Electronic Flora of South Australia Species Fact Sheet
Phylum Phaeophyta – Order Chordariales – Family Leathesiaceae
Selected citations: Hamel 1935: 150, fig. 341.
Thallus (Fig. 24A) in minute tufts or forming spreading, pulvinate, low and moderately dense patches, with base endophytic in Liagora (or Helminthocladia) and determinate cortical filaments extending in a layer of even height beyond the host. Basal filaments (Fig. 24A) branched, extending laterally in host cortex, of irregularly shaped and variably sized cells 4–6 µm in diameter and L/B (1–) 2–3. Medulla slight, of erect, simple or branched filaments continuing as emergent cortical filaments and with scattered phaeophycean hairs. Determinate cortical filaments (Fig. 24A) of fairly even height, simple or rarely branched, slightly increasing in diameter upwards, 70–150 µm and 5–8 (–10) cells long, 3–6 µm in diameter with cells L/B 4–6 below and (1–) 2–3 above. Phaeoplasts several per cell (Fig. 24B), irregularly shaped, usually with a pyrenoid. Phaeophycean hairs occasional to rare, arising from basal or medullary cells. with a meristem 2–4 cells above their base, 3–6 µm in diameter.
Reproduction: Unilocular sporangia (Fig. 24A) clavate to ovoid, (20–) 30–50 (–80) µm long and 12–18 in diameter, borne on basal or medullary filaments. Plurilocular sporangia (Fig. 24C) 30–65 µm and 6–12 cells long, 5–7 µm in diameter, borne on medullary filaments.
Type from Guêthary, France (Thuret & Bornet, 8.ix.1854); in Herb. Thuret-Bornet, PC (?).
Distribution: Western and mediterranean France.
In southern Australia, known from Point Sinclair, S. Aust., on Liagora harveyiana in reef pools (Womersley, 8.ii.1954; ADU, A49565). Pennington Bay, Kangaroo I., S. Aust., on L. wilsoniana, lower eulittoral ( Womersley, 22.i.1947; ADU, A49567) and L. harveyiana, lower eulittoral (Womersley, 22.i.1948; ADU, A49566). Nora Creina, S. Aust., on L. harveyiana, lower eulittoral (Skinner, 11.ii.1979; ADU, A50268) and on Helminthocladia densa, upper sublittoral (Moore, 22.ii.1983; ADU, A54929). Apollo Bay, Vic., on L. harveyiana, mid eulittoral pools (Skinner, 24.ii.1977; ADU, A47959).
Taxonomic notes: Strepsithalia liagorae is probably more widespread in Liagora on southern Australian coasts than the above records indicate. The Australian specimens agree well with Sauvageau's description and have been checked with one of his specimens from Guethary, France. S. liagorae is one of the commonest of the several epiphytes on Liagora.
HAMEL, G. (1935). Phéophycées de France. Fasc. II, pp. 81–176. (Paris.)
SAUVAGEAU, C. (1896a). Note sur le Strepsithalia. J. de Bot. 10, 53–65.
SAUVAGEAU, C. (1925). Sur la culture d'une Algue phéosporée epiphyte Strepsithalia liagorae Sauv. C.R. Acad. Sci. Paris 180, 1464–1467.
The Marine Benthic Flora of Southern Australia Part II complete list of references.
Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
©Board of the Botanic Gardens and State Herbarium, Government of South Australia
Illustration in Womersley Part II, 1997: FIG. 24 A–C.
Figure 24 enlarge
Fig. 24. A–C. Strepsithalia liagorae (A,B, ADU, A49565; C, ADU, A54929). A. Thallus with determinate cortical filaments, phaeophycean hairs and unilocular sporangia arising from basal filaments. B. Cells of a determinate cortical filament, with phaeoplasts. C. Thallus with plurilocular sporangia, and phaeophycean hairs arising from erect or basal filaments. D,E. Strepsithalia leathesiae (ADU, A49777, holotype). D. Thallus with determinate cortical filaments, phaeophycean hairs and unilocular sporangia arising from basal filaments. E. Cells of a determinate cortical filament with phaeoplasts. F–H. Strepsithalia aemula (ADU, A49564, holotype). F. Thallus with branched determinate cortical filaments, phaeophycean hairs and unilocular sporangia arising from basal filaments. G. Cells of a determinate cortical filament, with phaeoplasts. H. Basal filament with a probable plurilocular sporangium. I–K. Acrotrichium amphibolis (ADU, A52820, holotype). I. Thallus (diagrammatic) on Amphibolis, showing basal filaments, medullary filaments, stratum of plurilocular sporangia, and determinate cortical filaments with some continuing as phaeophycean hairs. J. Ditto showing cell detail with central parts of cortical filaments omitted. K. Detail of plurilocular sporangia.
State Herbarium of South Australia