A shrub or bush is a small-to-medium-sized perennial woody plant . Unlike herbaceous plants , shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple stems and shorter height , less than 6–10 m (20–33 ft) tall. Small shrubs, less than 2 m (6.6 ft) tall are sometimes termed as subshrubs . Many botanical groups have species that are shrubs, and others that are trees and herbaceous plants instead.
29-425: A bush or shrub is a small or medium woody plant. Bush or Bushes may also refer to: Shrub Some define a shrub as less than 6 m (20 ft) and a tree as over 6 m. Others use 10 m (33 ft) as the cutoff point for classification. Many trees do not reach this mature height because of hostile, less than ideal growing conditions, and resemble shrub-sized plants. Others in such species have
58-466: A " stool ", removes everything but vital parts of the plant, resulting in long new stems known as "canes". Other shrubs respond better to selective pruning to dead or unhealthy, or otherwise unattractive parts to reveal their structure and character. Shrubs in common garden practice are generally considered broad-leaved plants , though some smaller conifers such as mountain pine and common juniper are also shrubby in structure. Species that grow into
87-399: A behavior known as " marcescence " whereby dead leaves are not shed in the fall and remain on the tree until being blown off by the weather. This is caused by incomplete development of the abscission layer. It is mainly seen in the seedling and sapling stage, although mature trees may have marcescence of leaves on the lower branches. A number of deciduous plants remove nitrogen and carbon from
116-577: A century ago) is called a shrubbery , shrub border or shrub garden. There are many garden cultivars of shrubs, bred for flowering, for example rhododendrons , and sometimes even leaf colour or shape. Compared to trees and herbaceous plants, a small number of shrubs have culinary usage. Apart from the several berry -bearing species (using the culinary rather than botanical definition), few are eaten directly, and they are generally too small for much timber use unlike trees. Those that are used include several perfumed species such as lavender and rose , and
145-602: A greater rate of transpiration (and hence CO 2 uptake as this occurs when stomata are open) during the summer growth period. The deciduous characteristic has developed repeatedly among woody plants. Trees include maple , many oaks and nothofagus , elm , beech , aspen , and birch , among others, as well as a number of coniferous genera , such as larch and Metasequoia . Deciduous shrubs include honeysuckle , viburnum , and many others. Most temperate woody vines are also deciduous, including grapes , poison ivy , Virginia creeper , wisteria , etc. The characteristic
174-547: A part that is no longer needed or useful" and the "falling away after its purpose is finished". In plants, it is the result of natural processes. "Deciduous" has a similar meaning when referring to animal parts, such as deciduous antlers in deer , deciduous teeth (baby teeth) in some mammals (including humans); or decidua , the uterine lining that sheds off after birth. In botany and horticulture , deciduous plants , including trees , shrubs and herbaceous perennials, are those that lose all of their leaves for part of
203-456: A reasonable length beforehand. Many trees can grow in multiple stemmed forms also while being tall enough to be trees, such as oak or ash . An area of cultivated shrubs in a park or a garden is known as a shrubbery . When clipped as topiary , suitable species or varieties of shrubs develop dense foliage and many small leafy branches growing close together. Many shrubs respond well to renewal pruning , in which hard cutting back to
232-512: A shrubby habit may be either deciduous or evergreen . In botany and ecology , a shrub is more specifically used to describe the particular physical canopy structure or plant life-form of woody plants which are less than 8 metres (26 ft) high and usually multiple stems arising at or near the surface of the ground. For example, a descriptive system widely adopted in Australia is based on structural characteristics based on life-form, plus
261-595: A wide range of plants with medicinal uses. Tea and coffee are on the tree-shrub boundary; they are normally harvested from shrub-sized plants, but these would be large enough to become small trees if left to grow instead. Shrubs are perennial woody plants, and therefore have persistent woody stems above ground (compare with succulent stems of herbaceous plants ). Usually, shrubs are distinguished from trees by their height and multiple stems. Some shrubs are deciduous (e.g. hawthorn ) and others evergreen (e.g. holly ). Ancient Greek philosopher Theophrastus divided
290-598: Is a deciduous woody shrub found in Japan . Forests where a majority of the trees lose their foliage at the end of the typical growing season are called deciduous forests. These forests are found in many areas worldwide and have distinctive ecosystems, understory growth, and soil dynamics. Two distinctive types of deciduous forests are found growing around the world. Temperate deciduous forest biomes are plant communities distributed in North and South America, Asia, Southern slopes of
