EXPLANATION OF PLATE VI. 
Fig. 1. CAsuiVHmA. (Family Com/erte.)* A large tree of New Holland. Truna 
hick, head branched; branches flexible, pendent, verticillate, articulated. Monoecia 
Monandria. 
Fig. 2. Agave americana.i (Family Narcissi.) A succulent plant which grows 
in South America. Leaves radical, crowded, more than four feet long, tapering grad- 
ually to a point, channelled, bordered with spinose teeth. Scape more than 'iO feel 
high, cvlindric, rectilinear, vertical, with sr-attering, scale-like, appressed leaves. Pan- 
icle simple, pyramidal. Flowers erect, numerous, grouped at the extremity of a long 
peduncle. This magnificent plant belongs to Hexandria Monogynia. 
Fig. 3. Stizolosium altissimum. (Family Le^uminoscB.) A climbing plani 
which ascends tlie loftiest trees of the equatorial region. Stem flexible. Leaves al 
ternate, pinnate, trifoliate. Peduncle axillary, filiform, very long, pendent, termrpateo 
bv an umbel of large and beautiful flowers. Legume acinaciform, wrinkled. Diadel- 
phia Decandria. 
Fig. 4. Passiflora quadrangularis.t Climbing plant of warm regions of Anuri- 
ca. Stem quadrangular, slender, cirrose. Leaves alternate, petioled, oblong-oval 
7'endrils axillary. Flowers large, axillary. Berries large, ellipsoid. 
Fig. 5. CvPERus papyrus. Herbaceous plant, perennial, aquatic; fifteen feet high; 
a native of Egypt. Stem erect, three-sided, aphyllous, sheathing at the base: unvbela 
Urge, terminal, compound, with an involucrum and an involucel. Triandria Mo 
nogynia. 
Fig. 6. Iris germanica.% (Family Iridece.) Herbaceous plant of Europe, three oi 
four feet high, with a perennial root. Leaves radical, equitant, compressed, ensif(>rm. 
Stem leafy, branching at its summit. Flowers terminal. Perianth simple, six-lobed ; 
three lobes exterior, reflexed ; three lobes interior, erect. Triandria Monogynia. 
Fig. 7. Hippunvs vulgaris. Perennial plant growing in wet grounds. Stem cy 
lindncal, very simple. Leaves linear, verticillate. Flowers very small, verticillate. 
Monandria Monogynia. 
• Mirbel establislies a natural order, Casiiaririeae, in which he places this genus ; Lindley considers it a.s be- 
•onginfr to Myriceie. or the Gale tribe ; he says, " the nearest approach made by these plants is to the Elm 
tribe, (tllmacese,) and to the Birch tribe, (Betulineae,) from the former of which they are readily known by 
liieir amentaceous flowers, and want of a perianth; from the latter they are distinguished by their erect 
ovules, aromatic leaves and one celled ovary. Casuarina has the habit of a gigantic Equisetam, (fern,) 
niiJ can scarcely be compared with any other dicotvledonous tree-" Brown considers the genus Casuarina 
Uii approximating to ConifenK, where it was placed by Jussieu, who.se arrangement we have followed. 
t By Lindley, this is placed in his natural order Rromeliacese, called Bromeliie by Jussieu. The habit of 
Agave is similar to that of Aloe in the order Asjjhodeieae. 
I Botanists are much divided witb respect to that place in the natural method which the Passion <flowei 
tribe should occupy. Jussieu and De Candollo, in view of the organization of the fruit, consider it as nearlj 
allied to Cucurbitacpae. A separate order, Pa.ssifiore8B, is now established among botanists, for this inteiest- 
ing tribe of plants. Jussieu considered that the parts taken for petals, are nothing but inner divisions of the 
calyx, usually in a coloured state, and wanting in some species. Lindley considers the outer species of the 
floral envelopi's as the calyx, and the inner as the corolla, for two principal reasotis ; first, they have the 
ordinary position and appearance of calyx and corolla, the outer being green, the inner coloured ; second, 
there is no essential difterence between the calyx and corolla, except one being the outer, the other the in- 
ner of the floral envelopes. " The nature of the filamentous appendages, or rays as they are called," sayi 
Lindley, " which proceed from the orifice of the tube, and of the processes which lie between the petals and 
Btamens, is ambiguous. I am disposed to refer them to a peculiar form of petals rather than to stamens. 
There can be no doubt, at least, of their being of an intermediate nature between petals and stamens." 
The zealous Catholics who discovered them In the woods of South America, attached to the form of theii 
corolla ideas connected with their religious faith. 
§ The Iridese difler from the Narcissi and Amaryllideae in being triandrous, with the anthers tuned, out- 
wards ; from O rchideae, to which they are in Bome rocpects nearly allied, in not being gynandrous, and in all 
their anthers bs. tag distinct. 
