Potamogeton. 135 



P. gramineus X mucronatus Aschers, et Graebner, Synops. mitteleurop. Fl. I. 

 (1897) 348. — P. lanceolatus Smith in Engl. Bot. XXVIII. (1809) t. 1985; Engl. Fl. 

 ed. 2. I. (1824) 233; Cham, et Schlechte!, in Linnaea II. (1 82") 230; Hook, et Arnott, 

 Brit. Fl. ed. 6. (1860) 469, 470; Babingt. Man. ed. 8. (1881) 380; in Journ. of Bot. 



XIX. (1881) H, 54; A. Benn. in Journ. of Bot. XIX. (4881) 65 t. 217 nee Davall, 

 Wolfgang etc. — P. lucens var. lanceolatus Benth. Handbook, ed. 1. (1858) 493. — 

 P. rufescens Gorski ex A. Bennett in Ann. naturhist. Hofmus. Wien VII. (1892) 290. 

 — P. heteropkgllus X Fricsii Fryer in Journ. of Bot. XXXII. (1894) 339. — Bhizoma 

 repens. Caulis gracilis, ramosissimus. Folia submersa plerumque alternantia, plerum- 

 que 3 — 9 cm longa, lineari-lanceolata, basi et apice angustata, acuta vel subacuta, 

 integerrima, diaphana, 3 — 6-nervata, area mediana reticulata distineta instrueta. Folia 

 superiora oblongo-lanceolata, opposita, in petiolum brevem angustata, subcoriacea vel 

 diaphana, 7 — 9-nervata. Stipulae liberae anguste subulatae vel lineares, superiores 

 lanceolatae, 2-nervatae. Pedunculi plerumque 2 — 7 cm longi, apice non incrassati. Spica 

 brevis 4 — 10 mm longa, ovoidea. Sepala rhomboideo-orbiculata. Ovarium oblongo- 

 ellipticum. Fructus ignotus, semper deest. 



England: Burwell Fen, Cambridgeshire (A. Ben nett in Journ. of Bot. XVIII. 

 [1880] 276); Wales: in Lligny, Anglesea (A. Bennett in Journ. of Bot. XIX. [1881] 

 66). — Irland (A. Bennett in Journ. of Bot. XX. [1882] 20), determinationes 

 autorum aliorum erroneae sunt; Cahira Biver (O 'Kelly ex Levinge in Journ. of Bot. 

 XXIX. [1891] 344). — Korfu, Cressidu (Letourneux ex A. Benn. in Bull. Herb. Boiss. 

 III. [1895] 257). 



Nota. P. lanceolatus planta critica est nunc pro hybrida inter P. gramineum et speciem 

 foliis linearibus donatis habita, nunc pro specie propria sumpta (cf. aut. div. in Journ. of Bot. 



XX. (1882) 20). 



P. gramineus X nitens Aschers, et Graebner, Synops. mitteleurop. Fl. I. (1897) 

 3 2 6, cf. Fryer in Journ. of Bot. XXVIII. (1890) 178. — P. {graminea X perfoliata) 

 a. X graminea [P. innominata Tisel. Herb.) Almquist in Hartman, Skand. Fl. 12. uppl. 

 (1889) 49. — P. intermedius Tisel. Herb, ex Fryer, 1. c. (1890). — P. nitens f. inter- 

 medius Tisel. ex Fryer I.e. (1890); Potam. suec. exsicc. n. 48; Bot. Not. (1864). — 

 P. nitens £. merloensis Tisel. Pot. suec. exsicc. (1894) 50. — P. nitens? s. innomi- 

 natus Tisel. Potam. suec. exsicc. n. 49; Bot. Not. (1894). 



Europa: England, Orkney: Birsay Lock (Boswell). Holstein (Th. Bernhard!). 

 Skandinavien. 



Huc pertinet 



Var. ß. falcatus Aschers.. et Graebner 1. c. (1897), conf. etiam Beeby in Journ. 

 of Bot. XXVII. (1889) 66. — P. falcatus Fryer in Journ. of Bot. XXVII. (1889) 65 

 t. 286, XXVIII. (1890) 210. — Folia submersa plus minis falcata. 



Nota. Cl. Fryer etiam formam terrestrem observavit. 



P. gramineus x natans (P. graminea X natans) Tiselius ex Almquist in 

 Hartman, Handb. Skand. Fl. 12. uppl. (1889) 48; P. gramineus X natans Fischer 

 in Ber. Bayr. Bot. Ges. XI. (1907) 73. — P. Tiselii Bichter, PI. Europ. I. (1890) 

 13 nomen solum. — P. dubius Tisel. Potam. suec. exsicc. (1894) 19. — P. 

 natans X gramineus Aschers, et Graebner, Synops. mitteleurop. Fl. I. (1897) 333. — 

 Folia infima fere phyllodia. 1) Folia submersa papyracea, sessilia vel basin versus in 

 petiolum angustum contraeta, linearia, protractim acuta. 2) Folia natantia superiora 

 ovati-cordata, coriacea, iis P. natantis similia, inferiora angusliora, breviter vel euneatim 

 in petiolum decurrentia. 



Europa: bisher nur mit Sicherheit mehrfach in Skandinavien. Die Angabe in 

 Irland unsicher (vergl. Fryer in Journ. of Bot. XXVI. [1888] 273); Ostseeprovinzen 

 (Kupffer, Korresp. bl. Naturf. Ver. Biga IL. [1906] 170). — Wohl weiterverbreitet. 



Bayern. 



Nota. Conf. etiam P. natans proles sparganiifolius p. 44. — Haec planta, ut multae 

 aliae hujus generis, exemplura non dubium praebere videtur formarum, quae nondum sint prorsus 



