Goldback fern in Idaho: a coastal disjunct

Publication Type:

Magazine Article

Authors:

Gray, Karen; Walker, Sarah; Hayes, Mike; Moseley, Bob

Source:

Sage Notes, Idaho Native Plant Society, Volume 20, Issue 4, p.12-13 (1998)

Call Number:

U98GRA01IDUS

Keywords:

Pentagramma triangularis ssp. triangularis

Abstract:

Goldback fern (Pentagramma triangularis ssp. triangularis-formerly Pityrogramma triangularis) is a distinctive fern with a pale to bright yellow waxy powder on the underside of its leaves. The mature leaves are leathery and green on the upper surface and have a triangular or pentagonal shape (depending on whether you are counting the bottom two pinnules as sides of the polygon). New leaves begin to appear in late summer and remain green during the winter. How did these plants come to be separated from the main distributions of their species? It is possible they had a more continuous distribution in the past, but the populations connecting Idaho and the west coast no longer exist. Alternatively, their spores may have dispersed from the west coast up the Columbia River Canyon to Idaho. Another possibility is that there may presently exist undocumented occurrences in the outcrops along the Columbia. Steep, mossy rocks are hard to explore, and future collectors may discover a more continuous distribution of goldback fern and the two associated mosses. Wilhelm Suksdorf collected Amphidium californicum around Bingen, Washington, which is about one third of the way up the Columbia toward Idaho.