Working with the National Museum of Wales and the Countryside Council for Wales, the Garden is collecting the seeds of, and propagating, some of Wales’s rarest plants. These include Britain’s rarest and most critically-endangered trees, the Ley’s Whitebeam (Sorbus leyana) and a hawkweed that only grows naturally on rocks around a single waterfall in the Brecon Beacons. The Garden’s estate is managed as a low intensity organic farm. Its flocks of sheep and herds of Black Welsh cattle are controlled to conserve and increase the range of many rare and nationally declining native wild plants and fungi. These include the greater butterfly orchid, whorled caraway and waxcap fungi. The Great Glasshouse, the Garden’s iconic visitor attraction which houses plants from the Earth’s Mediterranean climatic regions, doubles up as a refuge for some of the world’s rarest plants. An example of this is McCutcheon’s Grevillea (Grevillea maccutcheonii). Five years ago, there were only 10 of these small Western Australian shrubs left in the wild, all growing together in one small patch. One of these plants was micropropagated at King’s park Botanic Garden in Perth, Western Australia and sent to the National Botanic Garden of Wales in 1999. Visitors to the Great Glasshouse saw its lovely red and yellow flowers for the first time in 2003.