Sulcaria spiralifera is a species of fruticose lichen in the family Parmeliaceae. It is found in the northwestern United States, where it grows as an epiphyte, hanging from a variety of tree species in open or shaded maritime forests.
The species was first formally described in 1977 by lichenologists Irwin Brodo and David Hawskworth as a species of Bryoria. It was transferred to the genus Sulcaria in 2014 by Leena Myllys, Saara Velmala, and Trevor Goward. Using DNA analysis and molecular phylogenetics, they also determined that Bryoria pseudocapillaris, another taxon described by Brodo and Hawskworth in 1977, was actually the same species as Sulcaria spiralifera, and placed the former taxon in synonymy with the latter.
The thallus of Sulcaria spiralifera usually hangs in a more or less fashion, extending from 4cmto12cmcm (02inchesto05inchescm) in length. Displaying colours ranging from pale to dark brown, the exterior can either be dull or exhibit a subtle sheen, frequently appearing, or powdery, in the norstictic acid chemotype. It features predominantly irregular branching without any apparent primary branches, and the angles created at these junctions are usually acute. The branches themselves have diameters falling between 0.10 and 0.35 mm, with small, spine-like side branches emerging near the tips.
One of the distinguishing characteristics of this lichen is the presence of pseudocyphellae, or small pores on the surface of the thallus. These typically stand out due to their white colour and can be straight or wrap around the branches in a spiral fashion. Their size ranges from 1 to 4 mm in length, they sometimes exhibit a furrowed texture, and they may be found either densely packed or sporadically. However, soralia and isidia, structures associated with vegetative reproduction, are absent in this species. The presence of apothecia and conidiomata, structures linked to sexual and asexual reproduction, respectively, have yet to be observed in this species.
Chemically, Sulcaria spiralifera presents two distinct chemotypes. The first chemotype responds to a potassium hydroxide (K) spot test with a yellow colour and is known to contain alectorialic acid, barbatolic acid, and an unidentified substance. The second chemotype also yields a yellow result when tested with K, which then turns red. It contains norstictic acid, connorstictic acid, and atranorin.
Found along the west coast of North America, Sulcaria spiralifera is a seldom seen yet occasionally locally abundant species native to regions spanning from northern California to Washington. Its preferred habitats include open or shaded maritime forests, where it is found growing on lodgepole pines (Pinus contorta), sitka spruces (Picea sitchensis), and an array of shrubs and deciduous trees.