§2 p - Graebner. — Potamogetonaceac. 



Afrika: Madagaskar (A. Bennett in Journ. of Bot. XXXIII. [1 895] 139, Hum- 

 blot n. 352). 



Nota. Planta valde variabilis in tempestatibus diversis formas valde variantes producit. 

 (Conf. etiam Fryer in Journ. of Bot. XXVIII. [1890] 174). — De formis bavaricis conf. Fischer 

 in Ber. Bayr. Bot. Ges. XI. (1907) 66 ff. 



Var. a. elongatus Reichb. Icon. fl. germ. helv. VII. (1845) 24 t. 39 fig. 68; 

 Aschers, u. Graebner, Synops. mitteleurop. Fl. I. (1897) 320. — P. angustifolins 

 Berchtold et Presl, Rostlinär I. (1821) 19 sens. strict. — P. Jieterophyllus y. elon- 

 gatus Mert. u. Koch, Deutschi. Fl. I. (1823) 845. — P. lanceolatus Wolfg. ex Reichb. 

 1. c. (1845) sens. strict. nee Smith. — Internodia elongata, usque ad 2 dm longa. 

 Folia lanceolata vel elongati-lanceolata, superiora usque ad 2,5 cm petiolata, spicis 

 multo brevioribus (saepe i / i longitudinis spicarum tantum). — Plerumque in aqua pro- 

 funda. 



Subvar. 1. splendidissimus F. Schultz, Herb. norm. nov. ser. Cent. 27 (1890) 

 2693 nee Tisel. — Folia ca. 1 cm lata, anguste lanceolata vel fere linearia. — 

 Forma rara. 



Subvar. 2. Tiselii Graebner 1901. — P. Zixii var. splendidissima Tisel. Pot. 

 scand. exs. 4 s. (manuscr.) (1896) nee F. Schultz. — P. lucens i>. splendidissimus 

 Tisel 1. c. (1896) 65. — Internodia elongata, usque ad 2 dm longa et peduneuli spicarum 

 ad 3,5 dm usque longi. 



Schweden. 



Subvar. 3. longipedunculatus Tisel. Potam. suec. exsicc. (1896) 64. — Folia 

 subsessilia. Peduneuli valde elongati, valde incrassati. 



Schweden: Prov. Jemtland, in stark fließendem Wasser. 



Subvar. 4. longipetiolatus Tisel. Potam. suec. exsicc. (1896) 60, 144. — Pe- 

 duneuli paulo elongati. Folia superiora longe-petiolati. 



Schweden: In stehendem und fließendem Wasser. 



Nota. Specimina aquae currentis valde elongata sunt et ad var. elongatum pertinent, ea 

 aquae stagnantis breviora sunt et ad var. validum vergent. 



Subvar. 5. subviridis Tisel. Potam. suec. exsicc. (1896) 61. — Peduneuli bre- 

 viores. Folia subsessilia laete viridia. 



Schweden: Prov. Upland. 



Subvar. 6. foliosus Tisel. Potam. suec. exsicc. (1896) 63. — Planta valde fo- 

 liosa, longior et omnibus partibus validior. Folia subsessilia. 



Schweden: Prov. Medelpad. 



Var. ß. validus Fieber, Potam. Böhm. (1838) 26; Reichb. Icon. fl. germ. helv. 

 VII. (1845) t. 38 fig. 66, 67. — P. heterophyllus ö. latifolius Mert. u. Koch, Deutschi. 

 Fl. I. (1823) 845. — Internodia breviora, plerumque 1,5 cm longa. Folia ovata vel 

 ovati-elliptica, inferiora brevissime petiolata, saepius fere sessilia, superiora petiolo ca. 

 1 cm longo instrueta, spicis longiora vel breviora, saepe natantia (P. lucens hetero- 

 phyllus Fries, Novit, fl. suec. [1828] 34). — Plerumque in aquis stagnantibus. 



Var. y. coriaceus (Nolte) Aschers, et Graebner, Synops. mitteleurop. Fl. 1. (1897) 

 320 conf. Cham, et Schlechtd. in Linnaea II. (1 827) 201 . — P. lucens var. lacustre Thore, 

 Chloris des Landes (1803 vel' 1798?) 46? — P. lucens var. coriaceus Nolte ex Mert. 

 u. Koch, Deutschi. Fl. I. (1823) 850; Reichb. Icon. Fl. germ. helv. VII. (1845) t. 37 

 fig. 65. — P. lucens y. amphibius Fries, Novit, fl. suec. ed. 2. (1828) 34. — P. 

 gramineus a. platyphyllus Meyer, Chloris hannov. (1836) 530 nee Reichb. (sens. strict.). 

 — P. Zixii a. validus a. Fieber, Potam. Böhm. (1838) 26. — P. coriaceus A. Ben- 

 nett et Fryer in Journ. of Bot. XXIV. (1886) 223; Fryer 1. c. XXVII. (1889) 8. — 

 P. lucens var. F. terrestris [minor] Tisel. Potam. suec. exsicc. n. 66, 67. — Caulis usque 

 ad 1 m longus. Folia submersa peduneulata vel sessilia, oblonga vel obovata, plana 

 vel subundulata. Folia natantia obovata vel oblonga vel rotundata 5 — 8 cm longa et 



