Cypripedium reginae

The royal cypripède, Cypripedium reginae is largest and most spectacular orchis of North America.

Synonyms:

Showy Lady' s-Slipper, royal Cypripède, Queen lady' s-slipper, Cypripedium spectabile Salisbury, Royal Lady' S Slipper

Morphology:

The royal cypripède can reach up to one meter in height. Its floral stem, measuring between 40 and 80 cm in height, comes directly from the very large cylindrical Rhizome. It is robust and strong, hirsute, with sheets until the top. The 3 to 9 sheets are oval with elliptic.

On these high - stems, one or two flowers appear (seldom up to 4). They alternate and are distributed on all along the stem. They present white sepals and petals. The labelle, very inflated, presents a coloring going of pale pink to magenta. The royal cypripède is covered with a fine sleeping bag on all the parts of the plant. This sleeping bag can cause dermatites of contact and eczema. The irritant hairs are inhabited by a filamentous mushroom and are finished by a gland filled with a brownish, soluble oily substance in alcohol.

Generally, the royal cypripède forms large colonies. Largest can reach to 3000 individuals. This characteristic makes it vulnerable to the decimation caused by an extensive gathering, the chattering of the herbivores, or the deterioration of the habitat (drainage of the ground or fire).

Flowering:

End of spring, at the beginning of the summer (from May to August)

Reproduction:

Cypripedium reginae generally reproduces in a vegetative way. This way of reproducing produced clones having the same genetic material exactly. A population of cypripèdes royal thus presents a very weak genetic variation.

The royal cypripède, although it is largest representing orchises in Quebec, probably has the smallest opening of the labelle one. At the C. stemless , the opening is enough large to let pass the bumblebees but that of C. reginae seems to be too small to let pass these insects. Its pollinating is not yet known with exactitude but, a black bee, probably of the family of the Megachile, was observed entering its labelle. This bee is come out from it covered with Pollen. Another study carried out with the Vermont shows that the pollination of this orchis is made there most of the time by a fly ( Syrphus torvus ) and by the “flower beetle” ( Trichiotinus assimilis ). In short, the insect or the insects able to pollinate the royal cypripède is still unknown for us.

The seeds of this cypripède have an impermeable film which must be digested by bacteria or mushrooms before being able to germinate. This characteristic limits the chances of germination of the immature seeds which could freeze thereafter.

Kéry (2004) brings back episodes of Dormance being able to last between 1 and 4 years for a colony of C. reginae . Between 8 and 33% of the seedlings of a population are door frames each year. Small % of plants in dormancy represents a population in health.

The royal cypripède pushes very slowly. Germination is carried out with a depth of less than 5 cm. For germination in favorable conditions, it will be necessary to wait 3 years before seeing leaving the ground its first sheet. After 7 years, it is only 8 cm high. Fifteen to sixteen years after germination, C.reginae is close flowering.

It has 2n = 20 chromosomes.

Habitat:

The royal cypripède lives the wet habitats of the Scandinavian areas. The peat bogs, the marshes and the banks of the lakes belong to its privileged places. He lives also the forests of conifers or leafy trees. He grows between 0 and 600 meters of altitude.

He prefers the grounds limestones but pushes on the slightly acid grounds with slightly basic. Kéry (2004) brings back a ground to the pH from 5,8 to 6,8 while Curtis (1943) described the favorable conditions with the germination of C. reginae having a pH ranging between 6,9 and 7,7. The seeds located under a dense cover of Sphaigne cannot germinate because of too large acidity. A constant moisture of the ground and the semi-shade are favorable conditions with the growth of this orchis. The royal cypripède is vulnerable to the prolonged dryness and an excessive shade harms its growth seriously.

The contamination of water or the draining of the grounds is also harmful for him.

Distribution:

The royal cypripède lives all is of North America. In the west, he believes until in Saskatchewan and in the North Dakota and until in Arkansas in the south.

He is widely distributed and of many large populations of more than 1000 individuals were counted. The majority of the populations much are restricted and count between 10 and 100 individuals.

The number of seedlings of Cypripedium reginae has tended to decrease for a few years, especially in the areas more in the south of its distribution.

The presence of a very large population of stags of Virginia is one of the causes of the disappearance of the royal cypripède in its habitat. Indeed, the stags of Virginia graze the cypripèdes which cannot then produce seeds any more.

References

Natural Serf, www.natureserve.org
Demographic analysis off dormancy and survival in the terrestrial orchid Cypripedium reginae, Kéry, Mr., Gregg, K.B., Newspaper off Ecology (2004) 92,686-695.
Germination and seedling development in five species off Cypripedium L., Curtis, J.T., Amer.J.Bot. 30 (3): 199-206, March 1943
Environmental factors and the growth off native orchids, Stuckey, I.H., Amer.J.Bot. 54 (2): 232-241, 1967
Flora off North America, www.efloras.org
Cypripedium reginae Walt, Rare seedling fact sheet, Maine Department off Conservation Natural Areas Program, 2004
Pollination Notes One Minnesota Orchids: The Lady' s-slippers Charles L. Wire-drawer, Winter 1994, Minnesota Seedling Close 13 (2)
Laurentienne Flora, Marie Victorin, 1995

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