Seeds produced by the central flowers in the head are cream colored, grooved and sticky with a plume of dirty white barbed hairs. Fleshy fruit attract animals and provide them with food, and they defecate the seeds at a. Lecturenotes on weed sc matched with the syllabus of 2nd sem,1st yr in tsrdam 1. The spines are hooked, enabling the bur to break off and be carried easily in animal fur for dispersal of the seeds. Have everyone in your group pick a seed to dissect and see if everyone can find all the seed parts. 2) _____is a plant’s response to water. Wind dispersal of weed seed Wind dispersal is a function of: a. Plants have evolved many different strategies to accomplish this, with weeds and crops being some of the best! Plants use the wind to disperse their seeds. Burs are a big bother for us, but from a plant's point of view, the hitchhiker method of seed dispersal is brilliant. Dispersal occurs naturally and artificially. The seed coat protects the seed from injury, insects, and water loss. Fruit/Seed Description Dispersal Method: The fruit of the Balsam Fir are upright, cylindrical cones. Examples of dehiscent fruit are follicles, pods and capsules. Birds can carry seeds in the mud that they pick up on their feet. Disturbing the plants at harvest greatly facilitates seed dispersal, but dispersal is also accomplished by water, on farm machinery, or as an impurity of commercial seeds. Mangrove trees have seeds that float, making the most of their watery environment. It is found throughout California except in the Great Basin and non-irrigated desert areas up to 1640 feet (about 500 m). of seed dispersal, including being carried by wind, water, or animals or even being eaten by animals. Dispersal of seeds Definition : Scattering of seeds away from their parent plant is known as dispersal of seeds. These seed‐retention data are used in correlated random walk simulations to estimate adhesive seed‐dispersal distances. The seeds of many Asteraceae species are distributed in a variety of ways, often aided by modifications of the floral pappus. Hitchhiking dispersal is a commensalism since the plant is helped but the mammal gets no benefit. The wings of the maple, elm, and ailanthus fruits and the parachutes of the dandelion and the thistle are blown by the wind; burdock, cocklebur, and carrot fruits have barbs or hooks that cling to fur and clothing; and the. Full text of "Agricultural plant pest control : a study manual for commercial and governmental pesticide applicators" See other formats. The seeds of countless wildflowers, trees, grasses and other plants are ripening now, if not ripe already. ) In this unit students will discuss how seeds are dispersed and describe the importance of seed dispersal. fruit, matured ovary of the pistil of a flower, containing the seed. Unlike many other members of the family Asteraceae, whose seeds are airborne with a plume of silky hairs resembling miniature parachutes, cocklebur seeds are produced in a hard, spiny, globose or oval double-chambered, single-seeded bur 0. In order for plants to start new colonies, they spread their seeds through a process called seed dispersal. From raking up the pods of sweetgums to cleaning the fluff of cottonwood seeds from window screens, seed dispersal isn't always appreciated when it impacts our lives. It probably originates in North America and has been extensively naturalized elsewhere. For the seeds to be able to disperse, the plant flowers and the seeds fall to the ground, are eaten and carried away, are blown by the wind or they are carried by a person or animal in the form of a bur. Each fruit consists of a pair of round or oblong carpels, which are attached to a slender axis, or columella. Cocklebur can also reduce yield in some crops. A persistent seed bank (Templeton and Levin 1979) plays a crucial role in maintaining False Hop Sedge populations. Animal dispersed fruits: Cocklebur Fruits are covered with stiff, hooked spines, which catch onto animal fur or onto our clothes. However, under good growing conditions, plants can regrow and produce seed so that a second mowing may be necessary. cocklebur Animal digestive system - persimmon, mistletoe, magnolia Gravity - coconut, canna, apple, salvia Animals burying - acorns, pecans, sunflowers -Touchme nots, Indian Pinks, yellow wood sorrel Human dispersal - any seeds on clothing, soil, animal feed, etc. By moving, they can grow in a place where there’s enough water, nutrients and light. ” Discuss your ideas with your research team. Birds may play a role in seed dispersal, and certainly the species is spread by haying of infested fields. It's too large to be eaten by birds or other animals and then deposited through the animal's droppings. The need for revegetation after fire can be based on the degree of desirable vegetation displaced by invasive plants prior to burning and on postfire survival of desirable vegetation. Full text of "Agricultural plant pest control : a study manual for commercial and governmental pesticide applicators" See other formats. This dispersal can be achieved by animals, wind, water, or explosive dehiscence. 