Osmose, the movement of fluids through membranes or thin partitions.
Oxygen, a gas which forms one-fifth of the air. Its presence is necessary to the life of all green plants and all animals.
Ovary, the part of the pistil that bears the developing seeds.
Ovule, an immature seed in the ovary.
Perennial, living through several years.
Phosphoric acid, an important plant food found in phosphates.
Pistil, the part of the flower which produces seeds.
Propagate, to increase in number.
Pollen, the powdery substance produced by stamens.
Pollination, the transfer of pollen from stamens to pistils.