THE FOURTH ZONE.
The trees which reach timber line are the alpine fir, the alpine hemlock, the Alaska cedar, and the white-barked pine. There are a few gnarled specimens of the latter on the ridges west of Sluiskin Falls, but the alpine fir, alpine hemlock, and Alaska cedar are the common trees. The trailing juniper, Juniperus communis sibirica, is common at timber line and extends down far below, trailing over rocky ledges. Its trailing habit, sharp foliage, and green berries readily distinguish it. One of the most characteristic plants at timber line is the golden aster, Erigeron aureus. This dainty little plant, about 3 or 4 inches high, has bright golden-colored ray flowers and a solitary head. The three heathers are common at timber line, at which elevation another rather rare heather is added, Harrimanella stelleriana. This plant spreads out flat on the ground with the leaves extending out from the two sides of the stem, with a terminal single flower. Some of the heathers are called Scotch heather, but there is very little similarity between our plants and the European.
A small goldenrod, Solidago algida, 6 inches to a foot high, grows among the rocks and gnarled trees. This dwarfed plant, with its small yellow flowers, looks puny when compared with the large plants of the fields in lower altitudes. Several asters, erigerons, pentstemons, and painted cups from the lower slopes reach timber line, while two or three of these extend beyond into, the pumice fields. This is also true of the two little woolly cudweeds before mentioned.
Last Updated: 15-May-2007