Electronic Flora of South Australia Species Fact Sheet
Phylum Chlorophyta – Order Caulerpales – Family Udoteaceae
Chlorodesmis pusilla Womersley 1955: 389, fig. 4.
Thallus (Fig. 83B) dark green, 0.5–1.5 cm high, densely and irregularly tufted but not compressed, with basal filaments weakly or not attached by lateral tenacula (Fig. 85B).
Filaments (Fig. 85A) of erect branches sparsely subdichotomously or irregularly branched, 24–50 µm in diameter, linear but with undulate walls and usually constricted shortly above the branchings; wall thin, very slightly thickened at the constrictions; heteroplastic, chloroplasts dense, round to elongate-ovoid, 1–2.5 µm long, amyloplasts present (Fig. 85C).
Type from Pennington Bay, Kangaroo I., S. Aust. in a shaded pool ( Womersley, 4.i.1948); in ADU, A7020.
Distribution: Only known from the type locality and from heavily shaded pools on the south side of Ellen Point, Vivonne Bay, Kangaroo I. (Womersley, 29.viii.1950; ADU, A15460, 30.i.1956; ADU, A20290, 29.i.1957; ADU, A20789 [illustrated by Ducker (1967, pl. 43 fig. 1) but incorrectly cited as A20290], and 22.xi.1968; ADU, A32893).
Taxonomic notes: While this taxon is clearly not a Chlorodesmis, it also differs from other species placed in Rhipilia and until further studies are carried out on possibly more mature plants, its systematic position remains uncertain. It differs from typical Rhipilia in that a complanate thallus is not formed and the filaments are loosely aggregated, weakly attached by tenacula only near their base. If a Rhipilia, it is probably a simple, perhaps primitive, species.
DUCKER, S.C. (1967). The genus Chlorodesmis (Chlorophyta) in the Indo-Pacific Region. Nova Hedwigia 13, 145–182, Plates 25–43.
WOMERSLEY, H.B.S. (1955). New marine Chlorophyta from southern Australia. Pacif. Sci. 9, 387–395.
The Marine Benthic Flora of Southern Australia Part I complete list of references.
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 83B, 85 A–C.
Figure 83 enlarge
Fig. 83. A. Callipsygma wilsonis (ADU, A37818). B. Rhipilia pusilla (ADU, A32893). C. Rhipiliopsis peltata (ADU, A37817). D. Rhipiliopsis robusta (ADU, A41215). E. Avrainvillea clavatiramea (ADU, A33962).
Figure 85 enlarge
Fig. 85. A–C. Rhipilia pusilla (ADU, A32893). A. Filaments of thallus. B. Filaments with lateral tenaculum attachment. C. Filament with tenaculum, and chloroplasts and amyloplasts. D–E. Rhipiliopsis peltata (ADU, A51874). D. Filaments with lateral zooidangia on lower filaments and several lateral attachment areas. E. Details of filaments near surface, with chloroplasts and amyloplasts. F–H. Rhipillopsis rohusta (ADU, A41215). F. Filaments with several lateral connections as seen in lengthwise section of the thallus. G. Segments with perforated end walls and lateral connections. H. Part of segment with chloroplasts and amyloplasts. I–K. Avrainvillea clavatiramea (ADU, A33962). I. Filaments from upper thallus. J. Upper branch. K. Branch of a filament, with chloroplasts and amyloplasts.
State Herbarium of South Australia