Electronic Flora of South Australia Species Fact Sheet
Phylum Chlorophyta – Order Derbesiales – Family Bryopsidaceae
Thallus (Fig. 93C–E) delicate, usually much branched, (2–) 3–6 (–8) cm high, axes and laterals naked or not below, simple or branched, arising from a branched rhizoidal system, epilithic or on shells; mature plants with 3–4 orders or branching, branches lanceolate in outline. Axes and laterals radially branched (Fig. 94C,D) ramuli simple or with 1–2 laterals, regularly and fairly densely arranged but separated by two to several times their basal width, denuded below with scars slightly to moderately conspicuous above, becoming inconspicuous. Axes 0.5–1 mm in diameter, laterals 130–200 µm in diameter, ramuli 0.5–1 mm long and 70–110 µm in diameter below, scarcely or distinctly tapering (to 40 µm near tips) and with rounded ends.
Reproduction: Reproduction unknown.
Type: Type locality: King Head, Rottnest I., W. Aust., low eulittoral on platforms (Womersley, 6.ix.1979).
Holotype: ADU, A50706. Isotypes distributed as "Marine Algae of southern Australia" No. 233.
Distribution: Known by the specimens from Rottnest I., W. Aust. (Harvey, Aig. Aust. Exsicc. 572A). Point Peron, W. Aust., rear reef pools (Womersley, 23.viii.1947; ADU, A5921). Near entrance to Kellidie Bay, Coffin Bay, S. Aust., uppermost sublittoral (Womersley, 24.ii.1959; 22.viii.1967, 13.v.1968; ADU, A22560, A31816, A32482 resp.). American River inlet, Kangaroo I., S. Aust., from buoys and tidal flats, just subtidal ( Womersley, 25.i.1946; 6.ix.1946; 24.vii.1947; ADU, A3467, A4121, A5782 resp.). St Leonards, Port Phillip, Vic., 1–3 m deep (Womersley, 9.viii.1959; ADU, A52189). Swan Bay, Port Phillip, Vic., 0.5 m deep (Watson, 30.ix.1973; ADU, A44123).
Taxonomic notes: Harvey's 572A, as B. australis Sonder, is entirely radially branched and is placed under B. macraildii in contrast to true B. australis which is bilateral.
B. macraildii is related to B. hypnoides in the radial arrangement of the ramuli, which are distinctly shorter and of smaller diameter than in the latter species. In B. macraildii they are fairly regularly arranged for some distance from the ends of axes and laterals and of fairly uniform length. B. macraildii is slenderer and has more widely spaced ramuli than B. foliosa or B. vestita.
Unfortunately the reproduction of B. macraildii is unknown and it is distinguished on morphological features only. While it seems to be a distinct species in southern Australia, comparisons with little known species froni the Mediterranean and elsewhere may bring to light an earlier name for this taxon.
References: The Marine Benthic Flora of Southern Australia Part I
Womersley, H.B.S. (31 May, 1984)
The Marine Benthic Flora of Southern Australia
©Board of the Botanic Gardens and State Herbarium, Government of South Australia
Illustrations in Womersley Part I, 1984: FIGS 93 C–E, 94C,D.
Figure 93 enlarge
Fig. 93. A. Bryopsis minor (ADU, A4124, type). B. Bryopsis minor (ADU, A54041). C. Bryopsis macraildii (ADU, A50706, type). D. Bryopsis macraildii (ADU, A18368, Harvey 572A). E. Bryopsis macraildii (ADU, A5782).
Figure 94 enlarge
Fig. 94. A,B. Bryopsis minor (ADU, A54041). A. Branching system. B. Chloroplasts with starch plates surrounding indistinct pyrenoids (upper from ramuli, lower from axes). C,D. Bryopsis macraildii. C. Branching (ADU, A50706). D. Upper branch (ADU, A5782). E. Bryopsis foliosa. Axes with laterals and ramuli (ADU, A50704).
State Herbarium of South Australia