79 inches (0. Many of them that bear edible fruits, in particular, have propagated with the movements of humans and animals in a symbiotic relationship as a means for seed dispersal and nutrition, respectively; in fact, humans and many animals have become dependent on fruits as a source of food. The intent of the NC Native Plant Society Invasive Exotic Plant list is to rank exotic (alien, foreign, introduced, and non-indigenous) plants based on their invasive characteristics, to educate the public and resource managers, and to encourage early detection of invasive exotic species so that a rapid response can be implemented when needed. Sign up to view the full version. The coconut palm embryo is nourished by the white coconut meat called the endosperm. Seeds can be spread by clinging to feedsacks or in contaminated hay. org Page 3 of 7 Activity Educator Materials Dispersal when seeds are released from the parent plant is called primary dispersal. Some seeds that require special environmental conditions to germinate, such as exposure to light or cold temperatures, will break dormancy if they are treated with gibberellins. Thistle is a group of flowering plants which have sharp prickles on around the flower and are in the Asteraceae family. How Do I Control It? Mechanical Control. The thick, woody stems slow combine speed and decrease harvesting efficiency. This is a good fall activity because you can access actual seeds in the woods. The wings of the maple, elm, and ailanthus fruits and the parachutes of the dandelion and the thistle are blown by the wind; burdock, cocklebur, and carrot fruits have barbs or hooks that cling to fur and clothing; and the. "Have Seeds Will Travel," page 139. Home School Series: Sensational Seed Dispersal We will hike along the wetland paths and collect a variety of seeds such as acorns, exploding jewelweed, billowing milkweed, and barbed cocklebur just to name a few. new habitats or expansion of a species’ range. Once the unit is mowed, it is typically flooded within 24 hours and the water is then held for approximately three days to kill cocklebur. Long and short seed dispersal. Fruits are the means by which flowering plants disseminate seeds. Seed plants appeared about one million years ago, during the Carboniferous period. Seeds can remain viable in the soil for more than a century. It invades agricultural lands and can be poisonous to livestock, including horses, cattle, and sheep. High on the list of plants with nasty burs is burdock. An example would be disruption of adjacent upland vegetation to a level that would adversely affect the ecological function of the wetland, such as where such. Seed dispersal. One group of leaves, the T group, came from trees that had been defoliated by gypsy moths the previous year. Yanking out every small seedling as they appear is one option. Examples: milkweed, dandelion, cottonwood. "Dispersal" means to spread or scatter. Pacific Union College. The Angsana was then widely planted during the initial phase of Singapore’s Garden City campaign, which was launched in 1967. The fruits of leguminosae is shaped in order to burst open through two “weak points” so when the fruit bursts open, the seeds will go further away from the mother plant as possible. Many of them that bear edible fruits, in particular, have propagated with the movements of humans and animals in a symbiotic relationship as a means for seed dispersal and nutrition, respectively; in fact, humans and many animals have become dependent on fruits as a source of food. Additionally, seeds can go dormant until favorable conditions come around again. Plants should be pulled before burs develop to prevent seed dispersal and establishment. The water and meat are contained in a hard bony layer called the endocarp. The seed-containing capsule of a cocklebur has tiny burs along the top. Not allowing them to flower is key to eliminating seed dispersal, which is its only means of reproduction. Seed production starts when trees are 20 years old and 15 feet tall and are produced yearly. Seed dispersal dispersal by animals multiple choice questions (MCQs), seed dispersal dispersal by animals quiz answers to learn online courses for O level biology classes. Velcro and Seed Dispersal. Some plants have developed the ability to "launch" their seeds away from the parent plant. They will be unimpressed by the rough trilling of the letter r, as in Scottish pronunciation. Other seeds are expelled or released from the fruit prior to dispersal. the world's worst agronomic weeds but cocklebur is r-selected and johnsongrass is K-selected. seed dispersal • DO NOT use fire - it creates favorable conditions. Seed dispersal. 