The reported sporophyte of this species forms light green delicate blades, 1.5-10 cm tall, growing commonly on surf grass (Image A) and fucoids (Image B) among other substrata. Individual blades are anchored by a compact cushion of cells (Image C) with the adjacent vegetative cells being irregular and cuboid to typically rectangular in shape (Image D), 5-12.5 µm in dimensions. Toward the plant tip the cells are more regularly cuboidal and tiny, only 2.5-5 µm in dimensions (Image E). The margins are irregular, even slightly dentate locally (Image F) and the monostromatic blades are only 10-22 µm wide in cross section (Image G). Chloroplasts are parietal and pyrenoids are not obvious.
All of our collections to date are from BC, although this species is also reported in the NW Atlantic. We have uncovered a related sister group from the subtidal (10 m) in the Bay of Fundy, NB – taxonomic work is needed. In BC we have collections from both Vancouver Island and Haida Gwaii indicating that in the right habitat this species is found throughout the province. This species is commonly found on various marine grasses, fucoids and other substrata, with a preference for estuaries and other sheltered habitats, a late winter to mid summer (longer to the north) annual.
Sequences for rbcL (HQ603384), tufA (HQ610252) and UPA (HQ603329) in Saunders & Kucera (2010) were incorrectly assigned to this species and are correctly assigned to Gayralia oxysperma (Kützing) K.L.Vinogradova ex Scagel & al.
Image A. Pressed individuals on surf grass from near Pachena Beach, BC (GWS003446).
Image B. Individuals on Fucus distichus Linnaeus from a semi-exposed low intertidal site on Koga Islet, Gwaii Haanas, BC (GWS019939).
Image C. Whole mount of the cushion-like holdfast (GWS003446; rehydrated from press).
Image D. Whole mount of the slightly rectangular cells adjacent to the holdfast (GWS003446; rehydrated from press).
Image E. Whole mount of cells near the tip (GWS003446; rehydrated from press).
Image F. Whole mount of the irregular margin (GWS003446; rehydrated from press).
Image G. Cross section mid thallus revealing the thin monostromatic blade (GWS003446; rehydrated from press).