Seed Dispersal

Jewelweed has soft semi-succulent stems and leaves, and prefers shade to bright sunlight. They hang suspended from tiny ítems and grows in huge clusters in shady forested areas, particularly where it can find moist soil. You can recognize these clusters immediately by the smooth and almost luminous appearance of the jewelweed leaves, and by the uniformity of the foliage. Jewelweed clumps manage to grow so densely that they prevents other plants from growing around. Its common name (touch-me-not) comes from the way this plant disperses its seeds. The little hanging structures on the plant are its seedpods. After the pods have grown to maturity, when touched, they burst with a little pop.
Explosive dehiscence (spontaneous opening at maturity of a plant structure) ballistically disperses seeds in a number of plant species. During dehiscence, mechanical energy stored in specialized tissues is transferred to the seeds to increase their kinetic and potential energies. In this species the valves forming the seed pod wall store mechanical energy.
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Parachute seeds
1.-Seeds with an elevated umbrella-like crown made of branched hairs at the top
2.-Similar dispersal systems as the dandelion
3.-the slightest gust of wind catches the branched hairs elevating the seed as a real parachute
4.-This seed is often produced in globose heads or puff-like clusters.
5.-belongs to the sunflower family (world's largest plant family with about 24,000 described species).
6.- Hundreds of parachute seeds (each with a tuft of silky hairs) are produced within large, inflated pods called follicles.
7.-Seeds get very far away from their parent plant in order to avoid competition. It is ñight so with a small gust of wind the seed can fly across valleys or mountain slopes.
8.-Seed dispersed by the wind agent.

Acorns, are too heavy for wind dispersal, and so require other ways to spread. Oaks therefore depend on biological seed dispersal agents to move the acorns beyond the mother tree and into a suitable area for germination (including access to adequate water, sunlight and soil nutrients) ideally a minimum of 20–30 m from the parent tree[citation needed].>Many animals eat unripe acorns on the tree or ripe acorns from the ground, with no reproductive benefit to the oak. But, some animals serve as seed dispersal agents. Jays and squirrels that scatter-hoard acorns in caches for future use, effectively plant acorns in a variety of locations in which it is possible for them to germinate and thrive. Although jays and squirrels retain remarkably large mental maps of cache locations and return to consume them, the odd acorn may be lost, or a jay or squirrel may die before consuming all of its stores. A small number of acorns manage to germinate and survive, producing the next generation of oaks.Scatter-hoarding behavior depends on jays and squirrels associating with plants that provide good packets of food that are nutritionally valuable, but not too big for the dispersal agent to handle. The beak sizes of jays determine how large acorns may get before jays ignore
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Parachute seeds
1.-Seeds with an elevated umbrella-like crown made of branched hairs at the top
2.-Similar dispersal systems as the dandelion
3.-the slightest gust of wind catches the branched hairs elevating the seed as a real parachute
4.-This seed is often produced in globose heads or puff-like clusters.
5.-belongs to the sunflower family (world's largest plant family with about 24,000 described species).
6.- Hundreds of parachute seeds (each with a tuft of silky hairs) are produced within large, inflated pods called follicles.
7.-Seeds get very far away from their parent plant in order to avoid competition. It is ñight so with a small gust of wind the seed can fly across valleys or mountain slopes.
8.-Seed dispersed by the wind agent.

passion fruit is natively grown in Paraguay, Brazil and Argentina, but it is also grown in many other countries. There are two types of this fruit:
-The bright yellow variety of passion fruit, which is also known as the Golden Passion Fruit, can grow up to the size of a grapefruit, has a smooth, glossy, light and airy rind, and has been used as a rootstock for the Purple Passion Fruit in Australia.
- The dark purple passion fruit is smaller than a lemon, though it is less acidic than the yellow passion fruit, and has a richer aroma and flavor. In Colombia, the purple passion fruit is referred to as "gulupa", to distinguish it from the yellow maracuya.
Passion fruit is dispersed by gravity. The effect of gravity on heavier fruits causes them to fall from the plant when ripe. Gravity dispersal also allows for later transmission by water or animal.
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SEED DISPERSAL OF A TOMATO (ENDOZOOCHORY)


