Glechoma hederacea

Life-forms

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Asterids
Cladus: Lamiids
Ordo: Lamiales

Familia: Lamiaceae
Subfamilia: Nepetoideae
Tribus: Mentheae
Subtribus: Nepetinae
Genus: Glechoma
Species: Glechoma hederacea
Name

Glechoma hederacea L.
Synonymy

Homotypic
Calamintha hederacea (L.) Scop.
Chamaecissos hederaceus (L.) Nieuwl. & Lunell
Chamaeclema hederacea (L.) Moench
Glechonion hederaceum (L.) St.-Lag.
Nepeta hederacea (L.) Trevis.
Heterotypic
Glechoma borealis Salisb.
Glechoma bulgarica Borbás
Glechoma heterophylla Opiz
Glechoma hederacea var. heterophylla (Opiz) Nyman
Glechoma intermedia Schrad. ex Benth.
Glechoma lobulata Kit.
Glechoma longicaulis Dulac
Glechoma magna Mérat
Glechoma hederacea var. magna (Mérat) Lej.
Glechoma micrantha Boenn. ex Rchb.
Glechoma hederacea var. micrantha (Boenn. ex Rchb.) Nyman
Glechoma rigida A.Kern.
Glechoma rotundifolia Raf.
Glechoma serbica Halácsy & Wettst.
Glechoma hederacea subsp. serbica (Halácsy & Wettst.) Soó
Glechoma hederacea var. breviflora Coss. & Germ.
Glechoma hederacea var. grandiflora Hoffmanns. & Link
Glechoma hederacea var. hirsuta Coss. & Germ.

Distribution
Native distribution areas:

Europe
Northern Europe
Denmark, Finland, Great Britain, Ireland, Norway, Sweden,
Middle Europe
Austria, Belgium, Czechoslovakia, Germany, Hungary, Netherlands, Poland, Switzerland,
Southwestern Europe
Corse, France, Portugal, Spain,
Southeastern Europe
Albania, Bulgaria, Greece, Italy, Romania, Turkey-in-Europe, Yugoslavia,
Eastern Europe
Belarus, Baltic States, Krym, Central European Russia, East European Russia, North European Russia, South European Russia, Northwest European Russia, Ukraine,
Africa
Northern Africa
Morocco (doubtful).
Asia-Temperate
Siberia
Altay, Irkutsk Krasnoyarsk, Tuva, West Siberia, Yakutiya,
Russian Far East
Kamchatka, Khabarovsk, Primorye,
Middle Asia
Kazakhstan, Kirgizstan,
Caucasus
North Caucasus, Transcaucasus,
Western Asia
Turkey,
China
Xinjiang.

References: Brummitt, R.K. 2001. TDWG – World Geographical Scheme for Recording Plant Distributions, 2nd Edition
References

Linnaeus, C. 1753. Species Plantarum. Tomus II: 578. Reference page.
USDA, ARS, Germplasm Resources Information Network. Glechoma hederacea in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 07-Oct-06.
Euro+Med PlantBase: Glechoma hederacea

Vernacular names
azərbaycanca: Sarmaşıqvarı yersarmaşığı
башҡортса: Бесәй үләне
беларуская: Блюшчык плюшчападобны
català: Heura de terra
čeština: Popenec obecný
Cymraeg: Eidral
dansk: Almindelig Korsknap
Deutsch: Gewöhnlicher Gundermann
English: Ground-ivy
español: Malvela gallega
eesti: Harilik maajalg
فارسی: پیچک باغی
suomi: Maahumala
français: Glechome faux-lierre
Frysk: Tongerblom
Gaeilge: Eidhneán talún
Gaelg: Ard-losserey
hrvatski: Dobričica
hornjoserbsce: Poponc
magyar: Kerek repkény
Ido: Hederaceo
italiano: Corona di terra
日本語: カキドオシ
қазақша: Шырмауық барқытжапырақ
lietuvių: Šliaužiančioji tramažolė
Nederlands: Hondsdraf
norsk nynorsk: Korsknapp
norsk: Korsknapp
polski: Bluszczyk kurdybanek
português: Erva-de-são-joão
русский: Будра плющевидная
slovenčina: Zádušník brečtanovitý
slovenščina: Bršljanasta grenkuljica
српски / srpski: Добричица
svenska: Jordreva
Türkçe: Yer sarmaşığı
українська: Розхідник звичайний
中文（简体）: 金钱薄荷
中文（繁體）: 金錢薄荷
中文（臺灣）: 金錢薄荷
中文: 金錢薄荷

