What Is Oxalis Weed?

What Is Oxalis Weed
When found occasionally in landscape beds, the yellow woodsorrel (Oxalis stricta) may be simply plucked out by hand. LayLa Burgess, Copyright 2017 HGIC, Clemson Extension Oxalis or yellow woodsorrel (Oxalis stricta) is a widespread, perennial, cool-season weed that thrives nearly year-round in lawns in the Southeastern United States.

It is reported to thrive irregularly in landscaping beds amid shrubs and flowers, in vegetable gardens, and in container plantings. Oxalis has an upright shape with somewhat hairy stems that branch around ground level from the plant’s base. Erect stems give birth to an alternating leaf arrangement. The leaves of Oxalis stricta are green, whereas those of O.

corniculata range from green to purple. Oxalis leaves are trifoliate (consisting of three leaflets) and have a heart-like shape, similar to clover leaves. Summer heat, bright light, and darkness frequently cause the leaves to fold along the midrib and hang downward.

Creeping woodsorrel (Oxalis corniculata) is a common invader of flowerpot containers, although it is simple to eradicate by hand. The bloom of Oxalis has five yellow petals and is followed by a seed capsule. LayLa Burgess, Copyright 2017 HGIC, Clemson Extension Oxalis produces yellow flowers with five petals individually or in bunches on a branching stem.

The formation of tiny fruiting capsules in the shape of okra that contain minute seeds. When mature, seeds are expelled from the capsule at great distances from the parent plant. Oxalis reproduces mostly by seeds, but can also spread underground via slender rhizomes.

Is oxalis useful in any way?

The San Francisco Forest Alliance has written a good piece on the futile and damaging endeavor to eliminate oxalis from so-called “natural areas” in San Francisco. We appreciate SFFA’s exceptional research and permission to reprint the piece. The season for oxalis is over, and the cheerful yellow blooms have disappeared for another year.

Next spring, these Bermuda buttercups will return to San Francisco’s so-called “Natural” Areas, bringing delight to those who adore them, anger to others who despise them, and Tier I herbicides aimed against them. THOSE WHO DISLIKE OXALIS AND WISH TO POISON IT WITH GARLON The springtime visibility of these blooms prompted Bay Nature magazine to publish an article about them in March 2015: A Natural History of the Currently Pervasive Little Yellow Flower It referenced Jake Sigg, the doyen of San Francisco’s native plant movement and former SF Recreation and Parks gardener.

He dislikes the exceedingly invasive oxalis pes caprae. Without assistance, he is quoted as saying, “after X years, Twin Peaks will be a solid yellow mass with no other vegetation.” An oxalis-dominated landscape, according to the paper, “drives away coyotes, hawks, and owls that feast on grassland foragers, and the situation is particularly grave for endangered Mission blue butterflies, who rely largely on local wildflowers.” As we’ll demonstrate below, the majority of these oxalis “facts” are false.

  1. Mr. Sigg’s beliefs are consistent with those of the Natural Areas Program (NAP) of the San Francisco Recreation and Parks Department (SFRPD), which utilizes the herbicide Garlon (triclopyr) to combat oxalis despite its questionable effectiveness.
  2. The Department of Environment in San Francisco classified Garlon 4 Ultra as Tier I: Most Hazardous.

It is marked as IMPORTANT TO FIND AN ALTERNATIVE (their caps). Since oxalis is the primary reason NAP utilizes Garlon, we advise that neither Garlon nor any other herbicide be used on oxalis. Based on a comprehensive analysis by the Marin Municipal Water Department, a post on SaveSutro.com highlights some of the problems with Garlon: Garlon “causes serious birth abnormalities in rats at quite modest exposure levels.” Rat pups were born without eyelids or with their brains outside their skulls.

Exposed adult female rats had a higher rate of miscarriages. Studies on rats and dogs revealed kidney, liver, and blood damage. Approximately 1% to 2% of Garlon that falls on human skin is absorbed within 24 hours. It is absorbed twelve times faster by rats. What happens to predators such as hawks who consume impacted rodents is unknown.