Tomatoes (which are high in Vitamin A, Vitamin C and lycopene helps prevent many cancers) they have the same method for dispersing their seed as strawberries, raspberries, grapes, etc. They contain seeds which are surrounded by a gelatinous coat which allows the seeds to pass through an animal digestive system without hurting the seed itself. This biological process is called endozoochory, and can be done by birds, foraging animals or mammals. These seeds are excreted by the animals without being digested. Later, a natural process in the earth produce the outer coating to dissolve and leave the seed to germinate and produce a new plant. Tomatoes require a quick-draining and acidic soil, a lot of sun, plenty of warmth and they need a lot of water. They do not grow well in cold conditions or if they are exposed to frosts. When seeds have germinated, the plants do best with a lot of nutrition also, such as fertilizer extracted from a nursery or orchard or the trash of garbage. Unless these needs are met, tomatoes are unlikely to flourish.










Kelly Mullen 1B

Plants need to disperse their seeds away from themselves to stop overcrowding and to create new colonies. It’s the movement of seeds away from the parent plant to expand and spread its range as the seeds is carried to a suitable environment for development. Nearly all seeds are produced within “fruits”. These fruits enable seeds to be dispersed in a variety of ways. Some of this ways are wind, bursting, shakers, water, animal, drop and roll and others.

By wind: The kind of seeds which are often wind dispersed are smaller seeds that have wings or other hair-like or feather-like structures. Plants that produce wind blown seeds, like the dandelion shown in the video clip below, often produce lots of seeds to ensure that some of the seeds are blown to areas where the seeds can germinate.

Busting: Another less common method by which plants disperse seeds is by means of explosive fruits. Many frits burst with a sudden jerk, as a result the seeds are dispersed to a little distance e.g. balsam, castor, night jasmine etc.

By water: The plants which grow among the banks of rivers and streams or in water disperse their fruits and seeds by water currents. Such fruits and seeds being light float on the surface of water due to the presence of spongy tissue containing air. The seeds of water lilies have buoyant covering that enable them to float. The fibrous fruits of coconut are carried to long distances on rover or sea coast without causing any damage to the fruits. Fruits are provided with a coat, which is water proof, salt resistant and buoyant.

Animal dispersal: Animals disperse seeds in several ways. One is that in some plants like burr, have barbs or other structures that get tangled in animal fur or feathers, and are then carried to new sites. Other plants produce their seeds inside fleshy fruits that then get eaten by an animal. The fruit is digested by the animal, but the seeds pass through the digestive tract, and are dropped in other locations. Some animals bury seeds, like squirrels with acorns, to save for later, but may not return to get the seed. It can grow into a new plant.


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Seed Dispersal
Shakers

Some plants, like, Opium poppy, have a very special way of seed dispersal. The head of this plants (also known as poppy seed heads), after being dried by the sun, have little hloes all around their top (like pepper or salt shakers). These shake when it's windy and the tiny seeds are thrown out of the shaker the holes on the top of the plant.

Seed Dispersal by shaking can also occur with the help of an animal. For example, the African Elephant eats the Acacia plant and helps to disperse the seeds by shaking the trees. When the elephant eats the seeds, they find a fertile home in the elephant's droppings.

SEED DIPERSAL THROUGH FIRE

The way a plant stores its seeds and disperses them is an example of a fire adaptive strategy.
The intensity of the fire ( it is important the fire reaches the right temperature) is crucial to the seeds dispersal.
Also important is how often the fires occur.

A number of species of pine have cones that only open after a fire. These are called serotinus.
Jack pines have cones that are held closed by a resin sensitive to high temperatures.
These cones will not open to release their seeds until a critical temperature is reached.
Another type of pine called Lodgepole pine ( this is a western U.S. variety of tree) is both serotinus and free opening.



In some cases if fires are frequent and do not reach the correct temperature, the species will be killed and the seeds not dispersed
(the right heat is crucial to the seeds dispersal mechanism).

Some species store their seeds in the soil until a fire reaches the right heat for germination to be triggered.
Again if the fires are low intensity the parent plant may die but germination not triggered.
Fires are often deliberately lit in the bush to trigger germination from soil seed banks and to kill weeds.

