Basic structure of dicotyledonous stem-Sunflower stem. Inner structure of dicotyledonous stem reveals epidermis, cortex and stele. Epidermis. Epidermis is protective in function and creates the outermost layer of the stem. Epidermis is a single layer of parenchymatous rectangular cells.
Culture. Plumbago is propagated from cuttings in the summer, but you can also grow it from seed. Plant plumbago in light, sandy, well-drained soils, spacing each shrub 36 to 60 inches apart to allow room to grow. If spaced properly, blue plumbago will naturally cascade in a fountain shape.
The species varies widely depending on local circumstances. An individual plant can be from 3 feet to 25 feet tall and wide, but they usually form thickets, which can spread much farther. Chickasaw plum or sandhill plum (Prunus angustifolia, USDA zones 5 through 9) is a larger native plum that can grow to 35 feet.