]> GH barcode-01746130 United States of America Pennsylvania along Big Elk Creek, Elkdale Potamogeton pusillus subsp. tenuissimus (Mertens & Koch) R. R. Haynes & Hellquist (Mertens & Koch) R. R. Haynes & Hellquist 2020-11-18 10:36:56 F. W. Pennell