Under the head of malformations we place cases of atrophy of parts or general dwarfing, due to starvation, the attacks of Fungi or minute insects, the presence of unsuitable food-materials and so on, as well as cases of transformation of stamens into petals, carpels into leaves, and so forth.
Axillary or terminal spikes; they have four stamens, which bear at the back four small herbaceous petal-like structures, and four free carpels, which ripen to form four small green fleshy fruits, each containing one seed within a hard inner coat;.
The parts of the flower are most frequently arranged in fives, or multiples of fives; for instance, a common arrangement is as follows, - five sepals, succeeded by five petals, ten stamens in two sets of five, and five or fewer carpels; an arrangement in fours is less frequent, while the arrangement in threes, so common in monocotyledons, is rare in dicotyledons.
In some orders the parts are numerous, chiefly in the case of the stamens and the carpels, as in the buttercup and other members of the order Ranunculaceae.
Within the perianth, and springing from its sides, or apparently from the top of the ovary, are six stamens whose anthers contain pulverulent pollen-grains.