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Electronic Flora of South Australia Species Fact Sheet

Urospora penicilliformis (Roth) Areschoug 1874: 4, figs 1–6.

Phylum Chlorophyta – Order Acrosiphoniales – Family Acrosiphoniaceae

Selected citations: Abbott & Hollenberg 1976: 94, fig. 49. Gain 1912: 32, figs 36–42. Kylin 1949: 46. Papenfuss 1964: 8. Taylor 1957: 77.


U. mirabilis Areschoug 1866: 15. Printz 1932: 273, figs 1–3, 8, 9, 14, 15, 18–20. Rosenvinge 1893: 918. Scagel 1966: 78, pl. 36A–D.

Hormiscia penicilliformis (Roth) Fries. Chapman 1956: 469, fig. 128.

Thallus (gametophyte) dark green (Pl. 12, fig. 3), to 3 cm high, of slender, somewhat mucoid filaments forming a dense felt on rock at a lower eulittoral level; filaments unbranched, cylindrical (15–) 20–25 Aim in diameter near the base, attached by the basal cell and external descending rhizoids from the lower several cells (Fig. 74A): mature cells 25–40 µm in diameter, L/B (0.5–) 1–3, not or only slightly incised at cross walls (Fig. 74B,C); chloroplast (Fig. 74D,E) parietal, continous, with perforations and often open on one side, containing several polypyramidal pyrenoids. Sporophyte (the Codiolum stage) unknown in Australia.

Reproduction: Reproduction by anisogametes from upper cells of the filaments (Fig. 74F), liberated through a simple pore; gametes arranged more or less radially, with their pointed posterior ends inward.

Type from Germany (North Sea); probably lost.

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

Distribution: Cold temperature waters of both hemispheres; Arctic and Antarctic.

Australian record: Tesselated pavement, Eaglehawk Neck, Tasmania, lower eulittoral densely covering a single rock about 50 cm across (Parsons & Womersley, 30.x.1982; ADU, A54021).

Taxonomic notes: This single collection is placed in U. penicilliformis provisionally. It agrees in form and dimensions, but has frequent longer cells than given in most descriptions which- record their L/B as about one, or within the range 0.5–2. However, Scagel (1966, p. 79) extends the range to 4, Chapman to 2.5 for New Zealand material, and Gain (1912, p. 34) to 3 for Antarctic specimens. Rosenvinge (1893, p. 918, fig. 35) described a var. elongata from Greenland, with cells L/B 2.5–6, and Hagem (1908, p. 295, fig. 5) raised this variety to a species and gave L/B 4–10.

Clearly the Australian taxon needs further study from living material and other collections, but the habitat is very similar to that of the species from the northern hemisphere.


ABBOTT, I.A. & HOLLENBERG, G.J. (1976). Marine Algae of California. (Stanford Univ. Press: Stanford.)

ARESCHOUG, J.E. (1866). Observationes Phycologicae I. Act. Reg. Soc. Sci. Upsala, Ser. III, 6. 1–26, Plates 1–4.

ARESCHOUG, J.E. (1874). Observationes Phycologicae. II. Act. Reg. Soc. Sci. Upsala, Ser. III, 9, 1–13, Plates 1–2.

CHAPMAN, V.J. (1956). The marine algae of New Zealand. Part I. Myxophyceae and Chlorophyceae. J. Linn. Soc. Bot. 55 (360), 333–501, Plates 24–50.

GAIN, L. (1912). La flore algologique des régions Antarctiques et subantarctiques. In Deuxième Exped. Antarct. Francaise, 1908–1910. pp. 1–128, Plates 1–8.

HAGEM, O. (1908). Beobachtungen über die gattung Urospora im Kristiania fjord. Nyt Mag. Naturvidensk. 46, 289–299, Plate 1.

KYLIN, H. (1949). Die Chlorophyceen der Swedischen Westküste. Lunds Univ. Årsskr. N.F. Avd. 2, 45(4), 1–79.

PAPENFUSS, G.F. (1964). Catalogue and bibliography of antarctic and subantarctic benthic marine algae. Amer. Geoph. Union. Antarctic Res. Ser. 1, 1–76.

PRINTZ, H. (1932). Observations on the structure and reproduction in Urospora Aresch. Nyt. Mag. Naturvidensk. 70, 274–287, Plates 1, 2.

ROSENVINGE, L.K. (1893). Grønlands Havalger. Med. Grønland 3, 765–981, Plates 1, 2.

SCAGEL, R.F. (1966). Marine algae of British Columbia and Northern Washington, Part I: Chlorophyceae (Green Algae). Natl Mus. Can. Bull. 207, i-viii, 1–257.

TAYLOR, W.R. (1957). Marine algae of the Northeastern Coast of North America. Rev. Edn. (Univ. Mich. Press: Ann Arbor.)

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

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (31 May, 1984)
The Marine Benthic Flora of Southern Australia
Part I
©Board of the Botanic Gardens and State Herbarium, Government of South Australia

Illustrations in Womersley Part I, 1984: PLATE 12 fig. 3; FIG. 74 A–F.

Plate 12 image

Plate 12   enlarge

PLATE 12 Fig. 1. Ulva australis in a mid eulittoral pool, Sorrento, Victoria (ADU, A51984 collection);
Fig. 2. Prasiola crispa (and yellow lichen) on a rock 3-4 m above high tide level, Lady Bay, Southport, Tasmania (ADU, A53837 collection). (Photo by M.J. Parsons.)
Fig. 3. Urospora penicilliformis on a lower eulittoral rock, Tesselated Pavement, Eaglehawk Neck, Tasmania (ADU, A54021 collection).

Figure 74 image

Figure 74   enlarge

Fig. 74. A–F. Urospora penicilliformis (ADU, A54021). A. Base of filament with rhizoids. B. Upper filament with recently divided cells. C. Mid filament with elongate cells. D. Mid cells showing chloroplast, pyrenoids and lipid bodies. E. Ditto from upper cells. F. Upper cells with zooids and empty cell with pore. G–J. Dictyosphaeria sericea (ADU, A53381). G. Surface view of thallus, showing recently divided cells and rows of hapteroid lenticular cells. H. Cross section showing old cell walls and lenticular cells prior to sloughing off of older walls. I. Detail of hapteroid lenticular cells. J. Chloroplasts with pyrenoids.

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