Dogs may be more susceptible; their kidneys may not be able to process Garlon as well as those of rats or humans. Dow Chemical complained when the Environmental Protection Agency identified decreased red-dye excretion as an undesirable consequence, so now it is simply described as a “effect.” It most likely modifies soil biology. The Natural Areas Program treats oxalis using Garlon. First, a brief discussion of the natural history of oxalis. This plant does not produce seeds in California and spreads only by putting out roots and generating subterranean bulbils (similar to miniature potatoes).

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It is typically seen in areas where the soil has been disturbed by road construction, gardening, or trail development. In certain instances, the disruption is caused by landslides or something like. It cannot tolerate frost. If nothing is done, it will likely die out rather than spread wildly. In disturbed areas, its proliferation can be rapid.

Because of this, it may be a nuisance in gardens. People do not want to abandon their gardens for years to let nature take its course with the oxalis, and not every garden design features dazzling yellow as the dominating hue for a few weeks. The only method to eradicate it in the near term is to carefully dig it out every time you see it, being sure to remove the majority of bulbils.

  • Or apply strong herbicides, which may not be effective.
  • In a natural setting, though, the situation is different, and here’s why.1) OXALIS IS GOOD FOR BEES AND BUTTERFLIES Bee on an oxalis bloom Oxalis is a very beneficial plant for bees and butterflies.
  • When in bloom, it produces “ample nectar.” In fact, it freely distributes its nectar.

It does not benefit from pollinators because it does not produce seeds, but it is a food source for honey bees, bumblebees, and butterflies. (You can read a two-page, somewhat technical explanation of the plant HERE.) Note in PDF format from Barry A. Prigge and Arthur C.

Gibson of UCLA.) Bee on an oxalis bloom In reality, a 2014 study demonstrates that plant communities with exotic plants had more plant species and pollinators, that pollinators did not prefer native plants, and that even expert pollinators relied on invasive plant species. True, the Mission Blue butterfly requires (native) lupine as a larval host plant.

(It is not dependent on any other natural wildflowers; just three types of lupine are present. Carduus pycnocephalus, a non-native and invasive Italian thistle, is one of the most important nectar sources for the Mission Blue butterfly. Insect on oxalis flower NAP has planted lupine on Twin Peaks in an effort to restore the Mission Blue butterfly there.

  1. However, lupine is also a plant of disturbed places, therefore the NAP must maintain it or it will go when the environment stabilizes.
  2. They must continue planting it, weeding it, and mowing the grass surrounding the lupine areas so that it remains appealing to butterflies.
  3. According to the SFRPD assessment on the reintroduction effort, “unmanaged habitat degrades rapidly.” Presumably, Garlon is not used near lupine areas since it would likely destroy the lupine as well.

Contrary to what is claimed in the Bay Nature article, oxalis is not the problem. The true problem is another native plant, the coyote bush, which naturally takes over grasslands.2) OXALIS IS GOOD FOR WILDLIFE The bulbils of Oxalis serve as a food source for animals.

Mice and other rodents consume them. In reality, the Bay Nature article states, “Their expansion is aided by pocket gophers and scrub jays, who have been observed transporting the bulbs and burying them, therefore seeding them in new regions.” Since gophers are a foundational species in the food chain, serving as prey for predators ranging from hawks to coyotes to great blue herons, these plants provide habitat advantages regardless of whether or not they are flowering, as the bulbils remain there throughout the year.

Wherever there are moles, predators will follow. Like the coyotes seen in these photographs, which have obviously not been driven away by an oxalis-dominated terrain. Coyote pouncing amid a field of oxalis. Copywritten by Janet Kessler Coyote on a field of oxalis.