Glechoma hederacea (syn. Nepeta glechoma Benth., Nepeta hederacea (L.) Trevir.) is an aromatic, perennial, evergreen creeper of the mint family Lamiaceae. It is commonly known as ground-ivy, gill-over-the-ground,[1] creeping charlie, alehoof, tunhoof, catsfoot, field balm, and run-away-robin.[1] It is also sometimes known as creeping jenny, but that name more commonly refers to Lysimachia nummularia. It is used as a salad green in many countries. European settlers carried it around the world, and it has become a well-established introduced and naturalized plant in a wide variety of localities. It is also considered an aggressive invasive weed of woodlands and lawns in some parts of North America. In the absence of any biological control research conducted by the USDA[2] herbicides are relied upon (despite their drawbacks) particularly for woodland ecosystems. The plant's extensive root system makes it difficult to eradicate by hand-pulling.
Description

Glechoma hederacea can be identified by its round to reniform (kidney or fan shaped), crenate (with round toothed edges) opposed leaves 2–3 cm (0.79–1.18 in) diameter, on 3–6 cm (1.2–2.4 in) long petioles attached to square stems which root at the nodes. The plant spreads either by stolon or seed, making it exceptionally difficult to eradicate. It is a variable species, its size being influenced by environmental conditions, from 5–50 cm (2.0–19.7 in) tall.[3]

Glechoma is sometimes confused with common mallow (Malva neglecta), which also has round, lobed leaves; but mallow leaves are attached to the stem at the back of a rounded leaf, where ground ivy has square stems and leaves which are attached in the center of the leaf, more prominent rounded lobes on their edges, attach to the stems in an opposite arrangement, and have a hairy upper surface. In addition, mallow and other creeping plants sometimes confused with ground ivy do not spread from nodes on stems. In addition, ground ivy emits a distinctive odor when damaged, being a member of the mint family.

The flowers of Glechoma are bilaterally symmetrical, funnel shaped, blue or bluish-violet to lavender, and grow in opposed clusters of two or three flowers in the leaf axils on the upper part of the stem or near the tip. It usually flowers in the spring.

Glechoma thrives in moist shaded areas, but also tolerates sun very well. It is a common plant in grasslands and wooded areas or wasteland. It also thrives in lawns and around buildings since it survives mowing. Part of the reason for its wide spread is its rhizomatous method of reproduction. It will form dense mats which can take over areas of lawn and woodland and thus is considered an invasive or aggressive weed in suitable climates where it is not native.[1]
Ecological aspects

A number of wild bees collect pollen from this plant, including Anthophora furcata, Anthidum manicatum, Anthophora plumipes, Anthophora quadrimaculata, Osmia aurulenta, Osmia caerulentes, and Osmia uncinata. The plant is also galled by several insects,[4] including Rondaniola bursaria (Lighthouse Gall),[5] Liposthenes glechomae[6] or Liposthenes latreillei (Kieffer, 1898) (a gall wasp).[7]
Reproduction

