Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Acrochaetiales – Family Acrochaetiaceae
Selected citations: Garbary 1979b: 478; 1987: 28.
Thallus (Fig. 14A) largely or entirely endophytic, usually 100–300 µm high; sporelings unknown. Prostrate system (Fig. 14A) consisting of sparingly irregularly branched non-confluent filaments creeping within the gelatinous matrix of the host. Cells more or less cylindrical, 3–5 µm in diameter and 20–45 µm long, L/D 6–10; each cell containing an irregularly lobate rhodoplast (Fig. 14B) which sometimes becomes divided into several irregularly discoid portions; pyrenoids absent. Erect filaments (Fig. 14A) 100–300 µm high (exclusive of hairs), arising at irregular intervals from cells of the prostrate filaments; simple or with several short unbranched laterals. Cells (Fig. 14A) cylindrical, 5–8 µm in diameter and 15–30 µm long, L/D 2–4 (–4.5), each cell containing a parietal, irregularly lobate rhodoplast (Fig. 14C), pyrenoids absent. Terminal and pseudolateral hairs up to 300 µm long occur.
Reproduction: Monosporangia (Fig. 14A) ovoid, each 7–10 µm in diameter and 15–18 µm long, solitary, sessile, and scattered on the erect filaments.
Thalli probably dioecious. Carpogonia (Fig. 14D) sessile or stalked, on lower part of erect filaments, dividing transversely after fertilization and giving rise to short gonimoblast filaments bearing terminal carposporangia (Fig. 14E), each (4–) 5–6 (–8) µm in diameter and 8–12 µm long.
Spermatangia and tetrasporangia unknown.
Type from Antechamber Bay, Kangaroo I., S. Aust., in Helminthocladia australis, upper sublittoral on jetty piles (Woelkerling, 20.xi.1967); holotype in AD, A31980; isotypes distributed in "Marine Algae of southern Australia" No. 61.
Distribution: Only known from the type locality, in Helminthocladia australis Harvey and H. densa (Harvey) Schmitz & Hauptfleisch.
Taxonomic notes: Audouinella blumii is distinctive in having prostrate filaments narrower than the erect filaments, most erect filaments simple and under 300 µm long, rhodoplasts without pyrenoids, and sessile monosporangia.
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.
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. 14A--E.
Figure 14 enlarge
Fig. 14. A–E. Audouinella blumii (AD, A32121). A. Habit of plant with monosporangia, showing slender prostrate system and erect filaments. B. Cell of prostrate system with rhodoplast. C. Two cells of erect filaments with rhodoplasts. D. Branch bearing a stalked carpogonium. E. Nearly mature carposporophyte. F–H. Audouinella polyidis (F, G, AD, A32255; H, AD, A18660). F. Thallus with prostrate system and erect filaments bearing monosporangia. G. Cells with dissected rhodoplasts and single pyrenoids. H. Short erect filaments bearing mature and young tetrasporangia. [A–E, G, H after Woelkerling 1971.]
State Herbarium of South Australia