In stems, the vascular bundles surround the pith . For African Violets, potential vectors include Aphids , Mealy Bugs , Mites , Nematodes , Scale , Thrips and Whiteflies . See Saintpaulia velutina . Optimara variety, part of the Artist's Palette series. Named for the 17th century Dutch painter, Jan Vermeer.
Flowers are pink and purple.
Leaves are medium green. More information . A light, porous mineral mined from mica and heated to make it expand. Vermiculite is sometimes added to potting soil to help buffer changes in pH and increase aeration . More information .