98 FORMS AND DISTmBUTION OF BiTRACllIUM. 



13. ELONGATUS. 



R. elonrjntm, Bntrachium elongntam, P. Schultz ! iu ' Billotia,' vol. i. 

 p. 113. n. 3802 (1869). R. aqnat'dis^ y. qiiinqiielobus, Koch in Sturm. 

 Deutschl. Fl. Hf. 67. f. (1835), seems scarcely to differ, except that 

 the lobes are more uniformly rounded and nearly equal. 



Occurs in Lapland (Fellman ! 3, a poor specimen, from the Arctic re- 

 gions, seems to belong here), England (Hampshire!, Lancashire qn'mque- 

 lobus), Wales, France, Germany, Spain. R. aquutilis, heterophjllus, sub- 

 truncatm, Rchb. Fl. Germ. vol. iii. p. 3, is intermediate between elon(/atits 

 and truncatus. 



14. PENICILLATUS. 



Batrachium penicillatum, Dumort. Monogr. Batr. p. 12 (1863). R. aqna- 

 iilis, a. lougifuliiia, Rossmann, Beitr. Kenntn. Wasserhahu. p. 58 (185-t). 

 R. aquatiUs, ^3. heterophyllns, siibtruncati(S, pleiopetalus, Rclib. Fl. Germ. 

 3. t. 3 (1838). R. pseudojiiitiins, Bab., minore parte (1867). R. pdta- 

 ius, y. pseiuhjiuitans, Syme, part (1863)". 



Occurs in England, Ireland, Belgium, France, Germany, and probably 

 in other countries. Differs homjl/ntaii-i, with which it is likely to be con- 

 founded, by its hairy receptacle, and from psendojlnitans by the presence of 

 floating leaves. The petals are occasionally more than five in number, as 

 is also the case in fitdlans. E. Fries in ' Botaniska Notiser' for 1845, p. 

 122, reports " Batrachium quoddam singulare penicUlatum'" from the 

 Malar Lake, in Sweden, having leaves with long petioles, and with veiy 

 numerous but quite short setaceous segments in a very dense pencil. He 

 was uncertain whether these characters would prove constant, and I have 

 no further information regarding the plant. 



15. FLORIBUNDUS. 



R. aquatiUs, a. peltatus, Koch in Sturm, Deutschl. Fl. Hf. 67. f. 

 (1835). R. aquatiUs, a. cordatus, Doll, Rheinisch. Fl. p. 549 (1843). 

 R.Jloribundas, Bab. in Ann. Nat. Hist. ser. 3. vol. xvi. p. 397 (1855). 

 R. irii/acrius, E. and A. Huet du Pavilion in Plant. Sic. Exsicc. n. 1 

 (1856, state deprived of submersed leaves). Batrachium aquaiile and 

 iioribundum, Dumort. Monogr. Batr. p. 1»2 (1863). R. pdtatus, ^. flori- 

 hnndus, Syme (1863). Fig.— Fl. Dan. t. 2416; Eng. Bot. Suppl. 

 2969. 



Occurs in England, Scotland, Ireland, France, Sicily, Spain, Portugal, 

 S. E. Europe, Smyrna, Algiers, etc. R. aquaticus, var. irUubus, Frivaldczky 

 ]\IS. Rumelia. 1837. A common and widely distributed form, especially 

 in Europe. 



16. TRUNCATUS. 



R. aquaticus, /3. truncatus, Koch in Sturm, Deutschl. Fl. Hf. 67 f. 

 (1835). R. peltatus, ^^.\.c. 1855 (nearly). Batrachium. truncatum, 

 Dumort. Monogr. Bat. p. 11 (1863). R. peltatus, a. vulgaris, Syme 

 (1863) (nearly). Fig.— Eng. Bot. Suppl. t. 2965 (not good). 



Occurs in West Russia (Herb. Fl. Ingric. Cent. ix. n. 12 !), 

 Britain, Belgium, France, etc., Teneriffe (state always with glabrous 

 carpels, often with very large flowers and numerous veins on the petals, 

 s.\i\iYOd.Q\img penicillatus, E. Bourgeau, PI. Canar. n. 407 !). 



R. diversifolius, Srhrank, Baier. Fl. p. 103 (1789). Ba- 

 trachium heterophylhim. Fries, Sum. Veg. Scand. i. p. 140. 

 part (1846). R. hjdrocharis, A. hderophyllus, a. vulgaris 

 Spenncr, Fl. Frib. (1829). Forms 17-19. 



