Urtica ferox
| Urtica ferox | |
|---|---|
| |
| Urtica feroxleaves and spines | |
Scientific classification
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Rosales |
| Family: | Urticaceae |
| Genus: | Urtica |
| Species: | U. ferox
|
| Binomial name | |
| Urtica ferox | |
Urtica ferox,commonly known astree nettleand, inMāori,ongaonga,taraonga,taraongaonga,оrokaoka,is a species of nettleendemicto New Zealand. Unlike the other species in the genusUrticafound in New Zealand, all of which are herbaceous, ongaonga is a large woody shrub that can grow to a height of 3 m (9.8 ft), with the base of the stem reaching 12 cm (4.7 in) in thickness. It has large spines that can result in a painful sting that lasts several days.[1]
The plant is the main source of food for larvae of theNew Zealand red admiralbutterfly.[2]
Description
[edit]U. feroxcan grow to a height of 3 m (9.8 ft) with the base of the stem reaching 12 cm (4.7 in) in thickness. The pale green leaves are very thin like a membrane and the surface of the leaf, stems and stalks are covered in stiff stinging hairs that can grow up to 6 mm (0.24 in) long. These spines are prominent along the salient mid-vein and leaf margin. The leaves range from 3–5 cm (1.2–2.0 in) in width and 8–12 cm (3.1–4.7 in) in length, these are oppositely arranged and there are two stipules per node. The leaf shape is ovulate-triangulate with a serrated leaf margin each bearing a spine of up to 1 m (3 ft 3 in). The spines covering the leaf surface, stem and stalk are generally no larger than 6 mm (0.24 in) in length, the spines on the older darker bark are smaller and softer - these don't cause a sting. This nettle is winter deciduous in cold climates, evergreen in mild climates and can lose its leaves in drought conditions if it is growing in shallow soils.[1][3][4]
Flowering occurs from November to March and becauseU. feroxis adioeciousshrub it willcross pollinate,[5][6]with transferral between the flowers enabled by the wind. Pollen grains are collected by the densely packedstigmason the flowers and seed dispersal is carried out by rolling, wind, and by birds.[7]The fruit, which areachenes,mature in January, each containing one 1.5 mm long, brown coloured, ovoid-shaped seed[8]which takes one month to germinate. In his study on the germination behaviour of 5 different vascular seeding species, C. J. Burrows found thatU. feroxhad the lowest germination rate of 59% compared to >85% for the other similar species. He surmised that it is capable of building up a largeseed bankin the soil which may survive for several years, citing that European species in the genusUrticaproduce seed banks.[4]
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Needles along the leaf mid-vein -
Buds and flowers developing -
Growth habit
Toxin
[edit]The toxin present in the spines contain the neurotransmittershistamine,serotoninandacetylcholine.A 2022 study in theJournal of Biological Chemistryfound that twopeptides:Δ-Uf1a and β/δ-Uf2a, are likely responsible for the painful sensations. Δ-Uf1a is suggested to create pain by disturbing cell membranes and β/δ-Uf2a the same by modulatingvoltage-gated sodium channels.Stings have a painful reaction which causeshives,numbness, and itchiness. In severe cases it can also cause:ataxia,blurred vision, confusion,polyneuropathy,respiratory distress, andhypersalivation.The reaction can potentially be fatal.[9][10][11]
There has been one recorded human death from contact—a lightly clad hunter who died five hours after walking through a dense patch.[12]There is also one other likely death, with the mystery of the death only being solved by the pathologist years afterwards.[13]
Distribution and habitat
[edit]U. feroxis endemic toNew Zealandand inhabits coastal and lowland forests and shrublands in the North, South, and Stewart Islands.[1]It is commonly found in clearings or forest margins, often forming large patches, from 0–600 m above sea level.[12][4]It has also been recorded on theHen and Chicken Islandsalong stream-beds.[14]
Ecology
[edit]AlthoughU. feroxis a toxic shrub, it also plays a significant part in thephenologyof a native butterfly, namely thered admiral(Vanessa gonerilla). The leaves of the tree nettle is the preferred food and provide protection for the butterfly larvae. When the larvae arrives in the leaves, it will curve the tip of nettle leaf, use the silken threads to make the leaves stick together, and construct a secure place where it can eat the food.[2][15]Due to the caterpillar's activities, the leaves of shrub can fall off. The eggs of butterflies, also including theyellow admiral(Vanessa itea), are laid on the leaves of nettle during the spring and summer. It takes eight to ten days for the eggs to incubate. Beside these butterflies, some mammalian pests also eat the leaves of tree nettle, like theCommon brushtail possum,[16]goats and deer.[17]However, because no non-flying, non-marine mammals existed in New Zealand prior to human arrival in the last one thousand years, it is unadapted for them.
