Shadows and seeds

Seed structures are composed of a protective seed coat surrounding a plant embryo, and a food store for the developing embryo. The embryo contains the precursor tissues for leaves, stem, and roots. The endosperm and cotyledons—seed leaves—act as the food reserves for the growing embryo.

Most plants are seed plants—characterized by seeds, pollen, and reduced gametophytes. Seed plants include gymnosperms and angiosperms.

Seedless Vascular Plants Were the First Tall Plants on Earth

Light plays a significant role in regulating the growth and development of plants. In addition to providing energy for photosynthesis, light provides other important cues to regulate a range of developmental and physiological responses in plants.

The diverse plant life on Earth—consisting of nearly 400,000 species—can be divided into three broad categories based on biological characteristics: nonvascular, seedless vascular, and seed plants.

Overview