Pentagramma triangularis subsp. triangularis
Petiole glabrous, not viscid-glandular. Blade thin and herbaceous to somewhat thick and leathery, not viscid-glandular, abaxially densely pale to bright yellow, adaxially glabrous. Distal pinnae mostly regularly lobed. Proximal basiscopic lobes of basal pinnae pinnatifid, often deeply so. 2n = 60, ca. 90, 120.
Habitat: Chaparral, pine and oak woodlands
Elevation: 50–1800 m
B.C., Calif., Idaho, Oreg., Wash., Mexico in Baja California.
We here restrict Pentagramma triangularis subsp. triangularis to plants with yellow farina and glabrous adaxial leaf surfaces occurring throughout a large region in westernmost North America. This subspecies comprises a complex of morphological, cytological, and phytochemical variants, at least some of which may deserve formal taxonomic recognition, following more detailed studies. Plants with yellow farina reported from Arizona, Nevada, and Utah may represent tetraploid hybrids between P. triangularis subsp. triangularis and P. triangularis subsp. maxonii and are not mapped herein.