Plants form red to dark reddish-purple tufts up to 25 cm in height (Image A). Pericentral cells 12 (8-14), spirally twisted throughout the thallus (especially in lower portions); ecorticate throughout (Image B). Thalli arising individually or in clusters from compact stoloniferous systems bearing unicellular rhizoids (Image C) cut off from the bearing pericentral cells (Image D). Trichoblasts can be formed near branch apices (Image E). Tetrasporangia are formed in short lateral branches and occur in an elongate gradual series (can appear linear on first glance or over short regions) (Image F). Cystocarps are rounded (~300-400µm diam.; Image G) to squat (~400µm tall and ~500µm wide; Image H) in shape.
We have genetically verified records from throughout the Maritime provinces to CT. Individuals were found from the low intertidal to subtidal (14 m) growing on a variety of hard substrata and other algae.
Image A. Tetrasporic specimen collected from the subtidal at New River Beach, NB (GWS039125).
Image B. Spiralled pattern of the pericentral cells mid-thallus; ecorticate (GWS039125).
Image C. Unicellular rhizoids are commonly formed on the basal polysiphonous stolons (subtidal (2m) on rock, Duck Road Beach, NB; GWS044403).
Image D. Unicellular rhizoids are clearly cut off from the bearing pericentral cell (subtidal (2m) on rock, Duck Road Beach, NB; GWS044403).
Image E. Trichoblasts formed near the plant tips (GWS039125).
Image F. Tetrasporangia in an elongate spiral series (GWS039125).
Image G. Round cystocarp with two released carpospores (GWS044403).
Image H. Larger cystocarp with a squat shape (GWS044403).
Seaweed of Canada 