Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents. This is common among fruits, anthers and sporangia. Sometimes this involves the complete detachment of a part. Structures that open in this way are said to be dehiscent. Structures that do not open in this way are called indehiscent, and rely on other mechanisms such as decay or predation to release the contents.
Uncinula necator is a fungus that causes powdery mildew of grape. It is a common pathogen of Vitis species, including the wine grape, Vitis vinifera. The fungus is believed to have originated in North America. European varieties of Vitis vinifera are more or less susceptible to this fungus. Uncinula necator infects all green tissue on the grapevine, including leaves and young berries. It can cause crop loss and poor wine quality if untreated. The sexual stage of this pathogen requires free moisture to release ascospores from its cleistothecia in the spring. However, free moisture is not needed for secondary spread via conidia; high atmospheric humidity is sufficient. Its anamorph is called Oidium tuckeri.
A sclerotium, is a compact mass of hardened fungal mycelium containing food reserves. One role of sclerotia is to survive environmental extremes. In some higher fungi such as ergot, sclerotia become detached and remain dormant until favorable growth conditions return. Sclerotia initially were mistaken for individual organisms and described as separate species until Louis René Tulasne proved in 1853 that sclerotia are only a stage in the life cycle of some fungi. Further investigation showed that this stage appears in many fungi belonging to many diverse groups. Sclerotia are important in the understanding of the life cycle and reproduction of fungi, as a food source, as medicine, and in agricultural blight management.
Claviceps purpurea is an ergot fungus that grows on the ears of rye and related cereal and forage plants. Consumption of grains or seeds contaminated with the survival structure of this fungus, the ergot sclerotium, can cause ergotism in humans and other mammals. C. purpurea most commonly affects outcrossing species such as rye, as well as triticale, wheat and barley. It affects oats only rarely.
Common bunt, also known as hill bunt, Indian bunt, European bunt, stinking smut or covered smut, is a disease of both spring and winter wheats. It is caused by two very closely related fungi, Tilletia tritici and T. laevis.
Pseudomonas viridiflava is a fluorescent, Gram-negative, soil bacterium that is pathogenic to plants. It was originally isolated from the dwarf or runner bean, in Switzerland. Based on 16S rRNA analysis, P. viridiflava has been placed in the P. syringae group. Following ribotypical analysis misidentified strains of Pseudomonas syringae pv. ribicola and Pseudomonas syringae pv. primulae were incorporated into this species. This pathogen causes bacterial blight of Kiwifruit.
Urocystis agropyri is a fungal plant pathogen that causes flag smut on wheat.
Ramularia primulae is a fungal plant pathogen infecting Primula. Its primary host is Primula veris.
Exobasidium vaccinii, commonly known as “red leaf disease,” or “Azalea Gall,” is a biotrophic species of fungus that causes galls on ericaceous plant species, such as blueberry and azalea. Exobasidium vaccinii is considered the type species of the Exobasidium genus. As a member of the Ustilagomycota, it is a basidiomycete closely related to smut fungi. Karl Wilhelm Gottlieb Leopold Fuckel first described the species in 1861 under the basionym Fusidium vaccinii, but in 1867 Mikhail Stepanovich Voronin later placed it in the genus Exobasidium. The type specimen is from Germany, and it is held in the Swedish Museum of Natural History. Exobasidium vaccinii, in current definition from John Axel Nannfeldt in 1981, is limited on the host Vaccinium vitis-idaea. This idea is used in most recent papers on E. vaccinii.
This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnifying lens. This page provides help in understanding the numerous other pages describing plants by their various taxa. The accompanying page—Plant morphology—provides an overview of the science of the external form of plants. There is also an alphabetical list: Glossary of botanical terms. In contrast, this page deals with botanical terms in a systematic manner, with some illustrations, and organized by plant anatomy and function in plant physiology.
This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary of leaf morphology. For other related terms, see Glossary of phytopathology, Glossary of lichen terms, and List of Latin and Greek words commonly used in systematic names.
Urocystis is a genus of smut fungi containing plant pathogens, which infect grass species and other plants.
