The rare late spider orchid produces a single upright stem and between two and ten flowers on a spike (2). The pink, purple or sometimes whitish flowers have a broad lip which earns this species its common name due to the similarity of this structure to the body of a spider (2). An area towards the centre of the lip, called the 'speculum' or 'mirror' features a purple or blue pattern in two parallel lines or in the shape of an 'X' or an 'H' (2).
This perennial orchid flowers from June to July, after which the visible parts of the plant die, and it survives the summer as an underground tuber(6). The flowers are pollinated by bees, but very few have been observed in Britain and fruit set is usually less than two percent. The tiny seeds are dispersed by the wind in late July and August (6), and require a mycorrhizal fungus to develop (6). Rosette leaves are produced in the autumn and over-winter, withering after flowering (6). It is thought that most plants do not live very long (44 percent for one to three years, and only five percent more than ten years) but some plants may live for up to 30 years (6). It is capable of vegetative reproduction(5), but most reproduction is from seed (6). Some plants have flowered every year for five years, and others remain dormant under the ground for up to four to seven years (6).
The late spider orchid has never been common in Britain; it has only ever been recorded from east Kent and has declined (4). It has been recorded in about 20 sites, of which nine have been seen to be occupied by this orchid since 1990 (5). About 400 to 500 plants are known in Britain (5). In Europe it occurs throughout central southern Europe and reaches east to Asia Minor (4).
The late spider orchid occurs on chalk downs and banks, usually on steep south-west to east facing scarps, often on deep, well-drained, calcareous, nutrient-poor soils with very little organic matter (6). It grows in grassland less than 20 centimetres tall, but avoids very open dry places (6).
The main cause of the decline of the late spider orchid has been changes in agriculture, particularly conversion of grasslands to arable, the decline in grazing, and the use of chemical herbicides and fertilisers. (5). At some sites the late spider orchid is thought to have become extinct due to deep leaf litter and competition with tor grass Brachypodium pinnatum(5). Furthermore, fruit set is very poor, perhaps as a result of a lack of pollinators and poor climate, and reproduction by seed is at best sporadic (6).
At sites in Wye, east Kent, hand-pollination has been used to try to improve the amount of seed that is set (5). Funding from English Nature has allowed the species to be closely studied at Wye National Nature Reserve (4). All current populations occur within Sites of Special Scientific Interest (SSSIs) (5), and the species is fully protected under Schedule 8 of the Wildlife and Countryside Act, 1981 (5).
A fungus that forms a close physical association with the roots of a plant, this relationship is mutually beneficial.
Plants that live for at least three seasons; after an initial period they produce flowers once a year.
To transfer pollen grains from the stamen (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant.
In plants, a thickened stem or root that acts as an underground storage organ. Roots and shoots grow from growth buds, called 'eyes', on the surface of the tuber.
Type of asexual reproduction (reproduction without recombination of genetic material) that results in the propagation of plants using only the vegetative tissues such as leaves or stems. The resulting plant is genetically identical to the original plant. A well-known example of this is the reproduction of strawberry plants from 'runners'.
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