Studies of the surfaces of desert plant seeds: II. Ecological adaptations of the seeds of Blepharis persica

A study was made of the role of the hydrated mucilage which arises from the integumentary hairs of Blepharis seeds and inhibits germination where there is an excess of water, and of the anatomical and physiological basis for this phenomenon. It was found that this inhibition was not due to bacterial respiration. The appearance of the dry mucilage in the unimbibed seeds is described from scanning electron micrographs. The basic helical framework of the secondary wall thickenings and the very unusual second-order framework of trabeculae in the integumentary hair cells are described.