Potamogeton natans Linnaeus (1753:126)

Abbasi, Shabnam, Afsharzadeh, Saeed, Dinarvand, Mehri & Wiegleb, Gerhard, 2017, Synopsis of Potamogetonaceae in Iran with supplements to the Flora Iranica and a new identification key, Phytotaxa 311 (1), pp. 1-21 : 9-10

Potamogeton natans Linnaeus (1753:126) , Fig. 9

Perennial, rhizome robust, wintergreen with phyllodial shoots, stem robust, terete, dark-spotted at base. Leaves dimorphic; submersed leaves phyllodial, 100–600 mm long, 0.5–3.5 mm wide, acute at apex, straight at base, 1–3- veined; floating leaves petiolate, oblong-lanceolate to ovate, 50–80 mm long, 50–100 mm wide, acute or obtuse at apex, rounded or subcordate at base, 20-veined, petiole 40–100 mm long, with a flexible discolored joint and a distinct angle at the top; stipules not fused, 5–8 cm long, membranous, persistent. Spike 25–35 mm long, peduncle 70–85 mm long, as thick as stem. Tepals 1–2 mm long, anthers 1 mm long. Carpels 4, fruits 3–4 mm long, indistinctly keeled. Stele of proto type, endodermis of U-type, strong interlacunar bundles present, subepidermal bundles present.

Northern Hemisphere.

Distribution in Iran: —North, West.

Flowering time: —From spring to summer.

Specimen examined:— IRAN. Golestan: Northwest of national park of Golestan, 1349 m, 20August 1999, Akhani 17050 ( HUT!) ; Lorestan: Gahar lake, 2350 m, 8 Sep 2010, Dinarvand 20211 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; East Azerbaijan: Tikmeh dash, 1900 m, 12 Sep 2013, Bagheri 20210 ( HUI!) .

Figures

FIGURE 9. P. natans a. cross section of stem (Scale bar: 100 μm, objective lens 4), b. morphological shape. World distribution:—W Asia (Afghanistan, Pakistan, Turkey), circumpolar, boreal and temperate regions of the