Electronic Flora of South Australia Species Fact Sheet

Chaetomorpha melagonium (Weber & Mohr) Kützing.

Phylum Chlorophyta – Order Cladophorales – Family Cladophoraceae

Selected citations: Hamel 1930: 123, fig. 38F–H. Harvey 1847a: pl. 99A. Taylor 1957: 80.

Thallus (Fig. 54C) dark green, epilithic, with tufts of several erect, rigid filaments 2–3 cm long, attached by a spreading, lobed, discoid holdfast (Fig. 55K) and also rhizoids from elongate basal cells which are (1.5–) 2–3 (–4)mm long, clavate and 300–500 µm in diameter at their upper ends. Filaments only slightly increasing in diameter upwards (Fig. 55L). Cells 400–600 µm in diameter and L/B 1.5–2 below, and 400–800 (–1000) µm in diameter and L/B 1–1.5 (–2) above; cells not to moderately incised at cross walls, wall 30–50 µm thick, chloroplasts densely reticulate with numerous pyrenoids.

Reproduction: Reproduction unknown for Australian plants; in Europe, by biflagellate and quadriflagellate zoospores (Kornmann 1972, p. 18).

Type from Sweden (locality unknown).

Distribution map based
on current data relating to
specimens held in the
State Herbarium of SA

Distribution: N. Europe and temperate N. Atlantic Ocean.

In southern Australia, known from Belinda Beach; N. side of Middle I., Recherche Arch., W. Aust., in sand near shore on rock platform (Trudgen 818, 17.xi.1973; ADU, A51675), and Flat Rock Bay, S. coast of Yorke Pen., S. Aust., lower eulittoral (Shepley, 30.i.1961; ADU, A24699).

Taxonomic notes: The above two collections are referred to the northern hemisphere Ch. melagonium provisionally. They agree well with this species in dimensions of the filaments and basal cells but are shorter and more tufted than plants from northern Europe. They occurred in similar habitats to Ch. aerea but are distinctly more robust with longer basal cells than this species. Detailed studies of living material are necessary to clarify these records.

Chapman (1956, p. 460, fig. 116C) described from New Zealand a var. novae-zelandiae of Ch. melagonium, but the brief description does not agree well with the above Australian plants.

References:

CHAPMAN, V.J. (1956). The marine algae of New Zealand. Part I. Myxophyceae and Chlorophyceae. J. Linn. Soc. Bot. 55 (360), 333–501, Plates 24–50.

HAMEL, G. (1930). Chlorophycées des côtes francaises. (Paris.)

HARVEY, W.H. (1847a). Phycologia Britannica. Plates 73–144. (Reeve: London.)

KORNMANN, P. (1972). Ein Beitrag zur Taxonomie der Gattung Chaetomorpha (Cladophorales, Chlorophyta). Helgoländer wiss. Meeresunters, 23, 1–31.

TAYLOR, W.R. (1957). Marine algae of the Northeastern Coast of North America. Rev. Edn. (Univ. Mich. Press: Ann Arbor.)

The Marine Benthic Flora of Southern Australia Part I complete list of references.

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (31 May, 1984)
The Marine Benthic Flora of Southern Australia
Part I
©Board of the Botanic Gardens and State Herbarium, Government of South Australia

Illustrations in Womersley Part I, 1984: FIGS 54C, 55K,L.

Figure 54   enlarge

Fig. 54. A. Chaetomorpha coliformis (ADU, A53158). B. Chaetomorpha aerea (ADU, A52987). C. Chaetomorpha melagonium (ADU, A24699). D. Chaetomorpha linum (ADU, A53201).

Figure 55   enlarge

Fig. 55. A–C. Chaetomorpha coliformis (ADU, A52991). A. Base of filament. B. Mid part of filament with recent divisions. C. Upper part of filament, with zooid discharge pores. D–G. Chaetomorpha coliformis (ADU, A53158). D. Base of filament. E. Mid part of filament. F. Upper part of filament. G. Uppermost cells of filament. H–J. Chaetomorpha aerea (ADU, A52987). H. Base of filament. I. Mid part of filament. J. Upper part of filament. K,L. Chaetomorpha melagonium (ADU, A24699). K. Base of filament. L. Upper part of filament.

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