Annotated Check List of the Alpine Vascular Plants of Specimen Mountain, Rocky Mountain National Park, Colorado

Abstract

This investigation catalogues the vascular plant species occurring on a geographically easily definable alpine area in Rocky Mountain National Park, Specimen MVountain. In addition the abundance and environmental preferences of each taxon are noted. A total of 178 species in 35 families are listed for the area. Specimen Mountain lies on the continental divide in Colorado ap- proximately eighty miles northwest of Denver in the northwest corner of Rocky Mountain National Park. The elevation of the main summit of the mountain is 12,489 feet. Four other major summits and several minor ones, ranging in elevation from 11,526 to 12,429 feet, rise along the continental divide on roughly a north-south line from the main summit. The group of peaks and ridges forming Specimen Mountain represents a geographically somewhat isolated alpine area, separated from the Front Range to the southeast by the Cache la Poudre River, a tributary of the South Platte, and from the Never Summer Range to the northwest by the north fork of the Colorado River. Specimen Mountain is the remnant of an explosive Cenozoic vol- cano (Wahlstrom, 1944). It is an outlier of a formerly highly active volcanic area north of the Never Summer Range. The present high points of the mountain and the area surrounding them for about 1.5 square miles are highly eroded remnants of the volcanic plug formed following the last eruptions. Old lava flows are visible on the southern and western flanks of the mountain. The area surrounding Specimen Mountain shows evidence of in- tensive alpine glaciation. The northern and western slopes of the mountain are broken by deep, steep-walled glacial cirques. The ter- rain in this area is made even more irregular by mudflows and land- 423