Information was gained during joined research missions with the local cooperation partners in 2003, 2004, and 2005. In the areas of interest, at first fresh plant material was collected and then shown to the native population of this region (mountainous areas of the Republics of Uzbekistan and Tajikistan, mainly belonging to the Hissar mountain range and the Pamir). Because of strict ethnological rules, only male person were asked, but these often showed plant material to further members of the family, also female persons. People were interviewed in their native language. Because of significant migrations during the time of the former Soviet Union, results were not related to specific ethnological sub-populations. Also, results were not related to the age of interviewed persons, but in most cases they had an age of about 50 to 60 years and were often recommended by rural communities as experts for traditionally used plants. People were asked about the local name and whether they are using these plants, and if so, which part is taken, for what purpose, and how is it prepared and stored.

Afterwards, the presented plant material was transferred to the national living Allium collections of Tajikistan in Dushanbe (curator: Prof. Dr. H. Hisoriev, accessions beginning with '6'), or of Uzbekistan in Tashkent (curator: Dr. F. Khassanov, accessions beginning with '4'), resp., for further cultivation, documentation, and taxonomic determination. In Tashkent and Dushanbe also voucher specimens of the accessions are deposited. Duplicates of some accessions were also transferred to the Taxonomic Allium Reference Collection of the Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany, to be re-determined if necessary. All data concerning collecting, cultivation, and questioning the native population were assembled in an electronic database.

If possible, results from interviews were compared with data available from literature as indicated in Table 1. It must be noticed, that most literature data do lack an unambiguous botanical description of plant material. Also, specific plant parts (leaves, bulbs, stems) used by men were not mentioned in most cases. This lack of former knowledge was closed by the now presented study.

The obtained data confirm that a remarkable number of wild Allium species is collected for consumption by Uzbek and Tajik people. Inside the visited countries, no further differentiation into ethnic groups was done. Several species are only used as vegetable and/or spice plants. They have special importance in rural areas during springtime when vegetables cannot be bought in the shops or are too expensive, and the garden plots do not give yield yet. Such species will be not considered here, because investigations are ongoing. Other wild Allium species are eaten due to a special health benefit, or applied in case of medical indications (see Table 1).

Three wild Allium species growing in Tajikistan and Uzbekistan (A. oschaninii, A. pskemense, A. praemixtum) are closely related to common onion. They are traditionally collected and used as spice like common onion, but only A. oschaninii and A. pskemense are also medicinally applied. Thus, we can confirm reports about the use of A. oschaninii in Uzbekistan and Tajikistan 46810. We can also verify that A. pskemense is sometimes grown in home gardens in Uzbekistan (Fig. 4) for usage like common onion and as medicinal plant.

Although the only species of subgenus Allium mentioned in Tab. 1 (A. filidens) is taxonomically rather distantly related to garlic, but it is medically used in a similar manner. This kind of medical applications also holds true for two species from the rhizomatous section Campanulata and for four species from the bulbous subgenus Melanocrommyum. This usage is apparently not strictly related to the content of the cysteine sulphoxide alliin ('mother compound' of the active principle), which is high in garlic, A. filidens, A. barsczewskii, and A. jodanthum, but very low in the species of subgenus Melanocrommyum shown in Tab. 1 11. Further studies will show whether other related compounds not determined yet or completely different chemical compounds might be the reason for this usage.

Allium komarowii (Fig. 5) owns obviously a rather strong medical activity, because it is used as anabolic drug for horses 12. Also this kind of activity could not be correlated to high cysteine sulphoxide contents 11, but this species contains a conspicuous red dye, which is chemically a sulphurpyrrol 13. The purified substance showed a strong antioxidative effect but contribution to the health benefit of the entire plant is not clear until now.

Special dishes, which are much esteemed for strong tonic properties, are prepared from the leaves of three species of the subgenus Melanocrommyum: A. motor, A. rosenbachianum, and A. rosenorum. According to our information, these dishes are explicitly consumed because of the tonic property. Also these plants contain the above mentioned red dye, which is regarded as a 'sign of authenticity' when the leaves are collected in April and May. The term 'motor' means 'health', but the local names of the other two species are not related to application. The questioned people always denied that these plants are used as spice.

We were only able to get confirmation that pickled young bulbs of A. stipitatum are used as spicy vegetable and not as medicine. However, young bulbs of A. suworowii are identically prepared but medicinally used. Both species contain only traces of cysteine sulphoxides 11. Thus, we must conclude that other substances must be responsible for the differing usages also in this case.

Application against scurvy was only reported in the literature for A. talassicum and is not confirmed by own data. It can be assumed that this disease has lost importance because of a better general diet and availability of modern pharmaceuticals for treatment.

The wild Allium species listed above are mainly applied fresh or after boiling of mostly dried material (Tab. 1). Fumigation (A. fedschenkoanum) and alcoholic extraction (A. jodanthum) were only once reported.

In Uzbekistan and Tajikistan, most of the wild species shown in Tab. 1 are not simply used instead of common onion and garlic, but are very specifically applied. This fact may illustrate that collection and application of wild Allium species reflects an apparently rather ancient tradition. Several people interviewed during our expeditions underlined that often a certain plant is used by only a part of population living in a specific area, or when commonly applied species are missing in this area. The knowledge of wild Allium species was also not observed throughout a local population. Some persons questioned even did know nothing about any wild Allium species.

Because the interviews were not always successful and our research missions did not cover the whole territories of both countries, the presented data may only incompletely reflect the existing knowledge in Tajikistan and Uzbekistan. Nevertheless, we were able to find evidence that several Allium species mentioned in literature as "edible plants" without detailed specification were utilized for medical applications. Certainly some more edible wild Allium species than mentioned in Tab. 1 are also medically applied. Additional investigations seem to be essentially necessary.

The author(s) declare that they have no competing interests.

All authors took part in the research missions and in collecting and interpretation of the information gained. Additionally, planning and organisation the missions was managed by FOK in Uzbekistan and by HH in Tajikistan. RMF and FOK dealt especially with the botanical and MK with the chemical aspects of research.