Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Acrochaetiales – Family Acrochaetiaceae
Selected citations: Lee 1987: 19, fig. 8.
Acrochaetium phacelorhizum Boergesen 1915: 54, figs 57–59.
Colaconema phacelorhizum (Boergesen) Woelkerling 1971: 48, figs 17F–I, 26B.
Thallus (Fig. 9I) largely epiphytic, 2–5 mm high, with an endophytic base; sporelings unknown. Prostrate system (Fig. 9I) consisting of a funiform mass of branched, entangled filaments penetrating between the host (Codium) utricles. Erect filaments (Fig. 9I) moderately to richly branched, laterals irregularly to secundly arranged and generally tapering towards the tips. Cells (Fig. 9J, K) cylindrical, (10–) 16–24 µm in diameter and 25–75 (–90) µm long (L/D 2–5) in lower portions of erect filaments, 7–16 µm in diameter and 25–60 µm long in upper portions of erect filaments; each cell containing a single parietal rhodoplast (Fig. 9K) with one pyrenoid. Hairs unknown.
Reproduction: Monosporangia (Fig. 9J) ovoid, 10–15 µm in diameter and 22–30 µm long, sessile or occasionally stalked, solitary, senate along the lower portions of laterals or more scattered; monosporangial wall sometimes with a distinct apical thickening.
Tetrasporangia about 22 µm in diameter and 25 µm long, cruciately divided (one observed).
Other reproductive structures unknown.
Type from the Virgin Is, on Codium spp.; holotype in C.
Selected specimens: Head of the Great Australian Bight, S. Aust., on Codium spinescens, drift (Woelkerling, 4.xi.1968; AD, A32925).
Distribution: Virgin Is; Korea.
In southern Australia, from the Head of the Great Australian Bight, S. Aust., on Codium spinescens.
Taxonomic notes: Southern Australian plants of Audouinella phacelorhiza agree in general with the original description of Boergesen (1915) but are somewhat more robust.
Audouinella phacelorhiza and some plants of A. caespitosa superficially appear very much alike but are readily distinguished by differences in rhodoplast (and hence pyrenoid) numbers per cell. In addition, the latter species has mostly stalked monosporangia without apically thickened walls.
BOERGESEN, F. (1915). The marine algae of the Danish West Indies. Part 3. Rhodophyceae. Dansk bot. Ark. 3, 1–80.
GARBARY, D.J. (1979b). Numerical Taxonomy and generic circumscription in the Acrochaetiaceae (Rhodophyta). Bot. Mar. 22, 477–492.
GARBARY, D.J. (1987). The Acrochaetiaceae (Rhodophyta): An annotated bibliography. Bibl. Phycol. 77, 1–267.
LEE, Y.P. (1987). Taxonomy of the Rhodochortonaceae (Rhodophyta) in Korea. Korean J. Phycol. 2, 1–50.
WOELKERLING, W.J. (1971). Morphology and taxonomy of the Audouinella complex (Rhodophyta) in southern Australia. Aust. J. Bot. Suppl. 1, 1–91.
The Marine Benthic Flora of Southern Australia Part IIIA complete list of references.
Womersley, H.B.S. (14 January, 1994)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIA, Bangiophyceae and Florideophyceae (to Gigartinales)
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIA 1994, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.
Illustration in Womersley Part IIIA, 1994: FIG. 9 I–K.
Figure 9 enlarge
Fig. 9. A–H. Audouinella daviesii (A–D, H, AD, A31287; E, F, AD, A6499; G, AD, A30732). A. Upper erect filaments with monosporangia. B. Prostrate system with bases of erect filaments. C. Clusters of monosporangia. D. Filament with a cluster of monosporangia and cells with rhodoplasts and a single pyrenoid. E. Branch with carpogonia on unicellular stalks. F. Mature carposporophyte. G. Branch with spermatangia. H. Branch with tetrasporangia. I–K. Audouinella phacelorhiza (AD, A32925). I. Branching pattern, with prostrate system between utricles of Codium. J. Erect filaments with monosporangia, some with thickened apical walls. K. Cells with rhodoplasts and single pyrenoids. [B, C, E–H, K after Woelkerling 1971.]
State Herbarium of South Australia