2) _____is a plant’s response to water. Once the fruit is mature, it releases the seeds. But dispersal is perilous: an organism adrift can cross paths with harsh conditions, unexpected predators, and environs to which it is not adapted. The fruits of rough cocklebur cling to animal fur and human clothing for dispersal. 27 There was an urgent demand for rapid planting materials and the Angsana became a popular choice as it is readily propagated by seeds or cuttings and tends to do well after transplanting. We calculated seed retention on animal fur and human clothing from previously published data. Hooks and spines of clover, bur, and cocklebur attach to the fur of animals. The seeds which are shed in the field during one season, become the source of infestation during the coming years. The three main ways are: wind, water and animals. Seeds produced by the central flowers in the head are cream colored, grooved and sticky with a plume of dirty white barbed hairs. According to James L. Provided by the University of Arizona. Seed dispersal here is primarily the result of human activities. This is the Sandbur Control in Alfalfa article of the June 2004 Yuma Farm Notes, one of a series of documents on Yuma County, AZ crop management. The mature ovule's integuments thicken into seed coats around the seed. The seeds egested in the faeces, usually miles away from parent plant. The seeds are dispersed when animals feed on the fruits, either by swallowing the seed or discarding it after they have carried it somewhere else. Seed dispersal away from the maternal plant is an important strategy. 5) Dandelion is dispersewd by wind(0. Dispersal can take place through a number of ways including by the aid of animals, water, birds, wind and explosion. new habitats or expansion of a species’ range. The achenes were placed in pots of commercial potting soil, and covered by a thin layer of the soil. Seeds can remain viable in the soil for more than a century. Because this method of seed dispersal works so well, many of the plants that have this type of seeds are considered to be weeds. The seeds of a cocklebur plant can attach to the fur of animals, so it can be moved from place to place by the animal. It split open and twists, throwing out the seeds. Tumbleweed plants break off and blow along in the wind, all the while dispersing seeds as it bumps along. Seeds are dispersed by the help of water e. including: frugivory, and adhesive dispersal (Ridley, 1930). Burial in the soil also enhances seed survival by inhibiting germination and protecting seeds from predators and environmental stresses. The seed has virtually no endosperm; its reserve food is stored largely in the two cotyledons (seed leaves) of the embryo. ), mechanical injury, or removal of the seed coat. fruit / froōt / • n. Seeds and fruits are adapted to take advantage of the best methods of seed dispersal that their habitat provides. cocklebur This plant can be weedy or invasive according to the authoritative sources noted below. Consumption of seeds is fatal at about 0. The gametophytes of seed plants shrank, while the sporophytes became prominent structures and the diploid stage became the longest phase of the lifecycle. 79 inches (0. Seed dispersal starts first with the fruit and whether it stays on the mother plant and releases the seed (dehiscent fruit) or where the seed stay within the fruit (nondehiscent fruit) which then falls or is released from the plant. Ambrosia is a monoecious plant, i. Gymnosperms only had wind dispersal. This is the Sandbur Control in Alfalfa article of the June 2004 Yuma Farm Notes, one of a series of documents on Yuma County, AZ crop management. Plants such as burdock have hooks to which the seed is attached. Other varieties of seed can help attract different types of birds to round out your backyard visitors. Some fruits have coats covered with spikes or hooked burrs, either to prevent themselves from being eaten by animals or to stick to the hairs, feathers or legs of animals, using them as dispersal agents. Thus, species with seeds enclosed in capsules that fall to the ground (such as cocklebur and thornapple) are likely to have a more aggregated pattern than species with seeds that are dispersed by wind. Cocklebur seed viability decreases over time, and seeds do not survive more than a few years (Wapshere 1974b). Wind dispersal of weed seed Wind dispersal is a function of: a. Particularly for trees, seeds need to disperse away from the parent tree's canopy, where they have a chance of receiving enough light for growth after germination. Some seeds that require special environmental conditions to germinate, such as exposure to light or cold temperatures, will break dormancy if they are treated with gibberellins. MAPLE SEED DISPERSAL - THE FINAL This topic submitted by Katie, Wendi, Emily, and Leah ([email protected] Explosive seed dispersal is the kind of dispersal when the fruit bursts open by elastic contraction in tissue. The fruits float in water, and can also be effectively dispersed by water. Seed Hunt Answer Key: A seed that might stick to an animals (cocklebur. Fruit and Seed Dispersal. 