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botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek w ...
, a diaspore is a plant dispersal unit consisting of a
seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
or spore plus any additional tissues that assist dispersal. In some
seed plants A spermatophyte (; ), also known as phanerogam (taxon Phanerogamae) or phaenogam (taxon Phaenogamae), is any plant that produces seeds, hence the alternative name seed plant. Spermatophytes are a subset of the embryophytes or land plants. They inc ...
, the diaspore is a seed and fruit together, or a seed and
elaiosome Elaiosomes ( grc, ἔλαιον ''élaion'' "oil" + ''sóma'' "body") are fleshy structures that are attached to the seeds of many plant species. The elaiosome is rich in lipids and proteins, and may be variously shaped. Many plants have elaio ...
. In a few seed plants, the diaspore is most or all of the plant, and is known as a
tumbleweed A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumbl ...
. Diaspores are common in
weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...
y and
ruderal species A ruderal species is a plant species that is first to colonize disturbed lands. The disturbance may be natural for example, wildfires or avalanchesor the consequences of human activities, such as construction ( of roads, of buildings, mining, et ...
. Collectively, diaspores, seeds, and spores that have been modified for migration are known as ''disseminules''.


Role in dispersal

A diaspore of seed plus elaiosome is a common adaptation to
seed dispersal In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors ...
by ants (
myrmecochory Myrmecochory ( (sometimes myrmechory); from grc, μύρμηξ, mýrmēks ("ant") and ''khoreíā'' ("circular dance") is seed dispersal by ants, an ecologically significant ant–plant interaction with worldwide distribution. Most myrmeco ...
). This is most notable in Australian and
South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
n
sclerophyll Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes (the distance between leaves along the stem) and leaf orientation which is parallel or oblique to direct ...
plant communities. Typically, ants carry the diaspore to their nest, where they may eat the elaiosome and discard the seed, and the seed may subsequently
germinate Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...
. A diaspore of seed(s) plus fruit is common in plants dispersed by frugivores. Fruit-eating bats typically carry the diaspore to a favorite perch, where they eat the fruit and discard the seed. Fruit-eating birds typically swallow small seeds but, like bats, may carry larger seeded fruits to a perch where they eat the fruit and discard the seed. Diaspores such as achenes and samarae are dispersed primarily by
wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ho ...
; samaras are dispersed also by sailing or tumbling as they fall in still air. Drift fruits and some others are dispersed by water.
Tumbleweed A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumbl ...
s are dispersed by wind, sometimes over very long distances. These occur in a variety of
weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...
y and
ruderal species A ruderal species is a plant species that is first to colonize disturbed lands. The disturbance may be natural for example, wildfires or avalanchesor the consequences of human activities, such as construction ( of roads, of buildings, mining, et ...
native to steppes and deserts.
Grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns a ...
es have various units of dispersal: rarely the
caryopsis In botany, a caryopsis (plural caryopses) is a type of simple fruit—one that is monocarpellate (formed from a single carpel) and indehiscent (not opening at maturity) and resembles an achene, except that in a caryopsis the pericarp is fuse ...
alone, often a diaspore. Disarticulation occurs below, between, or above the
glume In botany, a glume is a bract (leaf-like structure) below a spikelet in the inflorescence (flower cluster) of grasses (Poaceae) or the flowers of sedges (Cyperaceae). There are two other types of bracts in the spikelets of grasses: the lemma and ...
s and at all nodes. Although in some species the diaspore is a foxtail, in a few (the "tumble grasses") it is like a tumbleweed.


See also

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Foxtail (diaspore) A foxtail is a spikelet or cluster of a grass, that serves to disperse its seeds as a unit. Thus, the foxtail is a type of diaspore or plant dispersal unit. Some grasses that produce a foxtail are themselves called "foxtail", also " spear g ...
* Lichen *
Propagule In biology, a propagule is any material that functions in propagating an organism to the next stage in its life cycle, such as by dispersal. The propagule is usually distinct in form from the parent organism. Propagules are produced by organisms ...
*
Seedbank A seed bank (also seed banks or seeds bank) stores seeds to preserve genetic diversity; hence it is a type of gene bank. There are many reasons to store seeds. One is to preserve the genes that plant breeders need to increase yield, disease res ...
*
Soil seed bank The soil seed bank is the natural storage of seeds, often dormant, within the soil of most ecosystems. The study of soil seed banks started in 1859 when Charles Darwin observed the emergence of seedlings using soil samples from the bottom of a lak ...
*
Sporogenesis Sporogenesis is the production of spores in biology. The term is also used to refer to the process of reproduction via spores. Reproductive spores were found to be formed in eukaryotic organisms, such as plants, algae and fungi, during their norma ...
*''
Wolffia ''Wolffia'' is a genus of aquatic plants with a cosmopolitan distribution. They include the smallest flowering plants on Earth. Commonly called watermeal or duckweed, these aquatic plants resemble specks of cornmeal floating on the water. Indivi ...
''


References

{{fruits Plant morphology Plant reproductive system Ecology