Thismia okhaensis (Thismiaceae) – a new fairy lantern from Vietnam
Thismia okhaensis - Photo by Luu Hong Truong
These heterotrophic plants contain no chlorophyll and therefore do not photosynthesize. They often live symbiotically with fungi to absorb nutrients and resolve complex organic compounds into simple substances (such as resolving cellulose and lignin into inorganic substances), and also to assimilate simple substances into complex compounds. Like mushrooms, they have an important role in the cyclical process of material and energy in nature.
The genus is known to have more than 30 mycotrophic species occurring mainly in the Asian and North American tropics, with a few species present in the subtropical and temperate areas in North America, East Asia and Australia. Thismia was traditionally classified in the Burmanniaceae, but a recent molecular work supports its position within the Thismiaceae.
During the last two years, researchers of the Southern Institute of Ecology under the Vietnam Academy of Science and Technology have collected samples of Thismia. After examination of the specimen and consulting the literature, the specimen labeled KH 638B was found to be a new species to world science, and also the fourth species of the genus for the flora of Vietnam. Prior to this paper, three species of Thismia had been recorded in Vietnam, namely Thismia annamensis, T. javanica and T. tentaculata.
The specimen was collected at the 800 elevation, in O Kha Valley, Khanh Son protection forest, Khanh Son District, Khanh Hoa Province.
Nomenclature: Thismia okhaensis Lưu, Tịch, G. Trần & Q.D. Đinh, sp. nov
The new species, Thismia okhaensis, belongs to the Sarcosiphon section on account of having mitre-like flowers. It is allied to T. angustimitra and T. mirabilis, but differs in having a convex top mitre with three digitate furrows, involucral bracts with round apex, apertures totally hidden under the mitre, and connective appendages with lateral teeth.
The species is very rare, only 3 individuals are known from the type locality even though scientists have been surveying biodiversity throughout Khanh Hoa Province and neighbouring provinces for many years. So the discovery and recording of the species is a fortunate development for the group of scientists.
The saprophytic plants are very sensitive to environmental changes, therefore they should be put in the list of species threatened by extinction. They need to be protected by maintaining and protecting characteristic habitats.
The protection forest in O Kha Valley, Khanh Son District, Khanh Hoa Province is an evergreen tropical forest and biodiversity site, however, it is threatened by human encroachment and agricultural plantation. This species should be considered for placement in the Endangered category of IUCN Red List.
The description of the new species was recently published on the website of Phytotaxa: http://dx.doi.org/10.11646/phytotaxa.164.3.4
Translated by Minh Tam
