TYPE. CANADA. British Columbia. Clearwater Valley, base of Battle Mtn, 1 km north of Philip Creek, 51°52' N, 119°59' W, on branch of Picea, 800 m, 2009, T. Goward 09-737 with T. Spribille & C. Björk (UBC, holotype; CANL, GZU, H, isotypes).

Description. Life form: lichenized fungus.

[Modified from Goward et al. 2012] Thallus loosely appressed to trailing, extremely variable, up to 5–8 (–13) cm across; lobes irregularly branched. First-tier lobes up to 2–3 (–4) mm wide, contiguous or loose, obscuring the substrate or sometimes not, at the tips weakly plane to concave in cross-section, inwards becoming convex. Second-tier lobes loosely overlapping or trailing, furnished with conspicuous apical and subapical soralopodia (see below), often massing into low side-on ridges and intervening depressions. Upper surface whitish to pastel green or blue, except chestnut brown in exposed sites, weakly shiny throughout, usually firm, except often readily abraded at lobe tips and in vicinity of soralia, with sparse or numerous (morph ‘‘tessellata’’) stress cracks, irregularly flecked with black mottling, usually with black borders as seen from above; soredia present or sometimes not (morph
‘‘tessellata’’). Vegetative propagules mostly restricted to second-tier lobes, arising in five ontological
contexts: (1) apical and/or subapical soralopodia, these copious to sparse (morph ‘‘tessellata’’), capitate
to mound-forming, in the latter case up to 0.8–1 mm across and 0.3–0.4 mm high (0.2–0.3 mm across in morph ‘‘tessellata’’), at length disintegrating or bursting open above, and then giving rise respectively to expansion cortidia or to rim cortidia 20–25 mm across; (2) laminal micropustules, these copious to sparse or often (in morph ‘‘tessellata’’) lacking, arising on ridges alone, absent in intervening
depressions, up to about 0.1 mm across, unevenly spaced, at length replaced by ultimately coalescent,
soredia-bearing soralia, the soredia to 30–40 mm across; (3) laminal diffuse soralia, these often present
toward thallus centre, bearing copious soredia. (4) laminal stress cracks and cortical flaps, these sparse
or often (in morph ‘‘tessellata’’) copious, sometimes disintegrating along the margins and then giving rise sparse to copious cortidia; and (5) laminal schizidia, these absent or, if present (morph ‘‘tessellata’’only), then usually sparse, patchy, restricted to to one side of the second-tier lobes, consisting of tiny cortical flakes up to 0.3–0.4 mm across. Perforations sparse or lacking on lower surface of first-tier lobes, sparse to copious along margins of second-tier lobes, the openings usually . 0.2 mm across. Medullary ceiling white except darkening in the vicinity of old ruptures in the lower surface. Lower surface mostly black, shiny, thin, easily torn, sharply winkled or folded. Apothecia rare, laminal, short stalked; disc concave, pale brown to dark brown, the largest ones 2–4 (–6) mm across, usually aborting; ascospores ellipsoid, at maturity up to (5.0–) 5.2–6.0 3 4.5–5.0 mm. Pycnidia absent or sparse over upper surface; conidiospores dumbbell-shaped, 4.5–5.0 3 1.0 mm.

Chemistry. Spot tests: cortex K+ yellow, KC-, C-, PD-; medulla K- (K+ pink after 30 minutes!), KC + pink, C-, PD-.  Lichen substances: Atranorin (cortex), physodic acid (major, constant), 3-hydroxyphysodic acid (submajor, usually present), 29-O-methylphysodic acid (present to trace, in about half the samples studied), and vittatolic acid (present to trace, in about one third of samples studied). Apinnatic acid is abundant and found in most samples at detectable levels in TLC. 

Substrate and habitat. Corticolous on tree trunks and branches. In southern inland British Columbia H. protea is most frequent within the dripzones (sensu Goward & Arsenault 2000) of deciduous trees, especially Populus. In nutrient-rich localities, however, it often becomes established – especially on Abies and Picea – in habitats not associated with dripzones.

Distribution. Western North America (Canada and United States), occurring in inland regions from Alaska east to the Northwest Territories, and south at least to Montana. South of the Canadian-US border, however, this species becomes infrequent.