5 plants per m of row. To build seed dispersal kernels, seed retention time by animals is assessed ex situ under controlled conditions (Picard et al. it has spines which help it to stick to the animal skin(0. Seed dispersal is the way seeds get away from the parent plant to a new place. Frequently associated with accessory structures (such as receptacle tissue). Common cocklebur was considered a beneficient herb in ancient times. new habitats or expansion of a species’ range. It inhabits open, often moist disturbed places in agricultural land and other areas. Started out as a drilled Pearl Millet field but wound up with 40% 8 Johnson grass, some of the Pearl I originally planted, volunteer Foxtail which got up over a couple of feet, and who knows what other local grass (lot of things I didnt recognize), plus your usual weed representation. It's not hard to see why animals need plants - most animals eat plants and cannot live without them. the seed-bearing structure of a plant, e. Fruits are the means by which angiosperms disseminate seeds. The dormancy of the upper seed of a cocklebur fruit can be broken by increasing the oxygen supply or by breaking the seed coat. Plant Adaptations For Pollination And Seed Dispersal www. tigernail seeds ,etc. Common cocklebur may also set seed without fertilization of the ovule. Seed dispersal. In some cases, a seed itself is the plant's dispersal unit, and in other cases, the entire fruit that contains one or more seeds is the dispersal unit. 468), Pandanus (Pandanaceae) and also of a few leguminous plants. In broad terms, a fruit is a structure of a plant that contains its seeds. fruit, matured ovary of the pistil of a flower, containing the seed. 2) _____is a plant’s response to water. They use barbs, burrs or hooks to do this. Why is it a problem? Competes with crop plants and indigenous species along riverbanks. Seed head in the fur of a Golden Retriever. -The seed coat usually prevents the digestion of the seeds. Cocklebur. Cocklebur (a dry fruit with surface burrs) Biotic Abiotic Tomato Dandelion Raspberry Cherry Maple fruit Plum. Some fruits have coats covered with spikes or hooked burrs, either to prevent themselves from being eaten by animals or to stick to the hairs, feathers or legs of animals, using them as dispersal agents. Ivy was observed in the canopies of overstory trees. Monocot floral parts in 4s or 5s or multiples of 4s. Xanthium strumarium (rough cocklebur, clotbur, common cocklebur, large cocklebur, woolgarie bur) is a species of annual plants of the family Asteraceae. When fertilized, the female cone enlarges and the scales separate. The seeds of alien plants are not only forced by the cold air in winter, but also might encounter stress of being soaked with icing water. Consumption of seeds is fatal at about 0. Control of these plants would greatly reduce seed production and spread. Muller-Landau, *Ran Nathan, and *Jérôme Chave Annual Review of Ecology, Evolution, and Systematics. The fruit has a single purpose: seed dispersal. In dandelions, for instance, the tuft on each "seed" is actually the top part of a fruit, while the real seed is. Seeds can be spread by clinging to feedsacks or in contaminated hay. Seed dispersal agents are of two basic types: biotic (animal, human, insect) and abiotic (wind, water). The coconut seed, which is technically a drupe, is one of the largest seeds. coconut and lotus. Each fruit consists of a pair of round or oblong carpels, which are attached to a slender axis, or columella. Choose one of the following methods for each type of seed: mechanically propelled, carried by wind, carried on an animal’s fur, or eaten by an animal. The "wings" of the maple, elm, and ailanthus fruits and the "parachutes" of the dandelion and the thistle are blown by the wind; burdock, cocklebur, and carrot fruits have barbs or hooks that cling to fur and clothing; and the buoyant. New!!: Fruit and Seed dispersal · See more » Seedless fruit. What other insects do you see on or around flowers? Edit File. Bathurst Burr because the seed is enclosed in a burr and it was introduced to Bathurst around 1850 trapped in the tails of horses imported from Chile. Fruit of cocklebur is oval-shaped achene enclosed in bur with hooked spines on the surface. Pollination and fruit production: Pollen transfer is by wind. Life Cycle, Reproduction, Seed Dispersal, Seed Dormancy, and Germination Pigweeds are frost-tender summer annuals that