Foxtail (diaspore)
Encyclopedia
A foxtail is a spikelet or spikelet cluster of a grass
, that serves to disperse its seeds
as a unit. Thus, the foxtail is a type of diaspore
or plant dispersal unit. Some grasses that produce a foxtail are themselves called "foxtail", also "spear grass". They can become a health hazard for dog
s and other domestic animals, and a nuisance for people.
. Not all of these are hazardous; most of the hazardous ones, in the genus Hordeum
, are also called "wild barley".
Grasses known as foxtails include:
Other grasses also produce hazardous spikelets. The spikelets are sometimes called foxtails, even though the grasses are not.
to which they attach. In other grasses, such as needlegrass
and brome
grasses, the foxtail consists of a single spikelet, with the callus being the hardened lemma tip. Retrorse barbs can be found on the callus, the lemma
s, and the awns.
s that inhabit the native ranges of foxtail grasses, the fur is ordinarily short enough that the foxtails will eventually become dislodged, dispersing the seed.
Especially in dogs and other domestic animals, the foxtails can become irreversibly lodged. Foxtails can also enter the nostril
s and ear canal
s of many mammals. In all these cases, the foxtail can physically enter the body.
Muscular movements (or air flow, in the case of nostrils) can cause the foxtails to continue to burrow through soft tissue
s and organs
, causing infection
and physical disruption, which in some cases can result in death. Take your dog to the vet if it has a wound which may indicate a foxtail has entered its body.
Foxtails can also work through clothing, particularly fabric shoes and socks, causing discomfort to people while walking.
s of disturbed habitats, and their growth is encouraged by foot traffic of humans and domestic animals. Control consists of restricting traffic to established paths, and eradication of wild barley by mechanical removal or herbicide
.
Some other foxtail-producing grasses, especially needlegrasses, are dominant species in stable grassland
habitats. Control attempts in these cases can actually be counterproductive, creating disturbed habitats where wild barleys may thrive.
s begin to disarticulate, and ending when the spikelets or spikelet clusters are mechanically abraded or incorporated into the soil
, turf
, or leaf litter. In some habitats, this can be a matter of weeks, but in others it may require months, especially if different species flower and fruit at different times during the season. Nevertheless, restricting dogs at these times from areas known to have foxtails is very effective.
rs and other detritus, but potentially the most dangerous foxtails are found in areas easily missed: the axillae, between the toes, and in nostrils and ear canals. These areas should be routinely examined in dogs. Occasionally they can even lodge in the conjunctiva
under the eyelid. In the latter three cases, dogs may exhibit symptomatic behavior, such as sneezing
or pawing. Discharge from a secondary bacterial infection may be noted as well.
s are ordinarily removed and the lesion treated with antiseptic
and bandage
d if necessary. Once a foxtail has passed beneath the skin, dogs are often treated with systemic antibiotic
s, and the foxtail either allowed to encyst and degrade, or in the case of actual or imminent organ damage, removed surgically (surgical removal can be problematic, since foxtails cannot easily be imaged by x-ray
or ultrasound
).
Foxtails imbedded in the nostrils can migrate into the nasal turbinate
s, causing intense distress, and in rare cases into the brain. Foxtails in the ear canal can puncture the eardrum and enter the middle ear
, causing hearing loss. In both cases, detection and early removal is the best treatment.
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
, that serves to disperse its seeds
Seed dispersal
Seed dispersal is the movement or transport of seeds away from the parent plant. Plants have limited mobility and consequently rely upon a variety of dispersal vectors to transport their propagules, including both abiotic and biotic vectors. Seeds can be dispersed away from the parent plant...
as a unit. Thus, the foxtail is a type of diaspore
Diaspore (botany)
In botany, a diaspore is a plant dispersal unit consisting of a seed or spore plus any additional tissues that assist dispersal. In some seed plants, the diaspore is a seed and fruit together, or a seed and elaiosome. In a few seed plants, the diaspore is most or all of the plant, known as a...
or plant dispersal unit. Some grasses that produce a foxtail are themselves called "foxtail", also "spear grass". They can become a health hazard for dog
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
s and other domestic animals, and a nuisance for people.
