Electronic Flora of South Australia Species Fact Sheet

Vaucheria longicaulis Hoppaugh 1930: 332, figs 1–4.

Phylum Chrysophyta – Class Xanthophyceae – Order Vaucheriales – Family Vaucheriaceae

Selected citations: Islam 1984: 898, figs 124–142. Ott & Hommersand 1974: 378, figs 46–50. Taylor 1952: 274, figs 1–11. Venkataraman 1961: 49, fig. 27.

Thallus dark green, forming loose turfs or tufts 1–30 cm (to several metres) across and 2–6 (–12) cm high. Filaments sparsely branched, 25–60 µm in diameter, coenocytic; chloroplasts discoid to ovate, 2–3 across, with a pyrenoid.

Reproduction: Aplanosporangia terminal, clavate, 180–280 µm long and 70–90 µm in diameter.

Thalli dioecious, with gametangia terminal but becoming lateral by extension of the vegetative filament from below. Oogonia (Fig. 169G) clavate to pyriform, 240–290 (–310) µm long and 110–140 µm in diameter, rounded apically, lying in line with the pedicel, not subtended by an empty cell but with a wall-ring in the mid region of the oogonium; oospores sub-spherical, 110–130 µm in diameter, occupying the upper part of the oogonium, with a smooth wall 2–4 µm thick, without a basal protoplasmic mass in the oogonium. Antheridia (Fig. 169H) single, terminal, becoming distantly sympodial by extension of the filament from below the antheridium, usually with an empty basal cell 30–40 µm in diameter and 30–60 µm long, cylindrical, tapering apically, 300–500 (–600) pm long and 35–50 (–80) µm in diameter, with a terminal and 3–6 lateral discharge pores on conical protuberances 10–40 (–60) µm long.

Type from Elkhorn Slough, Monterey County, California, U.S.A.; location?

Selected specimens: Port Augusta, S. Aust., 1 m deep in aquaculture ponds (Smallridge, 29.iv.1987: ADU, A57479). Rosetta Bay, Victor Harbor, S. Aust., lower eulittoral ( Womersley, 30.ix.1985; ADU, A56780). Noonameena, Coorong, S. Aust., 0–1 m deep (Robertson, 27.viii.1976; ADU, A47258). Robe, S. Aust., upper sublittoral pools, slipway reef ( Womersley, 16.x.1985; ADU, A56797). Nelson lagoon, Vic., upper sublittoral within entrance (Womersley, 15.x.1985; ADU, A56798).

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

Distribution: Temperate North America, Asia, South America.

In southern Australia, from Port Augusta, S. Aust., to Nelson lagoon, Vic., but probably more generally distributed along the coast.

Taxonomic notes: V. longicaulis is probably the commonest marine Vaucheria in sheltered to moderate wave action areas along southern Australia, and can form extensive mats in suitable situations. Field collections are commonly sterile or in some cases male only, but the characteristic oogonia and antheridia usually develop in culture.

References:

HOPPAUGH, K.W. (1930). A taxonomic study of species of the genus Vaucheria collected in California. Am. .1. Bot. 17, 329–347, Plates 24–27.

ISLAM, A.K.M.N. (1984). Studies on the genus Vaucheria (Xanthophyceae) in Iraq. Int. Rev. ges. Hydrobiol. 69, 877–902.

OTT, D.W. & HOMMERSAND, M.H. (1974). Vaucheriae of North Carolina. I. Marine and brackish water species. J. Phycol. 10, 373–385.

TAYLOR, W.R. (1952). Notes on Vaucheria longicaulis Hoppaugh. Madrono 11, 274–277.

VENKATARAMAN, G.S. (1961). Vaucheriaceae. Indian Council for Agric. Res., New Delhi. Monogr. Algae.

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. 169G,H.

Figure 169   enlarge

Fig. 169. A. Vaucheria velutina (ADU, A57435). An oogonium and three adjacent antheridia. B–E. Vaucheria conifera. (B,C,from Type after Christensen 1987b, figs 17 and 9; D,E. ADU, A57482.). B. Oogonium with oospore. C. Filament with 3 antheridia. D. Filament with two oogonia. E. Filament with three antheridia. F. Vaucheria piloboloides (ADU, A57155). Oogonia (with distal oospores) and antheridia on adjacent filaments. G,H. Vaucheria longicaulis (ADU, A57483). G. Two oogonia. H. Three antheridia from a single filament. I–J. Vaucheria glomerata (ADU, A19793, holotype). I. Two oogonia with thick-walled oospores, protoplasmic masses, and basal cavity, with chloroplasts in part of filament. J. Clustered antheridia borne laterally on a vegetative filament with one cross wall.

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