Conidiosporomyces is a genus of fungi in the smut family Tilletiaceae. The genus was described in 1992 to accommodate the species formerly known as Tilletia ayresii, first described by British naturalist Miles Joseph Berkeley in 1899. The species C. verruculosus was described in 1993. Species in the genus are plant pathogens that affect various grasses.
Salmacisia is a fungal genus in the family Tilletiaceae. It is a monotypic genus, containing the single species Salmacisia buchloëana, first described as Tilletia buchloëana in 1889, and renamed in 2008. Plants infected by the fungus undergo a phenomenon known as "parasitically induced hermaphroditism", whereby ovary development is induced in otherwise male plants. Because of the pistil-inducing effects of the fungus, the authors have named the species pistil smut; it is the only species in the order Tilletiales known to have hermaphroditic effects.
Monilinia oxycocci (Woronin) Honey,, common names cranberry cottonball, cranberry hard rot, tip blight, is a fungal infection of large cranberry and small cranberry. The tips of young flowering shoots wilt before they flower. Fruit that forms on the plant can then be infected by the asexual spores traveling through the plant, causing the berries to harden, turn cottony on the inside, and dry out instead of maturing. The berries are filled with a cotton-like fungus and are generally yellowish with tan stripes or blotches at maturity, making them unmarketable. It results in important economic impacts on many cranberry marshes, particularly in Wisconsin.
Botrytis is a genus of anamorphic fungi in the family Sclerotiniaceae. Botrytis belongs to the group hyphomycetes and has about 30 different species. It is a plant parasite as well as saprophytes on both agricultural and forest trees. It produces stout, dark, branching conidiophores that bear clusters of paler conidia on denticles from apical ampullae. It is a common outdoor fungus and can be detected in spore trap samples. The fungus is often found growing on indoor plants. Although no mycotoxin has been reported from this fungus, it may cause hay fever, asthma and keratomycosis. The most common species is B. cinerea, which is a plant pathogen causing gray mould on a very broad range of hosts including some common ornamental plants, such as geranium, begonia, rose, lily, dogwood, rhododendron, dahlia, magnolia, camellia and fruits and produce. This fungus is mainly of outdoor origin, although it may be from growth on fruits or flowers brought in from outdoors. Some houseplants can be infected by this fungus, such as cyclamen, poinsettia, chrysanthemum, and gerbera. Other species of Botrytis may be present, such as B. peoniae on peonies, B. squamosa on onion, and B. tulipae on tulips. These species of Botrytis share some common characteristics in pathology and ecology.
Entomophaga grylli is a fungal pathogen which infects and kills grasshoppers. It is the causal agent of one of the most widespread diseases affecting grasshoppers. This is sometimes known as summit disease because infected insects climb to the upper part of a plant and grip the tip of the stem as they die; this ensures widespread dispersal of the fungal spores. The fungus is a species complex with several different pathotypes, each one of which seems to be host-specific to different subfamilies of grasshoppers. The pathogen is being investigated for its possible use in biological pest control of grasshoppers.
Cladosporium cladosporioides is a darkly pigmented mold that occurs world-wide on a wide range of materials both outdoors and indoors. It is one of the most common fungi in outdoor air where its spores are important in seasonal allergic disease. While this species rarely causes invasive disease in animals, it is an important agent of plant disease, attacking both the leaves and fruits of many plants. This species produces asexual spores in delicate, branched chains that break apart readily and drift in the air. It is able to grow under low water conditions and at very low temperatures.
Microbotryum violaceum is a host-specific anther smut (fungus) disease that infects Silene latifolia and sterilizes the host plant. When infected with this disease, the flowers generate pathogenic spores, which can then be transferred to other plants by pollinating insects. Therefore, this disease is sometimes classified as a sexually transmitted infection.
This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found in glossary of biology and glossary of botany, among others. List of Latin and Greek words commonly used in systematic names and Botanical Latin may also be relevant, although some prefixes and suffixes very common in mycology are repeated here for clarity.
A dissected flower of Primula vulgaris infected with Urocystis primulae. Conidia are visible as a white powder around the anthers and ustilospores as a blackish brown mass in the ovary.
Spore balls of Urocystis primulae under the microscope. These are the ustilospores visible in the ovary in the image above.
