Potamogetones novae ab Arthur Bennett descriptae. 89 
Peduncules equal, 6—9 lin. long. 
Spikes 4—6 lin. long, closely packed with green fruits. 
Sepals (perianth-segments) 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 continuation; dorsal face 
rounded, with a more or less square base and 3 small basal bosses; 
central keel (carina) sharp, scarcely waved; lateral keels rounded, not 
prominent. 
Hab.: Mandshuria. Leg. Litwinow, 1902. 
Allied in habit to P. javanicus Haskl., P. Miduhikimo Makino, P. late- 
ralis Morong, and P. Vaseyi Robbins, but with the submerged portions of 
stiffer growth, and branching, at right angles nearly. but differs from all 
these in the submerged leaf-structure, and fruit. 
Referred to P. javanicus Haskl. by myself in 1903, but on a re-com- 
parison of the javanicus-section proved to be different. 
4, Potamogeton numasakianus Bennett, |. c., p. 104. 
Stems slender, almost filiform, branched. Floating leaves semi- 
coriaceous, petioles 4—6 lin. long, lanceolate or linear-lanceolate acute; 
7-nerved, with cross nerves all immersed in close chain-like areolation 
extending over the whole leaf; 9 lin. long X 2'/,—3 lin. broad. Sub- 
merged leaves sessile, linear-setaceous, or subulate, acuminate; 9—12 lin. 
long X ![, 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 thicken- 
ing upwards. Spikes about 9 lin. long remarkably interrupted, much as 
in P. pectinatus L. only in a lesser degree. Fruit 1!/, lin. long X */, lin. 
wide. Ventral edge forming a continuous 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; 
lateral keels not prominent, with a tooth at the base of each. 
Style relatively large, bent over towards the dorsal edge. 
Hab.: Lacs de Numasakii, Japon. Leg. Abbé Faurie, no. 20, 
Aug. 17, 1899. 
With the habit of P. javanicus Haskl. this differs from that and all 
other species by the structure of the leaves which is more like a Sagit- 
taria, and by the remarkable spike of fruit like a small pectinatus one (on 
a hybridus-type species) and by the fruit which bears some resemblance 
to P. condylocarpus Tausch in the graminifolius-section, 
It is possible that some poor non-fruiting specimens named P. Midu- 
hikimo Makino may belong here leg. Abbé Faurie no. 10806, Aug. 8. 
1893, but my exemple is too poor to be sure. 
