Lady Orchid (Orchis purpurea)
The first flowers form when the plant is about 10 years old. Increasingly heavy shade will drive populations into decline, with more plants failing to produce flowers but instead producing a larger rosette or becoming 'dormant' (remaining below ground).
There are 3 to 5 leaves (1 to 7) near the base, 6 to 13 cm (4 to 9 inches) in length and 2.5 to 5 cm (1 to 2 inches) in width. These lower leaves form a basal rosette whereas the upper leaves clasp the stem more (there may be an additional small leafy bract above the uppermost leaf. In shade the leaves become a darker green due to increased chlorophyll as an adaptation to dim light.
Each flower is subtended by a minute bract. Typical of orchids each flower has 3 sepals, and these form the helmet over the stigma and anther and are heavily pigmented by purple patches of anthocyanin. the labellum (lower petal or lip) is pale pink or white and studded with crimson papillae and is divided into a pair of lower lobes with a small triangular tooth in between them. The lateral petals are narrow and strap-shaped and also covered in purple papillae. The papillae are thought to function as osmophores, releasing scented volatiles to attract potential pollinators.
The ovary is green and glossy with 3 longitudinal ribs and about 2.45 cm (1 inch) in length.The spur is about half as long as the ovary. Upon fertilization, the ovary develops into a capsular fruit up to 3 cm long which splits open when ripe by 3 longitudinal slits. The many seeds are minute and easily dispersed dust seeds, characteristic of orchids.
The wasp above was seen sitting in the same spot for hours but sluggishly responded when prodded. It was either dying or heavily intoxicated? Below: a rare visit from a potential pollinator. Pollinators visit lady Orchids very infrequently because they soon learn that the plant offers no nectar reward, but a single insect may pick up the pollinia, carrying the large packets of pollinia to pollinate the many ovules in another flower, so a low rate of pollination is sufficient to maintain a population of these orchids.
Flowers open in late spring and fruit capsules scatter seeds at the end of summer / in early autumn (September). Lady Orchids are pollinated by small flies and small bees. Fruit set is apparently low. This has been accounted for by the fact that the flowers of the Orchis genus are deceit flowers: they promise a reward to potential pollinators but the spur in Orchis purpurea is dry and contains no nectar. this saves the plant's resources since they do not need to invest in expensive nutritious nectar, however, they clearly invest heavily in display to attract pollinators. Inexperienced insects will visit a few plants before they learn to ignore them. However, it has been pointed out that deceit apparently favors cross-pollination. When one considers that the pollen is transported as masses (pollinia) and each flower has many ovules, a single pollination event can pollinate a lot of ovules. thus, a high fruit set is not needed.
Forms growing in the open tend to develop darker flowers with more pigmentation. A gigantic form has been reported growing in rich meadowland, with leaves 27 cm in length.
Lady Orchid is southern Eurasian in distribution and grows on chalk scrub and in beechwoods in the South of England, particularly Kent (SE England) where it may be locally quite abundant and also very rare in surrey and Sussex. (These orchids were growing on chalk scrub in the middle of woodland). In Kent, England, populations west of the River Stour form shorter, denser flower spikes and generally produce flowers with more anthocyanin; whilst east of the Stour, populations tend to have longer laxer flower spikes and less pigmentation. These specimens are from an East Kent population, east of the Stour.
Lady Orchids thrive on dense chalk scrub with moderate light and extreme dryness, including steep chalky slopes in beechwoods (as here) and terraces formed by beech roots (but avoid the deep leaf litter preferred by Neottia nidus-avis (Bird's-nest Orchid) which can thrive in lower light levels). They prefer south facing slopes.
Click images to enlarge - large size images allow details of the glands on the labella to be seen.
The orchid below has a much narrower labellum, however, I do not think it is var. pseudomilitaris which has narrower labellum (lower lip) lobes but these lobes are reddish: these are quite narrow but not reddish.
Above:
some individuals have narrow lips due to the 'legs' being close
together. Druce reported a very rare form (var. pseudo-militaris)
with dagger-shaped labella with long narrow limbs and a prominent
median lobe. Pyloric forms are recorded: mutants with all 3 petals
developed into labella. Hybrids with Military Orchid (Orchis
militaris), Monkey orchid (Orchis simia to give O.
x beyrichii / O. x angusticruris), Man Orchid
(Orchis anthropophora, to give O. x macra)
and Early Purple orchid (Orchis mascula to give O. x
wilmsii) occur.
Below: the scarce var. albida (sometimes var. alba) which lacks a functional gene to make the red anthocyanin pigment. This rare (but well documented) albino form has straw-colored hoods.
All of these images above were taken from a single population of some 2000 Lady Orchids in East Kent, UK.Lady Orchids are also scattered across France and locally frequent there and extend to the mountains of Spain. They are rare in the Swiss and Austrian Alps but relatively common in mountain woodlands in central Italy. they are very rare in other parts of Europe and Asia Minor (a peninsula covering most of Turkey which is the westernmost extension of Asia). they are absent, however, in Scandinavia.
Sources and Further reading
Rose, F. 1948. Orchis purpurea Huds. J. Ecol. 36: 366-377.
Claessens, J. and Kleynen, J. 2011. The Flower of the European Orchid - Form and Function.
Harrap, A. and Harrap, S. 2009. Orchids of Britain & Ireland - A field and site guide, 2nd ed. Pub: A & C Black, London.
Summerhayes, V.S. 1969. Wild Orchids of Britain