  • Copyright Janet Kessler 3) OXALIS LEAVES THE GROUND COVERED According to the text, oxalis leaves “bare ground throughout the six months of the year when it does not blossom.” That is also not true.
  • The magnificent yellow bloom of the oxalis, which attracts honey bees and bumblebees, creates the impression that it is the only plant in the area.
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Even though it dramatically dominates the area when in bloom, it grows organically among grasses and other plants. Similar to the one above. In reality, oxalis prefers to add phosphorus to the soil, which is beneficial for grass. Therefore, when it finishes flowering – as it has already done – the earth will not be barren.

The image below depicts the same location as the first image in this post, but after the oxalis bloom has ended. It consists of grassland.4) OXALIS HAS MINIMAL IMPACT ON “NATIVE” PLANT SPECIES One reason, linked to the ‘bare ground’ argument, is that oxalis invades and kills grasslands, especially native grasses.

However, throughout the majority of California, including San Francisco, non-native grasses dominate grasslands. The transformation happened when these grasses were sown as pasture more than a century ago. Therefore, the grassland that NAP is protecting with herbicides is mostly non-native.

However, what proof exists that oxalis is genuinely harmful to native plants? It is true that several European research imply that an increase in oxalis is related with a loss in the variety of native plants, but it is unclear whether this is the reason. It may be taking advantage of human activities that alter the terrain.

Another research compared oxalis to lolium rigidum, a natural annual grass. The natural grass dominated the landscape. Their culmination: “Oxalis is not a formidable rival. This is consistent with Oxalis’s favored distribution in disturbed environments, such as ruderal habitats, and may explain its little impact on the native species cover in invaded locations.” The California Invasive Plant Council considers it to be moderately invasive in sand dunes and less so in coastal bluff regions.

Every location where oxalis thrives in San Francisco is already a disturbed habitat, a mixture of non-native grasses and plants and native species (some of which have been artificially planted). Here, oxalis appears to coexist well with other plants, such as the native California poppy seen above.5) Children enjoy it and it’s edible.

Children enjoy oxalis for both its beautiful bloom and the sour flavor of its eating stalks. Even young children enjoy collecting bouquets of Bermuda buttercups (though picking flowers is technically prohibited in Natural Areas). The blossoms are very resilient for wildflowers and keep pretty well as cut flowers in a vase of water.

The plant is edible, and its tangy leaves make a delicious salad ingredient. People like munching on the sour stems of this plant. In addition to Bermuda buttercup, it is also known as’sourgrass’ and’soursob.’ It does contain oxalic acid, similar to spinach, so you definitely wouldn’t want to eat it as a meal.

However, in South Africa it is prepared as a soup. Adding Garlon to it is most likely undesirable. Photographer: Badjonni (Creative Commons – Flickr) CONCLUSION There is no indication that oxalis has a harmful influence on animals, and there is ample proof that it is already a component of the natural food chain in our city.

  • Furthermore, the research shows that it has no harmful effect on other plants in San Francisco.
  • This bloom is appealing to a large number of individuals; one author compared it to a metropolis beaming with Bermuda buttercups.
  • In any event, even Doug Johnson of the California Invasive Plant Council does not believe it is worthwhile to attack on a landscape level; the return is not sufficient to justify the cost.

It is not as simple to eradicate it from hundreds of acres of Natural Areas as it is from a little yard where it clashes with the landscape design. It needs a great deal of labor, an abundance of potent pesticides, and a multiyear commitment — and for what? The argument for employing powerful pesticides such as Garlon to control it is weak.

2. Utilize Roundup® For Lawns – Roundup® for Lawns is precisely engineered to destroy specified weeds without harming your grass when applied as instructed; therefore, it is a foolproof method for controlling oxalis. But don’t be discouraged if a few new plants appear and you need to spray more than once; it’s very uncommon to need many treatments to manage this stubborn weed, especially if you have a substantial amount to begin with.

Does the Oxalis produce seed?

