Potamogeton. 67 



Var. e. amphibius Fries, Novit, fl. Suec. (1828) 30; Aschers, et Graebner 1. c. 



— P. natam acaule Wahlb. Fl. Gothob. (1820 — 24) 23. — P. polygonifolius y. erv- 

 cctorum Syme in Engl. Bot. ed. 3. (1869) 28. — Folia parva, brevissime pedunculata 

 lere rosulata. — In locis nunc siccis nunc aquaticis. 



Var. sphagnophila Neuman in Bot. Notis. (1896) 91. — P. Scheelei G. Preuß 

 in Herb. Berol. — Habitu P. colorato similis, foliis latissimis, basi interdum cordatis, 

 laete viridibus. 



Schweden: In Sphagnumsümpfen. 



Var. microcarpus A. Bennett in Journ. of Bot. XXIX. (1891) 75; Ann. naturh. 

 Hofmus. Wien VII. (1892) 287. — P. microcarpus Boiss. et Beut. Diagn. pl. nov. 

 Hisp. (1842) 2. — Forma terrestris vel subterrestris humilis. Fructus minimi, iis P. 

 colorati similes et subaequales. 



Spanien! 



Nota. Probabiliter proles vel subspecies. 



Formae dubiae: Specimina non certe determinanda collegit cl. Delavay in 

 China, Yunnan (conf. A. Bennett in Journ. Linn. Soc. XXXVI. [1903] 196). — 

 Cl. Dickson in Japan plantam affinem legit, sed robustior est, folia natantia elliptico- 

 ovata, medio dilatata, 13 — 15 nervia. Ex cl. A. Bennett in litt. nov. spec. quae nunc 

 descripsit et quae in correctura inserta est: 



31a. P. Franchetii A. Bennett et Baagoe in Journ. of Bot. XLV. (Juni 1907) 234. 



— P. polygonifolio similis, vel major. Caulis 2,5 — 4 dm altus, substrictus. Folia' 

 natantia lanceolata vel lanceolati-ovata, 4 — 6 cm longa et 2 — 3 cm lata, petiolis 6 — 

 11 cm longis, subcoriacea. Stipulae acutae 2,5 — 3,5 cm longae, subpersistentes. Spicae 

 ca. 4 cm longae pedunculo 6,5 — 8 cm longo, apice subangustata. Fructus magnis, iis 

 P. polygonifolio triplo majoribus, 3,5 mm longi et 2,5 mm lati, oblique-obovati, sub- 

 compressi; pagina ventrali subrotundata, dorsali lunata, apice subdepresso. Carina 

 centralis subproducta, subacuti-alata, carinae laterales subobsoletae; basis fructuum 2 

 gibbis parvis. 



Japan: Yososka, in Beisfeldern (Franchet n. 1244); Hirmnushria, Musaski 

 (Makino; Dickson n. 339. — Herb. Kew). 



32. P. pulcher Tuckerman in Americ. Journ. Sc. 1. ser. XLV. (1843) 38; 

 Morong in Mem. Torr. Bot. Club III. (1893) 2, 16, t. XXVIII. — Caulis simplex, teres, 

 nigripunctatus, plerumque 3 — 6 dm longus. Folia submersa forma varia sub anthesi 

 plerumque omnia emarcida, inferiora pauca, crassiora, opaca, spathulata oblonga vel 

 ovata, basi rotundata, petiolis 1,5 — 10 cm longis saepe dilatatis, superiora pellucida, 

 lanceolata, longe acuminata, undulata, 7 — 20 cm longa, 1 — 3,5 cm lata, basi in petio- 

 lum brevem attenuata, 10 — 20-nervata, medio irregulariter reticulata. Folia natantia 

 ovata vel rotundati- ovata, interdum lati-ovata vel orbiculata, subcordata, 5 — 12 cm longa 

 et plerumque 4 — 8 cm lata, 25 — 33-nervata. Petioli ± crassitudine caulis, 5 — 10 cm 

 longi, maculati. Stipulae obtusae vel longe acuminatae, bicarinatae. Pedunculi caule sub- 

 crassiores, 5 — 10 cm longi. Spicae ca. 2,5 cm longae, densae. Fructus aggregali, apice 

 in stylum apicalem angustati, ca. 4 mm longi, et 3 mm lati, dorso acute tricarinati, 

 carina media prominente, basi late rotundati. Embryo 1 ^-plex curvatus. — Fig. 1 6. 



Nordamerika: Sümpfe in Wells, Massachusetts (Harvey); Brattlebro (Frost); 

 Ost-Massachusetts! Idaho! bis Pennsylvanien, Georgia und bis St. Louis (Engelmann!), 

 Florida (Rugel sub P. natans in Brit. Mus.!); Kentucky (C. W. Short); Maine (vergl. 

 A. Bennett in Journ. of Bot. XL. [1903] 146). Nach A. Bennett briefl. außer in 

 den genannten Staaten in Vermont, Indiana! Rhode Island! Virginia! Blüht Juni, Juli. 



Variat foliis submersis coriaceis , et fluitantibus longissime petiolatis, petiolis supra 

 2,5 dm longis. In aqua profunda et in paludibus exsiccantibus valde variat et etiam 

 foimas terrestres format. 



In Herbario berolinensi multa specimina Tuckermannii adsunt. 



33. P. amplifolius Tuckerman in Amer. Journ. Sc. 2. ser. VI. (1848) 225; 

 Morong in Mem. of the Torrey Bot. ' Club III. 2. (1893) 16. — Caulis plerumque 



