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It is one of the most common viruses affecting cultivated orchids, perhaps second only to the Cymbidium mosaic virus. [1] It causes spots on leaves and colored streaks on flowers. [1] If a plant is also infected with the Cymbidium mosaic virus, it can lead to a condition called blossom brown necrotic streak. [1]
Outside of the "maculata group", D. majalis is very similar to D. maculata subsp. fuchsii, but is distinguished by the following characters: the spots of the leaves are less elongated, the bracts of the inflorescence are longer and the lower transcend the inflorescence itself; it tends to be less cylindrical (a little more 'globular'), the stem ...
The leaves are oblong or oval-lanceolate, with dark ellipsoid-shaped spots on the surface (hence the species name). The leaves are amplexicaul and can be either radical (basal) or cauline. The underground part of the stem has two webbed tubers, each deeply divided into several lobes or tubercles (characteristic of the genus Dactylorhiza ).
Black rot on orchids is caused by Pythium and Phytophthora species. [1] Black rot targets a variety of orchids but Cattleya orchids are especially susceptible. [1] Pythium ultimum and Phytophthora cactorum are known to cause black rot in orchids. [1] Pythium ultimum is a pathogen that causes damping-off and root rot on plants. [2]
Dendrobium is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is a very large genus, containing more than 1,800 species that are found in diverse habitats throughout much of south, east and southeast Asia, including China, Japan, India, the Philippines, Indonesia, Australia, New Guinea, Vietnam and many of the islands of the Pacific.
Platanthera orbiculata, the round leaved orchid [2] or lesser roundleaved orchid, [3] is a species of orchid native to forested areas of North America.It is widespread across most of Canada and parts of the United States (Alaska, New England, Appalachian Mountains, Great Lakes Region, Rocky Mountains, Black Hills and northern Cascades).
Orchid fleck dichorhavirus, commonly called Orchid fleck virus (OFV), is a non-enveloped, segmented, single-stranded (ss) RNA negative-strand virus, transmitted by the false spider mite, Brevipalpus californicus. OFV causes necrotic and chlorotic lesions on the leaves [1] of many genera in the family Orchidaceae.
Ansellia is considered a monotypic genus of orchid, with only one species, Ansellia africana, commonly known as African ansellia or leopard orchid, however, it may in fact be a complex group of species which share common floral structure and growth habit. The plants are found throughout tropical and subtropical Africa.