Blades forming a dense reddish carpet on upper intertidal rocks at the most exposed sites along with Porphyra linearis Greville, the latter dominating lower in the band while Pyropia peggicovensis dominates the upper range. Unequivocal identification best determined with reproductive material and or molecular data. A winter to early spring annual. Blades strongly linear, up to 22 cm tall and 0.2-0.5 cm wide, with a wedge-shaped base arising from a small discoid holdfast; olive grayish basally becoming red toward the tip (Image A). Vegetative cells in surface view near the blade base, cells 15-25 µm wide by 15-45 µm tall, axially elongate in loose rows and typically not paired (Image B). Phyllosporangia developing progressively from the tips to mid thallus, cells typically appearing paired or in groups of four more rounded than the lower vegetative cells and only 5-12 µm in dimensions (Image C). Blades monostromatic, 25-70 µm wide in cross section near the base, vegetative cells variable in shape, not strongly paired, and clearly contracted in rehydrated material (Image D). Sections of reproductive regions revealed blades 45-70 µm in width with irregular packets of phyllospores (eight or more per packet), no prototrichogynes were observed (Image E).
Genetically verified collections are confined to Peggys Cove, NS, although records from PEI, Denmark and Sweden are cited in Mathieson & Dawes (2017, p. 269).
Image A. Collection GWS041532 from Peggys Cove, Nova Scotia. Uppermost blade is fully intact from its discoid holdfast (closest to coin).
Image B. Surface view of vegetative cells near blade base (GWS041536).
Image C. Surface view of phyllosporangia near blade tip (GWS041536).
Image D. Vegetative section near blade base (GWS041536).
Image E. Section of phyllosporangia near blade tip (GWS041536).