Ergot "C. lutea" (on paspalum). "C. purpurea" most commonly affects outcrossing species such as rye (its most common host), as well as triticale, wheat, and barley. It affects oats only rarely. "C. purpurea" has at least three races or varieties, which differ in their host specificity: An ergot kernel, called a "sclerotium", develops when a spore of fungal species of the genus "Claviceps" infects a floret of flowering grass or cereal. The infection process mimics a pollen grain growing into an ovary during fertilization. Infection requires that the fungal spore have access to the stigma; consequently, plants infected by "Claviceps" are
Medullary ray (botany) also known as vascular rays or pith rays. In this context, the term refers to radial sheets or ribbons extending vertically through the tree across and perpendicular to the growth rings. Also called pith rays or wood rays, these formations of primarily parenchyma cells allow the radial transport of sap and are essential in the process of tylosis. In quartersawn material, where the wood is cut into boards with the growth rings roughly perpendicular to the face of the board, the medullary rays often produce beautiful figure such as silver grain, medullary spots, pith flecks, etc. Medullary ray (botany) Medullary