Potamogeton nodosus Poiret (1816: 535)

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 : 10

Potamogeton nodosus Poiret (1816: 535) , Fig. 10

Perennial, rhizome slender to robust, stem robust, terete. Leaves dimorphic; submersed leaves short to longly petiolate, in mature state often missing, 40–300 mm long, 11–30 mm wide, obtuse to acute at apex, cuneate at base, 7-veined; floating leaves 30–100 mm long, 11–50 mm wide, 20-veined, obtuse to acute at apex, petiole 70–200 mm long, stipules not fused, 30–75 mm long, membranaceous. Spike 15–55 mm long, peduncle 45–105 mm long, thicker than the stem. Tepals 1 mm long, anthers 1 mm long. Carpels 4, fruits 2.5–4 mm long, brownish to reddish. Stele of trio to 8 bundles type, endodermis of O-type, interlacunar bundles absent, subepidermal bundles absent.

This species is distinguished from morphologically similar P. natans Linnaeus (1753:126) by the lacking joint between petiole and lamina of the floating leaves.

Worldwide distribution: —Subcosmopolitan; Europe, Africa, W Asia ( Afghanistan, Pakistan, Iraq), temperate and tropical Asia, Australia, Pacific islands, North America, N and C South America.

Distribution in Iran: —North, Northwest, West, Central, Northeast, South.

Flowering time: —From winter to autumn.

Specimen examined:— IRAN. Mazandaran: Siahrood , 62 m, 12 Aug 2014, Abbasi & Afsharzadeh 20193 ( HUI!) ; Sorkhrood , 60 m, 29Aug 2015, Abbasi & Afsharzadeh 20195 ; Tajan , Abbasi & Afsharzadeh 20194 ( HUI!) ; Gilan: under Sefidrood bridge, - 2 m, 16 July 2014, Abbasi & Afsharzadeh 8212 ( HUI!) ; Isfahan: Dizicheh , 1692 m, 26 Sep 2014, Abbasi & Afsharzadeh 20196 ( HUI!) ; Chamaseman dam, 1750 m, 1 Aug 2013, Abbasi & Afsharzadeh 20222 ( HUI!) ; Lorestan: Pole Dokhtar, Lefone wetland, 1800 m, 12 July 2010, Dinarvand 8710 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Kurdistan: 78 km Pveh to Kermanshah, 1380 m, 15 July 2010, Dinarvand 27469 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Hamedan: Ghooshtapeh, 1850 m, 22 May 2008, Dinarvand 65017 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Kermanshah: West Gilan, 1000 m, 15 July 2010, Dinarvand 33920 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Ilam: under Simreh bridge, 100 m, 7 July 2010, Dinarvand 8285 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Kokiloye and Boyer Ahmad: 15 km to Yasouj , 2120 m, 7 June 2010, Dinarvand 8658 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Fars: Tjunction of Kamfirooz, 1630 m, 8 June 2010, Dinarvand 8673 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Khorasan: Hizomi spring, 1000 m, 10 July 2010, Dinarvand 5117 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Semnan: Ahmadabad Touran protected area, 1080 m, 1 September 1976, Freitag 14179 ( TARI!) ; Kerman: Golbaf, 1727 m, 24 July 2014, Abbasi & Afsharzadeh 20191 ( HUI!), Sistan va Baluchestan: Chabahar to Negor , river, 20 m, 25 May 2016, Abbasi & Afsharzadeh 20198 ( HUI!) ; Khuzestan: Shushtar , 127 m, 27 June 2014, Abbasi & Afsharzadeh 20189 ( HUI!) ; Izeh to Lordegan road, 1307 m, 27 June 2014, Abbasi & Afsharzadeh 20190 ( HUI!) ; Ahvaz to Shushtar, after Arab Asad village , 100 m, 21 June 2010, Dinarvand 8143 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Karoon river, 20 m, 20 June 2010, Dinarvand 8341 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Dezful: Hamid Abad, 120 m, 20 June 2010, Dinarvand 8341 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) .

Figures

FIGURE 10. P. nodosus a. cross section of stem (Scale bar: 100 μm, objective lens 4), b. morphological shape.