Seed dispersal is the movement or transport of seeds away from the parent plant. There are some advantages of dispersing like competition; they reduce their competition by moving away from its tree. Another benefit of dispersing is that it ensures genetic variablity by separating male gametes with female gametes. There are different ways if dispersing:

-Water: Many aquatic plants and plants that live near water have seeds that can float, and are carried by water. Plants living along streams and rivers have seeds that float downstream, and therefore become germinate at new sites

-Animals: Animals disperse seeds in several ways. First, some plants, like the burr at left, have barbs or other structures that get tangled in animal fur or feathers, and are then carried to new sites. Other plants produce their seeds inside fleshy fruits that then get eaten be an animal.

-Wind: The kind of seeds which are often wind dispersed are smaller seeds that have wings or other hair-like or feather-like structures. Plants that produce wind blown seeds, often produce lots of seeds to ensure that some of the seeds are blown to areas where the seeds can germinate.

15cm pods containing seeds surrounded by a fluffly, pale yellowish fibre that resembles cotton. It has been used as a filling for pillows. So as the fibre is not so resistant or strong, this tree uses a combined method of seed dispersal. The pods split open to expose the fluffly cotton which then requires wind to dislodge them from the pods.

Sebastián Muñoz 1°F

Animals can disperse plant seeds in several ways:
-Seeds can be transported on the outside of vertebrate animals (mostly mammals), a process known as epizoochory. Plant species transported externally by animals can have a variety of adaptations for dispersal, including adhesive mucus, and a variety of hooks, spines and barbs. Luckily for the plant the animal will continue his path and will take the seeds away from the area. By shaking, bathing, or moving, the seeds will fall from the animal and grow where they fall.
-Also the seeds can be transported in the interior of the animal after he has eaten the fruit. Seed dispersal via ingestion by vertebrate animals (mostly birds and mammals), or endozoochory, is the dispersal mechanism for most tree species. The plant creates edible, nutritious fruit as a reward to frugivorous animals that consume it. Birds and mammals are the most important seed dispersers, but a wide variety of other animals, including turtles and fish, can transport viable seeds. The seeds contained in the interior of the fruit cannot be digested by the animals body, so when the animal goes to excrete far away from the parent plant, he excretes the seeds which later grow into another plant.

An example of a plant which disperses his seeds via the interior of an animal is the Blackberry.
The Blackberry creates the fruits which attract birds, the birds eat the fruit and also the seed, but they do not digest the seeds, when they excrete, they drop the seeds into the ground and another blackberry starts to develop. At leats in the south of Chile after eating the fruit, the birds go and stand on the fences of the plantation fields and excrete, and thats why there are always Blackberries besides the fences.

Eucalyptus Torelliana Seed Dispersion

Seed dispersal is essential for the continuity of all tree and plant species, as it is the way that seeds produced by these get to somewhere suitable for their growing, and find another seed to start growing into a plant or tree.

Fruits of Eucalyptus torelliana produce resin which is collected by workers of the stingless bee Trigona Carbonaria. Seeds adhere to resin in the workers' corbiculate and are transported to the nest. Workers transport seeds distances of more than 300 m from the parent tree and seeds at the nest were viable and capable of germination. Seeds are removed from the nests by workers and discarded away from the nest, and Eucalyptus torelliana trees became established in the vicinity of colonies of Trigona carbonaria bees. Bees are the only invertibrates besides ants that help in a seed dispersal mechanism.
http://gislab.fiu.edu/treesofMiami/trees/images/Eucalyptus_torellianaFr.jpg

Pablo Cotera 1B

Dandelions Seed Dispersal.
A dandelion is a flower, made up by really tiny flowers bunched together, it has a straw like stem which colour is green.
After it blooms, each of the tiny flowers produce a seed, everyone of this seeds it is attached to the stem with white fluffy threads.

