Panicum virgatum
L.
Switch grass
(c) aarongunnar, some rights reserved (CC BY), uploaded by aarongunnar
no rights reserved
(c) emrys_fergus, some rights reserved (CC BY-NC), uploaded by emrys_fergus
What to Eat
Edible parts: Seeds, Cereal
None known.
Where to Find It
It is a temperate plant. It suits semi-arid regions.
Asia, Canada, Central America, China, Korea, Mexico, North America*, USA,
How to Identify
A grass. It grows 2.1 m tall. It forms large clumps and has rhizomes or underground runners. The leaf blades are 60 cm long by 6 mm wide. The flowering shoots are 50 cm long. They are open or spreading. The spikelets are 5 mm long.
How to Grow
It grows best in areas where annual daytime temperatures are within the range 17 - 32°c, but can tolerate 6 - 36°c. It can be killed by temperatures of -10°c or lower, though new growth can be damaged at -1°c. It prefers a mean annual rainfall in the range 500 - 1,100mm, but tolerates 350 - 2,700mm. Grows in any moderately fertile, well-drained soil in a sunny position. A drought resistant plant, it is easily grown in average to wet soils and in full sun to part shade. Prefers a pH in the range 6 - 7, tolerating 4.9 - 8.2. The plant has a high risk of becoming a weed in any new area into which it is introduced. Plants have particularly heavy growth in late spring and early summer. The plant has the potential to produce the biomass required for production of up to 380 litres of ethanol per metric ton. This gives it the potential to produce over 400 litres of ethanol per hectare, compared to 270 for sugarcane and 160 for corn. However, there is debate on the viability of switchgrass, and other bio-fuels, as an efficient energy source. University of California, Berkeley professor Tad Patzek argues that switchgrass has a negative ethanol fuel energy balance, requiring 45% more fossil energy than the fuel produced. The plant photosynthesize by a more efficient method than most plants. Called the 'C4 carbon-fixation pathway', this process is particularly efficient at high temperatures, in bright sunlight and under dry conditions. As an open pollinated species, switchgrass expresses tremendous genetic diversity, with wide variations in its basic chromosome number (2n = 18), typically ranging from tetraploid to octoploid. Morphologically switchgrass in its southern range can grow to more than 3 m in height, but what is most distinctive is the deep, vigorous root system, which may extend to depths of more than 3.5 m.. It reproduces both by seeds and vegetatively and, with its perennial life form, a stand can last indefinitely once established. Standing biomass in root systems may exceed that found aboveground, giving perennial grasses such as switchgrass, an advantage in water and nutrient acquisition even under stressful growing conditions.
Propagation: Sow seed in a nursery seedbed in a sunny position, covering only just lightly, and ensure the compost does not dry out. Germination should occur within a week. Prick out seedlings into individual pots and plant out when large enough. Division can be done as the plant comes into new growth. Larger divisions can be planted directly into permanent positions; smaller divisions are better potted up and grown on in light shade until well established before planting out.
Medicinal Uses
None known.
Other Uses
A valuable soil-stabilization plant, switchgrass is used as ground cover to control erosion. It is often considered a strong candidate for biofuel production, particularly ethanol, due to its hardiness in poor soils and adverse climates, rapid growth, and low fertilizer and herbicide requirements. It is sometimes used as a windbreak in crop fields. Switchgrass is an excellent forage for cattle, but has shown toxicity in horses, sheep, and goats.
Wikipedia
Source ↗Panicum virgatum, commonly known as switchgrass, is a perennial warm season bunchgrass native to North America, where it occurs naturally from 55°N latitude in Canada southwards into the United States and Mexico. Switchgrass is one of the dominant species of the central North American tallgrass prairie and can be found in remnant prairies, in native grass pastures, and naturalized along roadsides. It is used primarily for soil conservation, forage production, game cover, as an ornamental grass, in phytoremediation projects, fiber, electricity, heat production, for biosequestration of atmospheric carbon dioxide, and more recently as a biomass crop for the production of ethanol and butanol. Other common names for switchgrass include tall panic grass, Wobsqua grass, blackbent, tall prairiegrass, wild redtop, thatchgrass, and Virginia switchgrass.
Names & Synonyms
Common names for switchgrass include tall panic grass, Wobsqua grass, blackbent, tall prairiegrass, wild redtop, thatchgrass, and Virginia switchgrass.
