. dubium Deakin Florigr. Brit, ii, 576, t. 656 (1845) non A. Braun; P. litorale 
var. latifolium Grenier et Godron FI. France iii, 52 (1855); P. maritinium var. raii Lloyd FI. Ouest. France 6d. 2, 
430 (1868). 
leones : — Babington in Eng. Bot. Suppl. t. 2805 ; FI. Dan. t. 2772 ; Beck in Reichenbach Icon, xxiv, t. 204. 
Carnb. Brit. FI. ii. Plate 131. (a) Fruiting branches, (b) Persistent perianth enclosing achene (enlarged). 
(c) Achene (enlarged), (d) Portion of stem, with ochrea (enlarged). Hampshire (E. W. H.). 
Exsiccata : — Dorfler, 3076. 
Annual or biennial. Root long. Stem prostrate, branched ; branches long (up to nearly 1 metre). 
Ochreae much shorter than the internodes, scarious and silvery above, at first 2-cleft, becoming 
laciniate, with about 6 simple nerves. Petioles distinct. Laminae elliptical acute, margin not or 
only very slightly recurved at maturity, rather glaucous, rather thick, about 2 — 4 cm. long and 
0’4 — 07 wide, veins rather conspicuous underneath. Inflorescences of 2 — 6 flowers. Pedicels short. 
Perianth pink, or greenish-white, often with a broad white margin ; segments 5, rarely 4, over- 
lapping a little ; July to October. Stamens 8, about half as long as the perianth. Filaments 
dilated below. Anthers small. Style very short. Stigmas very small. Achenes large, about 4 — 6 mm. 
long and 2 '5 — 37 broad, much exserted, faces almost flat, smooth, shining, reddish-brown. 
Often confused with P. aviculare var. litorale from which it may be at once distinguished by its markedly exserted 
achenes. 
Rather local ; on the loose sand of the foreshore, a little above the limit of the high spring 
tides. Recorded for nearly all the maritime counties of Great Britain, from the Channel Isles, 
Cornwall, and Kent to western Inverness-shire and the Hebrides, and for nearly all the maritime 
counties of Ireland. 
Southern Scandinavia, Denmark, Germany, Belgium, France, northern Russia, Spain, Italy; 
west coast of North America. 
Series ii. A vicularia 
Avicularia nobis non Meisner ; group “00” Rouy FI. France xii, 111 (1910). 
For characters, see page 123. 
British species and hybrid of Aviculaj'ia 
16. P. aviculare (p. 125). Annuals. Laminae heterophyllous, the larger ones about 2*5 — y 5 cm. 
long, and the smaller ones about half this size or less ; often caducous, especially the larger ones ; 
smaller ones usually alone on the apices of the flowering shoots. Stamens 5 — 8, often 8. Achenes 
trigonous, with sides concave, usually a little exserted from the persistent perianth. 
1 7. P. rurivagum (p. 1 26). Ochreae longer and more silvery than in P. aviculare. Laminae 
narrower and more acute. Flowers smaller. Achenes usually a little exserted. 
18. P. aequale (p. 126). Laminae subequal in size, nearly as large at the apices of the 
flowering branches as below, more or less crowded at the apices of the branches. Stamens 
5 — 8, usually 5. Achenes usually trigonous, sides concave to subconvex, usually included within 
the persistent perianth. 
P. aequale x aviculare (p. 127). Laminae usually more or less heterophyllous, the larger 
ones often persistent at the apices of the branches, usually more or less crowded at the apices 
of the branches. Stamens 5 — 8. Fruit exserted or not. 
19. P. calcatum (p. 127). Laminae almost homophyllous. Stamens 5. Achenes subtrigonous 
to sub-bifacial (i.e., with two sides much wider than the third), sides convex, usually not exserted. 
1 After John Ray (1627 — 1705). 
