Potamogeton pusillus Linnaeus (1753: 127)

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 : 4

Potamogeton pusillus Linnaeus (1753: 127) , Fig. 2

Annual or biennial, rhizome filiform; stem filiform, terete, without or with indistinct nodular glands. Leaves submersed, sessile, green, linear, cuneate at base, 15–30 mm long, 1 mm wide, 3-veined without lacunar cells along distinct midrib, margins entire, acute to acuminate at apex; stipules 4–5 mm long, not fused, membranaceous, connate in the lower part. Spike 4–5 mm long, peduncle 4–5 mm long, as thick as the stem. Tepals 0.8–1 mm long, anthers 0.5 mm long. Carpels 4, fruits ca. 2 mm long. Stele of circular type, endodermis of O-type, interlacunar bundles absent, subepidermal bundles present.

Worldwide distribution: —Europe, Africa, W Asia ( Afghanistan, Pakistan, Iraq), N and E Asia, North and South America.

Distribution in Iran:—North, West, Central, South East.

Flowering time: —From spring to autumn.

Specimen examined:— IRAN. Gilan: Lahijan, Hasanbakandeh, Amirkelaieh wetland, - 25 m, 8 May 2010, Dinarvand 21407 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Astaneh: Kiashahr, Boujagh Conserved Area , 50 m, 10 May 2010, Dinarvand 29318 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; west of Rasht from Fouman road, 50 m, 10 May 2010, Dinarvand 22146 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Hamedan: Shirinsoo wetland, 1838 m, 1 June 2010, Dinarvand 8325 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Azerbaijan: Tabriz to Bostanabad, Ghoorigol lake , 1920 m, 5 July 2010 Dinarvand 8313 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Chaharmahal va Bakhtiari: Shalamzar wetland, 2052 m, 27 Aug 2014, Abbasi & Afsharzadeh 20212 ( HUI!) ; West Azerbaijan: Miandoab wetland, 8 Aug 2015, Abbasi & Afsharzadeh 20213 ( HUI!) ; Khuzestan: Shushtar: Arabhasan river , 800 m, 20 May 2009, Dinarvand 8137 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Dezful: Hamidabad river , 730 m, 20 May 2009, Dinarvand 8334 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Andica, Ghaleh Khaje Abzalo wetland, 738 m, 21 May 2009, Dinarvand 8554 (Herbarium of the Research Center of Agriculture & Natural Resources of Khuzestan!) ; Kurdistan: 48 km from Paveh to Kermanshah, Ravansar village, swamp, 1400 m, 1 Aug 1978, Runemark & Mozaffarian 2744 ( TARI!), Sistan: Hamoon lake , 470 m, 5 June 1978 Sharif 33929 ( TARI!) .

Figures

FIGURE 2. P. pusillus a. cross section of stem (Scale bar: 100 μm, objective lens 4), b. morphological shape.