70 NATURAL ORDERS AND 
GENERA. 
Flowers in cylindrical spikes ...........06 . Typua, v. 3. p 1150. 
Flowers in dense globose heads ........ ... SPARGANIUM, V. 8. p. 1148. 
ORDER XCIX. FLUVIALES.—Venz. 
Flowers perfect, or unisexual. Perianth of two or four pieces, 
often deciduous, rarely wanting. Stamens definite, hypogynous. 
Ovaries superior, one or more. Stigma simple. Ovule solitary, pen- 
dulous. Jruit dry, indehiscent, one celled, single seeded. Seed 
pendulous. Albumen wanting. Embryo with a lateral cleft, for the 
emission of the plumule. Aquatic plants. Leaves very cellular, with 
parallel veins. Flowers small, usually arranged in terminal spikes. 
GENERA. 
Flowers concealed in the base of the 
MOAVES 2.ccccsccvcscssecaccees Sastenee cei ZOstERA, V. 3. p. 1147. 
Flowers not concealed in the base of the 
leaves. 
Flowers perfect. 
Perianth of four segments ............ PoramMoGEToN, v. 1, p. 207. 
Perianth wanting, or of two seg- 
SO ONS Ae aab SoBe oosdodt cadsaces Roppta, v. 1. p. 214. 
Flowers imperfect. ‘Stamen one ...... ZANNICHELLIA,Y.3.p 1146. 
ORDER C. PISTIACEA-—-Ricu. 
Flowers two, naked, enclosed in a spatha. Male. Stamens 
definite. Female. Ovary one celled, with one or more erect ovules. 
Style short. Stigma simple. fruit membranous, or capsular, inde- 
hiscent, one or more seeded. Seeds with a fungous testa, and a 
thickened indurated foramen. 'mbryo either in the axis of fleshy 
albumen, and having a lateral cleft for the emission of the plumule, 
or at the axis of the nucleus.—Floating plants, composed of lenticular 
compressed fronds or leaves. LIlowers from the borders of the frond. 
GENERA. 
Perianth Wanting ...0. sccccscccccnereccsacsers iEMNA, V. 1. Pp. Bus 
