Rusts are fungal plant pathogens of the order Pucciniales causing plant fungal diseases.
Alcea is a genus of over 80 species of flowering plants in the mallow family Malvaceae, commonly known as the hollyhocks. They are native to Asia and Europe. The single species of hollyhock from the Americas, the streambank wild hollyhock, belongs to a different genus.
Stem rust, also known as cereal rust, black rust, red rust or red dust, is caused by the fungus Puccinia graminis, which causes significant disease in cereal crops. Crop species that are affected by the disease include bread wheat, durum wheat, barley and triticale. These diseases have affected cereal farming throughout history. The annual recurrence of stem rust of wheat in North Indian plains was discovered by K.C. Mehta. Since the 1950s, wheat strains bred to be resistant to stem rust have become available. Fungicides effective against stem rust are available as well.
Alcea rosea, the common hollyhock, is an ornamental dicot flowering plant in the family Malvaceae. It was imported into Europe from southwestern China during, or possibly before, the 15th century. William Turner, a herbalist of the time, gave it the name "holyoke" from which the English name derives.
Puccinia hordei is a species of rust fungus. A plant pathogen, it can cause leaf rust of barley, also known as brown rust of barley. It was originally found on the dry leaves of Hordeum vulgare in Germany.
Puccinia coronata is a plant pathogen and causal agent of oat and barley crown rust. The pathogen occurs worldwide, infecting both wild and cultivated oats. Crown rust poses a threat to barley production, because the first infections in barley occur early in the season from local inoculum. Crown rusts have evolved many different physiological races within different species in response to host resistance. Each pathogenic race can attack a specific line of plants within the species typical host. For example, there are over 290 races of P. coronata. Crops with resistant phenotypes are often released, but within a few years virulent races have arisen and P. coronata can infect them.
Puccinia kuehnii is a plant pathogen that causes orange rust disease of sugarcane. Orange rust was first discovered in India in 1914, but the first case of huge economical damage in sugarcane was registered in Australia in 2001. The first case in United States was in 2007 in Florida and has so far been the only state in the United States where sugarcane has been affected by this kind of rust. In order to treat the infected sugarcane at least three rounds of fungicide must be applied to the plant, costing growers $40 million a year. Currently scientists at the Agricultural Research Service are genetically analyzing the fungus that causes orange rust in order to help combat the problem.
Puccinia menthae is a fungal plant pathogen that causes rust on mint plants. It was originally found on the leaves of Mentha aquatica.
Puccinia purpurea is a fungal species and plant pathogen that causes rust on sorghum. It is found in temperate places worldwide, excluding colder parts such as Russia and Canada.
Puccinia subnitens is a fungal species and plant pathogen that causes rust on Beta vulgaris. It was originally found on Distichlis spicata in Montana, USA.
Puccinia recondita is a fungus species and plant pathogen belonging to the order of Pucciniales and family Pucciniaceae.
Puccinia thaliae is the causal agent of canna rust, a fungal disease of Canna. Symptoms include yellow to tan spots on the plant's leaves and stems. Initial disease symptoms will result in scattered sori, eventually covering the entirety of the leaf with coalescing postulates. Both leaf surfaces, although more predominant on the underside (abaxial) of the leaf, will show yellow to brownish spore-producing these pustulate structures, and these are the signs of the disease. Spots on the upper leaf-surface coalesce and turn to brown-to-black as the disease progresses. Infection spots will become necrotic with time, with small holes developing in older leaves. These infected leaves eventually become dry and prematurely fall.
Uromyces is a genus of rust fungi in the family Pucciniaceae. The genus was described by Franz Unger in his 1833 work Die Exantheme der Pflanzen. They have a worldwide distribution but large occurrences happen in North America and Europe.
Puccinia poarum, a species of fungus, known as the coltsfoot gall rust, or meadow grass rust, is a plant pathogen. This fungal parasite forms a yellow to orange gall, 1–2 cm in diameter, on the underside of leaves of coltsfoot. It also infects but does not gall grasses of the family Poaceae. P. poarum is a genetically diverse species that has been reported on at least seventy plant hosts. It was originally found on Poa fertilis and Poa nemoralis in Denmark in 1877.
Puccinia sessilis is a fungal species and plant pathogen, which is also known as arum rust or ramsons rust. It commonly infects Arum maculatum and Allium ursinum causing yellow to orange circular patches on leaves. On the underside of the leaves, it produces raised orange aecia commonly covered in spores. It is common in Eurasia in the spring.
Puccinia mariae-wilsoniae, commonly known as the spring beauty rust, is a species of rust fungus found in North America. A plant pathogen, it grows on the leaves of the spring beauty flowering plants Claytonia caroliniana and C. virginica.
Luigi Carlo Giuseppe Bertero was an Italian physicist, physician, naturalist, botanist, bryologist and pteridologist. He explored the West Indies between 1816 and 1821 coinciding with the Venezuelan scientist and later president, José María Vargas in Puerto Rico although there is no evidence of any exchange between them. During his two voyages, February 1828 to September 1830 and between March and May 1830, he collected and described the flora of Chile. He also examined plants native to the Pacific island of Juan Fernandez, as well as Guadeloupe, Haiti, Puerto Rico, and Colombia. He is presumed lost in a shipwreck while sailing from Tahiti to Chile.
Alcea rugosa, the Russian hollyhock, is a species of flowering plant in the family Malvaceae. It is native to Ukraine, Crimea, south European Russia, and the Caucasus, and has been introduced as a garden escapee into Wisconsin and Maryland in the United States. It is resistant to Puccinia malvacearum rust, and hardy to USDA zone 4.
Puccinia porri is a species of rust fungus that causes leek rust. It affects leek, garlic, onion, and chives, and usually appears as bright orange spots on infected plants.
Pucciniosira is a genus of rust fungi belonging to the family Pucciniosiraceae.
