Stigma (botany) from the base of the ovary, or between the ovary lobes and is characteristic of Boraginaceae. Subgynobasic styles characterise "Allium". Pollen tubes grow the length of the style to reach the ovules, and in some cases self-incompatibility reactions in the style prevent full growth of the pollen tubes. In some species, including "Gasteria" at least, the pollen tube is directed to the micropyle of the ovule by the style. Stigma (botany) The stigma (plural: stigmata) is the receptive tip of a carpel, or of several fused carpels, in the gynoecium of a flower. The stigma, together with the style and
Cortex (botany) Cortex (botany) A cortex is the outermost layer of a stem or root in a plant. In botany, the cortex is the outermost layer of the stem or root of a plant, bounded on the outside by the epidermis and on the inside by the endodermis. In plants, it is composed mostly of differentiated cells, usually large thin-walled parenchyma cells of the ground tissue system. The outer cortical cells often acquire irregularly thickened cell walls, and are called collenchyma cells. Some of the outer cortical cells may contain chloroplasts. It is responsible for the transportation of materials into the central