Seeking the northern boundary of the Cascade strawberry

Fragaria cascadensis K.E. Hummer, an endemic decaploid strawberry species, was described from the Oregon Cascade Mountains in the Pacific North-western United States. Its range occurs near Mt. Hood, the highest peak in the northern Oregon Cascades, in a band of higher elevation sites southwards to near Crater Lake in southern Oregon. The objective of this study was to examine in more detail, the distribution of this species at the northern end of its range. During summer and fall 2015, several excursions were taken in the vicinity of Mt. Hood to seek the wild distribution of Fragaria species. These excursions encircled the mountain by road and hiking. The most northerly observation of the occurrence of F. cascadensis was at Lolo Pass near the junction of the Pacific Crest Trail (PCT) and Route 18; the highest elevation occurrence was observed on Mt. Hood, 2 miles south of Timberline Lodge at 1589 m (5213RSQUO). Interestingly, the region to the east of the PCT and north of Hood, was populated with octoploid strawberries, Fragaria virginiana ssp. platypetala. This region included the Cooper Spur Recreational Area. The decaploid F. cascadensis was not observed in the north to northeast sector of the mountain. While the diploid F. vesca spp. bracteata (A. Heller) Staudt was present at the PCT at Cascade Locks near the Columbia River, no higher ploidy species were observed in that vicinity. Further research is ongoing regarding the distribution and phylogeny of the Cascade strawberry in Oregon.