Download
1 / 73
E N D
Plant Trivia • Stevia is a genus of about 240 species of herbs and shrubs in the sunflower family (Asteraceae), native to the neotropics. The species Stevia rebaudiana Bertoni, commonly known as sweetleaf, sweet leaf, sugarleaf, or simply stevia, is widely grown for its sweet leaves. As a sugar substitute, stevia's taste has a slower onset and longer duration than that of sugar, although some of its extracts may have a bitter or licorice-like aftertaste at high concentrations. • With its extracts having up to 300 times the sweetness of sugar, stevia has garnered attention with the rise in demand for low-carbohydrate, low-sugar, thus low calorie food alternatives.
Plant Families Poaceae Liliaceae Orchidaceae
Monocots and dicots • The flowering plants (angiosperms) have for many years been divided into two main categories of plants, the monocots and the dicots.
Monocotyledons • In general, monocots can be recognized by their parallel-veined leaves and three-part flowers. Their roots have disorganized vascular bundles, and if they are treelike (yuccas, aloes, dracaenas) their wood is unusually structured. Among the important monocots are grasses (including corn, rice, and wheat), lilies, orchids, palms, and sedges.
Dicotyledons • Dicotyledons have two seedling leaves as opposed to the single one in most monocotyledons.
Recent Developments • Several deoxyribonucleic acid (DNA) sequence studies subsequently demonstrated that there are still two groups of angiosperms, but these correspond not to the number of seed leaves but to two major pollen types.
Two Pollen Types • Pollen with a single aperture • Pollen with three (and often more) apertures
Monocotyledons • Deoxyribonucleic acid (DNA) studies of the monocot group of flowering plants (angiosperms with one seed leaf,) have revealed that, although monocots do constitute a group of closely related families, they are also closely related and now grouped into a classification called magnoliids, with which they share a pollen type with a single aperture.
Magnoliids • In addition to the monocotyledons, Magnoliids also include a group of former dicotyledons, which have pollen with a single aperture, including magnolia, avocado, black pepper, and pipeworts.
Dicotyledons • The term “dicotyledon” is no longer as meaningful because some plants of this type are more closely related to monocotyledons and are now grouped with the monocots in the classification Magnoliids.
Thus • The group of former dicotyledons which have pollen with a single aperture, are more closely related to the monocots and are now classified along with monocots as Magnoliids. • The other group of former dicotyledons, those with three (and often more) apertures in their pollen, are called eudicotyledons (true dicotyledons). The eudicots are much more distantly related to the monocots.
Magnoliids and Eudicots • Magnoliids include some plants which have two seedling leaves and all of the monocots (one seedling leaf). Pollen of Magnoliids has one single apperture. • Eudicots (aka ‘true’ dicots) have pollen with three (or more) appertures. All eudicots have two seedling leaves.
Poaceae • Poaceae or Gramineae is a family in the angiosperms (flowering plants). Plants of this family are usually called grasses. There are about 650 genera and 9700 species of grasses making it one of the largest plant families.
Poaceae • Herbs, often rhizomatous, but trees in tropical bamboos. Cosmopolitan in distribution, from deserts to freshwater and marine habitats. Grasses (and grasslands) account for about 24% of the world’s vegetation. This family is the most important of all plant families to human economies
Poaceae • The economic importance of grasses lies in their paramount role as food. According to our text, 70% of the world’s farmland is planted in crop grasses such as corn, wheat, and barley, and over 50% of human’s calorie intake comes from grasses.
Poaceae • Grasses are also used for livestock food, animal grazing, erosion control, turf production and sugar production. Bamboos are economically important in many tropical areas for their edible young shoots, fiber for paper, pulp for rayon, and strong stems for construction.
Poaceae • Poaceae ranks behind Asteraceae, Orchidaceae, and Fabaceae in number of species but ranks first in global economic importance. • Poaceae is unsurpassed among angiosperms in land surface area dominated.
Poaceae • Dorn 1984 lists approximately sixty genera of Poaceae occurring in Montana.
Famous Grasslands • The North American prairie and plains • The South American pampas • The African veldt • The Eurasian steppes
North American Prairie and Plains • The term prairie derives from the French and was the word French trappers and explorers gave to the sea of grass they encountered in the center of North America. As a vegetation type, the prairie is divided into three formations: • Tall-grass, mid-grass, and short-grass systems
North American Praire Grasslands Red – tall grass Orange – mid grass Dark Grey – short grass
Tall-grass Prairie • The easternmost section of the North American grasslands, the tall grass prairie extends into regions of humid climate, both continental and subtropical. These humid grasslands represent a fire or fire and grazing subclimax. With the extermination of the bison and the suppression of prairie fires in the late 1800s, that part of the prairie that had not been put under the plow reverted to oak-hickory forest in the US and to aspen woodland in the north, in Canada. Today prairie preserves are managed with controlled burns.
