Myriogramme cartilaginea (Harv.) Womersley
Mar.Benth.Fl.S.Australia 111 (2003)

Conservation Code: Not threatened
Naturalised Status: Native to Western Australia
Name Status: Current

Scientific Description
John Huisman & Cheryl Parker, Thursday 8 September 2016

Habit and structure. Thallus erect, dark red-brown, 4–8 cm high, cartilaginous, more-or-less complanately branched with irregularly alternate branches at intervals of 5–10 mm, branches of relatively uniform width of 4–6 mm from base to just below apices, apices rounded, margins irregular to crispate or with short, blunt, appendages; midrib and veins absent. Holdfast discoid, rhizoidal; epiphytic (?). Structure. Growth marginal, with distinct apical cells; marginal cells small, mature surface cells irregular, angular, 30–50 µm across and L/D 1–1.5(–2). Blades monostromatic when young, soon tristromatic and polystromatic centrally, cortical cells equivalent to primary cells, central (primary) layer not distinct. Rhodoplasts discoid.

Reproduction. Gametophytes unknown. Tetrasporangial sori scattered, round to ovate, 400–800 µm across and 160–200 µm thick, tetrasporangia in 2 layers, cut off from inner cortical cells, with 2 layers of smaller outer cortical cells; tetrasporangia subspherical, 45–75 µm in diameter.

Distribution. Only known from Garden I., W. Aust., Swan River., W. Aust., and Elliston, S. Aust., on Osmundaria (?), 7 m deep.

[After Womersley, Mar. Benthic Fl. Southern Australia IIID: 111 (2003)]