319-700: Is completed (marked by the transition from bright green spring leaves to dark green summer ones) the chlorophyll level in the leaves remains stable until cool temperatures arrive in autumn. When autumn arrives and the days are shorter or when plants are drought-stressed, the chlorophyll steadily breaks down, allowing other pigments present in the leaf to become apparent and resulting in non-green colored foliage. The brightest leaf colors are produced when days grow short and nights are cool, but remain above freezing. These other pigments include carotenoids that are yellow, brown, and orange. Anthocyanin pigments produce red and purple colors, though they are not always present in
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#1732837989846348-400: Is formed between the leaf petiole and the stem. This layer is formed in the spring during active new growth of the leaf; it consists of layers of cells that can separate from each other. The cells are sensitive to a plant hormone called auxin that is produced by the leaf and other parts of the plant. When auxin coming from the leaf is produced at a rate consistent with that from the body of
377-522: Is useful in plant identification; for instance in parts of Southern California and the American Southeast , deciduous and evergreen oak species may grow side by side. Periods of leaf fall often coincide with seasons: winter in the case of cool-climate plants or the dry-season in the case of tropical plants, however there are no deciduous species among tree-like monocotyledonous plants, e.g. palms , yuccas , and dracaenas . The hydrangea hirta
406-503: The foliage before they are shed and store them in the form of proteins in the vacuoles of parenchyma cells in the roots and the inner bark. In the spring, these proteins are used as a nitrogen source during the growth of new leaves or flowers. Plants with deciduous foliage have advantages and disadvantages compared to plants with evergreen foliage. Since deciduous plants lose their leaves to conserve water or to better survive winter weather conditions, they must regrow new foliage during
435-834: The Himalayas, Europe and for cultivation purposes in Oceania. They have formed under climatic conditions which have great seasonable temperature variability. Growth occurs during warm summers, leaf drop in autumn, and dormancy during cold winters. These seasonally distinctive communities have diverse life forms that are impacted greatly by the seasonality of their climate, mainly temperature and precipitation rates. These varying and regionally different ecological conditions produce distinctive forest plant communities in different regions. Tropical and subtropical deciduous forest biomes have developed in response not to seasonal temperature variations but to seasonal rainfall patterns. During prolonged dry periods
464-428: The earliest trees to lose their leaves in the fall. In sub-Arctic climates such as Alaska , leaves begin turning colors as early as August. However, for most temperate regions it takes place in late September through early November and in subtropical climates such as the southern US, it may be November into December. Leaf drop or abscission involves complex physiological signals and changes within plants. When leafout
493-677: The fall months and the Western United States as it has more evergreen and fewer deciduous plants, combined with the West Coast and its maritime climate. ( See also : Autumn leaf color ) Most of the Southern Hemisphere lacks deciduous plants due to its milder winters and smaller landmass, most of which is nearer the equator with only far southern South America and the southern island of New Zealand producing distinct fall colors. The beginnings of leaf drop starts when an abscission layer
522-426: The foliage is dropped to conserve water and prevent death from drought. Leaf drop is not seasonally dependent as it is in temperate climates. It can occur any time of year and varies by region of the world. Even within a small local area there can be variations in the timing and duration of leaf drop; different sides of the same mountain and areas that have high water tables or areas along streams and rivers can produce
551-439: The height and amount of foliage cover of the tallest layer or dominant species . For shrubs that are 2–8 metres (6.6–26.2 ft) high, the following structural forms are categorized: For shrubs less than 2 metres (6.6 ft) high, the following structural forms are categorized: Those marked with * can also develop into tree form if in ideal conditions. Deciduous In the fields of horticulture and botany ,
580-417: The humid maritime climate and lower overall species diversity . It is also a factor that the continental United States and southern Canada are at a lower latitude than northern Europe, so the sun during the fall months is higher and stronger. This combination of strong sun and cool temperatures leads to more intense fall colors. The Southern United States also has poor fall colors due to warm temperatures during
