Urticaceae

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The Creeping Charlies and Common Name Confusion

This is a guest post by John Tuttle.

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Most of us know creeping charlie as the all-too-often irritating weed which takes over our grassy lawns. This evergreen plant’s life cycle is year round. The garden-invading variety which sprouts little bluish-purple flowers has been given the title Glechoma hederacea (or sometimes Nepeta glechoma) via binomial nomenclature and is a member of the mint family, Lamiaceae. Additional common names for this creeping charlie include ground ivy, catsfoot, and field balm.

Travelers from Europe took the plant with them, distributing it throughout other parts of the globe, and it is now deemed an aggressive, invasive weed in various areas in North America. It has crenate leaves, and its size varies depending on its living conditions. It has two methods of reproduction. The first is made possible by offshoots called stolons (or runners), stems with the special function of generating roots and transforming into more plants. Thus, you will often find not an individual creeping charlie plant, but a whole patch, all of them connected via the runners. The other self-distribution method is simple: seeds.

creeping charlie (Glechoma hederacea) via John Tuttle

The creeper is edible, and if you were in a spot where you didn’t know when your next meal would be, this type of creeping charlie would probably be a welcome source of energy. Wild food educator, Karen Stephenson, suggests its use in simple dishes such as soups and omelets, but that’s probably for those who are cooking at home and not trying to fend for their lives in some forest. Starving in the woods is a bit of an extreme, but it has happened. Glechoma hederacea has also been used for making tea. It contains minerals like copper and iron, as well as a significant amount of vitamin C.

The weed also has a number of possible health benefits such as being a diuretic, anti-inflammatory, and antiviral. However, other researchers have cautioned people to be leery of consuming it as it has been known to be fatal to equines and bovines. It contains chemicals that can discomfit the gastrointestinal tract. It is further suggested that during pregnancy women should not intake any amount of any type of creeping charlie.

Up to this point you may have found the terms I’ve used, such as “this type of creeping charlie,” to be a little odd. In fact, the term creeping charlie does not refer to only a single species of creeper. It’s actually used for several.

Another plant hailed as “creeping charlie” is Pilea nummulariifolia of the family Urticaceae, a grouping otherwise known as the nettles. Pilea is the name of the genus of creeping plants; the artillery plant is also classified under this genus. Pilea nummularifolia is also known as Swedish ivy and is often grown as a houseplant. It is native to the West Indies and parts of South America. This viney plant flourishes when supplied with an ample amount of water.

creeping charlie (Pilea nummularifolia) via eol.org

Yet another plant commonly referred to as creeping charlie is Micromeria brownei, synonymously referred to as Clinopodium brownei. It is also used in some teas, but as mentioned above, pregnant women in particular should steer away from consuming it. Apart from the term creeping charlie, a few more common names for this plant include Browne’s savory and mint charlie. Like Glechoma hederacea, Browne’s savory is considered a mint. It produces flowers that are white with hints of purple on the petals and in the throat. This species is quite common in the state of Florida and in parts of Central America; although plants in this genus grow around the world.

Like Pilea nummularifolia, this species loves a good source of water. Its thirst for moisture is so strong, that it can actually adapt itself to an aquatic lifestyle, that is, one which occurs in water and not in dry soil. Many aquarists, people who enjoy keeping aquatic life, love this plant. It can also be trimmed with practically no damage to the plant. It is extremely durable and quite capable of adapting to different circumstances. For instance, Micromeria brownei can be situated midground inside a fish tank. The creeping charlie is perfectly at home totally submerged under water. If a plant floats to the surface then it should typically produce flowers. This adds a new dimension to some of the generic aquatic flora which is often used in many tank displays.

creeping charlie (Micromeria brownei syn. Clinopodium brownei) via wikimedia commons

There you have it. Three different types of plants that have different uses and dangers, and they are all called creeping charlie. Be advised when you’re talking about true creeping charlie – Glechoma hederacea: the invasive weed with the purple flower – that you remember to specify, because “creeping charlie” could mean one plant to you and some plant from an entirely different family to another.

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John Tuttle is a Catholic guy with a passion for the media and creativity. Everything about science and health interests him. He’s a writer for publications such as ZME Science and Towards Data Science. John has started his own blog as well called Of Intellect and Interest. He’s also a published ebook author and the 1st place winner of the youth category of the 2017 Skeena Wild Film Fest. You can follow him on Facebook here, and he can be reached anytime at jptuttleb9@gmail.com.

