At their most basic, most plants possess roots, stems and leaves, and most produce flowers as well. The pea plant is no exception -- it too has all of those structures -- but distinctive anatomical traits not only help the plant to compete and survive but settle it in an important economical niche.
Plant roots, including the roots of pea plants, consist of special tissues that help them to grow rapidly and absorb water and nutrients from the soil. Root hairs increase the surface area available for absorption. Because pea plants are legumes, their roots also contain special structures called nodules. Nodules form when pea plant roots form relationships with soil bacteria called rhizobia. The rhizobia produce nitrogen for the plant -- one of the essential nutrients plants need -- and the plant rewards them with sugar for energy.
Stems provide support for the plant but also present the disadvantage of distance: Plants must find a way to transport water and nutrients from the roots and sugars synthesized in the leaves to other parts of the plant. Pea plant stems contain tissues called xylem and phloem for that purpose. Xylem cells form early in the plant's life as long tubes that harden and die as the plant ages, contributing structure to the plant as well as a way to transport water from the roots. Phloem cells move water but also sugars produced in the leaves, distributing them throughout the plant.
Leaves are the powerhouse of the pea plant, absorbing sunlight and converting it into energy that the plant will use to produce flowers and fruit. Leaves contain a waxy cuticle that prevents water loss and tiny pores called stomata that act as gatekeepers, opening and closing to let gases in and out of the leaf. In the fleshy, middle cells of the leaf, the plant undertakes photosynthesis, producing sugar from sunlight.
Pea plants also have special leaves called tendrils. Because the stems grow too long to support themselves, tendrils allow the plant to grow and extend upward. Pea plant tendrils are modified leaves, according to a handout available on the Bellevue College website. They wrap around fences, lattice or even other plants and allow the plant to climb.
Legumes are one of the largest families of flowering plants, so pea plants produce flowers, which in turn develop into peas. Pea plants have five petals arranged in a distinct shape with a broad banner at the top and smaller wings and keels at the bottom. At the center of the flower, you will find the pistil and stamens, the female and male structures, and an ovary at the base, in which the plant produces seeds.