Farm Day 2012 Marin Master Gardener Teacher Packet Sights, Scents and Surfaces in the Garden for Plants’ Survival Teaching Objective ‐ Understanding that plants have evolved certain reproductive and structural characteristics that better ensure their survival. Master Gardener Farm Day Project Students will have the chance to feel, smell and see, through the eyes of a bee, some of the wonderful variety of adaptations that plants have developed to ensure survival. A plant’s flower color, shape, size and scent are geared to ensure pollination, so it can produce seeds. Seed production is a plant’s ultimate goal to survive. Seeds are necessary in most plants to start a new plant. Pollination is the fertilizations of the female parts (ovules) found in the interior of the flower, by the male plant parts, (pollen) found in the outer flower area. Once a flower is pollinated and fertilized, a seed is produced. Because most plants are stuck where they are to reproduce themselves, plants have developed some adaptations to help them in this process. A close look at plant’s flowers, buds, leaves, and stem will show many special characteristics that help them survive in their environment or habitat. Reproductive Adaptations  Bright colors and color patterns in plants have evolved to attract specific insects and hummingbirds that will move from one flower to another spreading the genetic material of pollen, ensuring the reproduction of the plant. When the sticky pollen is spread to the reproductive parts of the flower by the insects or hummingbird, the stationary plant is allowed to reproduce.  The honeybee is one of those insects that are attracted to yellow, purple, blue and lavender such as foxglove, salvia, and sweet William. They cannot see red. Hummingbirds are attracted to red flowers such as abutilon, coral honeysuckle and columbine. Moths that feed at night are attracted to white flowers. A very simple example of the color pattern as an attraction is the pansy. Below are two pictures of the same pansy. The left picture is how we see the flower. On the right is how a bee uses its ultraviolet vision to see the flower. The center of the flower has clear lines that run into the center. To a bee’s eyes these lines are like a runway to the nectar (food for bees). When the bee follows the color pattern of the flower to the flower’s center, it spreads pollen to the reproductive parts of the flower.
The shape of a plant can also help ensure pollination. Those plants with long, flexible stems, such as the salvias, attract more bees by swaying in the breeze making them more noticeable than short‐stemmed flowers. Salvia from: http://www.soonerplantfarm.com/index.cfm/fuseaction/specials.specDetail/recID/33
/index.htm Flowers with large, accessible blooms such as the foxglove, ensure that insects are able to have a nice big landing platform so they reach nectar easily and pick up sticky pollen in the process. Foxglove from http://picasaweb.google.com/lh/photo/t0FYTme3sDONb4Wy2
51sHg Flowers with a flat top such as the parsley, dill, fennel, and sunflower are very attractive to beneficial insects, which eat the insect pests AND pollinate at the same time. Fennel from http://www.naturalherbalextracts.com/Natural‐
Herbal‐Extracts/Sweet‐Fennel‐Extract.html Scent, fragrance or smell can also attract pollinators to ensure the plant’s reproduction and survival. Nocturnal moths and bats rely on smell to locate the flowers they visit, especially since they fly at night. As they feed on nectar, they spread pollen from one plant to another helping to pollinate or fertilize the plants. Some plants have scents that are given off only when they are ready to pollinate or release pollen. (wild anis and rosemary). Some plants give off uninviting scents or contain undesirable chemicals to keep predator insects from eating them. Structural Adaptations The primary purpose of leaf shape, location and size is to capture sunlight. Generally, leaves that are exposed to more sunlight are smaller than those in the shade. Some times there is a circle of leaves at the base of a stem designed to keep other plants from crowding it and taking away needed water, sun and soil nutrients. Dandelion showing protective circle of leaves http://www.aragriculture.org/horticulture/ornamentals/weed_id/dandelion.htm Another leaf adaption is the ability to keep or remove water from the plant. The dense, wooly leaves of Lambs‐Ear prevent water loss. Lambs Ear from: http://healthyhomegardening.com/Plant.php?compare=Lami
aceae&pid=353&ptype=plan Leaves with sharp tipped edges help water to drip off quickly. Coast Live Oak leaves from: http://www.ci.la.ca.us/boss/UrbanForestryDivision/index
_coastliveoak.htm The stem or stalk holds the leaves in the sun, provide support, and/or help avoid predators. An example is a stem of a vine that helps it find the necessary sun it needs to survive. Morning Glory Vine from: http://www.planandplant.com/ annual‐vines.html Morning Glory Vine from:
http://www.planandplant
.com/annual‐vines.html Thorns, unpleasant tastes, and poisons defend against predators. Milk Thistle from: http://en.wikipedia.org/wiki/Milk_thistle  Nuts and seeds must travel far enough from their parent plant to meet their own needs and to avoid competition. With their aren’t plant. Some seeds are covered with hard coats or spiny shells that limit the number of animals that can eat them. If they are eaten their coat keeps them from being digested so eventually the seeds will be dispersed through the animal’s feces. Some seeds have hooks or sticky coatings that catch in an animal’s hair and are opened and dispersed when the animal moves and tries to remove the seed from Sweet Gum pods from: http://bobklips.com/dirtytrees3.html
its coat. Forget‐me‐nots from http://www.freefoto.com/preview/12‐66‐1/Forget‐me‐not Some seeds such as dandelions have propellers that are dispersed by the wind. Dandelion puff from http://simple‐article10.blogspot.com/2010/10/that‐amazing‐
weedthe‐dandelion.html Some nuts like the coconuts can float many miles before landing on a shore where they can germinate. Every day we eat foods that required a plant to reproduce using their amazing adaptations. What did you eat this morning that came from a plant? Look in your garden or neighborhood and try to figure out some adaptations plants have developed to survive. Sources for materials and references: Western Pennsylvania Conservancy, www.paconserve.org Adams Cty Master Gardener, www.emmitisburg.net/gardens/articles/adams 2008 California Master Garden Handbook, UC Agriculture& Natural Resources, Pub. 3382 University of California, Davis Extension, www.ipm.ucdavis.edu This information has been prepared by Marin Master Gardeners in conjunction with Farm Day 2012