Several plants found in the mountains in the northeast part of the park, where rainfall is lighter, are more typical of the hot, arid lowlands of eastern Washington and Oregon. Some of these are nodding onion, woolly eriophyllum, and barestem lomatium—their presence in the mountains may be due to the fact that the broad ridgetop meadows in the northeastern part of the park are remnants of a lower plain where these plants grew before the Olympic Mountains had risen to their present height. As the mountains were pushed up, these plants could have continued to grow and reproduce despite changing conditions. On hillsides where the rock has weathered only into chips, or where little soil has formed, carpets of spreading phlox and rosettes of Lyall lupine are most conspicuous in early summer. Some plants grow on talus slides, on rocks broken and tumbled from peaks above, and on rocks laid bare by retreating glacial ice. Lichens and mosses, pioneers among plants, etch the rock with weak acids and thus start the slow conversion of rock into soil. Some flowering plants are pioneers, too. Common ones growing in crevices and soil pockets among the rocks in the Hudsonian zone are smooth douglasia, alumroot, and bluebell. Eventually, a flowered meadow or forested slope develops where first there was only bare rock. The Arctic-Alpine zone is the region above timberline. It corresponds to the arctic meadows of northern Canada. In the Olympics its lower limit is about 5,000 feet and its upper limit is the tops of the peaks. It is a harsh environment. Its shallow soil and rocks, its wind and prolonged snow and cold exclude all but the hardiest perennials. Annuals cannot live there. One growing season is too short for a plant to start from seed, complete its vegetative growth, flower, and ripen its seeds. Many of the plants are surface plants, such as mosses and lichens, which do not produce flowers. But even the flowering plants hug the ground. Their over-wintering buds are at or below the ground surface. It is a struggle for moisture and against time. Only low perennials, having small, tough leaves covered with hairs or wax, are able to survive. These properties help protect the plants against loss of water. There are 8 kinds of mountain plants in the Olympics that are not known to grow anywhere else. It appears that these plants grew in the Olympic Mountains before the ice came and were able to survive on ridgetops that remained free of glacial ice during the long cold periods. They are thus relicts from preglacier time. None of them are trees and only two are shrubs. All the rest are herbs. Several of these, among which piper bellflower and Flett violet are especially attractive, may be found on Hurricane Ridge and on the upper slopes of Mount Angeles.