Electronic Flora of South Australia Species Fact Sheet

Audouinella humilis (Rosenvinge) Garbary 1979b: 490; 1987: 88.

Phylum Rhodophyta – Class Florideophyceae – Order Acrochaetiales – Family Acrochaetiaceae

Synonyms

Chantransia humilis Rosenvinge 1909: 117, figs 44,45.

Acrochaetium humile (Rosenvinge) Boergesen. Levring 1953: 478.

Colaconema humile (Rosenvinge) Woelkerling 1971: 44, fig. 15J–O; 1973b: 569, figs 66–73.

Thallus (Fig. 13H–J) epiphytic, more or less pulvinate, 40–75 (–225) µm high (exclusive of hairs), developing from septate or occasionally aseptate spores. Prostrate system (Fig. 13J) consisting of simple or branched more or less confluent filaments forming a pseudoparenchymatous disc. Cells cylindrical to irregular, 4–6 µm in diameter and 5–7 1.1M long. Erect filaments (Fig. 13H–J) simple or with a few irregularly arranged laterals, usually 5–15 cells long. Cells (Fig. 13H–L) cylindrical, 3–7 µm in diameter and 8–12 (–15) µm long, L/D 1.5–3, each cell containing a lobate to stellate rhodoplast (Fig. 13K, L) with one pyrenoid. Terminal and pseudolateral hairs up to 150 µm long occur.

Reproduction: Monosporangia (Fig. 13H–J) ovoid, 6–9 µm in diameter and 11–15 µm long, sessile or stalked, single or in pairs, terminal or lateral and irregularly arranged. Other reproductive structures unknown.

Type from Spodsbjerg, Langeland, Denmark, on Polysiphonia nigrescens; holotype in C.

Selected specimens: Aldinga, S. Aust., on Heterozostera tasmanica, upper sublittoral (Woelkerling, 29.viii.1968; AD, A32701). Pelican Lagoon, Kangaroo I., S. Aust., on Dasya? (Levring, 10.i.1948; AD, A19856). Robe, S. Aust., on Audouinella caespitosa (Woelkerling, 26.i.1967; AD, A32118). Port MacDonnell, S. Aust., on A. caespitosa on Codium pomoides, upper sublittoral (Womersley, 25.i.1967; AD, A32114).

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

Distribution: Atlantic and Mediterranean shores of Europe; western tropical Africa.

In southern Australia, from Pelican Lagoon, Kangaroo I. and Aldinga, S. Aust., to Phillip I., Vic. (Levring 1953, p. 479).

Taxonomic notes: Woelkerling (1971, p. 45) pointed out that the relationship of Audouinella humilis to several other species needs clarification.

Rarely, plants of Audouinella unifila have a habit somewhat similar to that of A. humilis, but the former differs in the absence of pyrenoids, in cell dimensions, and in having a unicellular holdfast.

References:

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.

LEVRING, T. (1953). The marine algae of Australia. I. Rhodophyta: Goniotrichales, Bangiales and Némalionales. Arkiv för Bot. Ser. 2, 2, 457–530.

ROSENVINGE, L.K. (1909). The marine algae of Denmark. Part 1. Introduction. Rhodophyceae. 1. (Bangiales and Némalionales). K. danske Vidensk. Selsk. Biol. Skr., 7 Raekke, Afd. 7, 1–151, Plates 1, 2,2 maps.

WOELKERLING, W.J. (1971). Morphology and taxonomy of the Audouinella complex (Rhodophyta) in southern Australia. Aust. J. Bot. Suppl. 1, 1–91.

WOELKERLING, W.J. (1973b). The morphology and systematics of the Audouinella complex (Acrochaetiaceae, Rhodophyta) in northeastern United States. Rhodora 75, 529–621.

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

Author: W.J. Woelkerling & H.B.S. Womersley

Publication: 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. 13 H–L.

Figure 13   enlarge

Fig. 13. A–D. Audouinella nakamurae (AD, A19847). A. Young thallus with a terminal hair. B–D. Mature thalli with monosporangia. E–G. Audouinella macula (AD, A31372). Mature thalli with monosporangia. H–L. Audouinella humilis (AD, A32114). H, I. Thalli with erect branches and monosporangia. J. Prostrate system (from below) with erect branches. K, L. Cells each with a rhodoplast and pyrenoid. M–Q. Audouinella spongicola (M, AD, A32125; N, P, Q, AD, A32127; 0, AD, A32126). M–P. Variation in cell length in the prostrate system. Q. Cells with rhodoplasts. [A-0 after Woelkerling 1971.]

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