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Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Order Ceramiales – Family Ceramiaceae – Tribe Pterothamnieae
Selected citations: Athanasiadis 1996: 68, fig. 21. Silva et al. 1996: 421.
Synonym
Glandothamnus acicularis Wollaston 1981: 120, figs 37–40; 1984: 286.
Thallus (Fig. 62C) erect, 0.5–2 cm high, more or less complanately branched usually 3–4 axial cells apart, apices only slightly flexuous, with 4 whorl-branchlets of equal size, ecorticate. Holdfast rhizoidal; epilithic. Structure. Apices (Fig. 64A) of short cells 6–8 µm in diameter, enlarging below to axial cells 200–400 µm in diameter and L/D (1.5–) 2–3. Whorl-branchlets formed unilaterally (Fig. 64A) at branch tips, becoming 200–400 µm long, usually densely adaxially branched with branched pinnules 90–200 µm long, often in pairs from lower and central rachis cells; terminal rachis cells occasionally modified to form acute, slender, spines (Fig. 64B) with 2–4 arms, 2–4 cells long and 6–9 µm in diameter, probably caducous; basal cells of whorl-branchlets 35–45 µm in diameter and L/D 1.5–2.5, tapering to subterminal cells 10–12 µm in diameter and L/D 1.2–1.6, terminal cells mucronate. Lateral branches replacing a whorl-branchlet or arising on the basal cell of whorl-branchlets; gland cells occur on rachis or pinnule cells, 14–18 µm across, obliquely orientated. Cells uninucleate; rhodoplasts discoid, in chains or ribbon like in larger cells.
Reproduction: Gametophytes unknown.
Tetrasporangia (Fig. 64C) occur on lower cells of pinnules of whorl-branchlets, sessile, subspherical, 20–35 µm in diameter, decussately divided.
Type from Taroona, Tas., 2–3 m deep on rock (Shepherd, 19.iii.1975; holotype in AD, A46154).
Distribution: Only known from the type collection.
Taxonomic notes: P. aciculare was recorded with some doubt from Natal, South Africa, by Wollaston (1984, p. 286). Its presence in South Africa needs confirmation from further collections.
References:
ATHANASIADIS, A. & KRAFT, G.T. (1994). Description of Pterothamnion squarrulosum (Harvey) comb. nov. from south-eastern Australia and southern New Zealand, with a taxonomic re-assessment of the genera Pterothamnion, Platythamnion & Glandothamnus (Ceramiaceae, Rhodophyta). Eur. J. Phycol. 29, 119–133.
ATHANASIADIS, A. (1996). Morphology and classification of the Ceramioideae (Rhodophyta) based on phylogenetic principles. Opera Botanica No. 128, pp. 1–216.
SILVA, P.C., BASSON, P.W. & MOE, R.L. (1996). Catalogue of the Benthic Marine Algae of the Indian Ocean. (University of California Press: Berkeley, Los Angeles & London.)
WOLLASTON, E.M. (1981). Descriptions of two new genera, Scageliopsis and Glandothamnus (Ceramiaceae, Rhodophyta), including five previously undescribed species from southern Australia. Pacific Sci. 34, 109–127.
WOLLASTON, E.M. (1984). Species of Ceramiaceae (Rhodophyta) recorded from the International Indian Ocean Expedition, 1962. Phycologia 23, 281–299.
The Marine Benthic Flora of Southern Australia Part IIIC complete list of references.
Publication:
Womersley, H.B.S. (24 December, 1998)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIC. Ceramiales – Ceramiaceae, Dasyaceae
©State Herbarium of South Australia, Government of South Australia
Illustrations in Womersley Part IIIA, 1998: FIGS 62C, 64 A–C.
Figure 62 enlarge
Fig. 62. A, B. Pterothamnion francisianurn (AD, A38087). A. Upper slightly flexuous branches. B. Branches with pinnae hearing tetrasporangia. C. Pterothamnion aciculare (AD, A46154). Upper branches with tetrasporangia. D. Pterothamnion flexile (AD, A59341). Upper branches.
Figure 64 enlarge
Fig. 64. A–C. Pterothamnion aciculare (AD, A46154). A. Apical development. B. Immature whorl-branchlets with a terminal spinous process and continued development from the cell below the process. C. Whorl-branchlet with gland cells and tetrasporangia. D–J. Pterothamnion manifestum (AD, A41641). D. Mature subdichotomous whorl-branchlet with gland cells. E. Development of a gland cell. F. Rhizoids bearing gland cells. G. Apex of a lateral branch with carpogonial branches on basal cells of whorl-branchlets. H. Young carposporophyte with gonimoblast initials. I. Older carposporophyte with lateral gonimoblast initials. J. Spermatangial clusters. (All as in Wollaston 1981, courtesy of Pacific Science, Uni. of Hawai'i Press.)
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