196 156. NAIADACER. 
13. Potamogeton perfoliatus, Zinn. Sp. Pl. ed. 1, p. 126; 
Kunth, Enum. iii. p. 133; Hook. f. Fl. Brit. Ind. vi. p. 566. 
CHIHLI: near Peking (Bretschneider, 779!) ; Cura, without 
precise locality (Korolkow § Krause!) Herb. Kew. 
North temperate regions and Australia. 
14. Potamogeton polygonifolius, Pourr. in Mém. Acad. Tou- 
louse, iii. (1788) p. 825; Franchet, in Mém. Soc. Sc. Nat. 
Cherbourg, xxiv. (1884) p. 261. 
Cami: Peking (Bretschneider!); SuaxrUNG : Chefoo ( Fau- 
vel ex Franchet); Kansun (Potanin 1). 
Europe, including Britain. 
15. Potamogeton pusillus, Linn. Sp. Pi. ed. i. p. 127 ; Kunth, 
Enum. Pl. ii. p. 136; Franch. Pl. David. i. P 315; Hook. f. 
Fl. Brit. Ind. vi. p. 567. 
Cini: Jehol (David, 1916!); Kansun (Potanin!), Tangut 
(Przewalski!); Corea (Faurie!). Herb. Kew. 
Widely distributed, but absent from Australia. 
16. Potamogeton Robbinsii, Oakes, var. japonicus, Arth. Benn. 
in Bull. Herb. Boiss. iv. (1896) p. 549. 
Potamogeton serrulatus, Regel et Maack, in Regel, Tent. Fl. Ussur. 
p. 153. 
Corea (Faurie !). 
Japan. 
17. Potamogeton Tepperi, Arth. Benn. in Journ. Bot. xxv. 
(1857) p. 178. 
CHIHLI: Peking (Bretschneider, 778!); Formosa (Oldham, 
636 !); Huren : Ichang (4. Henry, 2366, 3603!); SZECHUEN : 
Hokiang (Faber, 314!); Corran ArcHIPELAGO: Long Reach 
(Oldham, 824!). Mus. Brit. ; Herb. Kew. 
Siberia, India, Japan, and Australia. 
Specimens from Yunnan, collected by Delavay, probably 
belong here. 
18. Potamogeton sp. 
Yunnan (Delavay !). 
This belongs to the group of P. polygonifolius, Pourr., but 
the material is iusuffieient for determination. 
