Polamo(jeton.\ 
VI. N-AIADIiiE. 
279 
not thickened upwards. Nut when fresh obtuse at the back, or obscurely 3- 
ribbed. 
Northern and Middle Islands: abundant in ponds, rivers, etc. A. most common 
aquatic herb in Europe and elsewhere throughout the globe. 
2. P. Iieterophyllus, Schreber ? Lower submerged leaves narrow-linear, 
membranous, 3-4 in. long, A— J in. broad, margins waved or rather crisped, 
upper submerged leaves broader, passing into the floating, which are petioled, 
1-lj in. long, oblong, obtuse, coriaceous ; stipules free. 
Middle Island: Clethra river, Otago, Lindsay. Without dower or fruit ; apparently 
the same as the Tasmanian plant, which is common in various temperate parts of the globe. 
3. P. granameuSj Linn.? — P . ockreatus, Raoul, Choix, t. 7 ; — FI. N. 'L. 
i. 236, and ii. 336. Leaves all submerged, membranous, grassy, 1-3 in. 
long, ^ in. broad, narrow-linear, 3-5-nerved ; stipules free, lacerate. Pe- 
duncle very stout, 1 in. long. Spike oblong, continuous. Nuts compressed, 
obliquely broadly ovoid, with a mucronate style, T ~- in. diam. 
Northern and Middle Islands : Akaroa and Bay of Islands, Raoul, Colenso ; Auckland, 
Sinclair. A very common European, Australian, aud Tasmanian plant ; also found in many 
other temperate countries. In the N. Z. Flora I referred this to P. compressus, Linn., ac- 
cording to Fries’ specimens : but Fries’ plant is apparently not the true compressus, and 
considered by Prof. Oliver to be more probably a form of ptisillus. My specimens from M. 
ltaoul are ticketed as from the Bay of Islands, but in his ' Choix’ he states it to be a native of 
Banks’s Peninsula. 
4. P. pectinatus s Linn. Leaves all submerged, membranous, grassy, 
very narrow-linear, 2-3 in. long, ~ in. broad ; stipules united with the base 
of the leaf into an entire sheath. Peduncle very long, slender. Flowers in 
distant fascicles. Nuts gibbous, compressed, obliquely very broadly ovoid, 
with a very short style. 
Northern Island : lagoon at Tangloio and Hawke’s Bay, Colenso. 
4. ilUPPIA, Linn. 
A slender brackish-water plant. Stems extremely slender. Leaves filiform 
with sheathing bases. Flower-spikes first included in the leaf-sheaths, then 
lengthening, often twisted spirally, and ascending to the surface. — Flowers her- 
maphrodite, small, green, ebracteate, remote on a slender spadix, the stamens 
and pistils sometimes so wide apart that the flowers appear to be monoecious. 
Perianth 0. Stamens .4; anthers sessile, 1-celled, or 2 with separate anther- 
cells. Pollen a long curved cell. Carpels 4, sessile, with sessile stigmas 
and solitary suspended ovules. Fruit of 1-4 minute, long stipitate, obliquely 
ovoid, obtuse or pointed nuts. Embryo hooked. 
Au abundant plant in Europe and many parts of the world. 
1. R„ maritima, Linn. ;—Fl. N. Z. i. 236. 
Northern and Middle Islands : abundant in salt-water ditches, etc., as far south as 
Otago. A very frequent plant throughout the northern aud southern hemispheres ; abundant 
in Australia and Tasmania. 
5. ZANNICHELLIA, Linn. 
Slender, fresh- or brackish- water herbs. Stems forked, capillary. Leaves 