emerge, grow, flower, and form mature seed within the frost-free period. Fruits have hooks that catch on fur or clothes. It's too large to be eaten by birds or other animals and then deposited through the animal's droppings. The six invasive tree species have the potential to increase by seed dispersal and should be controlled by cutting or girdling. It follows that it is an evolutionary advantage to get their seeds away from the parent plant. Predators target areas which have a high concentration of seeds as they have. 3 percent for lower and upper cocklebur seed, respectively, were observed for the 15 minute exposure time as shown by tetrazolium salt procedure. tract unharmed (berries), the seeds may end up some distance away from the parent plant. Today we are going to learn about the role animals play in seed dispersal. Indians included cocklebur seed in their diet. that would make D or E the possible answer, and if you look at D, you see it says the seeds are killed. Ivy was observed in the canopies of overstory trees. The Role of Fruits in Seed Dispersal The structure of a fruit often facilitates the dispersal of its seeds. Now that you've thought of some ways a seed might get moved, the next thing to do is to think about what you know about the seeds of conifers, holly, and acorns, and from that determine which of the above seed dispersal mechanisms seems the most likely. The plant is self-compatible and predominantly self-pollinated. Best Answer: E if you think about it, the cocklebur is a burr, and burrs stick to animals and people and clothes. The large carrot family has two principal means of seed dispersal. Coconut seeds disperse by action of the ocean waves and by being deliberately planted by human beings. Edible fruits. The wings of the maple, elm, and ailanthus fruits and the parachutes of the dandelion and the thistle are blown by the wind; burdock, cocklebur, and carrot fruits have barbs or hooks that cling to fur and clothing; and the. it has hair which act like little parachutes. The largest family of flowering plants is the ubiquitous sunflower family (Asteraceae or Compositae). The fruit has a single purpose: seed dispersal. It inhabits open, often moist disturbed places in agricultural land and other areas. If the seeds take root nearby they will. Not allowing them to flower is key to eliminating seed dispersal, which is its only means of reproduction. Common cocklebur is an annual that survives fire only if the seeds survive. These seed‐retention data are used in correlated random walk simulations to estimate adhesive seed‐dispersal distances. ), mechanical injury, or removal of the seed coat. Some fruits have coats covered with spikes or hooked burrs, either to prevent themselves from being eaten by animals or to stick to the hairs, feathers or legs of. Their tiny hooks grasp the fur and feathers to be taken way from their parent plants. Kordbacheh* 1, H. The filaments on wild oat seeds respond to moisture, turning into outboard motors that drive the seeds along the ground and into the soil. ), mechanical injury, or removal of the seed coat. Examples include cocklebur and unicorn plant. Finally, the role of animal fur as a long‐distance seed‐dispersal vector is discussed. Prairie Seed Dispersal. Many of them that bear edible fruits, in particular, have propagated with the movements of humans and animals in a symbiotic relationship as a means for seed dispersal and nutrition, respectively; in fact, humans and many animals have become dependent on fruits as a source of food. Question 20 1 / 1 pts Cytokinins may help promote the growth of new plants in tissue culture. Because of its burs, it probably reached New England mainly as a waste product of the wool-carding industry in the nineteenth century. pptx), PDF File (. A fruit an be fleshy and juicy like a peach or. It follows that it is an evolutionary advantage to get their seeds away from the parent plant. The main source of weed seeds in the seedbank is from local matured weeds that set seed. Best Answer: E if you think about it, the cocklebur is a burr, and burrs stick to animals and people and clothes. Seed dispersal agents are of two basic types: biotic (animal, human, insect) and abiotic (wind, water). Hooked spines facilitate dispersal of seed. Bur or burr, a fruit with seeds of cocklebur (Xanthium sp), meant to be carried on an animal fur for dispersal purposes, autumn, Danube riverbank Leaves of toxic plant Cocklebur, Xanthium strumarium, Burrs on burdock plant. Seed samples displayed at different stations (acorns, maple seeds, burrs, nuts in shells, coconut, milkweed. On average, plants produce 150 burs, each containing two seeds. The fruit has a single purpose: seed dispersal. ), and mustard, among others, impart a distinctly distasteful odor or flavor to milk and butter. The leaf arrangement is