Perennial plant


Perennial plant

A perennial plant or perennial (Latin "per", "through", "annus", "year") is a plant that lives for more than two years. [The Garden Helper. [http://www.thegardenhelper.com/planting.html The Difference Between Annual Plants and Perennial Plants in the Garden.] Retrieved on 2008-06-22.] When used as a noun, this term applies specifically to perennial herbaceous plants, even though woody plants like shrubs and trees are also perennial in their habit.

Perennials, especially small flowering plants, grow and bloom over the spring and summer and then die back every autumn and winter, then return in the spring from their root-stock rather than seeding themselves as an annual plant does. These are known as "herbaceous perennials". However, depending on the rigors of local climate, a plant that is a perennial in its native habitat, or in a milder garden, may be treated by a gardener as an annual and planted out every year, from seed, from cuttings or from divisions.

The symbol for a perennial plant, based on Species Plantarum by Linnaeus is, . [Stearn, William T. "Botanical Latin" (four editions, 1966-92)]

Life cycle

Perennial plants can be short-lived (only a few years) or they can be long-lived, as are some woody plants like trees which can live for over 3,000 years. They can vary in height from only a few millimeters to over 100 meters tall. They include a wide assortment of plant groups from ferns and liverworts to the highly diverse flowering plants like Orchids and Grasses.

Plants that flower and fruit only once and then die are termed "monocarpic" or semelparous. However, most perennials are "polycarpic", flowering over many seasons in their lifetime.

tructure

Perennials typically grow structures that allow them to adapt to living from one year to the next. These structures include bulbs, tubers, woody crowns, rhizomes plus others. They might have specialized stems or crowns that allow them to survive periods of dormancy over cold or dry seasons during the year. Annuals produce seeds to continue the species as a new generation while the growing season is suitable, and the seeds survive over the cold or dry period to begin growth when the conditions are again suitable.Many perennials, in contrast, have specialized to survive under extreme environmental conditions: some have adapted to survive hot and dry conditions, or to survive under cold temperatures. Those plants tend to invest a lot of resource into their adaptations and often do not flower and set seed until after a few years of growth. Many perennials produce relatively large seeds, which can have an advantage, with larger seedlings produced after germination that can better compete with other plants or more quickly develop leaves for photosynthesis. Annuals tend to produce many more seeds per plant since they will die at the end of the growing season, while perennials are not under the same pressure to produce large numbers of seeds but can produce seeds over many years.

Growth

In warmer and more favorable climates, perennials grow continuously. In seasonal climates, their growth is limited to the growing season. For example, in temperate regions a perennial plant may grow and bloom during the warm part of the year, with the foliage dying back in the winter. These plants are deciduous perennials. Regrowth is from existing stem tissue. In many parts of the world, seasonality is expressed as wet and dry periods rather than warm and cold periods. In some species, perennials retain their foliage all year round; these are evergreen perennials.

With their roots protected below ground in the soil layer, perennial plants are notably tolerant of wildfire. They are also less subject to extremes of cold in temperate and Arctic winters, with less sensitivity than trees or shrubs.

Location

Perennial plants dominate many natural ecosystems on land and in fresh water, with only a very few (e.g. "Zostera") occurring in shallow sea water. They are particularly dominant in conditions too fire-prone for trees and shrubs, e.g., most plants on prairies and steppes are perennials; they are also dominant on tundra too cold for tree growth. In forests, perennial plants are of secondary importance to trees and shrubs, but are often still abundant on the forest floor.

Perennial plants are usually better competitors than annual plants, especially under stable, resource-poor conditions. This is due to the development of larger root systems which can access water and soil nutrients deeper in the soil and to earlier emergence in the spring.

Types

Examples of evergreen perennials include "Begonia" and banana.

Examples of deciduous perennials include goldenrod and mint.

Examples of monocarpic perennials include "Agave" and some species of "Streptocarpus".

ee also

*Annual plant
*Biennial plant
*Perennial Tea Ceremony
*Herbaceous

References

External links

* [http://extension.oregonstate.edu/mg/botany/cycles.html Plant life cycles]
* [http://www.usna.usda.gov/Hardzone/ushzmap.html USDA Plant Hardiness Zone Map]
* [http://www.urbanext.uiuc.edu/perennials/ Gardening with Perennials]
* [http://www.oznet.ksu.edu/library/hort2/mf2772.pdf Prairie Bloom Perennial Flowers, Kansas State University ] (PDF)


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Look at other dictionaries:

  • perennial [plant] — perennial [plant]. См. многолетник. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Perennial (disambiguation) — Perennial is a commonly used adjective with several meanings relating to yearly activity; see the formal dictionary definition . More specifically, perennial may refer to:* Perennial plant, a plant which lives for more than two growing seasons,… …   Wikipedia

  • Perennial — Per*en ni*al, n. (Bot.) A perennial plant; a plant which lives or continues more than two years, whether it retains its leaves in winter or not. [1913 Webster] …   The Collaborative International Dictionary of English

  • perennial — ► ADJECTIVE 1) lasting through a year or several years. 2) (of a plant) living for several years. Compare with ANNUAL(Cf. ↑annually), BIENNIAL(Cf. ↑biennially). 3) lasting or doing something for a long time or for ever. ► NOUN …   English terms dictionary

  • Plant disease epidemiology — is the study of disease in plant populations. Much like diseases of humans and animals, plant diseases occur due to pathogens such as bacteria, viruses, fungi, oomycetes, nematodes, phytoplasmas, protozoa, and parasitic plants.cite book| last… …   Wikipedia

  • perennial — [pə ren′ē əl] adj. [< L perennis, lasting through the year < per , through + annus, a year: see PER1 & ANNUAL] 1. lasting or active throughout the whole year 2. lasting or continuing for a long time [perennial youth] 3. returning or… …   English World dictionary

  • perennial — 1. adjective /pəˈɹɛniəl/ a) Lasting or remaining active throughout the year, or all the time. a perennial stream b) (of a plant) Having a life cycle of more than two years. Compare , . The perennial existence of bodies corporate and their… …   Wiktionary

  • perennial — I UK [pəˈrenɪəl] / US adjective 1) always existing, or never seeming to change Money is a perennial source of disagreement among couples. The Wizard of Oz is a perennial favourite with children. 2) biology a perennial plant lasts for more than… …   English dictionary

  • perennial — per|en|ni|al1 [ pə reniəl ] adjective 1. ) always existing or never seeming to change: Money is a perennial source of disagreement among couples. The Wizard of Oz is a perennial favorite with children. 2. ) a perennial plant lasts for more than… …   Usage of the words and phrases in modern English

  • perennial — perenniality, n. perennially, adv. /peuh ren ee euhl/, adj. 1. lasting for an indefinitely long time; enduring: her perennial beauty. 2. (of plants) having a life cycle lasting more than two years. 3. lasting or continuing throughout the entire… …   Universalium


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