EXPLANATION OF PLATE Vni. 
Fig. 1. Vallisnkria spiralis. A dioecious aquatic plant of Europe, America, and 
New Holland. Leaves radical, riband-like. A, siaminate flower. Peduncles short} 
terminated by a spike ; ovate, spaihaceous, remainnig under water until the period for 
fertilizing the pistillate flowers. B, fertile plant, peduncles very long, spiral, uni- 
flowered. Flower spathaceous, floating. This singular plant, in which the two 
kinds of flowers are entirely separate, is fertilized by a curious provision of nature. 
When arrived at a mature state, the spiral peduncles of the pistillate flowers un4vvist 
themselves, and the flowers rise to the suriace ol the water ; the short spike of stam- 
inate flowers breaks off from its peduncle; the flowers light upon the other plant, 
and shower their poflen over it. After this period, the pistillate flowers disappear be- 
low the surface of the water, where their fruit is produced. 
Fig. 2. PisTiA stratiotcs. The Duckweed tribe. A floating, stoloniferous plant. 
Leaves radical, spreading, flabelliform. ^ 
Fig. 3. Trapa natans* {Onagrce.) An aquatic plant. Stem sub-merged, pro- 
ducing radical filaments of two sons; the one simple, filiform; the other ramified 
and pinnate ; they appear to be transformed leaves. The leaves are terminal, diverg- 
ing ; petioles broad, dentate. A, a plant soon after germination ; a, the fruit; b, peti- 
ole from one of the two cotyledons which remain enclosed in the fruit ; c, ttie other 
cotyledon; d, root; e, stem. B, a plant more developed. 
Fig. 4. BuTOMUs umbellatws.i Flowering-rush tribe. A plant which grows on 
the border of lakes and rivers. Leaves radical, erect, riband-like, pointed at the sum- 
mit. Scape rectilinear. Umbel simple, terminal, involucred. 
Fig. 5. PoTAMOGETON compvessum.t An annual, aquatic plant, common in brooks 
and ditches. Stem compressed, slender, leaj'y. Leaves alternate, linear. Spikes 
terminal, interrupted. Flower whorled. 
Fig. 6. JNelumbo nuci/cra.% An aquatic, perennial plant found in Egypt, India, 
and America. Leaves radical, peduncled, peltate, round, concave. Peduncle one- 
fiowered. Calyx caducous. Corolla of muny spreading petals. Stamens numerous ; 
style, very short ; stigma, like a cup ; a, young leaves ; 6, flower ; c, fruit. 
Fig. 7. JuNcus conglomeratus.W The Rusli tribe, wuticcc.) Stem very simple, 
aphylious, rectilinear, vertical, terminatiug in a point. Panicle crowded, unilateral. 
Fig. 8. Fucus articulatus.^ The Sea-weed tribe. {Alffce.) A marine plant of 
the Atlantic Ocean. Frond cartilaginous, dichotoinous, moniliform, articulated, each 
joint containing fruit. 
Fig. 9. Fucus digitatus. Stem simple, cylindric. Frond compressed, digitate, 
flabelliform. 
Fig. 10. Fucus natans. A marine plant which, detaching itself from the rocks 
where it originates, floats in vast quantities upon the surface of the sea, forming 
islands which retard navigation. Stem filiform. Frond branching, lanceolate, den- 
tate. 
Fig. 11. Fucus obtusatus. A marine plant of Cape Van- Diemen. Frond com- 
pressed, coriaceous, branching, linear. • 
* This plant is in the order Hydrocaryes of De Candolle, calletl the Water- r hestnut Tribe. It is coasidered, 
by the late modiliei'S of the natural method, to be nearly allied to Onagite, distiuguislied from it only by soli- 
tary, pendulous ovules. 
+ This is the leading genus in the order ButomesB, of Lindley ; by De Candolle and Mirbel, placed in Alia- 
macese, to which it is closely allied. 
I Of the order Naides of Jussieu, or Fluviales of more modern botanists. "In this order," Lindley re- 
marks, " we have the nearest approach, except in Pistiaceas, to the division of flowt-rless plants. 'I'l.e peri- 
anth is reduced to a tew miperfect scales, the hahit is alm ist that of Coai.eiiE, and there is in some of the 
genera, eilher a total absence of spiral vessels^ or that tbrm of tissue exists in a very rudimentary state." 
The affinity of this order to Aroideae is manifest trom ihe tendency of some species to produce a rudimentary 
Bpatha. Mirbel places this in the order Alismacuee. 
§ In the order Nelumbonece of De Candolle ;— by most writers united to NymphKaccaj, with which it dif' 
fers in the structure of ihe fruit, but agrees in the foliage and liowers. The fruit ol'une species of Neiu.nbiuin 
is thought to be the Egyptian bean ot ancient writers. 
H "This plant," according to Lindley, "stands between Petaloideous and Glumaceous Monocotyledons, 
agreeing with the former in the tioral leaves, having assuin d ihe Verticillat.j srato necrssary to coiisiitute a 
perianth, and with the latter in their texture. From Palms, independniily of their habit, they are distin- 
guished by the con.stant tendency to produce more than one ovule in each cell, and by tne embryo never be- 
ing remote from the hilum. Juncus is an instance of a monocotyledonous plant having a distinct pith." 
IT Lindley describes the order Alga? as "aquatic, iealless, flowerlesS plants."' He says, " Whatever in* 
geiiuity may be employed in determining the relative degree of dignity in the vegetable creation betweea 
rungi, Lichens, and Alga;, it seems to me that ihe conclusion constantly arrived ut is, tluit Alyui are only 
to be distint;ui-ihed from the other two by tlieir being in water, and that but for the influence wincli ihat me- 
dium exercis s on them, they would be identical with Licht^ns on the one hand, and Fungi un the other. 
Those who h.ne ever examined the surfaces of stones constantly moiisiened by water, the glass of hothouses, 
tlic face of rocks in the sea, or of walls where ihe sun never shines, or the hard paths in the damp parts of 
gardens after rains, cannot fail to have remarked a given, mucous slime, with which ihcy are covered. This 
elime consists of Alpo in their simplest state of organization, belonging to the frenera Palmella, Nostoc, &c. 
This slime is l:ke a layer of albumen spread with a brush." This albumen, Lindksy says, imiy be the origin 
of either vegetable or animal matter, according to the nature of ihe corpuscles which peiieirate or develop 
themselves in it j and, according to some late discoveiies, it seems to be ascertained that many of the sea- 
weed consists ol congeries of animalculse. Thus we see that ihe vegetable and animal kiiJsdoms nut only 
slpaely approximate, but that they do, in fact, exist in the most iiitunale union. 
