Above the limit of trees, in what have been called "pumice fields," a characteristic series of plants appears. This belt ranges in altitude from 6,500 to 10,000 feet. It is best developed on the east side of the mountain, where the avalanches from Little Tahoma have covered great areas with more or less finely divided basalt. Conspicuous plants of this region are Lupinus lyallii, Spraguea multiceps, Polemonium elegans, Hulsea nana, Erigeron aureus, Oreostemma alpigena, Polygonum newberryi, Poa suksdorfii, Draba aureola and Smelowskia ovalis. The last three ascend to above Camp Muir, altitude 10,000 feet.
The first botanist to visit Mount Rainier was Dr. William F. Tolmie, surgeon of the Hudson's Bay Company, who reached the mountain in 1833. He made considerable collections, which were sent to Sir William Hooker. Among Tolmie's plants were several not previously known.
The writer collected on the mountain in 1888 and again in 1889 and 1895. Since then the following botanists have made collections on Mount Rainier: Rev. E. C. Smith, in 1889 and 1890; Dr. E. L. Greene, in 1889; Mr. J. B. Flett in 1895, 1896 and since; Mr. M. W. Gorman in 1897; and Mr. O. D. Allen from 1895 to about 1905.
Most of the work done thus far has been in Paradise Park and its immediate vicinity. Next to this, the flora of Spray Park is best known. The east slopes of the peak have been partially explored, but to the knowledge of the writer no botanist has ever yet collected on the west slopes.
The list of plants here given numbers 315 species. In preparing it, Longmire Springs, altitude 2,850 feet, has been selected as the lowermost limit on the south side of the mountain, and Crater Lake, altitude about 3,500 feet, as the limit on the north side. It is quite certain that a considerable number of lowland plants will have to be added to the list here given, and it is possible that a few have been included that will have to be dropped, as the exact place of collection of some species is not clearly indicated on the labels of the specimens. Unless otherwise stated, the notes are based on the writer's observations and specimens, and refer mainly to the Paradise Park region.
There yet remains much to be done in the study of the Mount Rainier flora. A particularly interesting phase of it lies in the matter of altitudinal distribution of the various species.
No attempt is here made to list the plants lower than the ferns. The writer has made considerable collections of the fungi, liverworts and mosses; and Mr. O. D. Allen has also collected the mosses. These plants should receive a larger amount of attention from botanists who visit the mountain in the future.
The following plants were first described from specimens obtained on Mount Rainier:
Petasites nivalis Greene.
Luina piperi Robinson.
Prenanthes stricta Greene.
Oreostemma alpigena (Torrey & Gray) Greene.
Aster amplifolius Greene.
Arnica aspera Greene.
Castilleja rupicola Piper.
Mimulus caespitosus Greene.
Veronica allenii Greenman.
Pedicularis ornithorhyncha Bentham.
Pedicularis contorta Bentham.
Pentstemon tolmiei Hooker.
Pentstemon newberryi rupicola Piper.
Gentiana calycosa Grisebach.
Gentiana calycosa stricta Grisebach.
Hydrophyllum congestum Wiegand.
Polemonium elegans Greene.
Polemonium bicolor Greenman.
Dodecatheon crenatum Greene.
Vaccinium deliciosum Piper.
Ligusticum purpureum Coulter & Rose.
Hesperogenia stricklandi Coulter & Rose.
Lupinus volcanicus Greene.
Stellaria washingtoniana Robinson.
Potentilla flabellifolia Hooker.
Luzula arcuata major Hooker.
Sitanion rigidum J. G. Smith.
Sitanion rubescens Piper.
Poa saxatilis Scribner & Williams.
The type specimens of Saxifraga tolmiei were collected by Tolmie on the "N. W. Coast." It is altogether probable that he got them on Mount Rainier, where the plant is so abundant.