EXPLANATION OF PLATE VIIL 
Fig. I. Vallisneria spiralis. A dioecious aquatic plant of Europe, Amenca, and 
Ntjw Holland. Leaves radical, riband-like. A, siaminate flower. Peduncles short, 
terminated by a spike; ovate, spathaceous, remaining under water until the period for 
fertilizmg the pistillate tiowers. 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 flower? untwist 
themselves, and the flowers rise to the surface of the water ; the short spike of stara- 
inate flowers breaks off from its peduncle; the flowers light upon the other plant, 
and shower their pollen over it. After this period, the pistillate flowers disappear be- 
low the surface of the water, where their fruit is produced. 
Fig. 2. PisTiA stratiotes. The Duckweed tribe. A floating, stoloniferous plant 
Leaves radical, spreading, flabelliform. 
Fig. 3. Trapa naians.* {Onagrce.) An aquatic plant. Stem sub-merged, pro- 
ducing radical filamenis 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; 6, peti- 
ole from one of the two cotyledons which remain enclosed in the fruit; c, the other 
cotyledon; d, root; e, stem. B, a plant more developed. 
Fig. 4. BuTOMus umbeLlatus.i Floweri««;-rush tribe. A plant which grows on 
the border of lakes and rivers. Leaves ra.x.cal, erect, riband-like, pointed at the sum- 
mit. Scape rectilinear. Umbel sim'^'3, te...iinal, involucred. 
Fig. 5. PoTAMOGETON co7npress An. annual, aquatic plant, common in brooks 
and ditches. Stem compresse' , Glender, leafy. Leaves alternate, hnear. Spikes 
terminal, interrupted. Flower v.'horled. 
Fig. 6. Nelumqo nucifera.% An aquatic, perennial plant foupid in Egypt, India, 
and America. Leaves radical, peduncled, peltate, round, concave. Peduncle one- 
flowered. Calyx caducous. Corolla of many spreading petals. Stamens numerous ; 
style, very short ; stigma, like a cup ; a, young leaves ; 6, flower ; c, fruit. 
Fig. 7. JuNcus conglomeratus.W The Rush tribe. Ounccn.) Stem very simple, 
aphylious, rectilinear, veriical, terminatnij^ in a point. Panicle crowded, unilateral. 
Fig. 8. Fucus articuiatus.^ The Sea-weed tribe. {ALgcB.) A marine plant of 
the Atlantic Ocean. Frond cartilaginous, dichotomous, monililbrm, articulated, each 
joint coataming fruit. 
Fig. 9. Fucus digitatus. Stem simple, cylindric. Frond compressed, digitate, 
flabelliform. 
Fig. 10. Fucus nutans. 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. U. 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, called the Water-chestnut Tribe. It is considered, 
by the late modifiers of the natural tuethod, to be nearly allied to Onagrae, distinguished from it only by soli- 
tary, pendulous ovules. 
t Tills is the leading genus in the order ButomesB, of Lindley ; by De Candolle and Mirbel, placea in Alls- 
njaceae, to whi.;h it is closely allied. 
I 01' the order Naides of Jussieu, or Fluviales of more modern botanists. " In this order," Lindley re- 
marks, " we have the nearest approach, e.\ci pt in Fistiacoaj, to the division of flowcrless plants. Tlie peri- 
anth is reduced to a few imperfect scales, the habit is alm;)St that of Coniliirae, and there is in some ot the 
genera, either a total absence of spiral vessels, or that tbrm of tissue exists in a very rudimentary state." 
The affinity of this order to Aroidea; is maiiitest from the tendency of some species to produce a rudimentary 
spatha. Mirbel place.s this in the order Alisniacese. 
§ In the order Nelumbonoae of De Candolle ;— by most writers united to Nympha;aceae, with which it dii 
fers in the structure of i he fruit, but agrees in the foliage and flowers. The Iruit of one species of Neluaibium 
is thought to be the Egyptian bean of ancient writers. 
N "This plant," according to Lindley, "stands between Petaloideous and Glumaceous Monocotyledons, 
agreeing with the I'onner in the tlurai leaves, having assum. d ihe Verticillati; slate necessary to constitute a 
periantli, and with the latter in tlieir icxture. From Palms, independently of their habit, they are distin- 
guished by the c((nstai;t tendency to produce more than one ovule in each cell, and by the embryo never bo- 
ing remote from the hiluni. J uncus is an instance of a monocotyledonous plant having a distinct pith ' 
H Liudiey describes the order Algae as " aquatic, leafless, flowerless plants." He says, " Whatevci* ui' 
genuity may be employed in determining the relative degree of dignity in the vegetable creation between 
Fungi, Lichens, and Algse, it se. ms to me that ihe conclusion constantly arrived at is, that Algaj are only 
to be distinguished from the other two by their heiug in water, and that but for the influence which that mo 
dium exercis .s on them, they would be identical with Lichens on the one hand, and Fungi on the other. 
Those who have ever examined the surfaces of stones constantly moistened by water, the glass of hot-houses, 
the face of rocks in the sea, or of walls where ihe sun never sniiies, or the hard paths in the damp parts of 
gardens after rams, cannot fail lo have remarked a green, mucous slime, with which they are covered. This 
slinie con.si.sis ot' Ai^-ie in their simplest slate of organization, belonging to the genera Pahnefla, No.<?toc, &c. 
Th'.s sliine is like a layer oi albumen spread with a brush." This albumen, Lindley says, may be the origin 
of eiiher vcircialilu or animal matter, according to the nature of the corpuscles w.hich penetrate or develop 
thein.selves in ii j and, according to some late discoveries, it seems to be ascertained that many of the sea- 
weed consists of congeries of animaliuila). Thus we see that the vegetable and animal kingdoms uot unis 
uumly a;ppioxiiuate, but that they do. in fact, exist in the most intiinutu luiioii. 
