KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 55. NIO 5. 



245 



f. nieinelanus n. f. — P. Heidenreichii Asch. et Graebner, Syn. 327, p. p.: 

 Folia caulina 200 — 240 x 16 — 22 mm basi apiceque valde angustata. — Fig. 113. 



This form approaches to f. lithuanicus which has shorter stem-leaves; from f 

 upsaliensis it is distinguished by more elongated leaf-points, which have the 

 somewhat recurved position, peculiar to P. decipiens, and by narrower, 

 slightly rounded leaf-bases. It is to be looked upon as a cross of lucens 

 var. longifolius X perfoliatus. Cf. Kupffer in Riga Korr. BL, 1906, 171! 

 — Dr. G. Fischer has established a »f. subperfoliatus = ser. Vollmanni 

 F.», which seems to be identical with f. typicus Tis. 



Distribution: Siveden, Scania: Krageholm Lake, 49, Z:dt (hb. 

 Uppsal.). — Halland, Frillestad, hb. E. Fries (hb. Uppsal.). - - Stock- 

 holm and vicinity: Brunnsviken, 51, Z:dt and others (hb. Stockholm., 

 Uppsal., Lund., Gothenb.); Blockhusudden, 63, Fredriksson (hb. Go- 

 thenb.); Norrström, 46, Lagerheim (hb. Stockholm.), f. upsaliensis; Tre- 

 hörningen, 27, Beurling (hb. Stockholm.); Långsjön, 26, Beurling (hb. 

 Stockholm.). — Uppland: Lake Mselar ad Runsa, 88, Floderus and Tise- 

 lius (hb. Stockholm., Uppsal.); Sigtuna: Skålgrund, 83, and Garnsviken, 

 88, Floderus and others (hb. Stockholm., Uppsal., Lund.), f. pulchellus; 

 Funbo, Danielsson (hb. Stockholm.); Säfva å, 60, Tiselius (hb. Stock- 

 holm.), f. pulchellus ; Norrsunda, Holmboda Lake, in the outlet, 94, Lund- 

 berg and others (hb. Stockholm., Uppsal., Lund.); Fyris River at Ulfva, 

 28, Wahlenberg and others (hb. Stockholm., Uppsal., Lund., Gothenb.); 

 at Ensta, hb. E. Fries and others (hb. Stockholm., Uppsal., Lund., 

 Gothenb.), Leaves sometimes very large, as much as 170 X 60 mm ; at Ekeby 

 mill, 59, Tiselius (hb. Stockholm., Uppsal.); at Jäsevad, 84, Tiselius near 

 (hb. Stockholm., Uppsal., Lund.). — Sudermania in Uttran and Malmsjön, 

 Södertälje; and West-Gothia in Husgärde lake and Ökull lake (hb. Hagstr.). 



Benmark, Susa, Ssell., 95, Ostenfeld— Hansen and others (hb. 

 Stockholm., Lund.); Hald so Jutl., 70, Nielsen (hb. Uppsal.); Gudenå 

 ad Kongensbro, Jutland, 97, Baagöe (hb. Stockholm.). — England, Cam- 

 bridgeshire, 84, Fryer (hb. Stockholm., Uppsal., Lund.). This plant, be- 

 side a specimen of P. proelongus Wulfen, labelled »Herb. Flora? germa- 

 nicse exsicc. curante Ludwig Reichenbach N:o 2501 Potamogeton longi- 

 folius Gay. Golssen in der Nieder Lausitz. Apoth. Burkhardt», are 

 determined by P. Graebner as »Potamogeton prcelongus X lucens (P. de- 

 cipiens Nolte in Koch Syn. ed. 2. 779 (1844)) var. Babingtonii (Benn. 

 Journ. of Bot. XXXTT, 204, (1894)) A. u. G., Syn. I, 332» (hb. Berolin., 

 P. Graebner's own hand). — Germany, Vratislavise, Uechtritz (hb. 

 Stockholm., Uppsal.). Kilise, Nolte (hb. Stockholm., Uppsal.), »P. dici- 

 piens Nolte»: Stem-leaves 75 — 120 x 20 — 30 mm, ligules short, very soon decaying; 

 Holstein und Lauenburg, E. F. Nolte (hb. Uppsal.), ex hb. E. Fries, labelled: 

 »Herb. der Schl.— Holst.— Lauenb. Fl. no. 715 (1838) publicirt Nolte» (Nolte's own 

 hand) : Leaves 100 X 25 mm. These specimens are the so-called P. lucens X prce- 



Fig. 113. P. 

 <li cipiens Nolte 

 f. memelanus 



Hagstk. Stem- 

 leaf at the pri- 

 mary spike, i, 

 ca. 13-nerved. 