U. feroxrequires high nutrient levels found in cycling forest systems such as those found in native New Zealand forest. In these environments an “A type”soil horizonof richleaf litterand humus between 10 – 80 cm is common. This is significant as the species doesn't directly compete with other flora, this is achieved through inhabiting the boundary zones between strata, therefore the high soil fertility.[4]Like other species in the nettle family it grows well in soils with high nutrient levels; especially in high quantities of nitrogen.[18]Access to open sunlight and rainwater results in a rapidly growing plant able to take advantage of natural tree fall and other natural events such as land slides and flooding which clear dominating old growth species.
Cultural uses
[edit]InMāorifolklore,Kupewas said to have placed several obstacles, includingongaonga,to hinder pursuers whose wives he had stolen.
Tree nettle has been eaten, and used medicinally.[medical citation needed]Māori used the bark of tree nettle and the leaves ofkawakawa,boiled together, to make a liquid that can be used internally and externally (though pre-european maori didnt practice internal medicine as they were an animistic culture and non visually presenting illnesses were treated spiritually not medicinally) for eczema and venereal disease.[19]Also, the leaves of tree nettle play a significant part in the treating of pains. The decoction of leaves and young twigs dipped in boiled water is said to have been used for stomach ache and as treatment for gonorrhea.[20][21][unreliable medical source?]Urtica feroxwas also a food source for Māori. The inner stems were sometimes consumed after the leaves and outer bark had been removed,[22]the thin film that makes up the inner bark was also eaten raw and is said to have a sweet taste, it is also documented that stems were cooked after having the leaves removed.[23]
See also
[edit]References
[edit]- ^abcEagle, Audrey Lily (2006).Eagle's complete trees and shrubs of New Zealand.Audrey Lily Eagle, Audrey Lily Eagle. Wellington, N.Z.: Te Papa Press. p. 416.ISBN978-0-909010-08-9.OCLC85262201.
- ^abBarron, M.C.,Wratten, S.D. & Barlow, N.D.(2004) "Phenology and parasitism of the red admiral butterfly Brassaris gonerilla (Lepidoptera: Nymphalidae)."New Zealand Journal of Ecology, 28/(1), 105-111
- ^"Urtica ferox".New Zealand Plant Conservation Network.Retrieved2021-04-20.
- ^abcdBurrows, C. J. (1996-06-01)."Germination behaviour of seeds of the New Zealand woody species Melicope simplex, Myoporum laetum, Myrsine divaricata, and Urtica ferox".New Zealand Journal of Botany.34(2): 205–213.Bibcode:1996NZJB...34..205B.doi:10.1080/0028825X.1996.10410685.ISSN0028-825X.
- ^Eagle, A. (1986). "Eagle’s tree and shrubs of New Zealand: volume one revised".Auckland, New Zealand: Williams Collins (NEW ZEALAND) Ltd
- ^Wardle, J. (2011). "Wardle’s Native Trees of New Zealand and their story".Wellington, New Zealand: New Zealand Farm Forestry Association
- ^Webb, C.J., Johnson, P.R., Sykes, W.R., (1990). "Flowering Plants of New Zealand".Christchurch, New Zealand: Botany Division, D.S.I.R
- ^Salmon, J.T. (1998). "Native Trees of New Zealand 2".Auckland, New Zealand: Reed Books
- ^Xie, Jing; Robinson, Samuel D.; Gilding, Edward K.; Jami, Sina; Deuis, Jennifer R.; Rehm, Fabian B.H.; Yap, Kuok; Ragnarsson, Lotten; Chan, Lai Yue; Hamilton, Brett R.; Harvey, Peta J.; Craik, David J.; Vetter, Irina; Durek, Thomas (2022)."Neurotoxic and cytotoxic peptides underlie the painful stings of the tree nettle Urtica ferox".Journal of Biological Chemistry.298(8): 1.doi:10.1016/j.jbc.2022.102218.ISSN0021-9258.PMC9352542.PMID35780839.
