KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 55. N:0 5- 219 



On ligules etc, see under P. lucens x notans, p. 239! wherc thc difference be- 

 tween the two is more closely determined. 



The anatomy of the stem behaves as in all the other hybrids. It generally 

 approaches to that of P. natans, but occurs with deviations, more or less obvious, 

 toward P. gramineus. It exhibits noticeable similarities to the anatomy of P. lucens 

 X natans. In many cases, however, the number of the cortical interlacunar bundles 

 is considerably reduced in P. sparganifolius. 



Distribution. Sweden. Lapland, Karesuando, 29 (and several following years) 

 LiESTADius (hb. Stockholm., Uppsal., Lund., Gothenb.). This station is the original 

 habitat. Ljestadius first regarded this hybrid as a deformed P. natans, but con- 

 founded it låter with P. gramineus. The earliest specimens are named »P. tereti- 

 caule» and »P. lineare», låter on also »P. subcoriaceus» (specimens with floating 

 leaves). Torne lpm, Pysäkoski, 52, Fristedt (hb. Stockholm.); Little Lule River, 

 96, Vesterlund (hb. Lund.); Majtum, 04, Wolf (hb. Lund.); Jockmock, 06, Wolf 

 (hb. Stockholm.). -- Nordbothnia, Pajala, L^stadius (hb. Stockholm., Uppsal., Lund.); 

 Pite River, 65, Håkansson and others (hb. Stockholm., Uppsal., Lund., Gothenb.). — 

 Angermania, Gideå River, 37, J. A — m (hb. Uppsal.). — Jemtland, Ottsjöns utlopp 

 (outlet), 91, Collijn (hb. Stockh., Uppsal.). - Herjedalia, Sveg in the Ljusnan, 98, 

 Exander (hb. Stockholm., Lund.). — Vermland, Sunne in Fryken, 14, Fröding 

 (hb. Fröd.). — Stockholm, Drottningholm, 98, Hagström & Lagerwall, 99, Lager- 

 wall (hb. Stockholm., Lund.). — Sudermania, Gryt in Båven, 06, Sondén (hb. 

 Stockholm.). — Smoland, Målilla, Hagelsrum, 64, Björkgren (hb. Stockholm.), 81, 

 Hagström and others (hb. Stockholm., Uppsal., Lund., Gothenb.): »P. dubius Tis.»; 

 Misterhult, L. Laxemar, 65, Ekstrand (hb. Stockh.); Järeda, Klöfdala intheEmån, 

 65, Ekstrand (hb. Stockholm.). — Scania, »hb. C. M. Nyman» (hb. Stockholm.) 

 lab. »P. jluitans Roth»; Billinge, RönneJL at Stockamöllan, 93, Cöster (hb. Stock- 

 holm., Lund.); Tjörnarp, 81, Nilsson (hb. Lund.). — More Swedish stations than 

 those are not knovvn to me; consequently this hybrid is much rarer in Sweden than 

 X P. Zizii. 



Norway, Dovre: Goverlivandet, 65, Falck (hb. Uppsal., Lund.); Porsanger, 63, 

 hb. T. M. Fries (hb. Uppsal.); Laugen in the outlet into Mjösen, 96, Landmark 

 (hb. Stockholm., Lund.); East Finmarkia, South Varanger: Elvena?s, 64, Fries (hb. 

 Uppsal.). — Lapponia rossica et fennica: Nuortijaur, 83, Hollmén (hb. Stockholm., 

 Uppsal., Lund.); Kola peninsula, Lovanserski reka, 90, Ekstam (hb. Stockholm.); 

 Lapp. inarensis: Kaamos, 03, Torckell (hb. Stockholm., Uppsal., Lund.); Lapp. 

 kem., Par. Sodanskyla, 82, Blom (hb. Stockholm.); Lapp. Imandra?, 92, Kihlman 

 (hb. Stockholm.). — Finland: Valkjärvi, Metsakylä, Saijoki, 95, Lixdeberg (hb. 

 Stockholm.); Alandia: Bräkträsk, 01, Palmgren et Klingstedt (hb. Stockholm.). — 

 Denmark, Odenseaa, Funen (Fyen), 47, Lange and others (hb. Stockholm., Uppsal.) 

 »P. jluitans rivularis Lge»; Gudenå, 95, Baagöe (hb. Stockholm.); Hanbjergå, Jutl., 

 99, Baagöe (hb. Stockholm.); I have also seen it from Snesere, Ssell., Stora at Hol- 

 stebro, Jutl., and Kongeå, Jutl and (hb. Hagström). — East Baltikum, see K. R. 

 Kupffer, 1. c. — Germany: »Saxenwalde Nolte» (hb. Stockholm.), labelled: »P. 