Introduction – Despite lacking muscles like mammals, plants and fungi have evolved diverse mechanisms to achieve organ deformation throughout the development and reproductive processes 1, 2, 3, 4, 5, 6, 7, 8. Mother plants or fungi can expel seeds or spores to specific locations with the aid of specialized structures, which are crucial for the survival of species (9, 10).

  1. When the falling liquid is captured within the trumpet-shaped peridium of Nidulariaceae, for instance, the splashing droplets can transport the inner spores to the outside 11.
  2. The coalescence of droplets close to the Ballistospore can bend its supporting rod, i.e.
  3. Sterigma, and release the strain energy necessary to discharge spores 12 and 13.
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Other plants or fungus, like Arceuthobium, Coprophilous fungi, and Sphagnum fimbriatum 14, 15, 16, 17, might compress water or air in their capsules for energy storage, to create fluid jets for seed or spore ejection. Moreover, water evaporation can result in the geometrical incompatibility of the bilayers of some ballistic dispersion structures, such as the fern sporangium.

  • The whole annulus is bent as a result of the evaporation-induced contraction of its outer annulus layer.
  • Then, cavitation in the layer causes the annulus to revert to its previous shape, releasing the elastic energy necessary to expel spores 18, 19.
  • Some plants, such as Erodium cicutarium, Tetraberlinia moreliana, Bauhinia, and Equisetum spores, utilize structural incompatibility to induce rapid coiling or buckling in order to expel seeds triggered by dehiscence 20, 21, 22, 23, 24, 25, 26.

In addition, certain plants or fungus can expel seeds or spores with less energy expenditure. Due to the presence of partial fissures, the form of the seedpod of Impatiens glandulifera has been finely engineered to limit energy dissipation 27. Another method for the long-distance ejection of spores is to lessen the air pulling force; for instance, Sphagnum fimbriatum has vortex rings.16,

  1. Ascomycete fungus have evolved the most efficient spore morphologies, which have the lowest drag forces for specified volumes.
  2. Roper et al.
  3. Mathematically demonstrated this by reducing the ratio of drag to mass 28.
  4. In addition, several plants, such as Acanthaceae 23 and Hura crepitans 29, are capable of launching seeds at appropriate angles to reach lengths of several meters and tens of meters, respectively.

It should be noted that neighboring catapults of the aforementioned plants or fungi have no effect on one another, meaning that the seeds or spores in one catapult are expelled only by their host catapult. Therefore, in order to completely release the seeds or spores, all related catapults must be activated.

  • In contrast to these traits, we have studied an Oxalis species that contains a unique ballistic dispersion structure to produce a domino-like seed ejection that spends very little energy by activating the initial seed.
  • Based on morphology and collecting site, we believe that this species is Oxalis corniculata, however we were unable to confirm the identification.

As a widespread plant 30, 31, 32, Oxalis sp. may likewise shoot seeds at an appropriate angle, although for a different cause than other plants and fungi. Therefore, the purpose of the present study is to get a full knowledge of the seed ejection process of the Oxalis sp., with a focus on energy transformation, optimal launching angle, and successive ejection.

How do I eliminate them? – Put on a pair of gloves and begin excavating dandelions from the ground. This works best when the ground is soft after a rainstorm. Utilize a digging instrument to remove as much of the taproot as possible, as dandelions have a deep taproot that is difficult to completely extract.

Other weeds, such as black medic, oxalis, and purslane, can be removed manually. However, like dandelions, if you do not remove the entire root, there is a chance that it may come back. Using hot water, vinegar, Epsom salts, and dish soap as a substitute for conventional pesticides may be effective against some weeds.

Almost any consumer pesticide intended for broadleaf weeds will kill dandelions without difficulty. Effective choices are Ortho Weed B Gon and Trimec Lawn Weed Killer. Always follow the instructions on the label before spraying herbicides.

Is Oxalis a therapeutic plant?

Oxalis corniculata is a significant medicinal plant that has both therapeutic and nutritional use.

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