EXPLANATION OF PLATE VIU. 



Fig. 1. Yallis¥!eb.ia spiralis. A dioecious aquatic plant of Europe, Amenca, and 

 New Holland. Leaves radical, riband-like. A, staminate flower. Peduncles short, 

 terminated by a spike ; ovate, spathaceous, remaining under water until the period for 

 fertiUzing the pistdlate 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 flovvers untwist 

 themselves, and the flowers rise to the surface of the water ; the short spike of stam- 

 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 stratiotcs. The Duckweed tribe. A floating, stoloniferous plant. 

 Leaves radical, spreading, flabellifonn. 



Fig. 3. Teapa nutans.* {Onagrcs.) An aquatic plant. Stem sub-merged, pro- 

 ducing radical filaments of two sorts; 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, the other 

 cotyledon; c/, root; e, stem. B, a plant more developed. 



Fig. 4. BuTOMUs umbellatus.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 conipressurii.t An annual, aquatic plant, common in brooks 

 and ditches, Stem compressed, slender, leafy. Leaves alternate, linear. Spikes 

 terminal, interrupted. Flower whorled. 



Fig. 6. Nelumbo nucifera.% An aquatic, perennial plant found in Egypt, India, 

 and America. Leaves radical, peduncled, peltate, round, concave. Peduncle one- 

 flowered. Caly.x caducous. Corolla of many spreading petals. Stameiis numerous ; 

 style, very short ; stigma, like a cup ; a, young leaves ; b, flovver ; c, fruit. 



Fig. 7. JuNcus conglomeratus.W The Rush tribe. {JunccB.) Stem very simple, 

 aphyllous, rectilinear, vertical, terminating in a point. Panicle crowded, unilateral. 



Fig. 8. Fucus articulatus.% The Sea-weed tribe. {Algw.) A marine plant of 

 the Atlantic Ocean. Frond cartilaginous, dichotomous, momliform, 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, called the Water-chestnut Tribe. It is considered, 

 by the late raoditiers of the natural method, to be nearly allied to Onagrse, distinguished from it only by soli- 

 tary, pendulous ovules. 



^ This i» the leading genus in the order Butomea?, of Lindley ; by De Candolle and Mirbel, placed in Alis- 

 inaceie, to which it is closely allied. 



: 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 Pistiaceee, to the division of flowerless plants. The peri- 

 anth is reduced to a few imperfect scales, the habit is almost that of Coniterie, and there is in some of the 

 genera, eiiher a total absence of spiral vessels, or that form of tissue exists in a very rudimentary state." 

 The affinity of this order to Aroideae is manifest trom the tendency of some species to produce a rudimentary 

 spatha. Mnbel places this in the order Alismactffi. 



§ In the order Nelumboneae of De Candolle ;— by most writers united to Nymphjeacea;, with which it dif- 

 fers in the structure of the fruit, but agrees in the foliage and flowers. The fruit of one species of Nelunibium 

 is thought to be the Egyptian bean of ancient writers. 



II " This plant," according to Lindley, " stands between Petaloideous and Glumaceous Monocotyledons, 

 agreeing with the former in the tiural leaves, having assuniLd the Verticillate slate necessary to constitute a 

 perianth, and with the latter in their texture. From Palms, independently of their habit, they are distin- 

 guished by the constant tendency to produce more than one ovule in each cell, and by the embryo never be- 

 ing remote from the hilum. Juncus is an instance of a monncotyledonous plant having a distinct pith." 



IT Lindley describes the order Algfe as " aquatic, leailess, flowerless plants." He says, " Whatever in- 

 genuity may be employed in determining the relative degree of dignity in the vegetable creation between 

 Fungi, Lichens, and Algae, it seems to me that the conclusion constantly arrived at is, that Algs are only 

 to be distinguished from the other two by their lieing in water, and that but for the influence which that me- 

 dium exercises 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 the sun never shines, or tlie hard paths in the damp parts of 

 gardens after rains, cannot fail to have remarked a green, mucous slime, with which they are covered. This 

 slime consists of AIsdb in their simplest state of organization, belonging to tlie genera Palmella, Nostoc, &c. 

 This slime is like a layer of albumen spread with a brush." This albumen, Lindley says, may be the origin 

 of either vegetable or animal matter, according to the nature of the corpuscles which penetrate or develop 

 themselves in it : and, according to some late discoveries, it seems to be ascertained that many of the sea- 

 weed consists or congeries of animalcule- Thus we see that the vegetable and animal kingdoms not only 

 elosol} approxiraate, out tliat they do, in fact, exist in the most intimate union. 



