Zizania texana | |
---|---|
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Clade: | Commelinids |
Order: | Poales |
Family: | Poaceae |
Genus: | Zizania |
Species: | Z. texana |
Binomial name | |
Zizania texana | |
Zizania texana is a rare species of grass known by the common name Texas wild rice. It is endemic to Texas, where it is found only on the upper San Marcos River in Hays County. It is threatened by the loss and degradation of its habitat. It is a federally listed endangered species of the United States. [2] [3] [4] [5]
This grass, a member of the same genus as commercially sold wild rice, is an aquatic plant that grows in the water with only its stem tips rising above the surface. It grows 1 to 2 metres (3.3 to 6.6 ft) long but the stems have been known to reach 5 metres (16 ft) in length. The ribbon-like leaves are up to a meter (3.3 ft) in length. The inflorescence is a panicle up to 31 centimetres (12 in) long by 10 centimetres (3.9 in) wide. The male spikelet is somewhat oval in shape and the female is lance-shaped with a long awn which may be a few centimeters in length. [6] The male and female flowers are on different branches of the panicle. Pollen is carried to other plants by wind. [7] The plant can asexually propagate by cloning and sometimes forms mats of cloned stems. [5]
This plant is limited to the first two miles of the San Marcos River in Texas. [4] There are 140 clumps of stems in this population. [5] It covered over 10,000 square metres (110,000 sq ft) in 2008 and is reportedly growing exponentially from plantings. [1] There is also an introduced population at Spring Lake at the San Marcos Springs and a number of specimens are kept in an enclosure on the Texas State University campus. [5] The natural habitat of the grass is the clear water of the San Marcos River, which is fed by springs originating in the Edwards Aquifer. [1] The grass occurs in a relatively narrow range of water conditions, including temperature, pH, and turbidity, flow rates, and substrate types. [8]
This plant was once locally common in the area, growing thick enough to become a nuisance as recently as the 1930s. It has been reduced to its rare status because the Edwards Aquifer has been drained of its water for use in agriculture and other industries, lowering the flow on San Marcos River. [5] The rare plant continues to be threatened by reductions to the aquifer, [1] and is also threatened by recreational activities on the river and by nutria, an introduced mammal. [4] Stems are broken, bent, or submerged by floating debris, including masses of vegetation mowed upstream and sent floating. [9]
The grass is inefficient in reproduction. It rarely accomplishes successful sexual reproduction. Pollen is released for a short time each day, typically only between 2 and 4 am. It is sometimes released a second time around 9 am. Within a few minutes the pollen loses its viability and it becomes nonfunctional within one hour. [7] Because the pollen is carried on the wind, the inflorescence must rise above the surface of the water; the stem cannot be broken or submerged. Pollen generally moves less than one meter (3.3 ft) from its parent inflorescence, so plants must be close together to reproduce and cannot be isolated. Today the plant is rare and the population is fragmented, making it difficult for the pollen to reach a receptive flower. The male flowers of the grass do not pollinate the female flowers on the same inflorescence because they do not release pollen at the same time the female flowers are receptive. The grass can also reproduce vegetatively by producing tillers. Tillers can break off and root to produce new stems, but these will be genetically identical to the parent plant. [7]
Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that grows in or near water and is either emergent, submergent, or floating. In lakes and rivers macrophytes provide cover for fish, substrate for aquatic invertebrates, produce oxygen, and act as food for some fish and wildlife.
Wild rice, also called manoomin, mnomen, Psíŋ, Canada rice, Indian rice, or water oats, is any of four species of grasses that form the genus Zizania, and the grain that can be harvested from them. The grain was historically and is still gathered and eaten in North America and, to a lesser extent, China, where the plant's stem is used as a vegetable.
The San Marcos River rises from the San Marcos Springs, the location of the Meadows Center for Water and the Environment, in San Marcos, Texas. The springs are home to several threatened or endangered species, including the Texas blind salamander, fountain darter, and Texas wild rice. The river is a popular recreational area, and is frequented for tubing, canoeing, swimming, and fishing.
The Edwards Aquifer is one of the most prolific artesian aquifers in the world. Located on the eastern edge of the Edwards Plateau in the U.S. state of Texas, it is the source of drinking water for two million people, and is the primary water supply for agriculture and industry in the aquifer's region. Additionally, the Edwards Aquifer feeds the Comal and San Marcos Springs, provides springflow for recreational and downstream uses in the Nueces, San Antonio, Guadalupe, and San Marcos river basins, and is home to several unique and endangered species.
Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from either parent. Asexual reproduction produces new individuals without the fusion of gametes, resulting in clonal plants that are genetically identical to the parent plant and each other, unless mutations occur.
San Marcos Springs is the second largest natural cluster of springs in Texas. The springs are located in the city of San Marcos, Texas, about 30 miles (48 km) southwest of Austin and 46 miles (74 km) northeast of San Antonio.
This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnifying lens. This page provides help in understanding the numerous other pages describing plants by their various taxa. The accompanying page—Plant morphology—provides an overview of the science of the external form of plants. There is also an alphabetical list: Glossary of botanical terms. In contrast, this page deals with botanical terms in a systematic manner, with some illustrations, and organized by plant anatomy and function in plant physiology.
This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary of leaf morphology. For other related terms, see Glossary of phytopathology, Glossary of lichen terms, and List of Latin and Greek words commonly used in systematic names.
Allolepis is a genus of North American plants in the grass family.
Potamogeton compressus is a species of aquatic plant known by the common names grass-wrack pondweed, flatstem pondweed and eel-grass pondweed.
Thalassia testudinum, commonly known as turtlegrass, is a species of marine seagrass. It forms meadows in shallow sandy or muddy locations in the Caribbean Sea and the Gulf of Mexico. Turtle grass and other seagrasses form meadows which are important habitats and feeding grounds. The grass is eaten by turtles and herbivorous fish, supports many epiphytes, and provides habitat for juvenile fish and many invertebrate taxa.
Lemnoideae is a subfamily of flowering aquatic plants, known as duckweeds, water lentils, or water lenses. They float on or just beneath the surface of still or slow-moving bodies of fresh water and wetlands. Also known as bayroot, they arose from within the arum or aroid family (Araceae), so often are classified as the subfamily Lemnoideae within the family Araceae. Other classifications, particularly those created prior to the end of the twentieth century, place them as a separate family, Lemnaceae.
Panicum hemitomon is a species of grass known by the common name maidencane. It is native to North America, where it occurs along the southeastern coastline from New Jersey to Texas. It is also present in South America.
Panicum repens is a species of grass known by many common names, including torpedo grass, creeping panic, panic rampant, couch panicum, wainaku grass, quack grass, dog-tooth grass, and bullet grass. Its exact native range is obscure. Sources suggest that the grass is native to "Africa and/or Asia", "Europe or Australia", "Eurasia", "Australia", "Europe, Asia, and Africa", or other specific regions, including the Mediterranean, Israel, and Argentina. It is present in many places as an introduced species and often a noxious weed. It has been called "one of the world's worst weeds."
Chloris texensis is a species of grass known by the common name Texas windmill grass. It is endemic to Texas in the United States, where it occurs on the coastal prairies.
Poa fendleriana is a species of grass known by the common name muttongrass. It is native to western North America, where its distribution extends from western Canada to northern Mexico.
Zizaniopsis miliacea is a species of flowering plant in the grass family, Poaceae. It is known by the common names giant cutgrass, water millet, and southern wildrice. The name giant cutgrass refers to the plant's large, rough-edged leaves, and the name southern wildrice refers to its resemblance to wildrice. It is native to the southeastern United States and it can also be found in central Mexico.
Ustilago esculenta is a species of fungus in the Ustilaginaceae, a family of smut fungi. It is in the same genus as the fungi that cause corn smut, loose smut of barley, false loose smut, covered smut of barley, loose smut of oats, and other grass diseases. This species is pathogenic as well, attacking Manchurian wild rice, also known as Manchurian ricegrass, Asian wild rice, and wateroat. This grass is its only known host.
Zizania latifolia, known as Manchurian wild rice, is the only member of the wild rice genus Zizania native to Asia. It is used as a food plant. Both the stem and grain are edible. Gathered in the wild, Manchurian wild rice was an important grain in ancient China. A wetland plant, Manchurian wild rice is now very rare in the wild, and its use as a grain has completely disappeared in Asia, though it continues to be cultivated for its stems. A measure of its former popularity is that the surname Jiǎng, one of the most common in China, derives from this crop.
The monocots are one of the two major groups of flowering plants, the other being the dicots. In order to reproduce they utilize various strategies such as employing forms of asexual reproduction, restricting which individuals they are sexually compatible with, or influencing how they are pollinated. Nearly all reproductive strategies that evolved in the dicots have independently evolved in monocots as well. Despite these similarities and their close relatedness, monocots and dicots have distinct traits in their reproductive biologies.