FORMS AND DISTRIBUTION OF BATKACHIUM. 99 



17. KHIPIPIIYLLUS. 



R. rhipipht/lliis, Bast in Boreau, Fl. Cent. Fr. ed. 3. vol. ii. p. 11 

 (1857). 



France. A specimen with very few submersed leaves, and with only 

 3-5 veins on the petals, from Leipzi<^; in Hb. Kew, labelled R. aquatiUs, 

 var. micranthiis, probably is a state of this form, also some British speci- 

 men ; but I have not seen an authentic specimen. 



18. RADIANS. 



R. radians, Revel in Act. Soc. Linn. Bord. vol. xix. p. 114, f. (1853). 

 R. heterophyllus, Bab. part (1855). 



Occurs in Scandinavia, Scotland, England, Ireland, France, Switzer- 

 land, Spain (weak state, with leaves approaching those oi Jlonbundus), 

 etc. Not uncommon, 1 believe, in the North of England. I have it from 

 Lancashire, Staffordshire, and Cambridge. 



19. GODRONII. 



R. Godronii, Gren. in Schultz Arch. pp. 169, 173 (name only), (1850). 

 R. aquutilis, /3. lirevifolius, Kossmann, Beitr. Kenntn. Wasserhahn, p. 58 

 (1854). 



Occurs in England (Warwickshire !) and France, and probably else- 

 where. Professor Babington, in 1855, united this form with R. Drouetii, 

 and now he unites it with R. trkliophyllus. Floating leaves tripartite 

 with cuneate and incise or crenate lobes, membranous and cjuite glabrous, 

 or occasionally with a few scattered weak appvessed hairs beneath; flowers 

 usually smaller than in radians ; subm.ersed leaves finely capillary ; carpels 

 more or less hispid; fruit-receptacle rounded and hairy. 



R. pantothri'X, Brot. Fl. Lusit. vol. ii. p. 375 (1804). R. Jlnvia- 

 tilis, Wahl. Helvet. n. 597. p. 109 (1813), non Web. R. JiydrocJiaris, 

 B. honwiophyllus, /3. y. e. C, Spenn. Fl. Frib. (1829). All Indian 

 specimens belong to this group, and all American ones except those 

 which belong to R. /lederaceus, L. Forms 20-85. 



R. fanic/flaceiis, Gilib. Fl. Lith. vol. v. p. 262 (1782). R. 

 aqualilis, y. foeuicnlacens, Hagen, Ranunc. Pruss. (1783) in Ludw. 

 Del. Opusc. p. 488 (1790). R. aqnatilis, Web. in Wigg. Prim. 

 Fl. Holsat. p. 43 (1780). Forms 20-34. 



20. CIRCINATUS. 



R. aqnatilis, (3, Linn. Sp. PL p. 781 (175"3). R. aqnatilis, B. mille- 

 folius, Liljeblad, Sw. Fl. p. 229 (1792), ex Schlechtendal. R. circinatns, 

 Sibth. Fl. Oxon. p. 175 (1794). R. aqnatdis, a. orbiculatus, Schnra. 

 En. PI. Saell. p. 171 (1801). R. stagnatilis, Wallr. Sched. Crit. p. 285 

 (Lower leaves subferruginous 1822). R. aqi:atilis, 8. stagnatilis, De 

 Cand. Prod. vol. i. p. 27 (1824). R. rigidus. Roth, En. PI. PhEenog. 

 Germ. I. ii. p. 633 (1827), non Pers. nee Godr. R. hydrocharis, B., ho- 

 moiopJiyllus, y. c<pspitosiis, Spenn. Fl. Frib. p. 1 008 (1829). R. divaricatits, 

 Koch in Sturm. Deutschl. Fl. H. 67, fig. (1835), non Schrank. Ba- 

 trachinm circinnatnm, Spach, Hist. Nat. Veg. vol. vii. p. 201 (1839), 

 Fries, Hb. Norm. fasc. 9. n. 29 (specimen, 1846). ButracJiinm dlvari- 

 catum, Schur. Enum. PI. Transsilv. 12 (1866). Fig.— Godr. Essai, f. 7 ; 

 Eng. Bot. t. 2869; FL Dan. t. 2236; Rchb. Fl. Germ. 3. 2; Cossou 

 and Germ. Atl. t. 1. f. 9 ; Schkuhr, Handb. t. 152. 



Occurs in Scandinavia, Belgium, Russia, England, Scotland, Ireland, 

 France, Germany, Switzerland, I'yrol, Italy. A Swedish form approaches 

 coufcn-oides. This is one of the best marked and n.ost distinct, but I 



H 2 