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How a Plant Could Just Kill a Man, part two

Plants falling on people was a major theme in the Caustic Soda podcast Killer Plants episode, which is why part one of this two part series was devoted entirely to the subject. Yet, in the process of discussing death by falling branches and fruits, the hosts also mentioned at least three other highly dangerous and potentially deadly plants: ongaonga, gympie gympie, and the little apple of death. Those plants are featured here.

The nettle family, Urticaceae, includes a number of species that are best admired from a distance. Several genera (out of around 53 total) in this family are equipped with stinging hairs – sharp protrusions on leaves and stems that contain a variety of toxic compounds. Contact with these plants is ill-advised. Reactions vary from mild to extreme depending on the extent of the contact and the species in question. Two of the plant species mentioned by the hosts of Caustic Soda are members of this family – ongaonga (Urtica ferox) and gympie gympie (Dendrocnide moroides) – both of which are on the extreme side of the scale.

Urtica ferox is a New Zealand endemic that is commonly found in coastal and lowland areas as well as forest edges and shrublands. It is a shrub that reaches up to three meters tall and often occurs in dense thickets. The margins and midribs of its leaves are adorned with stiff hairs that are just a few millimeters long and poised to inject toxic compounds including histamine and acetylcholine upon contact. The “sting” is painful and can cause a variety of reactions including itching, inflammation, difficulty breathing, paralysis, blurred vision, and convulsions. Symptoms can last for several days, and neurological disorders occur in extreme cases.

Ongaonga has been blamed for killing several animals, including dogs and horses, but is charged with only one human death. In 1961, two hikers ventured into a patch of the stinging nettles. Shortly after contact they had trouble walking, breathing, and seeing. One of the men died a few hours later; the other recovered.

Ongaonga (Urtica ferox) - photo credit: www.eol.org

Ongaonga (Urtica ferox) – photo credit: www.eol.org

Several species in the nettle family can be found in Australia, one of which is particularly dangerous. Dendrocnide moroides, commonly known as stinging tree or suicide plant, is an early successional species, colonizing disturbed sites and sunlit gaps in the rainforest canopy. It grows to about three meters tall and has large heart-shaped leaves with sawtooth margins. All aboveground parts of the plant are covered in silicon hairs that are packed with a highly potent neurotoxin. The hairs detach easily from the plant and embed themselves in the skin of its victims. The “sting” is extremely painful and can last anywhere from days to months, possibly even returning from time to time years after contact. A rash, swelling, and itching sensation accompany the intense pain.

Following an encounter with the stinging tree, the “stingers” should be removed from the skin with a hair removal strip or some other sticky material, taking care not to break off the embedded tips. The affected area can be treated with diluted hydrochloric acid (1:10 by volume) to reduce the pain. Live plants are not the only ones to be wary of, as even old herbarium specimens have been said to sting those that handle them. Touching the plant isn’t even necessary, as the hairs easily dislodge from the plant in the wind and can be breathed in. One researcher reports developing a severe allergic reaction to the plant after working around it for several years and was advised by a doctor to abandon her research.

The spurge family, Euphorbiaceae, has many toxic plants among its ranks, including a species that Guiness World Records has awarded the world’s most dangerous tree. Commonly known as manchineel or beach apple, Hippomane mancinella demands respect, as a highly toxic latex sap is found throughout the entire plant. Just standing near it can result in painful blistering of the skin. Manchineel occurs along shorelines and in coastal woodlands and swamps in Central America and the West Indies, including southern Florida and the Florida Keys. It is a deciduous tree that grows to about fifteen meters tall, has thick grey bark, and glossy, elliptical leaves. Its fruits look like yellow-green crabapples and are sweet smelling and initially sweet tasting, that is until the burning and swelling starts followed by severe gastroenteritis.

Manchineel tree a.k.a. little apple of death (Hippomane mancinella) - photo credit: www.eol.org

Manchineel tree a.k.a. little apple of death (Hippomane mancinella) – photo credit: www.eol.org

Interaction with manchineel is inadvisable. The thick, milky sap seeps out of leaves, branches, bark, and fruits and causes intense blistering of the skin and temporary blindness if it gets near the eyes. During rainstorms, the sap becomes incorporated in raindrops and can drip or splash onto unwitting bystanders. Smoke from burning trees can also irritate the skin and eyes, and inhalation of the sawdust can result in bronchitis, laryngitis, and other respiratory issues. Modern history does not include reports of human fatalities resulting from eating the little apples of death, but descriptions offered by those who have consumed it confirm that it is an incredibly unpleasant experience.

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