Carpopeltis spongeaplexus Womersley & J.A.Lewis
The marine benthic flora of southern Australia 172 (1994)
Conservation Code:
Not threatened
Naturalised Status: Native to Western Australia
Name Status:
Current
Scientific Description
John Huisman & Cheryl Parker,
Monday 20 June 2011
Habit and structure. Thallus dark red-brown to grey-brown, 3–15(–18) cm high, cartilaginous, with most of the thallus irregularly branched, with flattened to flanged axes 1.5–3.5 mm broad, completely covered by tightly adherent sponge to a diameter of 0.5–1(–2) cm, with lower axes developing a secondary cortex with up to 9 growth rings; uppermost branch systems free of the sponge, 1–2(–6) cm long, mostly subdichotomously branched, branches 0.7–1.5(–2) mm broad and 80–150 µm thick (more when fertile), with rounded apices. Holdfast divided, fibrous, 5–15 mm across; epilithic. Structure of upper branch systems of a pseudoparenchymatous cortex 25–40 µm and 4–6 cells thick (thicker in fertile parts), outer cells 2–3 µm in diameter and L/D 2–3, becoming larger inwardly, and a dense and compact filamentous medulla 30–40 µm across; stellate and refractive ganglionic cells absent. Rhodoplasts discoid, few per cell.
Reproduction. Reproductive structures confined to upper parts of terminal branches extending beyond the sponge investment. Sexual thalli with ampullae and cystocarps in oval sori just below branch apices. Carpogonial branch ampullae simple, with 1–2 secondary branches, borne on inner cortical cells. Auxiliary cell ampullae arising in inner cortex, 30–40 µm across, with numerous erect secondary and some tertiary filaments of elongate cells, converging slightly above in the outer cortex. Carposporophytes closely adjacent, swelling branches to 250–350 µm thick, subspherical, compact, 100–160 µm across, with the basal auxiliary cell remaining; carposporangia ovoid to angular, 6–10 µm across. Involucre slight to moderate, formed from compacted ampullary filaments and inner cortical cells; ostiole present. Spermatangia not observed. Tetrasporangia in oval nemathecia near branch apices, among paraphyses 2–3 cells long, cut off from ovoid cells at the base of the paraphyses, 20–30 µm long and 6–10 µm in diameter, cruciately divided.
Distribution. Geraldton, W. Aust., to Port Elliot, S. Aust.
Habitat. Rough-water coasts, 2–30 m deep.
[After Womersley, Mar. Benthic Fl. Southern Australia IIIA: 172–175 (1994)]
