Plant Communities (continued)

ABOVE TIMBERLINE

Above the Subalpine Zone—timberline marks its lower limit—lies the Alpine, or Arctic-Alpine, Zone. This is the distinctive "Land of Lilliput" of the plant kingdom, where nearly all existing plant species are in dwarf form. Some of the zone is barren rock, with only algae and lichen growth. Vast expanses of it, however, are covered with a cold, wet soil mantle which, during the brief summertime, presents a myriad of low, cushionlike flower clumps. Sometimes—usually throughout July—the effect is that of a vast carpet of flowers. The list of plant species is great. Showiest of the alpine flowers are the ALPINE BUTTERCUP (Ranunculus adoneus), with large, yellow, poppy-like flowers, often blooming at the very edges of snowbanks; the ALPINE FORGET-ME-NOT (Eritrichium argenteum), which grows in dense, low clumps and presents thick patches of bright-blue flowers; the MOSS SILENE, or MOSS CAMPION (Silene acaulis), a mosslike cushion plant with pink flowers (also found in Greenland and Alaska); the GRAYLOCKS ACTINEA (Actinea grandiflora), sometimes called "Old Man of the Mountain," with bright-yellow flower heads, usually wind blown and ragged, almost as broad as the plant is tall; the TUFTED PHLOX (Phlox caespitosa), better known here as alpine phlox, the cushion of which is sometimes entirely covered with pale-blue or white flowers; the BISTORT (Polygonum bistortoides), with dense spikes of tiny white flowers standing like miniature bottle brushes above the tundra grasses; the KINGS CROWN (Sedum integrifolium), a fleshy plant with dark-red blossoms, the whole plant often turning completely red in late summer; and the MOUNTAIN DRYAD (Dryas octopetala), with its curious 8-petalled, cream-colored flowers.

TIMBERLINE IS AT ABOUT 11,500 FEET ALTITUDE NEAR TRAIL RIDGE ROAD.

The manner in which these plants have adjusted themselves to their harsh environment is a fascinating story—one told effectively by the ranger naturalists in the high-country conducted trips which the National Park Service offers in summer. Some plants have coverings of soft "fur," others store liquids in fleshy parts, while still others have a hard outer coat. These adaptations protect them from loss of vital fluids due to the cold, dry air of these high altitudes. Reduced size also helps to conserve the energies of the plant; the dwarf willows, for example, have stems scarcely longer than the seed catkins they bear. These plants must condense their year's active life into the short span—as little as 5 weeks-of the growing season.

The story of the park's trees and flowers is intensely interesting, but can best be understood by more careful study than is possible in this brief handbook. Several excellent botanical bulletins are available for the more interested visitor, and we urge you to invest in one of them.