Type of Dispersal
Dandelion seeds are carried away by the wind and travel like tiny parachutes.A strong wind can carry the parachutes miles away from the parent plant. The parachute process includes seed or achenes( one-seeded fruits), with puff-like clusters at the top. Then the slightest gust of wind catches the cluster, and shoots the seed up into the air like a parachute. This process it the most effective for dandelion seeds, as it has blown the seeds across mountain ranges,landed in open fields all across the western part of the USA.
Many types of seeds use wind dispersal since it the most common and useful






Martina Cuevas 1.D

Seed dispersal is the transport of the seed away from the parent.
It can be in different ways; wind, water or by animals. Every plant has its own characteristics for it to disperse its seeds.
An example of flower seed’s transported by insects or animals is the scarlet pimpernel.
This flower is very colorful (can be orange or purple). With these colors it attracts mostly Butterflies and bees. Its stamen is 65 mm outside from the level of the leaves so it can stick easily to animals, and in the middle it contains a sticky substance, that also attracts insects.

Dispersal of seeds: wind, animals, water, self dispersion.

Dandelion seeds have developed very light and fluffy parachute-like structures. These help the seeds to float in the wind and delays their fall to the ground. This delay allows the seeds to be carried further. The largest and heaviest wind-dispersed seeds, such as Sycamore cannot rely on hair-like parachutes to keep them airborne. They would have to be enormous to be effective. Instead they have developed a wing which causes them to spin through the air like mini helicopters. This again delays their fall.[url=http://www.google.cl/imgres?imgurl=http://api.ning.com/files/6*QSeE*-6uTcJO3LJmtvz6cOSX*In2N50xtvyUSbVv49l6BF*7FwRJ-dbdy10Pa8gRmVvWkBC748zlDNYIwrkxF55urI-

* It is very important that after the fertilization seeds are taken off away their parent plants, if not, it could be very dangerous because they both will have to fight for survival resourses like light, water, etc.

SEED DISPERSAL OF VIOLETS
Most violet species have ballistic seed dispersal, meaning that seeds can be dispersed up to 5 meters away from the mother plant.
Violets, like other plants have hermaphroditic flowers, at the beginning of the season the flowers must be pollinated by insects such as bees and butterflies, this is good to facilitate genetic exchange between populations, but bad because many days in the mountains there optimal conditions for flying insects. This does not scare the violets because at the end of the season produces violet flowers selfed allow reproduce clonally.

Its seeds disperse by::
Animals
Insects like bees, ants, etc

Wind
Wind is the only methos that we can always trust, because it will never dissapear or stop blowing off the seeds of their parent plants so they can develope.

It is very important that the seeds that are dispersed land in a suitable place to grow up, if not, this can be extremely dangerous for the development of the seed

Venus Fly Traps come out of dormancy and start growing sometime in mid to late February. In early spring,
they put out traps that are low to the ground. As the days get longer and warmer, they start putting out
growth that stands up a little higher off the ground. Sometime in May they usually start growing a flower stalk.
The flower stalk will mature and produce several white flowers that bloom in July. When a Venus Fly Trap is
sending up its flower stalk, it usually stalls its growth a bit.
If the flowers are pollinated, the seed pods will dry out and the seeds will start to disperse sometime in
late July or early August. The seeds will germinate immediately if they fall on moist soil.
As summer progresses into fall, the growth of the Venus fly trap again starts to hug the ground. Also, the plant
starts getting better coloration. Sometime near the middle or end of October, as the days get shorter and cooler,
the plant starts to enter dormancy. During dormancy, the plant will not grow much if at all and it actually looks
mostly dead because many of the traps and leaves turn completely black.
Dormancy lasts until mid February and then the cycle starts again.

Plants can be propagated by seed, although seedlings take several years to mature. More commonly, they are
propagated by division in spring or summer.
Raising flytraps from seed is difficult, requiring patience and a lot of care. Tissue culture, leaf cuttings
(pulling entire leaf off), and bulb division are common methods of propagating

Seed dispersal in Moth orchids:

The Moth Orchids disperse there seeds by attracting Moths into the plant ( known as a insect pollinated flower).
Many orchids use bright colours and strong scents to attract the insects. The Moth orchid has two long spurs and a long stalk.
The flower attracts the moths to the sticky spurs for getting the pollen all around the insects body.
The moth Orchids seeds have very small seeds so lots of seeds can stick into only one moth.

