This ridge indicates the point of union of the "raphe" or seed-stalk with the seed; it serves to distinguish the varieties of V.
The levatores ani have been separated along the median raphe, and drawn outwards.
There are five, or sometimes fewer, carpels, which unite to form an ovary with as many chambers, in each of which are one or two, rarely more, pendulous anatropous ovules, attached to the central column in such a way that the micropyle points outwards and the raphe is turned towards the placenta.
I I 1) is the commonest form amongst angiosperms. In this ovule the apex with the micropyle is turned towards the point of attachment of the funicle to the placenta, the chalaza being situated at the opposite extremity; and the funicle, which runs along the side usually next the placenta, coalesces with the ovule and constitutes the raphe (r), which often forms a ridge.
Then if a second integument be formed it covers all the free part of the ovule, but does not form on the side to which the raphe is adherent.
The connexion between the base of the ovule and the base of the nucellus is kept up by means of the raphe r.