This perennial, tuberous herb is found on S.-facing banks in grazed chalk grassland. It is tolerant of some degree of shade from scrub, and can also grow on woodland edges. Lowland.
First recorded in 1777 in Kent, this species declined in the 19th century through the ploughing of downland, and was thought to have become extinct in Britain until the extant native Kent population was found in 1955. Seed from this site was used to established a second population in Kent. In 1974, a few plants appeared in S.E. Yorkshire, but these only persisted until 1983. The extant Oxfordshire and Kent populations are increasing, assisted by management of grazing.
European Southern-temperate element.
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Light (Ellenberg): 8
Moisture (Ellenberg): 3
Reaction (Ellenberg): 8
Nitrogen (Ellenberg): 2
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 3.8
July Mean Temperature (Celsius): 16.4
Annual Precipitation (mm): 697
Height (cm): 30
Perennation - primary
Life Form - primary
Clonality - primary
Count of 10km squares in Great Britain: 10
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
Plantatt Conservation Status
RDB Species Accounts
Orchis simia Lam. (Orchidaceae)
Status in Britain: VULNERABLE. WCA Schedule 8.
Status in Europe: Not threatened.
O. simia is a plant of south-facing chalky banks in southern England. It occurs mainly in open, grazed chalk grassland, although it can tolerate some degree of shade from scrub, and sometimes grows at the woodland edge. The normally herb-rich turf supports a wide range of calciphilous species, amongst which are Bromopsis erecta, Carex flacca, Cirsium acaule, Festuca ovina, Knautia arvensis, Koeleria macrantha, Leontodon hispidus, Linum catharticum, Origanum vulgare, Sanguisorba minor and Thymus pulegioides.
This species is a long-lived perennial. The leaves emerge early in the year, the stem elongates in April, and the pale pink flowers open from late May into June. Inflorescences are irregular in appearance, and the flowers open more haphazardly, often from the top downwards, the opposite way to most orchid species. Seed-pods ripen in late July. Some natural pollination occurs in Britain. In the Netherlands, Willems (1982) observed that it took seven years to produce a flowering plant from seed. A similar time scale has been observed in Kent populations. Individuals can live for many years, and Willems & Bik (1991) record a plant which has flowered for nineteen consecutive years. Willems (1982) found that, in the Netherlands, the population development is strongly influenced by variable weather conditions, and that the long-term survival of populations depends on the longevity of one or a few individuals in the isolated populations. The colour and stature of the Kent and Oxfordshire plants are variable, the more robust Kentish plants most resembling those in continental Europe, though there is no evidence to suggest that the variation is anything more than phenotypic.
The first record for O. simia in Kent was from near Faversham in 1777. It was subsequently recorded from West Sussex, Surrey, and the Thames valley, where it was relatively abundant until the 1840s, but then declined dramatically. It was thought to be extinct in Britain until rediscovered near Faversham in 1955 (Wilks 1960). Assisted by hand pollination, the population reached 200 flowering plants by the mid-1960s (Wilks 1966). Seed from this population was introduced to several other sites in Kent and a population became established at one of them. The first flowering plants appeared seven years after the seed was sown. Both populations in Kent are now stable and increasing, with over 200 plants at the native site and more than 100 plants at the other, although only a small proportion flower. The only other extant site is in scrubby chalk grassland in Oxfordshire. The colony there is a remnant of a much larger one which was ploughed up in the early 1950s, only a few plants having escaped the plough at the top of a steep slope. Fencing of the site against rabbits has encouraged a population increase to over 100 plants, and it appears to be spreading down the slope following scrub clearance. A few plants appeared in 1974 in dune grassland in south-east Yorkshire, increased in subsequent years to a maximum of 25 plants with nine flowering (Crackles 1990), but the colony persisted only until 1983.
Short turf and open ground for seedling establishment provides ideal habitat for O. simia. Grazing or mowing maintains those conditions, but at some sites, flowering plants are protected by wire cages to prevent rabbits nibbling off the flowering heads. The main threats to Orchis simia are from a deterioration of the habitat through lack of grazing.
O. simia is widespread across southern and western Europe, north to Britain, and in the Mediterranean region to North Africa. It is abundant in France where it frequently hybridises with Orchis militaris.
J. M. Church and L. Farrell