Lessoniopsis littoralis (Farlow & Setchell ex Tilden) Reinke (BC)

This species forms a band at the low intertidal to uppermost subtidal at exposed locations (Image A). Splitting in the transition zone results in a thick and dichotomously divided stipe terminated by numerous fronds (Image B). The plant is anchored by a substantial hapteral holdfast, which with the lower stipe looking very much like a miniature tree with the roots pushing above the soil. Careful observation reveals that the blades are of two types. Vegetative blades directly terminate each stipe and contain a midrib, while the sporophylls are paired and attached to the stipe below the transition zone (Image C).

Another distinctive species in our Pacific flora. It brings to mind a branched Alaria marginata Postels & Ruprecht, which makes sense as they are closely related (Saunders & Druehl 1993, Lane et al. 2006). We have records from exposed locations along the entire span of the BC coast.

Image A. Individuals forming a dense band in the low intertidal at the point between Tana and Gudal Bays, Haida Gwaii, BC (EGWS000374).

Image B. Individual displaying the characteristic splitting at the transition zone to yield the thick dichotomously divided stipe and terminal fronds (low intertidal on rock, Lands End up the left side of Pachena Bay where it meets the ocean, BC; GWS003393).

Image C. Specimen revealing the vegetative blades (double arrow), each with a weak midrib, terminating each stipe and the paired sporophylls (arrows) coming off the stipe below the transition zone (low intertidal on rock Clashwun Pt. (west of Masset), Haida Gwaii, BC; EGWS000470).