circles of the flower are united, this is adnation; perigynous flowers are where pistils and stamens are inserted on the calyx; occasionally they are borne from the very summit;

epigynous, that is adnate to the ovary; the term hypogynous is used to designate when the parts of the flower are free; such flowers are said to be superior, having a superior ovary; when adnate to the calyx, inferior.

--st

CX

The different types of corolla are: Wheelshaped, like a tomato flower, parts diverge from the center; salvershaped or salver-form

Fig. 68. Flower of tomato: cx, calyx; c, corolla; p, pistil; st, stigma; s, stamen; o, ovary. (U. S. Dept. Agrl.)

Fig. 69. Irregular flower of bean, the upper part standard or beater, the two lower wings and the coiled keel.

when raised on a narrow tube and diverging at right angles, like some species of the phlox family, such as gilia; bell-shaped or campanulate, with a broad and short tube like a bell, as in the common harebell; funnel-shaped or funnel-form, like the flowers of the common morning glory; tubular, when prolonged into a tube, like the trumpet honeysuckle; in

some cases there are

Fig. 70. Ir little projections from regular flower the corolla, known as of aconite or

Monk's hood. claws, as in the com-
(Ada Hayden.) mon soapwort; the
conspicuous marginal
flowers of the sunflower are called
ray flowers; the central flowers are.
disk flowers, and the strap-shaped
corollas are spoken of as ligulate
corollas; the two-lipped corollas of the flower
mint are called labiate corollas; the (Ada Hayden.)

Fig. 71. Irregular of larkspur.

flowers of the sweet pea and clover are called papilionaceous; the chafflike scales of grass flowers are called glumes.

When the stamens are inserted upon the petals, they are called epipetalous; when the ristils and stamens are united, they are gynandrous; when the stamens are entireFig. 72. Regular flower of straw- lv separate, they are said to berry: 5 petals, 5 green sepals. be distinct; when the stamens The petals of separate pieces,

polypetalous. (Ada Hayden.) are united by the filaments in

one set, they are monadelphous; when in two sets, diadelphous, and so on. When there is one stamen, the flower is monandrous; two, diandrous; and so on. The parts of the stamen are the filament, anther, and pollen. When the pollen is united in a mass it is spoken of as a pollinium,

Fig. 73. Regular flower of rose: 5 green reflexed sepals, 5 petals (Ada Hayden.)

as in the milkweed. When the filament is attached in the middle it is versatile, when attached by its base it is innate, when attached by one face it is adnate. When the anther opens outwardly it is extrorse; inwardly, in

trorse.

Ovules, Fruits and Seeds.-There are two classes of flowering plants classified with reference to the manner in which the ovules occur. In the Gymnosperms, the ovules

and seeds are borne on the face of a scale, as in the pine, spruce and cedar. In the Angiosperms, the ovules and seeds are contained in a closed ovary, as in the bean, corn, maple, etc. The carpel is a modified leaf forming the ovary or a part of the compound ovary. The dorsal suture corresponds to the midrib of the leaf, the ventral

Fig. 74. various types. (Redrawn from Hamilton-Gibson. C. M. King.)

Pollen grains of

suture is where the leaves meet. The placenta is that part of the ovule where the ovules are borne. An arile placenta occurs in a compound pistil where two or more closed carpels cohere; such ovaries are two, three or more celled. A parietal placenta appears in a compound pistil when the ovules are borne on the walls of the ovaries, as in the poppy and Rocky Mountain bee plant. In pinks and purslane, the compound pistil is one-celled with a free placenta. The parts of an ovule are the two coats, an

outer and an inner, the chalaza at the base where the coats and nucellus blend; the nucellus, is the body of the ovule. The micropyle is the opening left after the passage of the pollen tube into the ovule. There is usually a stalk called the funiculus on the seed; the embryo sac contains the egg cell. Ovules may be erect when they arise from the bottom of the cell; ascending, when extending upward and attached at the side; horizontal, when borne on the side horizontally as in mandrake; suspended, when hanging from the apex; pendulous, when more or less hanging or

declining from the side. The term orthotropous is applied to the straight ovule, as in buckwheat; campylotropous,