Electronic Flora of South Australia Species Fact Sheet

Gononema ramosum (Skottsberg) Kuckuck & Skottsberg in Skottsberg 1921: 11, figs 2d-f, 4.

Phylum Phaeophyta – Order Ectocarpales

Synonym

Elachista (?) ramosa Skottsberg 1907: 54, figs 66–68.

Thallus (Fig. 14E) 1–2 mm long, forming elachistoid tufts in cryptostomata of Adenocystis (or Caepidium). Basal filaments closely associated laterally, bearing assimilatory filaments 300–500 µm long, 6–10 µm in diameter and (20–) 25–35 cells long (Fig. 14F), each L/B (1–) 1.3–2.0, with several discoid phaeoplasts per cell, and long phaeophycean hairs (to 2 mm long) extending beyond the assimilatory filaments, 8–10 µm thick.

Reproduction: Reproduction by basal plurilocular organs (Fig. 14F), uniseriate to occasionally biseriate, 6–12(45) µm broad and 40–70 µm long with 8–12 locules, dehiscing apically; lateral plurilocular organs on assimilatory filaments, 6–8 µm broad and 25–35 µm long with 5–8 locules (Fig. 14F, lower left). Unilocular sporangia (not seen on Australian specimens) basal, 75–100 µm long and 21–24 µm in diameter (Skottsberg 1921, p. 11).

Type from Fuegia, S. America; in UPS.

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

Distribution: Southern South America (Patagonia, Fuegia, Falkland Is).

In southern Australia, known from Safety Cove, Port Arthur, Tas., mid eulittoral on Adenocystis (Womersley & Parsons, 31.x.1982; ADU, A 55953).

Taxonomic notes: The Tasmanian specimens agree well with Skottsberg's descriptions and illustrations, though the plurilocular organs are slightly smaller and no unilocular sporangia have been seen in the former. It seems likely that G. ramosum may occur on Adenocystis through most of its range.

References:

SKOTTSBERG, C. (1907). Zur Kenntnis der Subantarktischen und Antarktischen Meeresalgen. I. Phaeophyceen. Wissenschaftliche ergebnisse der Schwedischen Südpolar-expedition 1901–1903, 4, 1–172, Plates 1–10.

SKOTTSBERG, C. (1921). Botanische Ergebnisse der Schwedischen Expedition nach Patagonien und dem Feuerlande, 1907–1909. VIII. Marine Algae. I. Phaeophyceae. K. Svenska Vetenskapsakad. Handl. 61(11), 1–56.

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

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
Part II
©Board of the Botanic Gardens and State Herbarium, Government of South Australia

Illustration in Womersley Part II, 1997: FIG. 14E,F.

Figure 14   enlarge

Fig. 14. A–C. Giffordia ovata (after Clayton 1974, fig. 17). A,B. Filaments with meristematic regions and plurilocular sporangia. C. Cell with phaeoplasts and pyrenoids. D. Streblonema fasciculatum (ADU, A55723). Filament with plurilocular sporangia, a hair, and basal (rhizoidal) filaments penetrating the host. E,F. Gonanema ramosum (ADU, A55953). E. Thallus (diagrammatic) on Adenocystis, showing erect assimilatory filaments with zone of plurilocular sporangia, long hairs, and basal filaments penetrating the host. F. Assimilatory filaments, hairs and plurilocular sporangia.

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