Glechoma hederecea is gynodiecious, with genets being either female or hermaphrodite. The females depend upon pollen from hermaphrodites for pollination.[3] Female flowers tend to be smaller than hermaphrodite flowers.[3] There is disagreement among biologists as to whether hermaphrodite flowers can pollinate themselves.[3] The plant spends the winter as either a small ramet or a small rosette. It produces flowers between April and July, which are visited by many types of insects, and can be characterized by a generalized pollination syndrome.[8] Each pollinated flower can produce up to four seeds, which are dispersed by the stem bending over and depositing the ripe seeds in the ground adjacent to the parent plant, although ants may carry the seeds further. The seeds germinate a few days after contact with moisture, although they can be stored dry.[3] Dry storage for a period up to a month is thought to improve the germination rate.[3]

The plant can also reproduce clonally, with the stems bending down to the earth and allowing roots to attach themselves.[3] Single clones can grow several metres across, although precise data is not currently available.[3]
Cultivation and medicinal and culinary uses
Illustration Glechoma hederacea0.jpg

Some people consider Glechoma to be an attractive garden plant, and it is grown in pots and occasionally as a groundcover. Easily cultivated, it grows well in shaded places. A variegated variety is commercially available; in many areas this is the dominant form which has escaped cultivation and become established as an aggressive, adventitious groundcover.

This species is considered a non-native invasive plant in the United States, and has invaded wild areas, sometimes choking out native wildflowers.[9]

Glechoma was also widely used by the Saxons in brewing ale as flavoring, clarification, and preservative, and later by the English, before the introduction of hops into brewing which changed the ale into beer, in the late 15th century. Thus the brewing-related names for the herb of, alehoof, tunhoof, and gill-over-the-ground.

Glechoma has been used in the cheese-making process as a substitute for animal rennet.[10]
Glechoma hederacea seedling: cot = cotyledons; ga = axillary bud. From (Warming 1884)
Traditional medicine

Glechoma hederacea has been used in the traditional medicine of Europe going back thousands of years: Galen recommends the plant to treat inflammation of the eyes. John Gerard, an English herbalist, recommended it to treat tinnitus, as well as a "diuretic, astringent, tonic and gentle stimulant. Useful in kidney diseases and for indigestion." It has also been used as a "lung herb." Its presence as an invasive weed in North America is the result of the value placed on it by European settlers as a medicinal herb and ale preservative; the species was imported and widely cultivated in herb and kitchen gardens.[11] Other traditional uses include as an expectorant, astringent, and to treat bronchitis.[12] In the traditional Austrian medicine the herb has been prescribed for internal application as salad or tea for the treatment of a variety of different conditions including disorders associated with the liver and bile, gastrointestinal tract, respiratory tract, kidneys and urinary tract, fever, and flu.[13]
Safety

Although it has been used by humans as a salad green and in herbal medicines for thousands of years, the species is also believed to be toxic to livestock, particularly horses. Wild pigs, however, are reported to feed on it. Some accounts report it is toxic to rodents, while bank voles in Great Britain have been observed to use it as a food source.[2] Like other members of the Lamiaceae, Glechoma hederacea contains bioactive volatile oils including terpenoids and pulegone; these are responsible for the characteristic "minty" odor and taste of plants in the mint family. Their activity in humans varies depending on many factors, including concentration, quantity of intake, and whether administration is internal or external. Lamiacaeae with very high volatile oil concentrations, such as European pennyroyal (Mentha pulegium), have traditional uses as disinfectants, flea-killers, and abortifacients, and are hepatoxic to humans, unsafe to ingest even at low doses.[14] Other Lamiacaeae such as Mentha spicata, spearmint, are widely and safely used in teas and flavorings for their volatile oils. The concentration of volatile oil in Glechoma is less than 1/30th that in European pennyroyal.[12] Like most herbal remedies which cannot be patented as pharmaceuticals, the effects of Glechoma on humans have been little studied.
Control

A non-native invasive in North America, Glechoma is familiar to a large number of people as a weed, a property it shares with many others of the mint family. It can be a problem in heavy, rich soils with good fertility, high moisture, and low boron content. It thrives particularly well in shady areas where grass does not grow well, such as woodlands, although it can also be a problem in full sun.

