Pleonosporium ricksearlesii C. W. Schneider & G. W. Saunders 2024, sp. nov.

• Main Authors: Schneider, Craig W., Saunders, Gary W.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2024
• Subjects: Biodiversity; Taxonomy; Plantae; Rhodophyta; Florideophyceae; Ceramiales; Wrangeliaceae; Pleonosporium; Pleonosporium ricksearlesii; Somerset Island
• Online Access: https://doi.org/10.5281/zenodo.10557093; http://treatment.plazi.org/id/03D09363F8769654FEDDF8BFE4E9FA5F

Pleonosporium ricksearlesii C.W.Schneider & G.W.Saunders, sp. nov. (Fig. 3) HOLOTYPE (DESIGNATED HERE). — Bermuda . Somerset Island, 32°16.783’N, 64°52.788’W, on wooden dock in Ely’s Harbour, depth 0-1 m, 30.VI.2015, C.W . Schneider & T.R. Popolizio 15-21-3 (holo-, MICH[1210917]), dried silica sample: BDA1944, GenBank: OR336107 (COI-5P), OR336112 ( rbc L). ISOTYPES. — Same data as holotype (iso-, NY, UNB, Herb. CWS). ETYMOLOGY. — Named for Prof. Richard Brownlee Searles, the first author’s graduate mentor, collaborator and friend, on the occasion of his 87th birthday. Joint cruises with the first author to study mesophotic seaweeds off Bermuda aboard the R/V Seahawk in the early 1980s initiated four decades of investigation on the macroalgal flora of this Atlantic archipelago. DISTRIBUTION. — Endemic to Bermuda as currently known. DESCRIPTION Delicate plants lignicolous or on mud-saturated wood, bushy, erect to 5.0 cm tall, Persian red in colour (Graf 1x 2023) and ecorticate (Fig. 3A); indeterminate axes fine with alternately irregular branching above with corymbose and narrowly-angled branches at apices, some with some branches overtopping the apex (Fig. 3B); most branches simple of 15 with fewer cells or once branched, indeterminate branches irregularly replacing these branches; in lower portions of indeterminate axes, the lateral branches markedly smaller than the axis that produced them (Fig. 3C), and with most lateral branches losing all but a few of their most proximal cells; in distal portions the axes only slightly larger in diam. than the branches they produce; indeterminate axial cells cylindrical and usually flared at their proximal ends in basal portions of main axes (Fig. 3C, F, G), 95-150 µm diam. and 370-530 µm long, gradually tapering distally to cells 20-30 µm diam. and 85-250 µm long several segments below the apices; upper branches incurved, apical cells slightly tapering but obtuse (Fig. 3D); tetrasporangia adaxially sessile on upper incurved branches, borne singly or in a series of ...