Polygonum halophilum (Polygonaceae): a new species from semi salty plain of Erzurum, Eastern Anatolia (Türkiye)
Polygonum halophilum is described as a species new to science from Erzurum Province (Eastern Anatolia, Türkiye). It is morphologically similar to P. acerosum and P. cappadocicum, but differs in having densely fibrous roots, elliptic or lanceolate leaf, 2−3-nerved ocreae, and 6 stamens. In addition, the habitat of the newly described species, which is semi-saline and ranges from damp to drying swamp, is distinctly different from that of the closely related taxa. While nuclear ribosomal DNA Internal Transcribed Spacer data support the new described taxa at specific level, they provide insufficient resolution for its sectional classification. This paper also provides an updated key to the relative species in Türkiye, photographic illustrations, and fruit (nut) anatomy, nut and leaf micromorphology and palynological features of the new species together with a discussion of conservation issues.