Figure 2.

Localization and Morphology of Pyrethrin Stores and Pyrethrum Glandular Trichomes.

(A) Cryo-scanning electron microscopy image of a complete disk floret showing the highest density of glandular trichomes in the indentations between the ribs of the ovary.

(B) Closer view of trichomes.

(C) Side section of a fully developed trichome indicating the location of basal and stalk cells and the presumed secretory cells and the oil sac.

(D) Perpendicular section of a disk floret showing the oil in the intercellular space between the embryo and the seed coat and in the intercellular space of cells (arrows).

bc, basal cell; Co, corolla; Os, oil sac; Ov, ovary; Po, pollen; sec, secretory cell; stc, stalk cell; Sti, stigma; Tr, trichome.