Vegetative reproduction | Description, Types, Horticulture, Examples, & Facts (2024)

vegetative reproduction, any form of asexual reproduction occurring in plants in which a new plant grows from a fragment of the parent plant or grows from a specialized reproductive structure (such as a stolon, rhizome, tuber, corm, or bulb). In many plants, vegetative reproduction is a completely natural process; in others it is an artificial one.For a general discussion of plant reproduction, see plant reproductive system. For an overview of the cultivation of plants for food and ornament, see horticulture.

In horticulture, vegetative reproduction has many advantages. Asexual reproduction facilitates the unchanged perpetuation of a superior plant, endlessly and without variation. In addition, vegetative propagation may be easier and faster than seed propagation, because seed dormancy problems are eliminated and the juvenile nonflowering stage of some seed-propagated plants is eliminated or reduced. However, vegetative propagation can result in horticultural plants that are exact genetic clones to one another, making them identically susceptible to diseases.

Vegetative reproduction by fragments

In many plant groups, fragmentation of the plant body, followed byregenerationand development of the fragments into whole new organisms, serves as an asexual reproductive system. Naturally fallen branches ofwillows(Salix) andpoplars(Populus)rootunder suitable conditions in nature and eventually develop into trees; many cacti and succulents also regenerate from naturally fallen fragments. Similarly, drooping bramble stems (Rubus) tend torootin contact with the soil. Fragments of the plant bodies ofliverwortsandmossesregenerate to form new plants. During prolonged drought, the mature portions of liverworts often die, but their tips resume growth and produce a series of new plants from the original parent plant. In mosses, small fragments of thestemlikeandleaflike structures(even single cells of the latter) can, with sufficient moisture and under proper conditions, regenerate and ultimately develop into new plants.

It is commonhorticulturalpractice topropagatedesirable varieties of garden plants by means of plant fragments, orcuttings. These may be severed leaves or portions ofrootsor stems, which are stimulated to regenerate missing parts, usually adventitious roots or shoots. The ability of stems to regenerate missing parts is variable; consequently, plants may be easy or difficult to root. The physiological ability of cuttings to form roots is due to an interaction of many factors. These include transportable substances in the plant itself: plant hormones (such asauxin), carbohydrates, nitrogenous substances, vitamins, and substances not yet identified. Environmental factors such as light, temperature, humidity, and oxygen are important, as are age, position, and type of stem. Other horticultural practices that exemplify asexual reproduction includebudding(the removal of buds of one plant and their implantation on another) andgrafting(the implantation of small branches of one individual on another).

Vegetative reproduction by specialized structures

The vegetative, or somatic, organs of plants may, in their entirety, be modified to serve as organs of reproduction. In this category belong such flowering-plant structures asstolons,rhizomes,tubers,corms, andbulbs, as well as the tubers of liverworts, ferns, andhorsetails, the dormant buds of certainmossstages, and the leaves of manysucculents. Stolons are elongated runners, or horizontal stems, such as those of thestrawberry (Fragaria), which root and form new plantlets when they make proper contact with a moistsoilsurface. Rhizomes, as seen iniris (Iris) and ginger (Zingiber officinale), are fleshy,elongated, horizontal stems that grow within or upon the soil. The branching of rhizomes results in multiplication of the plant. Tubers, such as those of the potato (Solanum tuberosum), are fleshy storage stems, the buds (“eyes”) of which, under proper conditions, can develop into new individuals. Erect, vertical, fleshy, subterranean stems, which are known as corms, are exemplified bycrocuses (Crocus)andgladioli (Gladiolus). These organs tide the plants over in periods ofdormancyand may develop secondary cormlets, which give rise to new plantlets. Unlike the corm, only a small portion of thebulb, as in lilies (Lilium) and the onion (Allium), representsstemtissue. The latter is surrounded by the fleshy food-storage bases of earlier-formed leaves. After a period of dormancy, bulbs develop into new individuals. Large bulbs produce secondary bulbs through development of buds, resulting in an increase in the number of individuals.

Bulblike structures known as bulbils may form on aerial stems in someliliesor in association withflowerparts, as in the onion.Budsin the axils (angle betweenleafand stem) of the fleshy leaves may form miniature bulbs, or bulblets. These structures can be planted for clonal offspring of the parent plant.

A number of plants, including agaves (Agave) and various cacti, form lateral shoots from the stem, which when rooted serve topropagatethe plant. These are known collectively asoffshootsbut are often called pups, offsets, crown divisions, ratoons, or slips. Roots may also be structurally modified as propagative and food-storage organs. These tuberous roots, fleshy swollen structures, readily formadventitious shoots. Thesweet potato (Ipomoea batatas)anddahlia (Dahlia)are propagated by tuberous roots. Shoots that rise adventitiously from roots are often calledsuckers. Raspberries (Rubus species)are often propagated by suckers.