Phragmidium
Encyclopedia
Phragmidium is a genus of rust
fungus
that typically infects plant species in the Rosaceae
. It is characterised by having stalked teliospore
s borne on telia
each having a row of four or more cells. All species have a caeoma which is a diffuse aecidium
lacking a peridium
There are a number of species of Phragmidium most of which are restricted to one or a few host species. Examples include: P. bulbosum on Rubus fruticosus and Rubeus caesius
P. sterilis on Potentilla sterilis
P. potentillae on Potentilla anglica
P. rubi-idea on Rasberry
P. tuberculatum on some Rose
cultivars P. violaceum on cultivated Blackberrry and Loganberry
Possible the most commonly encountered is P. mucronatum found on most species of wild roses including Rosa canina and Rosa arvensis
containing overwintering teliospore
s.
s some of which may have health implications for the gardener. Many cultivated roses are now bred to have resistance to rust diseases. In wild roses, Phragmidium infections are one of a normal range of pests and diseases which are part of the normal ecological
pressures affecting all species.
Rust (fungus)
Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales. About 7800 species are known. Rusts can affect a variety of plants; leaves, stems, fruits and seeds. Rust is most commonly seen as coloured powder, composed off tiny aeciospores which land on vegetation producing...
fungus
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
that typically infects plant species in the Rosaceae
Rosaceae
Rosaceae are a medium-sized family of flowering plants, including about 2830 species in 95 genera. The name is derived from the type genus Rosa. Among the largest genera are Alchemilla , Sorbus , Crataegus , Cotoneaster , and Rubus...
. It is characterised by having stalked teliospore
Teliospore
Teliospore is the thick-walled resting spore of some fungi , from which the basidium arises.-Development:They develop in telia ....
s borne on telia
Telia
Telia may refer to:*Telia - part of the reproductive cycle of Rusts*Telia Digital-tv - a Swedish TV platform*Telia, Nepal - a village in Nepal*TeliaSonera - a Swedish/Finnish telecom operator*Telia Challenge Waxholm - Golf tournament...
each having a row of four or more cells. All species have a caeoma which is a diffuse aecidium
Aecidium
Aecidium is a genus of rust fungi in the Pucciniales order. The widespread genus is estimated to contain about 600 species.-Selected species:*Aecidium aechmantherae*Aecidium amaryllidis*Aecidium breyniae*Aecidium campanulastri...
lacking a peridium
Peridium
The peridium is the protective layer that encloses a mass of spores in fungi. This outer covering is a distinctive feature of the Gasteromycetes.-Description:...
There are a number of species of Phragmidium most of which are restricted to one or a few host species. Examples include:
Rasberry
Rasberry may refer to:* Tom Rasberry, American exterminator who identified the crazy rasberry ant* Crazy rasberry ant, an invasive species of ant found near Houston, Texas...
P. tuberculatum on some Rose
Rose
A rose is a woody perennial of the genus Rosa, within the family Rosaceae. There are over 100 species. They form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp prickles. Flowers are large and showy, in colours ranging from white through yellows...
cultivars P. violaceum on cultivated Blackberrry and Loganberry
Loganberry
The loganberry is an hexaploid hybrid produced from crossing an octaploid blackberry and a diploid red raspberry. The plant and the fruit resemble the blackberry more than the raspberry, but the fruit colour is a dark red, rather than black...
Possible the most commonly encountered is P. mucronatum found on most species of wild roses including Rosa canina and Rosa arvensis
Pathology
Roses infected with species of Phragmidium will show a characteristic orange mass of spores and distorted growth at specific locations on the bush. The rose may be substantially weakened and lack vigour and may die. Later in the year small black spots or raised areas will be visible which are teliaTelia
Telia may refer to:*Telia - part of the reproductive cycle of Rusts*Telia Digital-tv - a Swedish TV platform*Telia, Nepal - a village in Nepal*TeliaSonera - a Swedish/Finnish telecom operator*Telia Challenge Waxholm - Golf tournament...
containing overwintering teliospore
Teliospore
Teliospore is the thick-walled resting spore of some fungi , from which the basidium arises.-Development:They develop in telia ....
s.
Prevention
Rose growers recommend the use of fungicideFungicide
Fungicides are chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality and profit. Fungicides are used both in agriculture and to fight fungal infections in animals...
s some of which may have health implications for the gardener. Many cultivated roses are now bred to have resistance to rust diseases. In wild roses, Phragmidium infections are one of a normal range of pests and diseases which are part of the normal ecological
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
pressures affecting all species.