On the Oslo Ridge, you find perennials from the coastal landscapes and islands of the inner Oslo fjord. The fjord and the protected location make the Oslo area a little warmer in spring and fall than the rest of the region.
Blooming in the spring are liverleaf (blue Hepatica), small pasque flower, wood anemone, buttercup anemone, cowslip and lilyofthevalley. Colorful eyecatchers in June/July are purple bloody crane’sbills, blue dragonheads, yellow willowleaved inulas and creamy white dropworts. Aromatic herbs like wild onion, thyme and oregano are also found here. Some of the around 100 species on the Oslo Ridge are threatened in nature due to afforestation and human wear and tear.
The preservation of viable populations of these threatened species is one of the most important tasks of the Botanical Garden. We serve as a living gene bank for dwarf thistle, rock cinquefoil, pea vetch, mountain clover, dragonhead and several other local, rare species.
Reverdin’s blue
A rare butterfly on the Oslo Ridge you also find licorice milkvetch. A very rare blue butterfly, Reverdin’s blue, is totally dependent on this plant – its larvae live only on this milkvetch. At present, it is uncertain whether there are any of these butterflies left, or if it is extinct in Norway.
