| The slipper orchids of the genus Cypripedium in the Minshan, northern Sichuan |
| Cypripedium smithii is closely related to Cyp. tibeticum but usually has a smaller flower with a yellowish basal coloration heavily overlaid with red, resulting in a dark plum color. It prefers grassy habitats between open shrubs, again on limestone . I found it between 2400 and 3300 m. |
 |
|
|
| Cypripedium flavum is not as widespread as Cyp. tibeticum, but were it occurs it often grows by the thousands at altitudes between 2400 and 3400 m. So in Huanglong valley and some other similar travertine areas in the region. Usually its flower is light yellow with a blackish staminode and brown spots inside the pouch. Sometimes the spots occur also outside the pouch like in the specimen on photo1 from Huanglong valley. The plant shown in photo 2 is from a population of exceptionally strong plants on a steep clay slope, through which a seepage rich in limestone goes. The plants have the dimensions of the northeast American Cyp. reginae and not rarely carry two flowers per stem. The sepals and petals are slightly pink in this population which grows some 100 km to the northwest of Huanglong |
 |
 |
|
|
|
|
Not far from the interesting Cyp. flavum population mentioned above a colony of Cyp. shanxiense is thriving. This species usually carries a pair of slender flowers of dull ochre to intensive copper-brown on tall leafy stems and are related to the Eurasian Cyp. calceolus and North American Cyp. parviflorum. However, Cyp. shanxiense is unique in being self-pollinating. Prof. Leonid Averyanov was the first who found this in specimens growing around Vladivostok near the Russian Pacific coast. The pollen has a wax- or honey-like consistence and drips on the stigma. This is also true for the plants in Sichuan, where the species occurs on thin soil above limestone in shady to half shady conditions in altitudes of 2500 to 3000 m. |
 |
|
|
 |
A close relative is Cypripedium henryi, which has usually two to three, sometimes even four and rarely five greenish-yellowish flowers per stem . When fresh, they have an intensive honey odor and seem to be successful in attracting their pollinator by this means. I could not find evidence, that this species is also self-pollinating, although it has a very high seed set. Cyp. henryi is scattered but not rare in the Danyun gorge, where it grows in soil above metamorphic rocks as well as above limestone in open shade, often at the roadside at altitudes between 1800 to 2300 m. |
|
|
| Cypripedium plectrochilum , a close relative of the similar dwarf North American Cyp. arietinum often grows together with Cyp. henryi in the Danyun gorge, covering the same altitudes and soil conditions. However, Cyp. plectrochilum is much more numerous and I know one colony at an altitude of 2250 m, which consists of about 1000 flowering stems, growing in dappled shade in open shrub. |
 |
|
|
 |
The small but colorful Cypripedium guttatum is not very abundant in the Minshan and I have only found it in small groups or as single specimens in open meadows or in bright places in open shrub at altitudes between 2900 and 3300 m, often in clay-rich soil above limestone. The thin creeping rhizome is always very near the surface of the friable soil. |
|
|
| Cypripedium bardolphianum is a strange little slipper orchid with only one true leaf. The other leaf is in fact the floral bract. It grows with a creeping rhizome like Cyp. guttatum, but prefers open shade. It is always found in thin soil or thin humus layers above limestone at altitudes between 3000 to 3400 m. |
 |
|
|
 |
Related to Cyp. bardolphianum but much bigger and with a pair of spotted leaves (one true leaf and a leaf-like bract) is Cypripedium sichuanense, a species I recently described from Northern Sichuan, where it grows in soil above limestone at altitudes between 2000 and 2500 m. I found it in shady situations as well as in nearly full sun, where it is smaller but produces more flowering stems from the short stout rhizome. |
|
|
| A curious little slipper orchid related to Cyp. debile is the tiny Cypripedium palangshanense. Because of its very small stature of just a few centimeters it is very difficult to find this plant in the wild and thus only very few records are found in the literature. I know only one site in the Jiuzhaigou reserve, where the species grows in open shrub in thin soil above limestone scree at an altitude of 2700 m. |
 |
|
|
| In the Minshan most cypripediums flower usually around the middle of June. The low growing species like Cyp. plectrochilum and Cyp. henryi flower in May. All cypripediums are vulnerable of being stolen from the wild regularly and in quantity by commercial collectors or occasionally by enthusiasts. DonŐt buy wild collected cypripediums, because this enormously drives the diminishing and even total destruction of their populations. And of course donŐt collect them in the wild! More and more laboratory grown seedlings are available, meanwhile in part also of the Chinese cypripediums. In the Huanglong reserve, which insures an excellent in situ conservation of the local cypripediums, we have established a nursery in 2002 that will produce cypripedium seedlings from seed (as well as other local plants, not only orchids), which subsequently will be offered for horticulture (within the next years) to reduce the pressure of illegal collections of wild cypripediums. |