opposite at the base, but becomes alternate higher on the stem. Electron Micrograph of Cocklebur Seeds. The hormonal balance between ABA and gibberellins (GAs) has been shown to act as an integrator of environmental cues to maintain dormancy or activate germination. Burial in the soil also enhances seed survival by inhibiting germination and protecting seeds from predators and environmental stresses. Seeds and fruits are adapted to take advantage of the best methods of seed dispersal that their habitat provides. Some seeds stick to the fur or hair of an animal. Question 20 1 / 1 pts Cytokinins may help promote the growth of new plants in tissue culture. They test different variables (lengths, width, weight, etc. Some seeds are transported by wind, and have seeds designed to float, glide or spin through the air. #12 Xanthium sp. Weeds have several seed-dispersal mechanisms assuring wide distribution. Storksbill seeds actually fold into a drill for driving the seeds into the ground. It split open and twists, throwing out the seeds. However, under good growing conditions, plants can regrow and produce seed so that a second mowing may be necessary. The large carrot family has two principal means of seed dispersal. It is necessary for young saplings to put roots down away from their parent trees, in order that they do not compete for growing space in the forest. 01 cm) long. Movement after seeds have landed on the ground, such as when the wind blows them, is called secondary dispersal. The seeds of alien plants are not only forced by the cold air in winter, but also might encounter stress of being soaked with icing water. Cocklebur reproduces only from seed. In the Engineering Inspired By Nature challenge, students investigate seeds that are dispersed by the wind. For my money, the dry fruits of #Xanthium strumarium (#cocklebur) are one of best in-class demos for adhesive or #exozoochoric #SeedDispersal. Seed Dispersal To explore ways plants spread seeds Plants use seeds to reproduce. When mature, swarms of the achenes are released by breezes, and can travel for long distances. common cocklebur rough cocklebur This plant and the related entity italicized and indented above can be weedy or invasive according to the authoritative sources noted below. Ambrosia is a monoecious plant, i. Humans are also a significant vector for dispersal when they plant the species or compost ornamental wreaths com-posed of its fruiting stems. Horseweed rosette. Indians included cocklebur seed in their diet. The common burdock is A. The most common forces that plants depend upon to disperse seeds are wind (dandelion and maple), water (coconut), forcible discharge (Touch-me-not and squirting cucumber) and animals (blueberry, mistletoe, and cocklebur). Invasive plants are usually characterized by fast growth rates, high fruit production, rapid vegetative spread and efficient seed dispersal and germination. Seed dispersal. Complete control of common cocklebur is often difficult because some of the seeds remain dormant in the soil for months or even years. Horseweed rosette. Birds and foraging animals ate the tomato fruit and dispersed seed throughout North America. -The tough seeds usually pass unharmed through the digestive tract. Definitions Fruits = ripened, mature ovary and contents (seeds). The six species of sticky seeds that I purposely placed on the sleeve of my jacket and subsequently removed were burdock, beggar ticks, cocklebur, avens, stick-tights and agrimony. Ingestion of cocklebur seedlings and seeds at 1% or more of body weight can be fatal to livestock. Phenology - Seeds germinate after late spring and summer rains, or irrigation, and young plants grow quickly. The seeds of alien plants are not only forced by the cold air in winter, but also might encounter stress of being soaked with icing water. RAJU Professor& Head Department of Agronomy. Humans also play a big role in dispersing seeds when they carry fruits to new places and throw away the inedible part that contains the seeds. The question of whether this constitutes effective seed dispersal remains to be seen. It is very important to scatter the seed because each new plant need enough food, water, sunlight and space to grow. This seems likely because the seeds are encased by a hard, woody bur and are thus somewhat insulated from the heat of fire. Hooks and spines of clover, bur, and cocklebur attach to the fur of animals. burial, soil type, and tillage. The story starts with a farmer and boy planting seeds in a garden. Hitchhiking dispersal is a commensalism since the plant is helped but the mammal gets no benefit. In spite of the seemingly endless number of times that we have to de-burr our pets or our socks, hitchhiking is not a common method of seed dispersal. It invades agricultural lands and can be poisonous to livestock, including