- ^Hammond-Tooke, Graeme D.; Taylor, Peter; Punchihewa, Saman; Beasley, Michael (2007)."Urtica ferox neuropathy".Muscle & Nerve.35(6): 804–807.doi:10.1002/mus.20730.ISSN0148-639X.PMID17206658.S2CID28044856.
- ^Kanzaki, Mami; Tsuchihara, Toyokazu; McMorran, Denise; Taylor, Peter; Hammond-Tooke, Graeme D. (2010)."A rat model of Urtica ferox neuropathy".NeuroToxicology.31(6): 709–714.doi:10.1016/j.neuro.2010.07.004.PMID20650289.
- ^abPoisonous native plants,Te Ara: The Encyclopedia of New Zealand
- ^"Cold-case twist: How a casual chat helped solve mystery of body in the bush".NZ Herald.2024-01-20.Retrieved2024-01-20.
- ^Cranwell, L. M.;Moore, L. B.(1935)."Botanical Notes on the Hen and Chickens Islands".Records of the Auckland Institute and Museum.1:301–318.ISSN0067-0464.JSTOR42905959.OCLC947984821.WikidataQ58676572.
- ^Landcare research.(2005). "Red Admiral." Retrieved fromhttp://www.landcareresearch.co.nz/resources/identification/animals/bug-id/alphabetic-list-of-bugs/red-admiral.
- ^Cowan, P.E. (1990) "Fruits, seeds, and flowers in the diet of brushtail possums, Trichosurus vulpecula, in lowland podocarp/mixed hardwood forest, Orongorongo Valley," New Zealand.New Zealand Journal of Zoology,17,549–566
- ^Brockie, R. (1992). "A living New Zealand forest."Auckland, New Zealand: David Batemann Ltd
- ^Rollwagen, A.(2006). Species Profile: Tree Nettle. Retrieved from Canterbury Nature:http://www.canterburynature.org/species/lincoln_essays/treenettle.php
- ^"Urtica ferox. Ongaonga. Tree nettle".Landcare Research Manaaki Whenua.Landcare Research New Zealand.Retrieved17 January2016.
- ^Adames, O.(1945). "Maori medical plants."Auckland, New Zealand: Auckland Botanical Society Bulletin.
- ^Wardle, J. (2011). "Wardle’s Native Trees of New Zealand and their story."Wellington, New Zealand: New Zealand Farm Forestry Association
- ^DoC.(2006, March).Retrieved from Department of Conservation:http://www.doc.govt.nz/documents/getting-involved/students-and-teachers/field-trips-by-region/kapiti-education-kit/Species%20cards/ongaonga-tree-nettle.pdf
- ^Best, E. (1903). "Food products of Tuhoeland: being notes on the food-supplies of a non-agricultural tribe of the natives of New Zealand; together with some account of various customs, superstitions etc. pertaining to foods."Wellington, New Zealand: Transactions of the New Zealand Institute.
Further reading
[edit]- Connor, H. E. (1977) [1952].Poisonous Plants in New Zealand (DSIR Research Bulletin 99)(2nd ed.). Wellington: Government Printer.ISBN0-477-01007.
- Crowe, Andrew (1999-09-07).Which Native Forest Plant?.New Zealand: Penguin.ISBN0-14-028631-4.
- Hutching, Gerard (1998).Natural World of New Zealand.New Zealand: Viking (Penguin).ISBN0-670-87782-4.
External links
[edit]
- Urtica feroxdiscussed onRNZCritter of the Week,28 April 2023