The genus Cypripedium (Orchidaceae) in the flora of Vietnam

Two species are Cypripedium subtropicum S.C.Chen & K.Y.Lang and Cypripedium lentiginosum P.J.Cribb & S.C.Chen .

The record of C. subtropicum in Sin Ho district  of  Lai  Chau  province  of  northwestern Vietnam  presented here is new for the flora of the country.  Early record in northern Vietnam in Ha Giang  province is based on literature data (Jiang, Liu,  2009). Description of C. singchii (Liu, Chen, 2009)  is based on material collected in the same place  and probably from the same population (Jiang, Liu,  2009).

With the species as Cypripedium lentiginosum, it is one of the most sensitive elements  of  primary  open  limestone  forests  and  scrub  associated with a specific set of habitat conditions,  such as rocky high elevations, nutrient availability,  mossy steep slopes and permanent humidity. Such  forests are critically endangered in the area and  occupy presently miserable table-like summits of  karstic remnant limestone hills or ridges surrounded  typically by vertical cliffs. This unique kind of  vegetation composed with many aboriginal species  disappears very fast due to timber exploitation,  forest fires, urbanization, soil erosion and climate  drought connected with wide deforestation. This species was claimed that growing in Quan Ba (Ha Giang).

Cypripedium subtropicum S.C.Chen & K.Y.Lang

Habitat, phenology and conservation status. 

Terrestrial rhizomatous herb. Primary and secondary  broad-leaved evergreen and semideciduous forests  (commonly with Alnus nepalensis D. Don) on steep  slopes composed with soft shaly limestone, often  along rocky stream valleys on moist alluvial well  drained thin soils rich in humus.  (1000)1400– 1600 m a. s. l. Fl. July–August.

Very rare.

Estimated  IUCN Red List status – EN.

Distribution

Southwestern and southern  China: southeastern Tibet (Medong county) and  southeastern Yunnan (Malipo county), northern Vietnam: Ha Giang (Quan Ba district) and Lai Chau  (Sin Ho district).

Cypripedium subtropicum on Cypridioideae-e-monocot.org

Cypripedium subtropicum on Turczaninowia 20(1)

Cypripedium subtropicum on Turczaninowia 20(1)

Cypripedium lentiginosum P.J.Cribb & S.C.Chen

Habitat, phenology and conservation status.

Terrestrial  and  lithophytic  rhizomatous  herb. Primary  and  secondary  broad-leaved  evergreen open forests and thickets on rocky steep slopes and mossy boulders just below ridges composed with solid karstic limestone, commonly in grassy places on wet, well drained soils rich in humus. 2100–2300 m a. s. l. Fl. May–June.

Very rare.

Estimated IUCN Red List status – EN.

Distribution.

Southern China: southeastern Yunnan (Malipo and Pingbian counties),

Vietnam: northwestern Ha Giang (Quan Ba district);

Cypripedium lentiginosum on Orchidspecies