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To make themselves space in the world, plants disperse their seeds. There are many ways they can do this,normally it is choosen the one most efficient in the environment. Some ways it can be dispersed are:
By wind: There are some fruits that adapted themselves to catch the wind and use it for their own benefit. For example the dandelion uses the wind to throw the seeds to a place far away.
By explosive mechanism: there are fruits that can function by its own. An important example will be the lupin a fruit that suddenly burst throwing their seeds in many directiones at the same time.
By water: Some seeds are resistable to water because they want to travel throw the water until reaching a straight land.
By animals: As many others, fruits are tasty to animals. This will make a easier travel for them because their eaten and not digested. This means no harm has been made to the seed, so the seed passes through the animal and thrown into any land with an extra fertiliser surrounding it.

Dandelion
The leaves are 5–25 cm long or longer, simple and basal, entire or lobed, forming a rosette above the central taproot. The flower heads are yellow to orange colored, and are open in the daytime but closed at night. The heads are borne singly on a hollow stem that rises 1–10 cm or more above the leaves and exudes a milky sap when broken. A rosette may produce several flowering stems at a time. The flower heads are 2–5 cm in diameter and consists entirely of ray florets. Each achene is attached to a pappus of fine hairs, which enable wind-aided dispersal over long distances.
The flower head is surrounded by sepals in two series. The inner sepals are erect until the seeds mature, then flex downward to allow the seeds to disperse; the outer bracts are always reflexed downward. Some species drop the "parachute" from the achenes; the hair-like parachutes are called pappus, and they are modified sepals. Between the pappus and the achene, there is a stalk called a beak, which elongates as the fruit matures. The beak breaks off from the achene quite easily, separating the seed from the parachute.
Taraxacum are seed dispersed ruderals that rapidly colonize disturbed soil, especially the Common dandelion which has been introduced over much of the temperate world. After flowering is finished, the dandelion flower head dries out for a day or two. The dried petals and stamens drop off, the bracts reflex , and the parachute ball opens into a full sphere. Finally, the seed-bearing parachutes expand and lift out of it. The parachute drops off the achene when it strikes an obstacle. After the seed is released, the parachutes lose their feathered structure and take on a fuzzy, cotton-like appearance, often called "dandelion snow".
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Seed dispersal in fruits, most commonly by animals, but also wind or water.
Plants, being stationary, require a mobile mode for seed dispersal. Modes for seed dispersal include self-projectile mechanisms, wind, water, and animals. Dispersal by animals falls into the category of plant-animal interactions, a subject of interest because of the reciprocal adaptations that can be observed. These reciprocal adaptations lead to coevolution, or change in organisms as a result of their interactions with each other.

Animal dispersal - This is the most common dispersal in fruits. Fruits of many plants are dispersed after passing through the digestive system of animals that have eaten the fleshy fruits.

http://ebd10.ebd.csic.es/ongoing/ongfigs/pmah_fruit.jpg

There are various ways of dispersion of seeds. Some of them can be by:
a) Wind:one of the most primitive ways of dispersion. The seeds may either float with the breeze or flutter to the ground. Some examples of this type of dispersion can be the Dandelion and Maple seeds.
b) Water:seeds that get dispersed this way can usually float. They are carried by water through a very long distance depending on the way the water acts.
c) Explosive mechanism: its when seeds are ejected from the fruits because of the elastic contractions of the fruit tissues.
d) Animals: Animals can disperse seeds either by eating them and then ejecting them to the ground (that why this fruits are very fleshy) or by carrying them (seeds attach to them)

Dispersion of the LOTUS seeds

- The Lotus is a plant that is native to North America. There are lots of types like the white lotus, blue, lotus, pale-yellow lotus, pink lotus, etc..
- They float in ponds because of their leaves
- The fruit is a conical shaped pod that is filled with (about 20) seeds, each of them in their own hole
- Dispersion happens once the seeds ripen and the start to come loose, then the fruit tips down and the seeds fall into the water and get carried away

PS: couldn't upload image sorry:(

Dominique Perramont 1B