Source
The name "foxtail" is applied to a number of grasses that have bushy spikes of spikelets that resemble the tail of a foxFox
Fox is a common name for many species of omnivorous mammals belonging to the Canidae family. Foxes are small to medium-sized canids , characterized by possessing a long narrow snout, and a bushy tail .Members of about 37 species are referred to as foxes, of which only 12 species actually belong to...
. Not all of these are hazardous; most of the hazardous ones, in the genus Hordeum
Hordeum
Hordeum is a genus of about 30 species of annual and perennial grasses, native throughout the temperate Northern Hemisphere, temperate South America, and also South Africa....
, are also called "wild barley".
Grasses known as foxtails include:
- AlopecurusAlopecurusAlopecurus L., or Foxtail Grass, is a genus of the grass family Poaceae with 25 to 35 species.Foxtails occur in northern temperate regions. They can be annual or perennial. They grow in tufts. They have flat leaves and blunt ligules...
(foxtail grasses - the scientific name literally means "fox tail") - Bromus madritensisBromus madritensisBromus madritensis is a species of brome grass known by the common name compact brome.It is native to Europe but it has been widely introduced elsewhere, such as North America, where it is found in many areas. It is now known nearly worldwide...
(foxtail brome) - Hordeum jubatumHordeum jubatumHordeum jubatum is a perennials plant species in the grass family Poaceae. It occurs wild mainly in northern North America and adjacent northeastern Siberia. However, as it escaped often from gardens it can be found worldwide in areas with temperate to warm climates, and is considered a weed in...
(Foxtail Barley) - SetariaSetariaSetaria is a genus of grasses in the Poaceae family.-Selected species:* Setaria cernua Kunth* Setaria dielsii R.A.W.Herrm.* Setaria faberi R.A.W.Herrm.* Setaria incrassata Hack. – Vlei Bristle Grass...
(foxtail millets)
Other grasses also produce hazardous spikelets. The spikelets are sometimes called foxtails, even though the grasses are not.
Structure
All foxtails have a hardened tip, sometimes called a "callus", and retrorse barbs, pointing away from the tip of the callus. Wild barleys have clusters of three spikelets, and the callus is the portion of the rachisRachis
Rachis is a biological term for a main axis or "shaft".-In zoology:In vertebrates a rachis can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the rachis usually form the supporting axis of the body and is then called the spine or vertebral column...
to which they attach. In other grasses, such as needlegrass
Stipa
This article is about a type of grass.For Speech Transmission Index for Public Address Systems, see Speech transmission index.For the Italian aircraft designer, see Luigi Stipa...
and brome
Bromus
Bromus is a large genus of the grass family . Estimates in the scientific literature of the number of species have ranged from 100 to 400, but plant taxonomists currently recognize around 160–170 species...
grasses, the foxtail consists of a single spikelet, with the callus being the hardened lemma tip. Retrorse barbs can be found on the callus, the lemma
Lemma (botany)
Lemma is a phytomorphological term used in botany referring to a part of the spikelet of grasses . It is the lowermost of two chaff-like bracts enclosing the grass floret. It often bears a long bristle called an awn, and may be similar in form to the glumes - chaffy bracts at the base of each...
s, and the awns.
Mode of Action
The spikelets or spikelet clusters of foxtails are adapted for animal dispersal: The foxtails disarticulate easily, the barbs cause the foxtail to cling to fur, and movement of the animal causes the foxtail to burrow into the fur, since the barbs permit it to move only in the direction of the callus. In wild mammalMammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s that inhabit the native ranges of foxtail grasses, the fur is ordinarily short enough that the foxtails will eventually become dislodged, dispersing the seed.
Especially in dogs and other domestic animals, the foxtails can become irreversibly lodged. Foxtails can also enter the nostril
Nostril
A nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation...
s and ear canal
Ear canal
The ear canal , is a tube running from the outer ear to the middle ear. The human ear canal extends from the pinna to the eardrum and is about 35 mm in length and 5 to 10 mm in diameter....
s of many mammals. In all these cases, the foxtail can physically enter the body.
