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White mold affects a wide range of hosts and causes sclerotinia stem rot. It is known to infect 408 plant species. As a nonspecific plant pathogen, [3] diverse host range and ability to infect plants at any stage of growth makes white mold a very serious disease. The fungus can survive on infected tissues, in the soil, and on living plants.
The English name 'common spotted' refers to the species' abundance and the spots on its leaves. The French and German common names also honour Leonhart Fuchs. This plant belongs to a problematic group of orchids. D. maculata subsp. fuchsii is very variable in flower colour and flower morphology, plant height and the scent of flowers.
The tuber is flattened and finger-like. The long leaves are lanceolate and, in most species, also speckled. They grow along a rather long stem which reaches a height of 70–90 cm (28–35 in). Leaves higher on the stem are shorter than leaves lower on the stem. The inflorescence, compared to the length of the plant, is rather short.
Dactylorhiza maculata, known as the heath spotted-orchid [2] or moorland spotted orchid, is an herbaceous perennial plant of the family Orchidaceae. It is widespread in mountainous regions across much of Europe from Portugal and Iceland east to Russia. It is also found in Algeria, Morocco, and western Siberia. [1] [3]
Cephalanthera austiniae is a species of orchid known as the phantom orchid and snow orchid [2] because the entire plant is white except for a few yellow markings on the flowers. The orchid is native to the western United States ( California , Oregon , Washington and Idaho ), and to British Columbia , Canada.
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]
Orchid seeds are very small (0.35mm to 1.50mm long), spindle-shaped, and have an opening at the pointed end. [5] Each seed has an embryo that is undifferentiated and lacks root and shoot meristems. [3] An orchid seed does not have enough nutritional support to grow on its own, and lacks endosperm. [2]
The pollination of orchids represents a complex aspect of the biology of this plant family, characterized by intricate flower structures and diverse ecological interactions with pollinator. Notably, the topic has garnered significant scientific interest over time, including the attention of Charles Darwin , who is recognized for his ...