Giáo sư Averyanov L., một chuyên gia hàng đầu về họ Orchidaceae tại Việt Nam, có ý kiến và nhận định như sau:
“...This very rare monotype genus endemic to southern Vietnam, is Christensonia vietnamica. Collecting of this species is really great success. This plant many last years was regarded extinct in the wild…”
Gần đây có rất ít thông tin về tình trạng của loài lan này trong tự nhiên. Christensonia vietnamica Haager chỉ được ghi nhận tại tỉnh Khánh Hoà (Haager, 1993; Christenson, 1996; Christenson, 2001).
Addition data for Christensonia vietnamica Haager
Christensonia vietnamica is an epiphytic orchid endemic to Viet Nam. It is the only member of its genus and was formally described in 1993 although is thought likely to have been traded within Viet Nam prior to this date. The only confirmed records are from a site in Khanh Hoa province in southern Viet Nam although there are indications that the species also occurs or occurred elsewhere. There is very little recent information on its status in the wild. It is listed as critically endangered in the most recent national orchid checklist and at least one authority believes the species may now be extinct in the wild.
ảnh theo caycanhvietnam.com
Limited wild export (~ 6500 specimens) from Viet Nam has been reported, almost all in the years 1998-2000. No export at all has been reported since 2003. The species is currently (2007) relatively widely offered commercially outside Viet Nam as artificially propagated plants, and there has been a small amount of international trade in artificially propagated specimens in recent years. The species has also been used to create hybrids with related species, for example those in the genera Renanthera and Vanda.
No recent illegal international trade has been documented.
No non-detriment findings have been conducted for C. vietnamica.
The absence of any recorded trade in wild plants in this species since 2003 and the lack of indication of any illegal trade mean that the species should be considered of Least Concern. However, it is possible that the cessation of export has been because plants are no longer available, and this could be because they have been almost or entirely collected out. Any increase in/ resumption of trade would be of concern, given the lack of information available upon which to base non-detriment findings. The species may merit inclusion in Appendix I of CITES
The orchid Christensonia vietnamica is an epiphyte recorded from the wild in lowland deciduous gallery forest on silicate basement rock substrate (Averanov and Averyanova, 2003; Haager, 1993). The species is endemic to Viet Nam (Nguyen Tien Ban, 2005; Nguyen Tien Tich, 2001; Pham Hoang Ho, 2001), with confirmed records from Khanh Hoa province (Haager, 1993; Christenson, 1996; Christenson, 2001). Stems stand 7-30 cm with strap-shaped leaves to 6 cm long. Plants contain 1-3 branching inflorescences, each containing 3-5 (usually 4) flowers, with yellow-green petals and white lip midlobe. Flowering occurs from April to August. C. vietnamica is closely related to Aerides, Vanda and Rhyncostylis (Schuiteman and de Vogel, 2000; Christenson, 2001).
International trade of Christensonia vietnamica appears to be exclusively confined to ornamentals. CITES trade data suggests that until 2004, approximately 95% of the global trade of C. vietnamica was in wild specimens (see Table 1). The recorded trade in C. vietnamica since 2004 has only been with artificially propagated specimens exported from Malaysia and Thailand mainly to Japan, France, Guadeloupe and the US.
The attractive appearance of the species, with its unusually coloured flowers, and its taxonomic distinctness evidently made the species desirable amongst orchid collectors when it was first discovered in the early 1990s. This is likely to have fuelled over-collection of wild plants. The species is now advertised for sale by a number of specialist orchid nurseries (e.g. in Belgium, South Africa and the USA) apparently as artificially propagated plants. These do not command premium prices indicating that demand for the species is not now particularly high.
The species has been used to create intergeneric hybrids, for example with Renanthera (X Chrisanthera) and Vanda (X Chrisanda)
Status in Vietnam
Christensonia vietnamica is not listed in Viet Nam’s Red Data Book (Anon, 1996; 2007). The species is confirmed in the wild from Khanh Hoa province only (Haager, 1993; Christenson, 1996; Christenson, 2001) with unconfirmed records from Ninh Thuan (Vu Anh Tai, 2007) and Gia Lai provinces (Anon, no date).
No data on population status or trends have been located, but the frequency of species occurrence has been listed as very rare with approximate conservation status given as critically endangered in the most recent national orchid checklist (Averyanov and Averyanova, 2003). Nguyen Tien Hiep (2007) considers that the species may already be extinct in the wild.
Management and trade
Recorded trade of Christensonia vietnamica from Viet Nam has been almost entirely in wild specimens, with only nine specimens recorded as being artificially propagated and 37 from legal confiscation since the species was first described in 1993. Trade in 1997 comprised just seven specimens, while in 1998 the trade peaked at 4547 recorded specimens. The vast majority (approx. 93%) were destined for the US market with most of the remainder imported by Japan. Trade in 1999 was dramatically reduced to 780 specimens, 62% of which were imported by Japan and 34% to the US. The year 2000 saw a slight increase in exported wild specimens to 1060, with 52% imported by Japan, 47% by Taiwan and 1% destined for Thailand. In 2001 no wild specimens were exported from Viet Nam, and only 92 more were exported to the end of 2003 and all of these to the US. Export of C. vietnamica of any source from Viet Nam has not been recorded by national authorities since 2003.
The species is not currently listed as a protected species under national Decree No. 32/2006/ND-CP which forbids, or restricts, commercial exploitation of listed taxa. National restrictions exist for ‘special use forest’ (SUF). According to Decision No. 186/2006/QD-TTg it is prohibited to extract natural resources from SUFs except in certain designated areas, such as administrative zones, and then with permission from the forest management board only. However, it is not known whether C. vietnamica is found in any SUFs. There is no evidence of artificial propagation or cultivation of this species in Viet Nam.
No non-detriment findings have been conducted for C. vietnamica (CITES Management Authority of Viet Nam, 2007).