Ovule is considered to be an integument mega sporangium. It is attached to the placenta by a slender stalk known as funicular.

The other end of the funicle is attached to the body of the ovule and the point of attachment is called hilum. An ovule which is attached to the placenta directly, without the funicle is known as sessile ovule.

The funicle continues beyond the hilum and may extend up to the base of the ovule (chalaza) forming a short ridge, called raphe. The main body of the ovule is called nucleolus. It is surrounded by two coats, the integuments.

There is no integument (ategmic) in parasitic plants like Santalum and Loranthus. A srim. Opening is found at the apex of of the integuments which is called micropyle.

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The ovule may be unitegmic with single integument (e.g., gymnosperms, family Asteraceae and sympetalous or gamopetalous dicotyledons), bitegmic with two integuments (e.g., monocotyledons and polypetalous dictyledons).

In addition there may be extra outgrowths in a few cases, known as Aril, a collar-like outgrowth from the base of the ovule often form the third integument (e.g., litchi, nutmeg, etc.) and Carcuncle, an outgrowth of the outer integument is present in the micropylar region of some plants (e.g., castor and other members of Euphorbiaceae).

There is a large oval cell, embedded in the nucellus towards the micropylar end which constitutes the most important part of the ovule, the embryo sac.

Based on the mutual position funicle, chalaza and micropyle, the ovules may be orthotropous, anatropous, campylotropous, hemianatropous, amphitropous or circinotropous. The most common type of ovule is anatropous or reversed type as shown in.

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In orthotropous, the ovule remains straight (e.g., family Polygonaceae, Piperaceae, Urticaceae, etc.) In amphitropous condition the ovule is placed at right angle to the funicle (e.g., Ranunculus, Lemna and poppy).

In campylotropous condition it is bent like a horse-shoe, so that micropyle is brought to the chalaza (e.g., many plants of family Cruciferae, Chenopodiaceae, Caryophyllaceae and other plants like Mirabilis).