Persicaria minor (Huds.) Opiz, Seznam Rostlin Květeny České, 1852

Funez, Luís A. & Hassemer, Gustavo, 2021, Novelties in Persicaria (Polygonaceae): description of a narrowly endemic new species from southern Brazil, and typification of the name Polygonum minus, Phytotaxa 490 (1), pp. 60-70 : 64-67

Persicaria minor (Huds.) Opiz, Seznam Rostlin Květeny České : 72. 1852

≡ Polygonum minus Huds., Fl. Angl. : 148. 1762

≡ Peutalis minor (Huds.) Raf., Fl. Tellur. 3: 14. 1837

Lectotype (designated here): —(illustration) figure on the lower-left (“ Persicaria minor ”) of plate 29 of section 5 in Morison (1680).

Epitype (designated here): — UNITED KINGDOM. Surrey, ditch near Ockham Court , 14 September 1935, E. C. Wallace s.n. ( BM barcode BM001072687 ! [ Figure 3 ]) .

Diagnosis: —Annual, decumbent to ascending, absence of rhizomes or stolons, stems unarmed, leaves linear to linear-lanceolate, petioles not winged, not auriculate, ochreae chartaceous, brownish, the margins ciliate with bristles, inflorescences spike-like, uninterrupted, perianth 5-lobed, campanulate, perianth and peduncles eglandular, styles exserted.

Photographs: — Figure 4 .

Notes: — Persicaria minor is a species native to Eurasia ( Komarov & Grigoriev 1936, Webb & Chater 1964, Villar 1990), and naturalised in eastern North America and Argentina ( Fernald 1917, Cialdella 1989). Molecular phylogenetic evidence presented by Bunawan et al. (2011) suggests that the current circumscription of P. minor is not monophyletic, so that the Southeast Asian populations referred to the species could perhaps constitute a separate entity. This very interesting question demands further studies for its resolution.

The protologue of Polygonum minus ( Hudson 1762: 148) informed no gatherings, but gave provenance as “ Anglis ” and “ In the meadows beyond Peterborough-house, and in Tothil-fields, Westminster”. Moreover, the protologue gave two pre-Linnean synonyms: “ Persicaria pusilla repens ”, for which “ Ger. Em. 446. Park. 857. R. Syn. 145.” (i.e., Johnson 1633, Parkinson 1640, Ray 1724) were given as references, and “ Persicaria minor ”, for which “ Bauh. pin. 101. Hiss. Ox. II. s. 5. t. 29. f. ” (i.e., Bauhin 1623, Morison 1680) were given as references. The following three illustrations were directly or indirectly cited, and thus comprise original material: figure on the left (“ Persicaria pusilla repens ”) on page 446 in Johnson (1633); figure on the lower-left (“ Persicaria pusilla repens ”) on page 857 in Parkinson (1640); and figure on the lower-left (“ Persicaria minor ”) of plate 29 of section 5 in Morison (1680).

No original specimens could be located for the name P. minus ; the majority of William Hudson’s herbarium was destroyed by fire prior to his death (Fred Rumsey, pers. comm., 19 August 2020), and the remainder of his specimens are kept at BM and LINN ( Lanjouw & Stafleu 1957). Thus, in accordance with Arts. 9.3 and 9.4 of the ICN, we designate here as lectotype the best among the original illustrations, viz. the figure on the lower-left (“ Persicaria minor ”) of plate 29 of section 5 in Morison (1680).

Illustrations alone could be insufficient for the accurate application of species names in genera with complicated taxonomy, such as is the case for Persicaria . In fact, Morison’s illustration is not sufficient for the unambiguous application of the name Polygonum minus . Therefore, in accordance with Art. 9.9 of the ICN, we designate here as epitype a complete and well-preserved specimen, viz. BM barcode BM001072687.

Figures

FIGURE 3. Epitype of Polygonum minus (E.C. Wallace s.n., BM barcode BM001072687). Copyright: Natural History Museum, London.

FIGURE 4. Field photographs of Persicaria minor. A. Inflorescence. B. Fertile stem. C. Habit (dense population). D. Ochrea and stem. E. Habit (isolate plant). Photographs by Richard V. Lansdown.