Piptochaetium avenaceum (L.) Parodi
Stipa avenacea - renamed Piptochaetium avenaceum, and commonly called black oat grass, blackseed needle grass or blackseed speargrass, is a perennial bunchgrass native to Eastern North America. It is a member of the grass family Poaceae.
Stipa avenacea is commonly found in the Eastern United States, within various types of habitats, which include:
- deciduous hardwood hammocks, thickets, and dry woods.
- upland woodlands and forests (such as dryer oak woodlands).
- savannas and clearings.
- rocky slopes and outcrops.
The species distribution is mostly found in the Southeastern and Northeastern United States. It is found in the Great Lakes region of the U.S. Midwest and Ontario (Canada), and the shortgrass prairies of the south-central U.S. as well.
The range has been documented in: Alabama; Pennsylvania; Rhode Island, New York and Florida, North and South Carolina; Georgia; Michigan; Illinois; Oklahoma, and many other states adjacent to these. 
Stipa avenacea, Black oat grass, consists of fine leaf texture that appear to be bristle-like. Its leaves are long and elongate, reaching up to 3 feet (0.91 m) in height.
The plant is easily recognizable when flowering or fruiting. It can be identified by its open inflorescences, which are thin and usually cannot be seen from a distance. The branches within these inflorescences are very thin and thus can create effects of spikelets that appear to be floating in mid air.
It also consists of awns, which are hairlike projections containing multicellular organisms that obtain nutrients through photosynthesis. The awns can twist and un-twist in circumstances depending on the humidity and temperature of the area, which is required for them in order to thrive within soil. They also protrude from individual flowers in the flowering clusters, which tend to develop between late spring and early summer (normally April - June).
Panicles also exist within this species where it rises above the plant's rolled and thread-like leaves. It contains slender open branches, a few narrow scales and spikelets that consist of one flower. The ripened flowering heads within the spikelet remain on the grass usually until autumn, in which the awns tend to bend and twist, spreading widely from the scales.
The seeds are formed as sharp needles. The palea (bract like organs found within species of grass) tends to be long and blackish, in which the upper part consists of bent and twisted awns.
Seed dispersion and burial
Many species of grasses are commonly used for studying botanical ratchets, which are referred to surfaces that are common in plant awns and grasses and are usually used for seed dispersion and burial. One specific aspect for which Stipa avenacea is used is the transport of plant awns through the net transport in deforming environments. With the use of Stipa avenacea, researchers were able to conclude several types of deformation within the use of this plant.
One kind of deformation is in the skins of animals, specifically with the dispersal of the foxtail, and shrinkage and swelling of the soil that is caused by the variation of temperature and humidity. The deformation of animal skin was believed to be caused by the wide dispersal of foxtail over large distances, posing a threat to animals if it enters the nostrils or ears of the animal, leading to infection and at times, death.
The second kind of deformation is swelling and shrinkage of soil due to the burial of the seed and awn into the soil, making it an important item for when germination begins. Along with the deformation of certain environments by net transport, lengths of certain grasses can also vary.
According to the study, Stipa avenacea, along with other Stipa species, appeared to reveal a kind of kinking and coiling of their awns, causing different variations of the length of the awns. This would eventually yield linear strains of up to 20%. Due to this, it was observed that strain variations were possibly rectified in the direction of the grass tips. From that, researchers were able to consider a combination of time periodic hydroscopic of the grass awn and the surrounding substrates by deriving certain mathematical and biological equations that determined the scaling relation of the mean propulsion velocity of the awn.
The end result they found was that the seed and displacement of each cycle shows a linear scale of grass length, revealing that the longer the length of the grass, the easier it is able to rectify larger fluctuations in proportion with the length of the grass. This would thus conclude that long grass awns would serve more efficiently as fluctuation amplifiers. It was recently[when?] claimed by the Pennsylvania Biological Survey and the Department of Conservation and Natural Resources that the Black Oat Grass is at risk to become an endangered plant species within Pennsylvania, even though it is found in several locations within the state and surrounding states.
Black oat grass or Blackseed speargrass is known to be a valuable food source. It is grown as cereal grain for commercial food purposes. A study done by the organization "Plants for a Future" concluded that people who consume any type of product made from oats (such as oatmeal) receive an average of 17% protein. It also consists of high fibers that can lower high cholesterol.
It has been used as a natural medicine, for various treatments. Seeds in oat grass consist of a compound called beta-Sitosterol, which can be used to fight against certain cancers by preventing the formation of tumors.
Stipa avenacea is cultivated as an ornamental grass by plant nurseries, for traditional and native plant gardens, and natural landscaping and habitat restoration projects. Black oat grass is drought-tolerant, and used in xeriscaping (water conserving landscape design).
The dried flower stalks can be used in floral arrangements, and created into feathery plumes in a variety of colors.
The Black oat grass or Blackseed speargrass plant, with the typically deep root system of a bunchgrass, is planted for erosion control—soil care. It can be planted along vulnerable areas (such as stream banks) where it can form a dense mat through water flow.
Stipa avenacea can be used as a cover crop, in which they are grown after a crop has been cut so that soil can be replenished, and is thus plowed back into the garden rather than being harvested. It is commonly said that oat grass is a good choice to use as a cover crop because when they die during the winter time, the residue will be much easier to handle when working with the soil, while preparing for planting season.
Black oat grass can also serve as a 'net' to cover other simultaneously planted seeds, and later seedlings, from bird deprivation.
- Ornamental grasses
- Bunchgrasses of North America
- Grasses of the United States
- List of Poaceae Genera
- USDA: Native range of Stipa avenacea . accessed 6.26.2012
|Wikimedia Commons has media related to Piptochaetium.|
- "Stipa avenacea". Global Biodiversity Information Facility. Retrieved 26 May 2011.
- "Stipa avenacea". Universal Biological Indexer and Organizer. Retrieved 26 May 2011.
- Kulic, I; M. Mani; H. Mohrbach; R. Thaokar; L. Mahadevan (2009). "Botanical ratchets" (PDF). Proceedings of the Royal Society B. 276: 2243–47. doi:10.1098/rspb.2008.1685.
- "Black Oat Grass". Plant Guide.org. Retrieved 26 May 2011.
- "PLANTS Profile—Piptochaetium avenaceum". United States Department of Agriculture. Retrieved 26 May 2011.