Seaside bone (Hypogymnia heterophylla) COSEWIC assessment and status report: chapter 4
Global range
Hypogymnia heterophylla is endemic to the Pacific coast of North America from California to the southern tip of Vancouver Island, British Columbia (Figure 2). Since the 1996 status report (Goward 1996a), its latitudinal range now includes the state of Washington, with six occurrences in the Puget Sound region (Glew pers. comm. 2007). Many occurrences are reported for coastal regions of Oregon and California as far south as Los Angeles/Santa Barbara (Glavich et al. 2005, OSU, SBBG herbaria databases).
Canadian range
Hypogymnia heterophylla, first found in Canada in 1991, is at the northern edge of its range in Canada (Goward 1996b). It has a distinctly restricted distribution (Figure 3) and ecology. The four known locations where it occurs are at the southwest tip of Vancouver Island in East Sooke Regional Park, Bentinck Island and Sheringham Point. These sites lie northwest across the Strait of Georgia/Juan de Fuca Strait from the Puget Sound occurrences in Washington State.
Figure 2.The global distribution of Hypogymnia heterophylla.
Figure 3. The distribution of Hypogymnia heterophylla in Canada.
All four locations of Hypogymnia heterophylla are within 100 m of the ocean coast in exposed, windswept, open shore pine forests.
Designatable units
Only a single designatable unit is recognized since all of the populations occur within relatively restricted shoreline stretches within a single COSEWIC National Ecological Area.