Distribution of Alpinia (Zingiberaceae) and their use pattern in Vietnam

The world population ca. 65-80% in developing countries depends on medicinal plants for primary health care, due to poverty and lack of access to modern medicine [1]. Vietnam is one of high biodiversity rich countries of the world with diverse flora. A total of 13766 plant species (2393 non-vascular and 11373 vascular plants) have been recorded in Vietnam, of which 3% of genera are endemic [2], and only ca. 3900 medicinal plant species has been used to treat various diseases [3]. The present paper deals with the distribution of Alpinia species and their traditional use by the local communities in Vietnam to cure various diseases. The people living in rural and mountainous areas are economically marginalized, but rich with natural resources in their vicinity. They don’t have enough access to modern medicine and mainly depends on natural resources for medicine based on their traditional knowledge received through generations.


Introduction
The world population ca. 65-80% in developing countries depends on medicinal plants for primary health care, due to poverty and lack of access to modern medicine [1]. Vietnam is one of high biodiversity rich countries of the world with diverse flora. A total of 13766 plant species (2393 non-vascular and 11373 vascular plants) have been recorded in Vietnam, of which 3% of genera are endemic [2], and only ca. 3900 medicinal plant species has been used to treat various diseases [3]. The present paper deals with the distribution of Alpinia species and their traditional use by the local communities in Vietnam to cure various diseases. The people living in rural and mountainous areas are economically marginalized, but rich with natural resources in their vicinity. They don't have enough access to modern medicine and mainly depends on natural resources for medicine based on their traditional knowledge received through generations.
In recent years, there has been an increasing interest in the study on plants as a medicinal source and their traditional uses in different parts of Vietnam. There have been many reports of traditional medicinal plants for curing diseases by Vietnams' ethnic minorities and indigenous communities (54 different ethnic communities). Most of the ethnic communities have their own cultural traditions of using locally available animal and plant species, while many traditional remedies are closely guarded cultural secrets. Traditional medicine systems in Vietnam comprises of Traditional Vietnamese Medicine and Traditional Chinese Medicine, have a history spanning over 2000 years. The Government of Vietnam launched a programme "Strategy for Development of Traditional Medicine in Viet Nam to 2010" in 2002 and encouraging community preventive and curative health care through these systems, which has become now state policy to equally support the use of traditional and western medicine [3]. Today, an estimated 75% percent of Vietnamese people use traditional medicine as their primary source of treatment for common health problems [3].

Study area
Vietnam is among one of the biodiversity rich countries in the world. Vietnam occupies the eastern and southern part of the Indo-Chinese peninsula in Southeast Asia, covering an area 3,31,123 km 2 (north to south length of 1,650 km) along with south China sea coast, China in the north and Laos and Cambodia are in the west with 63 provinces. Vietnamese are basically the descendants of nomadic Mongols from China and migrants from Indonesia.
The country varies from mountainous (the Hoang Lien Son mountain range in the northwest up to 3000m to coastal plains of the Red river delta and Mekong river delta) covers ca. 75% and only 15% of area is farm land [4]. The climate of Vietnam lies in the tropics and varies considerably from North to South and depends on the southwest monsoon in summer and rainy seasons and the northeast monsoon in winter season. The average rainfall ranges from 1300-3200 mm and the annual average temperature ranges between 21°C in north and 27°C in south [4]. With the complexity in topography and climate diversity 6 categories of the forest types has been identified viz., natural forest, timber forest, bamboo forest, mangrove forest, rocky mountain forest and plantations. The country is divided into 7 ecological zones (Northern Mountains, Red river delta, Mekong delta, North central, South central, Eastern highlands and southeast) and plantation of Acacia, Eucalyptus, pine and rubber was done long back for commercial purposes, which has contributed significantly to forest cover [4].

Collection of specimen
The survey was conducted throughout the country and the specimens including leaves, flower or fruit of different Alpinia species were collected and were identified [5]. The voucher specimens collected from the field have been deposited with the Institute of Ecology and Biological Resources at Vietnam Academy of Science and Technology (VAST) and Vietnam National Museum of Nature (VNMN).

Ethno-botanical survey
During the survey the information on the ethno-botanical use of different species of Alpinia in various provinces was conducted during 2010-2012. The information gathered through interviews of local people, traditional healers, collectors and traders independently considering their age groups and sex (mainly women as they use and keep indigenous knowledge), and also group discussions with the help of semi-structured questionnaire and the guided field walk in each province as described [6]. The information on ethno-botanical use, such as medicinal, parts' used and the modes of medicine preparation along with the availability of the plants in the area and the local name were documented and identified [7]. The data was analyzed in Excel spreadsheet.

Results and Discussion
The genus Alpinia (in memory of an Italian botanist; Prospero Alpina, 1533-1617) is the largest, most widespread and taxonomically complex genus under family Zingiberaceae with 230 species occurring throughout the tropical and subtropical Asia (Sri Lanka and the Western Ghats of India to China, Japan, all of southeast Asia, the Pacific as far as Fiji, Samoa, and the Caroline Islands, and Australia as far south as northern New South Wales) [8,9]. Alpinia species usually prefers to grow in humid places, like weather from cold to warm, hence their distribution is widespread in Vietnam.

Habitat preference and distribution
In all 31 species of Alpinia has been recorded from Vietnam shows high richness of Alpinia species as compared to the neighboring country Thailand (17 species with 2 varieties) [10]. Out of these 31 species, 16 are being used for medicinal purposes by the local people. The details including latin name, local name, altitude, habitat, parts used, mode of preparation and medicinal uses of each species is given in Table 1.
Most of the species of Alpinia prefers to grow in wet and shady places such as under forest canopy, while others like to grow along the road sides or grassy slopes, viz. Alpinia hainanensis and Alpinia oblongifolia (A. chinensis) at varying altitude from 30 to 1500 m. The distribution of each Alpinia species (Figure 1) which indicates that the majority of Alpinia species distributed in the northern provinces of the country. Much of Alpinia species are native to China followed by species from Indian origin.

Flowering and fruiting
Among important phenophases, flowering and fruiting of Alpinia species mainly depends on their habitat preferences ( Figure 2

Conclusion
In total 31 Alpinia species have been reported from Vietnam, of which 16 species are traditionally used for health care by Vietnamese. Most of the species used to treat common diseases, which are very effective in stomachache, indigestion, cholera, dysentery, diarrhea, vomiting, excessive urination at night and natural ejaculation from different plant parts (rhizome, tuber, leaves, flowers, seed and fruit) and among them rhizome is mostly used. Most of the medicinal preparations (decoction or extract) are administered orally. Until now, there are many species used to treat incurable diseases such as fatty liver, cirrhosis of liver and cancer, which are usually harvested from the wild. The traditional healers and the elderly people have familiarity with the plant species along with its uses. Whereas, the younger generation does not know most of the plants and their medicinal uses, due to which the folk is under threat and squeezing rapidly. Therefore, there is a need to identify young people who may take this folk ahead in the supervision of elders or traditional healers. The present distribution of Alpinia also suggests that the species specific sites may be identified for the conservation in nearby provinces in their natural habitats similar to Gardens at different places in the country (Sa Pa, Tam