Valeriana officinalis Linn., its polyploid forms and the structure of their rhizomes and roots

The primary organs of vascular plants are roots, stems, and leaves, but these structures can be highly variable, adapted for the specific needs and environment of different plant species.

Seedless Vascular Plants Were the First Tall Plants on Earth

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.

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

Plant tissues are collections of similar cells performing related functions. Different plant tissues will have their own specialized roles and can be combined with other tissues to form organs such as flowers, fruit, stem, and leaves. Two major types of plant tissue include meristematic and permanent tissue.Meristematic tissue, the primary growth tissue in plants, is capable of self-renewal and indefinite cell division. Every cell in the plant originates from a meristem. Meristematic tissue is...

Asexual reproduction allows plants to reproduce without growing flowers, attracting pollinators, or dispersing seeds. Offspring are genetically identical to the parent and produced without the fusion of male and female gametes.