Because the plant is stoloniferous and will continue to spread from its roots or bits of stem which reroot, even small infestations resist repeated hand weedings. Like crabgrass, glechoma's root has a tough-to-remove ball (un-belied by its delicate wide leaves).

There are no biological control agents to help to reduce its spread in North America.[2] Commercial herbicides containing triclopyr are used to control glechoma.

Glechoma is also unusually sensitive to boron, and can be killed by applying borax (sodium tetraborate) in solution. However, borax is toxic to ants and to animals at only slightly higher concentrations, and does not break down in the environment. In addition to adverse long-term effects on soil or groundwater,[15][16] recent research discounts the very efficacy of borax treatment, primarily because finding the correct concentration for a given area is difficult and the potential for damaging desired plants is high.[17]
References

Connecticut Invasive Plant List, Connecticut Agricultural Experiment Station, January, 2004
Waggy, Melissa (2009). "Glechoma hederacea". USDA FEIS. United States government. Retrieved 19 March 2018.
Hutchings, Michael J.; Price, Elizabeth C. (1999). "Glechoma hederecea". Journal of Ecology. 87 (205): 347–364. doi:10.1046/j.1365-2745.1999.00358.x.
"A Nature Observer′s Scrapbook" galls found on herbaceous, soft stemmed plants
[1] Archived July 8, 2008, at the Wayback Machine
Leafminers of Europe - Liposthenes glechomae Archived 2007-09-08 at the Wayback Machine
[2] Archived July 20, 2008, at the Wayback Machine
Van Der Kooi, C. J.; Pen, I.; Staal, M.; Stavenga, D. G.; Elzenga, J. T. M. (2015). "Competition for pollinators and intra-communal spectral dissimilarity of flowers". Plant Biology. 18 (1): 56–62. doi:10.1111/plb.12328. PMID 25754608.
U.S. Forest Service
Cheesemakingrecipe.com: Rennet for Cheese Making
Stubbendieck, James; Coffin, Mitchell J.; Landholt, L. M. 2003. Weeds of the Great Plains. 3rd ed. Lincoln, NE: Nebraska Department of Agriculture, Bureau of Plant Industry. 605 p. In cooperation with: University of Nebraska, Lincoln.
Joanne Barnes, Linda A. Anderson, J. David Phillipson, Herbal Medicines, 2nd ed., Pharmaceutical Press, London, 2002.
Vogl, S; Picker, P; Mihaly-Bison, J; Fakhrudin, N; Atanasov, AG; Heiss, EH; Wawrosch, C; Reznicek, G; Dirsch, VM; Saukel, J; Kopp, B (2013). "Ethnopharmacological in vitro studies on Austria's folk medicine - An unexplored lore in vitro anti-inflammatory activities of 71 Austrian traditional herbal drugs". J Ethnopharmacol. 149 (3): 750–71. doi:10.1016/j.jep.2013.06.007. PMC 3791396. PMID 23770053.
"Pennyroyal Uses, Benefits & Side Effects - Drugs.com Herbal Database". Drugs.com. Retrieved 2020-04-25.
Creeping Charlie Control - Borax Archived 2006-08-22 at the Wayback Machine University of Minnesota Info-U
Borax on Ground Ivy: Boon or Bane? Horticulture and Home Pest News, Iowa State University

"Archived copy". Archived from the original on 2008-06-08. Retrieved 2008-06-01. University of Wisconsin

Further reading
An, HJ; Jeong, HJ; Um, JY; Kim, HM; Hong, SH (2006). "Glechoma hederacea inhibits inflammatory mediator release in IFN-gamma and LPS-stimulated mouse peritoneal macrophages". Journal of Ethnopharmacology. 106 (3): 418–24. doi:10.1016/j.jep.2006.01.024. PMID 16530364.