Electronic Flora of South Australia Species Fact Sheet

Scytothalia dorycarpa (Turner) Greville 1830: synop. xxxiv.

Phylum Phaeophyta – Order Fucales – Family Seirococcaceae

Selected citations: Harvey 1858: pl. 9. Lucas 1936: 69, fig. 42. Naylor 1949a: 135, figs 1–4. Nizamuddin 1962a: 195, figs 1,4; 1968a: 84, figs 19–32, pl. II. Womersley 1967: 252.

Synonym

Fucus dorycarpus Turner 1811: 22, pl. 143.

Thallus (Fig. 126A) medium to dark brown, 0.5–2 m long, much branched irregularly laterally and essentially complanately, with long axes or primary branches bearing marginally alternate, distichous, laterals; stipe 1–12 cm long, subterete, 2–8 (–10) mm in diameter. Holdfast 1–3 (–6) cm across, developing a circular, raised, rim to the discoid-conical centre, with closely adjacent, simple or branched, haptera 1–4 cm long; epilithic. Axes or primary branches slightly flexuous, 3–6 mm broad, 1–2 (–4) mm thick, bearing alternate, simple, laterals at intervals of 0.4–3 cm. Laterals usually curved, linear but tapering above, basally not or slightly constricted, 5–8 (–12) cm long and (2–) 3–6 mm broad. Growth from 1–2 four-sided apical cells in an apical groove. Structure with a medulla of elongate cells and hyphae, and a cortex of isodiametric cells with a surface meristoderm increasing the cortex; outer cells densely phaeoplastic.

Reproduction: Thalli monoecious. Receptacles (Fig. 126B) clustered (few to many) along the adaxial margins of laterals and spreading to the adjacent margin of the parent branch, strongly compressed, ensiform to lanceolate, often rostellate, 10–15 mm long and (1–) 2–5 mm broad. Conceptacles (Fig. 1271) scattered over the flat surfaces, usually unisexual, occasionally bisexual; female conceptacles with simple or basally branched, moniliform, paraphyses, with ovoid cells 12–20 µm in diameter; oogonia (Fig. 127J) sessile, ovoid, with an apical mesochiton collar and a single egg, 160–280 µm long and 60–150 µm in diameter; antheridia on branched paraphyses, elongate-ovoid, 24–42 µm long and 6–12 gm in diameter.

Type from King George Sound, W. Aust.; in BM (ex K).

Selected specimens: Geraldton, W. Aust. (Lucas, July 1928; Lucas Herb., NSW). Garden I., W. Aust., 21 m deep (Kirkman, 27.iii.1980; ADU, A51003). Belinda Beach, Middle I., Recherche Arch., W. Aust., uppermost sublittoral (Trudgen 844, 23.xi.1973; ADU, A51689; PERTH). Smooth I., Isles of St Francis, S. Aust., 21 m deep (Shepherd, 29.iii.1980; ADU, A52166). Venus Bay, S. Aust., sublittoral fringe (Womersley, 12.ii. 1954; ADU, A19505). Seal Rock, West I., S. Aust., 12–18 m deep (Shepherd, Mar. 1966; ADU, A30440). Vivonne Bay, Kangaroo I., S. Aust., in large sublittoral pool (Womersley, 31.xii.1945; ADU, A3340). Yilki, Victor Harbor, S. Aust., drift (Womersley, 3.xii.1986; ADU, A57284). Point Lonsdale, Vic., drift (McLennan, Sept. 1948; MELU, 35190). Tamar Heads, Tas. (Irvine, 1893; HO, 66638).

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

Distribution: From Geraldton, W. Aust. to Point Lonsdale, Vic., and the north coast of Tasmania, on rough-water coasts from low water mark to 44 m deep.

Taxonomic notes: The Tamar Heads record appears to be the only one from the north coast of Tasmania.

References:

GREVILLE, R.K. (1830). Algae Britannicae. (Edinburgh.)

HARVEY, W.H. (1858). Phycologia Australica. Vol. I, Plates 1–60. (Reeve: London.)

LUCAS, A.H.S. (1936). The Seaweeds of South Australia. Part 1. Introduction and the Green and Brown Seaweeds. (Govt Printer: Adelaide.)

NAYLOR, M. (1949a). Some observations on the receptacles of Scytothalia dorycarpa, with special reference to the extrusion of the oogonia. Ann. Bot., N.S., 13, 135–149.

NIZAMUDDIN, M. (1962a). Classification and the distribution of the Fucales. Bot. Mar. 4, 191–203.

NIZAMUDDIN, M. (1968a). Morphology and anatomy of Phyllospora, Scytothalia and Seirococcus (Fucales). Bot. Mar. 11, 81–105.

TURNER, D. (1811). Fuci sive Plantarum Fucorum Generi a Botanicis Ascriptarum 'cones Descriptiones et Historia. Vol. 3, pp. 1–148, Plates 135–196. (London.)

WOMERSLEY, H.B.S. (1967). A critical survey of the marine algae of southern Australia. II. Phaeophyta. Aust. J. Bot. 15, 189–270.

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: FIGS 126, 1271,J.

Figure 126   enlarge

Fig. 126. Scytothalia dorycarpa. A. Habit (ADU, A52166). B. Branches with marginal receptacles (ADU, A57284).

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