Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.

Thallus: fruticose, caespitose, 1.5-5(-18) cm tall, +erect, variable in size, forming small to large cushions (up to 15 cm across), often richly but loosely, irregularly branched main branches: erect to decumbent, occasionally becoming pendent on branches and trunks of trees, up to 8 cm long, distinct, rather course, 0.5-1 mm in diam., rounded in cross-section secondary branching: irregular to anisotomic-dichotomous, usually with frequent lateral branching and numerous slender, coralloid, whitish fibrillae (adventitious) surface: olivaceous or rosy white to less often pale brown, smooth, generally dull and blotched with maculae, occasionally transversely annulate-cracked in some specimens with frequent coralloid or phyllocladial branchlets occurring singly or in fasciculate groups cortex: 90-130 µm thick, composed of thick-walled, gelatinized, fused hyphae intricated in various directions, covered by a thin (2-3 µm) colorless epicortex central medulla: composed of thick-walled, hyaline, longitudinally arranged hyphae, 4.5-7 µm in diam., generally distinct from each other and loosely intricate algal layer: 20-40 µm thick, usually completely surrounding the central medullary layer, but occasionally in larger branches may be absent on the lower side; algal cells: spherical, 8-10.5 µm in diam. Apothecia: rare, 12 mm in diam., terminal, globose,, at first immersed in swollen, stalked, branched apices, soon bursting apically to +expose a dry mass of black ascospores, surrounded by a +torn thalline exciple mazaedium: oriented apically, becoming exposed at an early stage of development by the irregular apical rupturing of the enclosing reeceptacle, when mature globose, black, partially surrounded by the receptacle asci: narrowly cylindrical, near maturity 4560 x 5-8 µm, 8-spored ascospores: green becoming dark violet-blue-black when mature, simple, spherical, 5-8 µm in diam. Pycnidia: occasional, forming at the terminal ends of the branches conidia: hyaline, rod-shaped, 4-5 x 1-1.5 µm Spot tests: medulla K- or +yellow, KC-, C-, P- or +yellow, I+ blue Secondary metabolites: sphaerophorin, although additional chemotypes are recognized elsewhere. Substrate and ecology: on bark including Myrica cali fornica and Pinus contorta (elsewhere on Pseudotsuga and Picea; sometimes also on humus or moss), lowland to montane or subalpine World distribution: boreal to temperate zones in Europe and North America (Pacific Northwest to Baja California) Sonoran distribution: reported from Baja California by Linder (1934), as S. coralloides Pers.; also reported from coastal California just north of the Sonoran region. Notes: The variety gracilis was originally described from trees on Guadalupe Island; it differs from the typical variety in that the thallus tends to have a smooth, +white (olivaceous to rosy), less often gray or brown surface, usually with much more lateral branching and numerous slender, coralloid, whitish fibrillae, and the spores are smaller than the typical variety. It also occurs more often on trees rather than soil or rock, and is the more common morphotype in temperate to boreal areas of the west coast of North America, where it sometimes grows side by side with the typical variety.