See F.A.- shyemn in K. B. VN. Hard bk 
DB: 55, Nos, 19416. 
Pr. 75, IST, 172, 1%a. 
Potamogeton. | NAIDACEAE. 127 
wanting or if present few and reduced to long and narrow phyliodes without 
any lamina. Peduncles stout, 2-4in. long, bearing a dense-flowered spike 
14-2in. long. Perianth-segments broadly rhomboidal. Fruit % in. long, 
turgid, obliquely ovoid, keeled on the back when dry, beak short.—Hook. 
f. Fl. Nov. Zel. i (1853) 236; Handb. N.Z. Fl. (1864) 278; Benth. #1. 
Austral. vii (1878) 170 (in part); A. Bennett in Journ. Bot. xxv (1887) 
177; Cheesem. Man. N.Z. Fl. (1906) 748. 
Norta anp SoutH Isitanps: I have seen specimens from both Islands, and 
have gathered it myself in the Waikato River near Huntly. Mr. Arthur Bennett, 
whose knowledge of the genus is unrivalled, also informs me that he has seen 
undoubted specimens from New Zealand. It must, however, be rare; for in an 
expedition made a few years ago along the whole course of the Lower Waikato I failed 
to find it, although ail the other species known from New Zealand were observed. 
2. P. polygonifolius Pourr. in Mem. Acad. Toul. i (1788) 325.— 
Stem creeping at the base, long or short, simple or sparingly branched. 
Floating leaves on long petioles; lamina 1-3in. long, elliptic-oblong to 
lanceolate, acute or obtuse, rounded or subcordate or acute at the base, 
not plicate, thinly coriaceous; stipules much shorter than in P. natans, 
1-I4 in. long. Submerged leaves linear-lanceolate, acute. Peduncles vari- 
able in length, rather slender; spike dense-flowered, #-l1}in. long. 
Perianth-segments transversely elliptic. Fruit small, reddish, 7-45 in. long, 
blunt and rounded on the back, not keeled, beak very short.—T. Kirk in 
Trans. N.Z. Inst. iii (1871) 165; Cheesem. Man. N.Z. Fl. (1906) 749. 
Nortu AND SoutH IstaAnps, Stewart Istanp: Ponds and small streams from 
the North Cape southwards, not uncommon. _ Sea-level to 4500 ft. | December—April. 
Distinguished from P. natans by the smaller and more membranous leaves, much 
shorter stipules, slender peduncles, and much smaller fruit not keeled on the back 
when dry. Several of my specimens have been examined by Mr. A. Bennett, who 
informs me that their identity with P. polygonifolius cannot be questioned. The 
species is widely spread in Europe and Asia, and has been recorded from Australia. 
3. P. Cheesemanii A. Bennett in Journ. Bot. xxi (1883) 66.—-Stems 
slender, striated, long or short, simple or branched. Upper leaves 
alternate or opposite, long-petioled; lamina 3-12 in. long, elliptic-oblong 
to oblong or lanceolate, obtuse, rounded at the base, coriaceous, 10-16- 
nerved with numerous cross-veins and minute areolation; stipules broad, 
subacute. Submerged leaves numerous, usually alternate but sometimes 
opposite, shortly petioled, 2-4in. long, +#in. broad, oblong-lanceolate 
to lanceolate or linear, very thin and membranous, translucent, 5-12-nerved 
with rather distant cross-veins, margins often undulate or crisped, not 
denticulate. Peduncles variable in length, rather slender; spike dense, 
3-?1in. long. Perianth-segments rhombic-orbicular. Fruit small, about 
75 in. long, broadly ovoid, slightly compressed, keeled on the back, beak 
short.—A. Bennett l.c. xxv (1887) 177; Cheesem. in Trans. N.Z. Inst. xvi 
(1884) 410; Man. N.Z. Fl. (1906) 749; JU. N.Z. Fl. 1 (1914) t. 206. 
P. heterophyllus Hook. f. Handb. N.Z. Fl. (1864) 742 (not of Schreber). 
P. natans var. australis T. Kirk ex, A. Bennett in Journ. Bot. xxv (1887) 
177, 
Norra AND SoutH IsLANpDs, StEwarT Istanp: Abundant throughout in streams, 
ponds, and lakes. Sea-level to 3000 ft. Manthi. November—March. 
The most abundant species, universally distributed throughout the Dominion. The 
numerous submerged leaves and smaller floating ones at once separate it from 
P. natans, to say nothing of other differences. According to Mr. Bennett, it is also 
found in Tasmania. 
