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Page:Illustrations of Indian Botany, Vol. 1.djvu/21

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ix
INTRODUCTION.


1. Peripetalae with several distinct petals inserted on the calyx towards its base, leaving the evary superior or free—Leguminosae, the section Potenlillece of Rosacece, and Salicariece all afford easily understood examples of this section.

2. Epipetalae.—In this section the tube of the calyx is prolonged and lined by the torus which forms a small disk on the summit of the ovary, and the ovary is enclosed by and coheres with calyx tube : the distinct petals and stamens are inserted on the outside of the disk. The ovary is here said to be inferior or adherent and the flower superior. Rosece, Pomeae and Combretacece, apparently afford examples of this section, but want the disk on the summit of the ovary. Umbelliferae, Araliaceae and Corneas are the only orders referred here as being truly epipetalous.

3. Epicorallce Corisantherae; this section differs from the last in having the petals united, forming a nionopetalous corolla, bearing the stamens inserted on its tube, and the anthers not cohering round the style. The common honey-suckle is a familiar example of this section to which also the elder, thecoffee, valerian &c, that is the orders Caprifoliacece, Rubiacece, Valerianece &c. belong.

4. Epicorollce Synantherce : the essential distinction between this and the preceding section consists in the anthers of this cohering by their edges, forming a tube round the style, and from the succeeding by the corolla being inserted on the top of the ovary not on the bottom or tube of the calyx.

5. To this section the vast order Compositce alone belongs ; as examples of which it may suffice to mention the humble Daisy, the common Thistle, the Artichoke, the Dandilion, and gaudy Dalia to enable every one to understand what is meant by a compound flower the general flower of each of these being made up of a congeries of small ones.

6. Pericorollae: in this, as in the two preceding sections, the petals are united into a mono- petalous Corolla, but in place of being inserted on the top of the ovary, it is inserted on the tube, or towards the base of the calyx; leaving the ovary either partially or all together free. The Lobelia, the Hairbell, and Heath tribes afford examples of this last section of the 2d <;lass.

III. Corrolliflor^. — This sub-class differs from the three last sections of the preceding in the insertion of the corolla only, like them the corolla is monopetalous bearing the stamens, but in place of being inserted on the calyx, (perigynous) springs from the receptacle or base of the flower, inferior to the ovary, (hypogynous) hence in the language of Jussieu the section is now named Hypocorollae (see table below). The Jasmines and Convolvulus afford the most familiar examples of this class but the Gentians, Trumpet flowers (Bignonia) Heliotropes/Verbenas, Solanums (Brinjal, Potatoe,&c.) all belong to it.

IV. Mo nochlamyde/E. — This sub-class is characterized by having a single perianth, that is, only one verticel or whorl of floral envelopes, or if two are any time present, the petals adhere to the calyx. It is divided into four sections.

1. Hypostamineae here the stamens are inserted on the receptacle and the ovary is free even though concealed within the tube of the calyx to which it does not adhere. The Marvel of Peru ( Mirabilis Jalapa J, so much prized as a garden ornament, and the Amaranthus ap- pertain to this section. The flower of the former often so delicately variegated is in truth only a petaloid expansion of the calyx, and not a corolla, in the glabose inflated bottom of which, the filaments and ovary are found perfectly free This lower portion of the calyx afterwards forms the black shell-like covering of the seed.

2. Peristamineae. In this- the stamens are inserted on the calyx, not hypogynous. Chenopodium, Polygonum and the beautiful Begonia-dve examples of this section.