609-507: The leaves are shed at the same time. Plants that are intermediate may be called semi-deciduous ; they lose old foliage as new growth begins. Other plants are semi-evergreen and lose their leaves before the next growing season, retaining some during winter or dry periods. Many deciduous plants flower during the period when they are leafless, as this increases the effectiveness of pollination . The absence of leaves improves wind transmission of pollen for wind-pollinated plants and increases
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#1732837989846638-526: The leaves. Rather, they are produced in the foliage in late summer, when sugars are trapped in the leaves after the process of abscission begins. Parts of the world that have showy displays of bright autumn colors are limited to locations where days become short and nights are cool. The New England region of the United States and southeastern Canada tend to produce particularly good autumn colors for this reason, with Europe producing generally poorer colors due to
667-783: The next suitable growing season; this uses resources which evergreens do not need to expend. Evergreens suffer greater water loss during the winter and they also can experience greater predation pressure , especially when small. Deciduous trees experience much less branch and trunk breakage from glaze ice storms when leafless, and plants can reduce water loss due to the reduction in availability of liquid water during cold winter days. Losing leaves in winter may reduce damage from insects; repairing leaves and keeping them functional may be more costly than just losing and regrowing them. Removing leaves also reduces cavitation which can damage xylem vessels in plants. This then allows deciduous plants to have xylem vessels with larger diameters and therefore
696-543: The plant world into trees, shrubs and herbs. Small, low shrubs, generally less than 2 m (6.6 ft) tall, such as lavender , periwinkle and most small garden varieties of rose , are often termed as subshrubs . Most definitions characterize shrubs as possessing multiple stems with no main trunk below. This is because the stems have branched below ground level. There are exceptions to this, with some shrubs having main trunks, but these tend to be very short and divide into multiple stems close to ground level without
725-469: The plant, the cells of the abscission layer remain connected; in autumn, or when under stress, the auxin flow from the leaf decreases or stops, triggering cellular elongation within the abscission layer. The elongation of these cells breaks the connection between the different cell layers, allowing the leaf to break away from the plant. It also forms a layer that seals the break, so the plant does not lose sap. Some trees, particularly oaks and beeches, exhibit
754-557: The potential to grow taller in ideal conditions. For longevity, most shrubs are classified between perennials and trees. Some only last about five years in good conditions. Others, usually larger and more woody, live beyond 70. On average, they die after eight years. Shrubland is the natural landscape dominated by various shrubs; there are many distinct types around the world, including fynbos , maquis , shrub-steppe , shrub swamp and moorland . In gardens and parks, an area largely dedicated to shrubs (now somewhat less fashionable than
783-426: The term deciduous ( / d ɪ ˈ s ɪ dʒ u . ə s / ) means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves , usually in the autumn ; to the shedding of petals , after flowering; and to the shedding of ripe fruit . The antonym of deciduous in the botanical sense is evergreen . Generally, the term "deciduous" means "the dropping of
812-702: The visibility of the flowers to insects in insect-pollinated plants. This strategy is not without risks, as the flowers can be damaged by frost or, in dry season regions, result in water stress on the plant. Spring leafout and fall leaf drop are triggered by a combination of daylight and air temperatures. The exact conditions required will vary with the species, but generally more cold-tolerant genera such as Salix will leaf-out earlier and lose their leaves later, while genera such as Fraxinus and Juglans can only grow in warm, frost-free conditions so they need at least 13 hours of daylight and air temperatures of around 70 °F (21 °C) to leaf out. They will be among
841-501: The year. This process is called abscission . In some cases leaf loss coincides with winter—namely in temperate or polar climates . In other parts of the world, including tropical, subtropical, and arid regions, plants lose their leaves during the dry season or other seasons, depending on variations in rainfall . The converse of deciduous is evergreen , where foliage is shed on a different schedule from deciduous plants, therefore appearing to remain green year round because not all
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