Corynophlaea cystophorae J.Agardh

Scientific Description

Habit and structure. Thallus dark brown, hemispherical to globose, firm but very mucoid, 2–4(–6) mm across, epiphytic on Cystophora and other algae. Basal layer of appressed radiating filaments on the host, with no or very slight penetration between the outer host cells, cells isodiametric to slightly elongate, 6–8 µmin diameter. Medulla 200–900 µmhigh, of erect, branched, closely adjacent filaments arising from every cell of the basal layer, cells ovoid to elongate-ovoid to sub-pyriform below, 20–40(–50) µmin diameter, becoming smaller above. Determinate cortical filaments arising in groups of 1–4 from upper medullary cells, 100–500 µm and (8–)15–35(–90) cells long, usually curved above, cells cylindrical below, 6–15µm in diameter and L/B3–6, and usually laterally inflated above (globose to often deltoid on their upper side), sometimes remaining cylindrical, (6–)8–15(–20) µmbroad or long and L/B 1–1.5(–2). Phaeoplasts several per cell, discoid to elongate or lobed, each usually with a pyrenoid. Phaeophycean hairs frequent, produced from upper medullary cells, 10–15 µmin diameter and greatly exceeding the cortical filaments in length.

Reproduction. Plurilocular sporangia borne on slender branch systems from the upper medullary cells, filiform, uniseriate, simple or once branched, 30–50 µmand 8–25(–36) locu1es long, 5–7 µmin diameter. Unilocular sporangia often on the same thallus as plurilocular sporangia, borne laterally at base of cortical filaments, ovoid, 50–100(–160) µm long, 20–30(–45) µm in diameter.

Distribution.From Rottnest I., W. Aust., around southern Australia and Tas., to Crookhaven Heads, N.S.W.

Habitat. C. cystophorae is common on several species of Cystophora, as well as on a variety of other algae along rough-water to moderately sheltered coasts of southern Australia.

[After Womersley, Mar. Benthic Fl. Southern Australia II: 95–97 (1987)]