Tall-grass Prairie • The tall grass prairie gets its name from the upright bluestems (Andropogon spp.) that reach heights of 6 feet or more by late summer. Their roots may extend to depths of 9 feet or more, binding the soil and enriching it with organic matter as roots die back at the end of the growing season. The above-ground parts of the plants also die down in winter and are converted to abundant humus when bacterial action begins in the spring.
Andropogon scopariusFamily: Poaceaesyn Schizachyrium scoparium Litlle bluestem
Andropogon gerardiiFamily: Poaceae Big bluestem aka turkeyfoot
Tall-grass Prairie • Three herb layers are apparent in the tall grass prairie, each characterized by relatively high species diversity. Both sod-forming and bunch grasses are present. Perennial forbs are abundant and varied; different species bloom at different times during the growing season contributing to an ever-changing palette of colors.
Tall-grass Prairie • Bluestems comprise the uppermost herb layer. Other, shorter upright grasses and forbs form an intermediate layer. Recumbent species such as the grama grasses (Bouteloua spp.) make up the lowest, ground-hugging layer. It is this formation that is associated with the darkest of the mollisols, the chernozems. Much of it today has been converted to corn production.
Mid-grass Prairie • The mid-grass (aka mixed) prairieis centrally positioned between the tall grass and short grass prairies; the mixed prairie is intermediate. It has two layers of grasses and, one reaching about 12 inches above the ground surface, the other, more open, about 48 inches. Both bunch and sod-forming grasses are present, as well as many forbs. Roots extend to depths of about 5 feet. The soils are dark brown, but lighter than chernozem of the tall-grass prairie.
Short-grass Prairie • Short-grass prairie (aka Steppe) is the westernmost and driest part of the North American grasslands. The short grass prairie occupies regions with 10 to 12 inches of precipitation a year primarily in the rain shadow of the Rocky Mountains and includes the high plains of Montana. A single herb layer exists and consists primarily of bunch grasses some 12 to 18 inches high. They have relatively shallow root systems.
Short-grass Prairie • Soils are lighter brown than those under the mid and tall grass prairies and the calcium carbonate layer is closer to the surface. These grasslands are used today as rangeland for cattle. Due to excellent game management practices some states like Montana and Wyoming with short grass prairie still have large populations of pronghorn, elk, deer, and in some instances, bison.
Liliaceae • The Liliaceae are monocotyledons, that is, they have only one seed leaf. Being monocots, they are now classified into the Magnoliid group and have pollen with a single apperture.
Liliaceae • Members of this Family usually have: • Bulbs or other storage organs • Long, thin leaves • Six petals or tepals • Six stamens • Superior ovary
Liliaceae • Many groups of plants once in the Family Liliaceae have now been given their own Family status BUT taxonomic disagreements seem to be widespread in the literature. These include Alliaceae, Alstroemeriaceae, Amaryllidaceae, Asparagaceae, Asphodelaceae, Aspidistraceae, Calochortaceae, Colchicaceae, Convallariaceae, Fritillariaceae, Hemerocallidaceae, Hyacinthaceae, Trilliaceae, and Zephyranthaceae. Some of these families may or may not exist at the present time.
Liliaceae • Even before these changes, it was difficult to know whether a plant belonged to the Lily Family, the Iris Family, or the Amaryllis Family. Here are some points of difference which might help: • Liliaceae - 6 stamens, superior ovary (inside the flower) Iridaceae - 3 stamens, inferior ovary (behind the flower) Amaryllidaceae - 6 stamens, inferior ovary (behind the flower)
Liliaceae • Before being divided, this was one of the largest plant families, but now contains 16 genera and 635 species. Widely distributed, mainly in the temperate regions of the Northern Hemisphere. Most are spring-blooming perennial plants of prairies and mountain meadows.
Liliaceae Lily Tulips
Fritillaria pudicaFamily: Liliaceae or Fritillaceae??? Yellow fritillary of Montana
Liliaceae • Dorn 1984 lists 23 genera of the family occurring in Montana, but his groupings are in conflict with other information on families.
Lilium philadelphicum L.Family: Liliaceae Wood lily of Montana
Orchidaceae • Orchidaceae (or Orchid family) is the second largest family of the flowering plants. Its name is derived from the genus Orchis. • Our text lists 788 genera and 19,500 species, but the exact number is unknown (perhaps as many as 25,000 because of taxonomic disputes. The number of orchid species equals about four times the number of mammal species, and more than twice the number of bird species. It also encompasses about 6–11% of all seed plants.
Orchidaceae • The many different genera of orchids, and the thousands of species throughout the family hybridize quite easily with each other. Therefore, horticulturists and hobbyists have created thousands of cultivars of various names. • Two fictional books worth reading on orchid passion are: • The Orchid Thief by Susan Orlean 2000 • The Gentle Kingdom of Giacomo by Evelyn Wells 1953
Orchidaceae • Widely distributed, the family is most diverse in tropical regions where it is frequently epiphytic (lives above ground in trees).
