172 CXXXVIII. NATADEX. [ Potamogeton. 
they are opposite, all sessile, ovate or almost orbicular, clasping the 
stem with broad rounded auricles which are sometimes united on the 
opposite side, thin and many-nerved, 2 to 1d in. long and often quite as 
broad. Stipules only on very young shoots. Peduncles longer than 
scarcely beaked.—R. Br. Prod. 343 ; F. Muell. Fragm. viii. 219; 
Reichb. Ie. Fl. Germ. t. 29. 
N.S. Wales: Hunter's Patersons and Williams Rivers, R. Brown. 
Victoria. Tamboand Lake Wellington, F. Mueller 
Tasmania. South Esk River, C. Stuart. 
Common in the northern hemisphere, 
5. P. prelongus, F. Muell. Fragm. viii. 217, but perhaps not of 
Wulf.—Leaves all submerged, alternate except under the peduncles 
and branches where they are opposite, mostly stem-clasping, oblong- 
lanceolate, obtuse, more or less contracted at the base, 2 to 4 in. ms 
the margins slightly crisped, many-nerved but the midrib broad an 
very prominent underneath towards the base, the lateral nerves fine 
and often faint. Stipules short and thin, very soon disappearing. 
Pedunceles mostly shorter than the leaves, the flowering spike dense, 
3 to 5 lines long. Fruit not seen. 
Victoria. Tambo River, F. Mueller. 
. Tasmani ecimens from South Esk River, C. Stuart, without flowers may 
possibly be the same species. 
I cannot match these specimens with any of the numerous ones we have of pi 
prelongus from various parts of the world. In the typical species the stipules 
remarkably conspicuous and persistent besides minor characters. 
crispus, Linn.; Kunth, Enum. ii. 193.— Leaves all p 
merged, alternate and contracted at the base, except when under 
seen on the young shoots. Peduncles rather long. Spikes us al rib 
4 to 5 lines long. Fruits rather large, distinetly beaked, the dors al 
Or ribs entire or rarely denticulate.—R. Br. Prod. 343; F. Mue! 
Fragm: viii. 217 ; Reichb. Ic. Fl. Germ. t. 29. 
N. Australia. Albert River, F. Mueller. 
Queensland. Rockhampton, O' Shanesy and other: 
N. Williams 
River, Mrs. Ford, : ` - 
Common in the northern hemisphere. The typical form has the leaves very ™ 
broader than in P. obtusifolius and much imde fm the edges, but the narrow-leaved 
forms come very to that species, 
-. T. P. obtusifolius, Mert. et Koch ; Kunth, Enum. iii. 195. —Sten* 
