Persicarioipollis frequens (Sah & Dutta) Doweld, 2017

Doweld, Alexander B., 2017, New names in Fallopia, Persicarioipollis, Polygonum and Reynoutria (Polygonaceae), living and fossil, Phytotaxa 308 (1), pp. 66-79 : 72

13. Persicarioipollis frequens (Sah & Dutta) Doweld , comb. nov.

Basionym:— Polygonacidites frequens Sah & Dutta (1968: 193) .

Type:— INDIA. Assam: Dhekiajuli beds, Digboi Oilfield (holotype slide 3/6, Sample 2792, Birbal Sahni Institute of Palaeobotany, Lucknow, India)–figured by Sah & Dutta 1968: pl. 2, fig. 22.

Stratigraphy:— Mio-Pliocene (Dhekiajuli beds).

Status:— Sporae dispersae (pollen).

IFPNI registration lsid:— 1691B8A2-F4B3-44C6-A1E2-AC2FD984240D

Note:— Sah & Dutta (1968: 192) established monotypic fossil genus Polygonacidites and mentioned that pollen of extant Polygonum glabrum Willdenow (1799: 447) [≡ Persicaria glabra (Willdenow) Gómez (1896: 278) ] and Polygonum strigosum Brown (1910: 420) [≡ Persicaria strigosa (Brown) Gross (1913: 308) ] exhibit comparable characters with their fossil-species ( Polygonacidites frequens Sah & Dutta 1968: 193 ), which was discovered in the younger Mio-Pliocene sediments of the Upper Assam ( India). However, pollen of P. glabra and P. strigosa are larger than pollens displayed by P. frequens , and the microfossils should be better attributed to some extinct Persicaria -like species ( Mandal & Kumar 2000: 199). Thus, upon priority, P. frequens is transferred into earlier established fossil pollen genus Persicarioipollis , serving a formal repository of fossil pollen taxa related to extant genus Persicaria . Therefore, Polygonacidites Sah & Dutta (1968: 192) is treated as heterotypic synonym of Persicarioipollis Krutzsch (1962: 282) .