Persicaria subsagittata (De Wildeman) S. F. Chen et B. Li, 2015

Chen, Shaofeng & Li, Bo, 2015, Two new combinations in Persicaria sect. Echinocaulon (Polygonaceae: Persicarieae), Phytotaxa 224 (2), pp. 196-198 : 196

Persicaria subsagittata (De Wildeman) S. F. Chen et B. Li , comb. et stat. nov.

Bas.: Polygonum pedunculare Wallich ex Meisner (1832: 58) var. subsagittatum De Wildeman (1930: 107) ≡ Polygonum subsagittatum C. W. Park (1986: 218) .

Type:— CONGO. Fendula (Nyakolonge), 1928, H.Scaetta 641 (holotype, BR-0000008975553!, image avaiable at http://www.br.fgov. be/RESEARCH/COLLECTIONS/HERBARIUM/zoomifyimaging.php?filename=0000008975553&herbarium= BR).

Distribution: — Persicaria subsagittata mainly occurs in Eastern-Africa ( Burundi, Kenya, Rwanda, Tanzania and Uganda).

Note: —This taxon had been originally described as a variety of Polygonum pedunculare Wallich ex Meisner (1832: 58) . Park (1988) pointed out that the two taxa obviously differs each other by their inflorescences structure (terminal branches as a very loose interrupted panicle of 4–7-flowered fascicles in P. subsagittata vs. dense panicle of many-flowered fascicles in P. dichotoma ). On the other hand, P. subsagittata appears to be morphological similar to P. praetermissa ( Hooker 1886: 47) Hara (1966: 73) concerning many characters, such as the linear-lanceolate to lanceolate leaf blades with weakly hastate to sagittate bases, the scarious and cylindrical ocreae with oblique apex, the inflorescence branches terminated by a very loose interrupted panicle of 4–7-flowered fascicles, and the dull and rugose achenes. Anyway, P. subsagittata can be easily distinguished from P. praetermissa by stems, leaf blades and inflorescences covering dense minute 2 − 4-rayed tufted hairs, and sparse to dense glandular hairs, and by its biconvex achenes.