Trichomes are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant is an indumentum, and the surface bearing them is said to be pubescent.
The Urticaceae are a family, the nettle family, of flowering plants. The family name comes from the genus Urtica. The Urticaceae include a number of well-known and useful plants, including nettles in the genus Urtica, ramie, māmaki, and ajlai.
Urtica dioica, often known as common nettle, burn nettle, stinging nettle or nettle leaf, or just a nettle or stinger, is a herbaceous perennial flowering plant in the family Urticaceae. Originally native to Europe, much of temperate Asia and western North Africa, it is now found worldwide. The species is divided into six subspecies, five of which have many hollow stinging hairs called trichomes on the leaves and stems, which act like hypodermic needles, injecting histamine and other chemicals that produce a stinging sensation upon contact.
Urtica is a genus of flowering plants in the family Urticaceae. Many species have stinging hairs and may be called nettles or stinging nettles. The generic name Urtica derives from the Latin for 'sting'.
Urticating hairs or urticating bristles are one of the primary defense mechanisms used by numerous plants, almost all New World tarantulas, and various lepidopteran caterpillars. Urtica is Latin for "nettle", and bristles that urticate are characteristic of this type of plant, and many other plants in several families. This term also refers to certain types of barbed bristles that cover the dorsal and posterior surface of a tarantula's or caterpillar's abdomen. Many tarantula species eject bristles from their abdomens, directing them toward potential attackers. These bristles can embed themselves in the other animal's skin or eyes, causing physical irritation, usually to great discomfort. The term "hairs" is technically a misnomer, as only mammals possess true hairs. The scientific term for plant hairs is trichomes.
Dendrocnide moroides, commonly known in Australia as the stinging tree, stinging bush, or gympie-gympie, is a plant in the nettle family Urticaceae found in rainforest areas of Malesia and Australia. It is notorious for its extremely painful and long-lasting sting. The common name gympie-gympie comes from the language of the indigenous Gubbi Gubbi people of south-eastern Queensland.
Pilea pumila, commonly known as clearweed, Canadian clearweed, coolwort or richweed, is an herbaceous plant in the nettle family (Urticaceae). It is native to Asia and eastern North America, where it is broadly distributed.
Urtica urens, commonly known as annual nettle, dwarf nettle, small nettle, dog nettle, or burning nettle, is a herbaceous annual flowering plant species in the nettle family Urticaceae. It is native to Eurasia, including the Himalayan regions of Kalimpong, Darjeeling and Sikkim in India and can be found in North America, New Zealand and South Africa as an introduced species. It is reputed to sting more strongly than common nettle.
Urera is a genus of flowering plants in the nettle family, Urticaceae. It has a pantropical distribution.
Urtica thunbergiana, also known as the Japanese nettle or hairy nettle, is a species of perennial herbs in the family Urticaceae. It is found in Japan, China and Taiwan. The habitat of the species is moist forests in the mountains. It is in flower from July to September, and its seeds ripen from August to October. The larvae of Vanessa indica, a species of butterfly, are known to feed on U. thunbergiana.
Dendrocnide excelsa, commonly known as the giant stinging tree or fibrewood, is a rainforest tree in the nettle family (Urticaceae) which is endemic to eastern Australia. It occurs from Tathra, New South Wales to Imbil in southeastern Queensland, and is very common at Dorrigo National Park and other rainforest walks in eastern Australia. The habitat of the giant stinging tree is subtropical, warm temperate or littoral rainforest, particularly in disturbed areas, previously flattened by storms or cyclones. It is well known for its extremely painful, long-lasting sting.
Urtica dioica subsp. galeopsifolia, the fen nettle or stingless nettle, is a herbaceous perennial plant found in Europe. It is considered to be either a subspecies of stinging nettle, or a species in its own right: Urtica galeopsifolia.
Dendrocnide sinuata is a poisonous plant called pulutus, pulus, stinging tree, fever nettle, or elephant nettle, growing in subtropical wet evergreen forests throughout Asia. Some of its uses in herbal medicine have been scientifically validated.
Dendrocnide meyeniana or the poisonous wood nettle is a species of tree in the family Urticaceae, native to the thickets and secondary forests of Taiwan and the Philippines. The specific epithet meyeniana honors Franz Meyen, who collected the type specimen in Manila during his world cruise.
Cnidoscolus urens is a perennial, tropical American stinging herb of the family Euphorbiaceae, and is one of some 100 species belonging to the genus Cnidoscolus. The plant is locally known as bull nettle, spurge nettle, bringamosa and mala mujer.
Urtica gracilis, commonly known as the slender nettle, tall nettle, or American stinging nettle, is a perennial plant without woody stems that is well known for the unpleasant stinging hairs on its leaves and stems. It is native to much of the North America from Guatemala northwards and temperate areas of South America. It is easily confused with the visually very similar Eurasian species Urtica dioica and is still listed in some resources as a subspecies of this plant. However, genetic analysis and experiments show that they are genetically distinct.
Urtica pilulifera, also known as the Roman nettle, is a herbaceous annual flowering plant in the family Urticaceae.
Nettle tree or tree nettle can refer to:
Spring greens, or spring vegetables, are the edible young leaves or new plant growth of a large number of plants that are most fit for consumption when their newest growth happens in the spring. Many leaf vegetables become less edible as they age and bitter, or potentially even toxic, compounds start to form. Harvesting of spring vegetables is common across Native American cultures.
