What is Center of Origin? The center of origin is a geographical area where the particular group of organisms (either domesticated or wild) first originated on earth. Center of Origin & Center of Diversity Many people believed that centers of origin are also centers of diversity. But, the centers of diversity …

External surfaces of the plant bear several secretory structures of epidermal origin or epidermal derivatives or emergences from deeper tissues (Kisser, 1958). These include Glands, Glandular Trichomes, Nectaries, Osmophores, Hydathodes etc.  In this article,  these external structures of  plant will be discussed briefly. Trichomes and glands In some leaves and flowers, more or less …

The tissues that are concerned with the secretion of gums, resins, volatile oils, nectar, latex and other substances are called Secretory tissues. These tissues are mainly divided into two groups: Laticiferous tissue. Glandular tissue. In this article, Laticiferous tissue will be discussed explicitly. Laticiferous tissue A laticifer is a type of …