164 CXXXVII. LEMNACEZ. [Lemna 
5. L. polyrrhiza, Lin»».—Fronds very broadly ovate or most 
frequently orbicular, mostly nearly 3. lines diameter, rather thin but 
more herbaceous than most species and often darker coloured, emitting 
ny fibres. Fr c 
N. S. Wales, Leichhardt. 
Victoria. Lagoons of the Towang, F. Mueller. 
Generally spread over the area of the genus, though not so common as L. minor. 
Appears to be rather frequent in East India. 
Oxper CXXXVII. NAIADER. 
Flowers hermaphrodite or unisexual, regular or very imperfect. 
Perianth of 6, 4 or 3.small scale-like segments or rudimentary or none. 
in longitudinal slits. Ovary of 6 or f : 
more or less connate or solitary, tapering into distinct entire 0° 
branched styles or with sessile stigmas; ovules 1 or rarely several 1 
pa cell, laterally attached at or above or rarely below the middle. 
ruit of i i 
rm 
testa and no a n mbryo the shape of the or more Colle 
or hooked at the upper cotyledonous end, the ula frequently pro 
ged p 
rarely erect marsh herbs with radical leaves. Flowers small, usually 
en, m spikes heads or solitary, on axillary peduncles or radic 
scapes, or entirely enclosed in the sheathing bases of floral leaves 
or braets. 
The Order, like Alismacea, i I ted in tl hes, ponds, and shallow 
of most parts of the „world, and includes some exclusively marine genera as ters 
. Utthe A ian genera six have a very wide range over the Wà v 
of both hemispheres, two are limited to the shores of the Old World, and one or t; 
‘lo a ^ c x rsp A or very reduced state of the perianth ieh 
sessile anthers opening outwards readily distin guish the order from Alismace@, 
are otherwise its nearest allies. T 
waters 
widely 
A 1 t 
Trine I, Potameæ. Flowers hermaphrodite. Anthers short and broad, sessile © 
the base of the scale-like perianth-segments. Carpels 3 to 6, 1-seeded. 
Flowers usuall 3-merous or 6-mero 
us. Carpels frequently 
ripe. irsh or aquatic plants, with erect 
scapes and erect € or rarely floating leaves . . 1. TRIGLOCHIN. 
Flowers usually 4-merous, Carpels free. Aquatic plants 
axillary 2o£ wo. €. 7. v. 2. PorAMOGEPON: 
II. 
TRIBE Zostereæ. Flowers hermaphrodite or uniserual, Perianth none © 
rudimentary or in one sex only. Carpels 1 to 3 or rarely more, 1-seeded or rarely several- 
seeded. Aquatic submerged plants, mostly marine or subsaline, 
