species, like Erythronium grandiflorum, can begin new shoot growth before snowmelt as they have their perennating buds located in bulbs buried deep in the soil. As new leaves protrude from the snow, the new shoots give off heat from thermal reradiation and/or respiratory heat which melts the surrounding snow. This exposes more soil to solar radiation, heating it up and allowing new growth to accelerate. Medicinal alpine plants There are a number of alpine plants that are used economically. In the Himalayas, hundreds of species are traded for medicinal and aromatic uses. It is estimated that the annual trade of these plants amounts to millions of US dollars. Many households in rural Nepal and India rely on medicinal alpine plant trade as a source of income. This creates an increased need to focus on plant conservation in these areas, ensuring sustainable harvest as well as ecosystem sustainability. Some of the species harvested in Nepal include Neopicrorhiza scrophulariiflora, Nardostachys grandiflora, Aconitum spicatum, Dioscorea deltoidea, Aconitum heterophyllum, Rheum australe, and Bergenia. In the Indian Himalayas, the alpine medicinal plants such as Dactylorhiza hatagirea, Picrorhiza kurrooa, Aconitum heterophyllum, Fritillaria roylei, Podophyllum hexandrum are under severe pressure due to over-exploitation for commercial purposes. See also Alpinum (garden) Alpine Garden Society Flora of the Alps Notes References External links Greek Mountain Flora The genus Dionysia in Iran and Oman The Alpine Garden, Rock Gardening on the Net Japanese Alpine Plants, etc. The Gardeners Resource The Alpine Garden Society Plants by habitat Montane ecology