60 J. O. HAGSTRÖM, CRITICAL RESEARCHES ON THE POTAMOGETONS. 



borg, 84, Wittrock (hb. Stockholm.), Malmö, Husie, 65, Brorson (hb. Uppsal, et 

 Lund.), Björka, Kropp, 64, Hultberg (hb. Lund.), f. longifolius Fieb., Ousbyholm, 

 hb. Diiben (hb. Lund.), narrow-leaved form, between Reng and Maglarp, 84, Nilsson 

 (hb. Lund.); Uppland, Uppsala, Wieslander (hb. Lund.). — Russia, Livland, Riga, 

 82, Cederwald (hb. Stockholm.). 



Other forms are: 



Var. COrillltllS Linton in The Journ. Bot. 1894, 186. — P. macrorrhi/ncus 

 Gandog. 1. c, p. p. — P. crispus L. var. macrorrh. (Gdgr) Asch. & Graebn., Syn. 

 1897, 336: — A form with the most elongated rostrum: »The spur stånds out Vao 

 in. from the surface of the drupelet, in the dried specimens." (Linton). 



The length, width, and crispness of the leaves vary. Thus Fieber discerns in 

 v. acutifolius two forms: 



f. vulgaris: Leaves about 5 cm long, and f. longifolius: Leaves more elongated. 



Var. obtusijolius also sometimes has elongated leaves: thus a forma elongatus. 



The same variety, besides, occurs narrow-leaved, f. angustijolius Fieb, and broad- 

 leaved, f. latifolius Fieb. The former is recorded from Siveden, Scania, Höganäs, hb. 

 Ag. (hb. Lund.) and from Ind. or. Hooker & Thomson (hb. Stockholm, et Lund.); 

 Japan, Tokio, Yatabe (hb. Uppsal.). 



Var. sinnat US Fries, Nov. Fl. suec. 1828, 43, has the crispest leaves and is 

 besides densly foliated. Two typical examples of this are deposited in the Museum 

 of Uppsala, both from Sweden, Smoland: one from Misterhult lake, labelled hb. Hart- 

 man, and the other from Hemsjön, 1824, E. Fries, labelled: »P. crispus v. crispatus 

 Wallm.». 



Var. najndoidcs Graebner in Engler, Pflanzenr. IV: 11, 1907, 100: — Leaves 

 very crisp, narrow and more removed from each other. 



Var. pl ii II Moll* ils Meyer, Chloris han. 1836, 523: — >Flachblättriges Laich- 

 kraut». P. crispus 7 serrulatus (Schrader) Reichb., Icones 1845, 18. — P. crispus 

 v. phialensis Post, Bull. Herb. Boiss. I, 1893, 409? (form with very faint denticula- 

 tion). — 



Var. nlatllS Zapalowicz might be nothing else than the usual form, see the 

 fig. 21, F. 



f. humilis Dumortier, Fl. belg. 1827, 163 is individuals of low growth and f. 

 gemmifer Rbiohb., 1. c, individuals with buds (turios). 



Distribution. As to Sweden P. crispus is a southern or south-east speeies. 

 The most Qorthern outposts of it occur al Hedesunda in Oestricia, 60° 30' N Lat.; 

 at Kärrbo, 55, Ckderstraiiee (hb. Uppsal.) and Ångsjön, 64, CedbbstbÅBXE (hb. 

 Stockholm.) in Weatmania; at Götlunda, 58, BloMBBBG (hb. Lund. et Gotenb.) in 

 Nericin; in Kolungen neax Mellerud, Dalin, 84, Fbyxell (hb. Stockholm.) and al 

 Kongälf (hb. Lund. et Gotenb.) in Bahusia. — In Nonoay it is recorded from Ringe- 

 rike. Its most northern limit in the Scandinavian Peninsula, therefore, is a line 

 <_M>ing from Hedesunda to Örebro and Mellerud in Sweden, to Ringerike, ca. 60° N. 

 Lat., in Norway, nearly corresponding to the year isotherm of I 4° C. It is probable 

 it doefl uot sm pass this line in general. Jn Sibcria, however, it goea as tar to the 