Muscular movements (or air flow, in the case of nostrils) can cause the foxtails to continue to burrow through soft tissue
Soft tissue
In anatomy, the term soft tissue refers to tissues that connect, support, or surround other structures and organs of the body, not being bone. Soft tissue includes tendons, ligaments, fascia, skin, fibrous tissues, fat, and synovial membranes , and muscles, nerves and blood vessels .It is sometimes...
s and organs
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...
, causing infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
and physical disruption, which in some cases can result in death. Take your dog to the vet if it has a wound which may indicate a foxtail has entered its body.
Foxtails can also work through clothing, particularly fabric shoes and socks, causing discomfort to people while walking.
Control
Many wild barley species are weedWeed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
s of disturbed habitats, and their growth is encouraged by foot traffic of humans and domestic animals. Control consists of restricting traffic to established paths, and eradication of wild barley by mechanical removal or herbicide
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...
.
Some other foxtail-producing grasses, especially needlegrasses, are dominant species in stable grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
habitats. Control attempts in these cases can actually be counterproductive, creating disturbed habitats where wild barleys may thrive.
Avoidance
Foxtails are a problem beginning when the grass inflorescenceInflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s begin to disarticulate, and ending when the spikelets or spikelet clusters are mechanically abraded or incorporated into the soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
, turf
Sod
Sod or turf is grass and the part of the soil beneath it held together by the roots, or a piece of thin material.The term sod may be used to mean turf grown and cut specifically for the establishment of lawns...
, or leaf litter. In some habitats, this can be a matter of weeks, but in others it may require months, especially if different species flower and fruit at different times during the season. Nevertheless, restricting dogs at these times from areas known to have foxtails is very effective.
Removal
Combing of fur removes foxtails along with burBUR
BUR may refer to:* Bur, a saying by Gucci Mane* Burs , a Germanic tribe* Bob Hope Airport, Burbank, California * Burmese language * Burkina Faso...
rs and other detritus, but potentially the most dangerous foxtails are found in areas easily missed: the axillae, between the toes, and in nostrils and ear canals. These areas should be routinely examined in dogs. Occasionally they can even lodge in the conjunctiva
Conjunctiva
The conjunctiva covers the sclera and lines the inside of the eyelids. It is composed of rare stratified columnar epithelium.-Function:...
under the eyelid. In the latter three cases, dogs may exhibit symptomatic behavior, such as sneezing
Sneeze
A sneeze is a semi-autonomous, convulsive expulsion of air from the lungs through the nose and mouth, usually caused by foreign particles irritating the nasal mucosa...
or pawing. Discharge from a secondary bacterial infection may be noted as well.
Treatment
Foxtails that have progressed no further than surface lesionLesion
A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :...
s are ordinarily removed and the lesion treated with antiseptic
Antiseptic
Antiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction...
and bandage
Bandage
A bandage is a piece of material used either to support a medical device such as a dressing or splint, or on its own to provide support to the body; they can also be used to restrict a part of the body. During heavy bleeding or following a poisonous bite it is important to slow the flow of blood,...
d if necessary. Once a foxtail has passed beneath the skin, dogs are often treated with systemic antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s, and the foxtail either allowed to encyst and degrade, or in the case of actual or imminent organ damage, removed surgically (surgical removal can be problematic, since foxtails cannot easily be imaged by x-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
or ultrasound
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
).
Foxtails imbedded in the nostrils can migrate into the nasal turbinate
Turbinate
In anatomy, a nasal concha is a long, narrow and curled bone shelf that protrudes into the breathing passage of the nose...
s, causing intense distress, and in rare cases into the brain. Foxtails in the ear canal can puncture the eardrum and enter the middle ear
Ear
The ear is the organ that detects sound. It not only receives sound, but also aids in balance and body position. The ear is part of the auditory system....
, causing hearing loss. In both cases, detection and early removal is the best treatment.