horses, cattle, and sheep. The seeds of some plants are dispersed by animals. The feather-like structure attached to the achene is the pappus, which aids in seed dispersal. typified by seed producing annuals such as smartweeds, wild millets, panicums, and sprangletop. Consumption of seeds is fatal at about 0. Baling Johnson Grass for Hay - posted in Alfalfa/Hay: Cut the hay patch today. There are many native perennials that have maturing seeds right now, several of which have some sort of hooked hairs or prickles that are ideal for attaching to animals as they pass by. The seeds are well adapted for dispersal by livestock or people because of the hooked spines on the fruit. The cocklebur and sticktights achieve dispersal of their seeds by sticking to the coat (or clothing) of a passing animal. Many introduced plants have become naturalized in North Carolina and some are replacing our native plant species. The three main ways are: wind, water and animals. For example, pine seeds possess papery wings that catch in air currents and help to disperse the new generation. MAPLE SEED DISPERSAL - THE FINAL This topic submitted by Katie, Wendi, Emily, and Leah ([email protected] The common cocklebur (Xanthium strumarium) is a native of North America. A familiar weed of fields and roadsides, cocklebur may have originated in the Mediterranean region and has plagued farmers and shepherds since Biblical times. In general, seeds develop within the ovary of the plant’s flower after either being fertilized by pollen from another. But dispersal is perilous: an organism adrift can cross paths with harsh conditions, unexpected predators, and environs to which it is not adapted. Plant seeds can be dispersed in a number of different ways. Seeds can be spread by clinging to feedsacks or in contaminated hay. Russian thistle plant movement and seed dispersal were studied in 1991 and 1992 by placing Russian thistle plants in the center of wheat fields in eastern Washington. Common cocklebur is an annual that survives fire only if the seeds survive. Some kinds of seeds are dispersed while still inside a fruit or cone, which later opens or disintegrates to release the seeds. Dispersal is the process of organisms spreading from one place to another. Other activities to help include hangman, crossword, word scramble, games, matching, quizes, and tests. Edible fruits. Seeds are dispersed by a variety of mechanisms including forcible discharge by the plant and by gravity, wind, water, animals, and people. Secondly, plants with burs rely largely on living agents to disperse their seeds; their burs are mechanisms of seed dispersal by epizoochory (dispersal by attaching to the outside of animals). Safety assessment of construction projects may be affected by various factors such as types and scale of projects, construction. Examples include cocklebur and unicorn plant. portion of the species' seed banks will be lost. The other, in clusters in the axils of the leaves, produces seed. The pappus is threadlike, hairy, or bristly in nature. Content of buried seeds in arable soil in Denmark and its relation to the weed population. Paper plates for each seed 3. 5) Dandelion is dispersewd by wind(0. -burrs: cocklebur, sandbur seed-appendages: beggarticks seed Human dispersal-new continent, region invasions-local dispersal: machinery, crop seed contamination Crop mimicry dispersal-weed seed adaptations to look like crop seed: plant body or seed same size, shape, morphology as crop. Their seeds can also last a long time in the soil without rotting. 3) In order for a seed to come out of a dormancy state, conditions have to be ideal. Some fruits have coats covered with spikes or hooked burrs, either to prevent themselves from being eaten by animals or to stick to the hairs, feathers or legs of. typified by seed producing annuals such as smartweeds, wild millets, panicums, and sprangletop. The seeds of alien plants are not only forced by the cold air in winter, but also might encounter stress of being soaked with icing water. Mechanisms of Seed Dispersal: Pacific Union College (2007). Seed dormancy, which was described earlier, allows plants to disperse their progeny through time: something animals cannot do. Despite prolific seed production, the plant doesn't have a well-developed mechanism for long-distance seed dispersal. d) Chlorination- The process in which chlorine is added to purify the water or to kill germs. Fruits are the means by which these plants disseminate seeds. Ungerminated seeds remain viable for several years in the soil. The other leaves, the C group, came from trees that had not been defoliated. If touched, picked or otherwise disturbed, they rupture like a broken spring; projecting their seeds several feet. Examples include cocklebur and unicorn plant. Animals; Seeds are dispersed by the action of humans and animals.