Aponogeton.] NAIADACE. 1121 
Order CXLYIII. NAIADACEZ. 
erbs, palustrine, stemless, scapigerous, with a tuberous or 
ri rootstock; or aquatic and submerged or floating, with 
elongated, branched stem. Leaves erect or submerged or floating, 
sheathing at the base. Flowers hermaphrodite or 1-sexual, green, 
inconspicuous, in spikes, racemes, or terminal or axillary peduncled 
spadices; bracts small or 0. Perianth absent or of 3-4 inferior, 
valvate segments, or tubular and very delicate. Stamens 1-6, 
to 
one anther-cell. Carpels 1-6, each 1- or more-ovuled; style long 
or short; stigmas usually simple, sometimes 2-3, capillary; ovule 
erect or pendulous. Fruit of 1 or more 1- or several-seeded 
utricles, achenes, follicles, or small drupes. Seeds erect, pendu- 
lous, or eer | peltate; testa coriaceous or somewhat fleshy ; 
albumen 0 ; embryo fleshy, straight. 
F si hermaphrodite; ; style short or 0; stigma discoid or decurrent on 
the oy 
fetatne of sepals present; carpels sessile :— 
Sepals 1-3, white or pink, membranous; stamens 6 or more 
ponoge 
Sepals 4, green, herbaceous; anthers 4, sessile......... Potamogeton. 
Perianth wanting ; carpels stipitate ; antics BORGHESE Avvivnn Ruppia. 
Flowers 1-sexual ; stamen solitar ary :— 
Style long, slender; stigma oblique, peltate; achenes 2-9, sessile or 
stalked ; male perianth wanting, female perianth cupular, hyaline 
Zanichellia. 
tyle wanting; stigmas 2-4, slender; achene solitary, sessile; male 
perianth double, an outer inflated or 4-fid tube and an inner hyaline ; 
female perianth wanting, or hyaline and adherent to carpel...... Naias. 
1019, Aponogeton Thunb. 
Herbs, scapigerous, with tuberous rootstocks, aquatic; leaves 
oblong, floating or submerged. Flowers bi-sexual, on long scapes, 
aring solitary or geminate, often unilateral spikes, the spikes 
when y oung enclosed in a conical, soon deciduous sheath. Perianth 
of 1-3 equal or unequal, pink or white segments, or obsolete. 
Stamens 6 or more; filaments subulate, unequal, persistent ; 
anthers didymous. Carpels 8-6, each 2- or more-ovuled; style 
