Morphology in biology is the study of the external form and structure of organisms. In flowering plants, or angiosperms, this involves examining the diverse array of shapes and forms of various plant parts, such as the roots, stem, leaves, flowers, fruits, and seeds. A typical flowering plant is fundamentally divided into two main systems: the root system, which is the underground part, and the shoot system, which is the aerial part.

The Root System is the non-green, underground part of the plant that primarily anchors it to the soil and absorbs water and minerals. In most dicotyledonous plants, the primary root develops directly from the radicle of the embryo, giving rise to a tap root system. In monocotyledonous plants, the primary root is short-lived and is replaced by a cluster of roots originating from the base of the stem, forming a fibrous root system. Roots that arise from parts of the plant other than the radicle are known as adventitious roots. The root tip is protected by a thimble-like root cap and is divided into distinct regions: the region of meristematic activity, the region of elongation, and the region of maturation, from which root hairs arise. Roots are often modified to perform specialized functions, such as storage (as seen in carrots and turnips), support (prop roots in banyan trees), and respiration (pneumatophores in mangrove plants).

The Shoot System consists of the stem, leaves, flowers, and fruits. The Stem is the ascending axis of the plant that bears branches, leaves, flowers, and fruits. It is characterized by the presence of nodes (where leaves arise) and internodes (the portion between two nodes). The primary function of the stem is to spread out branches, conduct water and minerals from the roots to the leaves, and transport the products of photosynthesis to other parts of the plant. Stems can also be modified for various purposes, including food storage (potato, ginger), perennation, vegetative propagation (runners, stolons), protection (thorns), and photosynthesis (in flattened stems like Opuntia).

The Leaf is a flattened, lateral structure that develops at a node on the stem and is the principal site of photosynthesis. A typical leaf consists of three main parts: the leaf base, the petiole (stalk), and the lamina (leaf blade). The arrangement of veins and veinlets in the lamina is called venation, which can be reticulate (a network, typical of dicots) or parallel (running parallel, typical of monocots). Leaves are classified as simple (with an undivided lamina) or compound (where the lamina is divided into multiple leaflets). The arrangement of leaves on a stem is known as phyllotaxy, which can be alternate, opposite, or whorled. Like other plant parts, leaves are also modified to perform special functions, such as support (tendrils in peas) and defense (spines in cacti).

The Inflorescence is the arrangement of flowers on the floral axis. Based on whether the apex continues to grow, there are two main types: racemose, where the main axis continues to grow and flowers are borne laterally in an acropetal succession, and cymose, where the main axis terminates in a flower, limiting its growth, and flowers are borne in a basipetal order.

The Flower is the reproductive unit in angiosperms. A typical flower is composed of four distinct whorls of floral appendages arranged on a swollen end of the stalk called the thalamus or receptacle. These whorls are the calyx (composed of sepals), corolla (composed of petals), androecium (composed of stamens, the male reproductive organ), and gynoecium (composed of one or more carpels, the female reproductive organ). Flowers can exhibit radial symmetry (actinomorphic) or bilateral symmetry (zygomorphic). Based on the position of the calyx, corolla, and androecium with respect to the ovary on the thalamus, flowers can be hypogynous (superior ovary), perigynous (half-inferior ovary), or epigynous (inferior ovary).

Following fertilization, the ovules develop into seeds and the ovary matures into a fruit. A fruit consists of a fruit wall (pericarp) and seeds. The pericarp can be differentiated into an outer epicarp, a middle mesocarp, and an inner endocarp. A seed typically consists of a seed coat and an embryo, which is made up of an embryonal axis and one (in monocots) or two (in dicots) cotyledons. The embryonal axis includes the plumule (which develops into the shoot) and the radicle (which develops into the root). In some seeds, a nutritive tissue called the endosperm is present. The morphology of flowering plants is systematically described using a floral formula and a floral diagram, which provide a concise summary of the floral characteristics of a plant family.