— 104 — (12) 



Stipules evanescent, scarcely to be found except at the extrême 

 apex of the stems, broad, 5 lin. long. 



Peduncules equal, 6-9 lin. long. 



Spikes 4-6 lin. long, closely packed with green fruits. 



Sepals (perianth-seginents) long-hafted, orbicular, green. 



Fruit small : ventral face nearly straight, with a more or less 

 prominent tooth in the centre, with the style forming a continua- 

 tion; dorsal face rounded, with a more or less square base and 

 3 small basai bosses; central keel (carina) sharp, scarcely waved: 

 latéral keels rounded. not prominent. 



Hab. : Mandshuria. Leg. Litwinow, 1902. 



Allied in habit to P. javanicus Haskl., P. Midnhihimo Makino, 

 P. Jateralis Morong, and P. Vaseyi Robbins, but with the 

 submerged portions of stiffer growth, and branching, at right 

 angles nearly, but differs from ail thèse in the submerged leaf- 

 struture. and fruit, 



Referred to P. javanicus Haskl. by myself in 1903. but on a 

 re-comparison of the javanicus-sectioii proved to be différent. 



18. P. numasakianus Ar. Bennett, sp. nov. 



Stems slender. almost filiform, branched. Floating leaves seini- 

 coriaceous. pétioles 4-6 lin. long, lanceolate or linear-lanceolate 

 acute ; 7-nerved, with cross nerves ail immersed in close chain- 

 like areolation extending over the whole leaf ; 9 lin. long X 2 7 2 

 — 3 lin. broad. Submerged leaves sessile, linear-setaceous, or 

 subulate, acuminate; 9-12 lin long X 7 2 lin. broad; 7-nerved 

 connected by cross nerves as thick as the longitudinal ones, but 

 without any chain-like areolation. Margin of the leaves of a 

 thicker texture, with a thinner band between that and the outer 

 nerve. 



Stipules soon decaying. Peduncules 12-15 lin. long, slightly 

 thickening upwards. Spikes about 9-lin. long remarkably inter- 

 rupted, much as in P. pectinatus L. only in a lesser degree. Fruit 

 1 V 2 lin. long X 3 A lin. wide. Ventral edge forming a continuons 

 tooth sharply keeled, curved from the base to centre, more 

 sharply from the centre to the style base. Dorsal edge rounded. 

 middle keel (carina) sharply winged with waved ontline and 

 three teeth, base with a prominent tooth directed downwards; 

 latéral keels not prominent, with a tooth at the base of each. 



