Order 2. POLYGONACEAE.
1. POLYGONUM, L.
1. P. bistorta , L. Native. British type. Area C, N, D. Range 1, 2.
Not unfrequent in meadows. Banks of the Aln, Tyne, Team, Derwent, Wear, and Tees, ascending to 350 yards in Irishope, and 400 yards near Langdon Bridge.
2. P. viviparum , L. Native. Montane. Highland type. Area N, D. Range 1, 2.
Not known amongst the Cheviots. In Weardale from the Main Limestone scars of Welhope down to the river-side at St. John's Chapel. In Teesdale from the Main Limestone scars of Harwood Dale down to the river from Langdon to Middleton Bridge. Range of elevation 550-550 yards.
3. P. amphibium , L. Native. British type. Area C, N, D. Range 1.
Frequent in ponds and by stream-sides, ascending in Coquetdale above Rothbury, in Weardale to Frosterley, 150 yards.
4. P. lapathifolium , L. Native. British type. Area C, N, D. Range 1.
Damp places and cultivated fields, frequent, but not noted anywhere in the dales.
5. P. persicaria , L. Native. British type. Area C, N, D. Range 1, 2.
In similar places to the preceding, frequent, ascending to 250 yards in Coquetdale, 400 yards in Teesdale.
6. P. hydropiper , L. Native. British type. Area C, N, D. Range 1.
Frequent in ditches and by stream-sides, ascending in Coquetdale to Holystone, 150 yards.