POLYGONUM 
127 
the top. Laminae much less heterophyllous than in P. aviculare and P. rurivagum , broadly 
or narrowly elliptical, obtuse, about ro — 2'o cm. long, often more or less crowded towards the 
ends of the branches. Flowers in few-flowered, axillary cymes; July to October. Perianth 
polypetalous, usually white or greenish white, sometimes pink or red. Stamens 5 — 8, usually 5. 
Achenes rather small, usually about to — 2^5 mm. long, three-sided; sides indistinctly striate or 
punctulate, rather shining, usually dark brown to nearly black in colour, not or only a little exserted. 
According to Lindman {loc. tit.) specimens of P. aequale in herb. Boreau (in Herb. Paris) are variously named 
P. agrestinum, P. arenastrum, and P. humifusum. 
Roadsides and waste places, locally abundant. Cornwall and Kent to Northumberland, Ayrshire, Fife- 
shire, Aberdeenshire. 
France, Sicily, and doubtless elsewhere. 
(/3) subvar. parvulum nobis. 
leones: — Camb.Brit.Fl.W. Plate 136. (d) Fruiting branches. ( e ) Persistent perianths with mature achenes 
(enlarged). Dorset (C. E. M.). 
Differs in its smaller leaves and achenes. 
Found by the Rev. E. F. Linton on sandy soil, growing along with full-sized plants, in Poole Harbour, 
Dorset. Specimens were distributed by Mr Linton through the Watson Botanical Exchange Club, in 1912. 
P. aequale occurs on roadsides and in waste places ; locally abundant, northwards at least 
to Aberdeenshire ; not recorded for Ireland, but doubtless it occurs there. 
Europe, and perhaps elsewhere. 
P. aequale x aviculare comb. nov. ; P. aviculare var. depressum Meisner in DC. Prodr. xiv, 98 (1856); 
P. heterophyllum var. caespitosum Lindman op. cit. p. 691, t. 25, fig. 5 ; P. aequale subsp. oedocarpum Lindman 
op. cit. p. 693, t. 23, fig. 14, et t. 26, fig. 4, 6, 7 ; P. aequale x heterophyllum ?, Lindman op. cit. t. 23, fig. 9. 
leones: — Lindman loc. cit.; Beck in Reichenbach Icon. t. 211, fig. 5. 
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. 
Cambridgeshire, and doubtless elsewhere. 
Europe, and perhaps elsewhere. 
19. POLYGONUM CALCATUM 
Polygonum calcatum Lindman in Bot. Notiser 139 (1904). 
Annual, a smaller plant than any of the preceding species of Avicularia. Stem prostrate, 
and branched ; branches short, usually closely appressed to the ground. Laminae almost homo- 
phyllous, elliptical, obtuse, subequal in size, smaller than in the preceding species of Avicularia. 
Inflorescences axillary, few-flowered. Flowers July to September. Perianth gamosepalous, small ; 
segments about as long as the tube, greenish- white with a whitish margin. Stamens 5. Achenes 
shining, small, about 2‘o — 2 ’5 mm. long, compressed-trigonous, with two of the sides much wider 
than the third ; sides convex, smooth or rarely punctulate, dark-coloured. 
The undescribed hybrid P. aequale x calcatum occurs {fide Professor Lindman) in three or four English counties : it 
seems likely, therefore, that P. calcatum will prove to be a widespread, though perhaps a local plant, in this country. 
Grassy roadsides. At present only known, as a British plant, on Arthur’s Seat, Edinburgh, 
where it was discovered in September, 1912. 
Scandinavia, Germany, Russia ; Asia. 
Subfamily 2. RUM I CO IDE A E 
Rumicoideae Dammer in Pflanzenfam. iii, pt. ia, 8 (1892); Ascherson und Graebner Syn. iv, 693 (1912). 
For characters, see page 108. 
In the non-British tribe Eriogoneae , ochreae are absent. 
