Fallopia palaeodonica Doweld, 2017

Doweld, Alexander B., 2017, New names in Fallopia, Persicarioipollis, Polygonum and Reynoutria (Polygonaceae), living and fossil, Phytotaxa 308 (1), pp. 66-79 : 68-69

3. Fallopia palaeodonica Doweld , sp. nov.

Type:— RUSSIAN FEDERATION. Rostov region, Krynka river, right tributary of Mius river, Matveev-Kurgan district (holotype BIN 958 /982! ( LE); figured in Kryshtofovich & Baikovskaja, 1965: pl. 17: 7, text-fig. 23) .

‒ Polygonum ukrainicum Baikovskaja (in Kryshtofovich & Baikovskaja 1965: 70), nom. inval. (Art. 40.1).

‒ “ Fallopia ukrainica ” in Pneva (1989: 1032), nom. inval. (Art. 40.1).

‒ “ Fallopia ukrainica ” in Pneva (2006b: 27), nom. inval. (Art. 43.1).

Diagnosis:— Leaves widely rounded, 8 × 7.5 cm; the base slightly sinuate and decurrent, with obtuse scallops; midvein 1 mm thick (at the leaf base) to 0.5 mm thick (in the leaf middle part), secondary and basal veins filiform; basal veins 1 This name was originally published as a new combination, but it is a replacement name in a new genus according to Arts. 6.11 and 58.1 (incl. Ex. 1).

diverged at 45° from the midvein, then slightly curved, with a thin veinlet parallel to the margin (one leaf side) and thin infrabasal veinlet parallel to the basis margin (another leaf side). Basal veinlets as secondary veinlets ended in looplike anastomoses, which in secondary veinlets separated from the leaf margin by a series of large loops. Secondary veinlets (6–7 pairs at the base) somewhat connivent, diverged at 45–50° from the main vein, in the middle of leaf they apart and diverged at large angle; there are numerous intercalated veinlets between them. Tertiary veinlets, spiderweblike, oblique to secondary veinlets.

Eponymy:— From the name of the valley of ancient river Palaeo-Don, locus classicus.

Stratigraphy:— Middle Miocene (Serravalian = Konkian horizon).

Status:— Leaves.

IFPNI registration lsid:— 69FB979D-BBD4-43CD-8608-F8AB35A7CBED

Note:— The distinctive fossil-species Polygonum ukrainicum Baikovskaja (in Kryshtofovich & Baikovskaja 1965: 70) (see IFPNI: http://fossilplants.info/names/ BDB188F2-73BA-4772-ADFC-E4B3FEE2A493) was based on the leaf remains from the famous fossil plant locality at Krynka river of Rostov region ( Russian Federation, European part). However, no holotype was indicated, but two fossil specimens were provided, i.e. # 958 and # 958ª (part and counterpart of the same specimen), and # 1321, which resulted in not validly published species name (Art. 40.1). Later Pneva (1989: 1032) recombined Polygonum ukrainicum under Fallopia , but no type was indicated again, so making the Pneva’s proposal as invalid (Art. 40.1) (see IFPNI: http://fossilplants.info/names/ 3632DAB9-39C1-4559-B5AB-4790564E6483). Again later Pneva (2006b: 27) provided a type, but Latin or English diagnosis was not given as required by the Art. 43.1 (since 1996). As a consequence, Pneva (2006b) did not validate the species name. Lacking further available name, the fossil taxon is validated as Fallopia palaeodonica related by leaf morphology and venation to the extant species F. baldschuanica ( Regel 1884: 684) Holub (1971: 176) .