Flowering at the beginning of July. 



Distribution: Europe, except the extreme south, the greater part of Asia, except the 

 extreme east. North America. 



Sparganium minimum Fries, Summa Veget. Scand. II (1849) p. 560; Meinsh. in 

 Bull. Acad. Petersb. Nouv. Ser. IV (XXXVI) p. 37 ; PoxepTT., EaterojioBKOBtm-Bi. $e«^eHKO, 

 $ji. AsiaT. PocciH I (1913) p. 34; Kptui. $ji. Ajt. VI (1912) p. 1258; Graebn. Sparganiaceae 

 in Engl. Pflanzenr. (IV, 10, 1900) p. 23. 



In eddies in the river Abakan, above Ust Abakansk. 



Distribution: Europe, Siberia, northern Japan, North America. 



Potamogetonaceae ASCHERS. 



Potamogeton natans L. Spec. PI. ed. II (1762) p. 182; Ledeb. Fl. Alt. I, p. 156; 

 Turczan. Cat. Baical. no. 1068; Ledeb. Fl. Ross. IV, p. 23; Turczan. Fl. Baical.-Dahur. 

 (1854, III) p. 62, no. 1087; Graebn. Potamogetonaceae in Engl. Pflanzenr. H. 31 (IV, 11, 

 1907) p. 42; Kpbut. $ji. Aot. VI (1912) p. 1269. 



In a small lake between Karatus and Kushabar. With flowers in the first half of 

 July. Rather common in still creeks, and in swamps on the Dora Steppe. 



Distribution: Europe, Asia, Africa, North America, and Australia. 



Potamogeton perfoliatus L. Spec. PI. ed II (1762) p. 182; Ledeb. Fl. Alt. I, p. 158; 

 Turczan. Cat. Baical. no. 1087; Karel. et Kiril. Enum. PL Fl. Alt. no. 833; Ledeb. Fl. 

 Ross. IV, p. 27; Turczan. Fl. Baical.-Dahur. (1854, III) p. 64, no. 1090; Graebn. Potamo- 

 getonaceae in Engl Pilanzenr. U. 51 (lY, 11, 1907) p. 92; KpMj. $.1. A.IT. VI (1912) 

 p. 1271. 



All the specimens collected are sterile. The stems are from 1 to 1,5 mm. thick, the 

 internodes from 3 to 8 cm. long. The leaves are rather narrow, not over 2,5 cm. broad, 

 commonly 1,5 cm. broad, and from 6 to 7 cm. long when full-grown, and with a slightly 

 undulating margin. The shape of the leaves is lanceolate, tapering upwards from the 

 cordate base, completely clasping the stem, and rather acuminated at the apex. 



Thus, in the form of the leaves, and in the long internodes, they agree perfectly 

 with the East-Asiatic /. mandschuriensis Bennett in Ann. Conserv. et. Jard. Geneve IX 

 (1905) p. 100. The latter, however, is especially characterized by its thick spike and 

 numerous fruits, the midribs of which are winged, and, all the specimens collected 

 being sterile, I dare not, with absolute certainty, refer them to this form. 



The species is very common in the territory explored, in ponds, still creeks and 

 slow rivers. 



The rivers Abakan, Yenisei, Amyl, Sisti-kem, and Bei-kem. 



Distribution: Europe, nearly all over Asia, North Africa, North America, Australia. 



Potamogeton pusillus L. Spec. PI. ed. II (1762) p. 184; Ledeb. Fl. Alt. I, p. 159; Tur- 

 czan. Cat. Baical. no. 1093; Ledeb. Fl. Ross. IV, p. 29; Turczan. Fl. Baical.-Dahur. (1854, 



114 



