Electronic Flora of South Australia Species Fact Sheet

Stilopsis harveyana Kylin 1940: 50, pl. 8 fig. 22.

Phylum Phaeophyta – Order Chordariales – Family Spermatochnaceae

Selected citations: Womersley 1967: 236.

Synonym

Stilophora lyngbyei J. Agardh sensu Harvey 1855c: 536 (at least in part); 1863, synop.: xii.

Thallus (Fig. 39D) medium brown, moderately mucoid, slender, much branched subdichotomously and laterally, usually 10–35 cm long with cylindrical, slightly tapering branches 0.5–1 mm in diameter below and 100–200 µm in diameter near the apices, probably attached by a small holdfast or entangled with the host, epiphytic. Medulla (Fig. 41E) of a single axial filament each cell of which cuts off 4–5 cortical laterals which divide further. Cortex (Fig. 41E) 100–400 µm and 4–5 cells thick, pseudoparenchymatous, with large, elongate inner cells 20–30 µm in diameter grading to smaller outer cells, usually not becoming hollow. Primary assimilatory filaments (Fig. 41E) rudimentary, covering the thallus surface, papillose, with filaments 15–25 and 1–2 (–3) cells long, the terminal cell subspherical to ovoid, 8–12 µm in diameter; older parts of branches often denuded. Secondary assimilatory filaments developed in older branches as scattered and somewhat spreading tufts, with filaments 60–90 µm and 4–6 cells long, slightly clavate with the terminal cell subspherical to ovoid, 9–12 µm in diameter. Phaeoplasts in assimilatory filaments and outer cortical cells in denuded parts, several per cell, discoid, each with a pyrenoid; physodes not seen. Phaeophycean hairs (Fig. 41E) among primary assimilatory filaments and in secondary tufts, 8–12 µm in diameter. Growth apical, by the single axial filament and lateral development of the cortex.

Reproduction: Unilocular sporangia (Fig. 41F) ovoid to broadly clavate, 30–45 µm long and 20–30 µm in diameter, borne at base of secondary assimilatory filaments. Plurilocular sporangia unknown.

Type from King George Sound, W. Aust.; in Herb. Agardh, LD, 47427.


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

Distribution: Known from the type and from Redbanks, Kangaroo I., S. Aust., upper sublittoral on Dictyota (Womersley, 28.xii.1949; ADU, Al2872). Port Arthur, Tas., drift (Levring 54–1, 30.i.1948; ADU, A56722). Burraneer, N.S.W. (Levring 9–8, 16.xi.1947; ADU, A56723).

Taxonomic notes: Stilopsis harveyana is known from the above specimens but other records may be confused with Stilophora rhizodes or Spermatochnus paradoxus. The type of S. harveyana is based on one of Harvey's Alg. Aust. Exsicc. 65B (as Stilophora lyngbyei) and other specimens of this number should be verified as being Stilopsis. Harvey (1855c, p.536) remarked that S. lyngbyei was very common in Princess Royal Harbor, King George Sound, in summer.

S. harveyana appears to be very closely related to the type species, S. lejolisii, and critical study is needed on their distinctions.

References:

HARVEY, W.H. (1855c). Some account of the marine botany of the colony of Western Australia. Trans. R. Ir. Acad. 22, 525–566.

HARVEY, W.H. (1863). Phycologia Australica. Vol. 5, Plates 241–300, synop., pp. 1–73. (Reeve: London.)

KYLIN, H. (1940). Die Phaeophyceenordnung Chordariales. Acta Univ. lund. N.F. Avd. 2, 36(9), 1–67, Plates 1–8.

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


Illustrations in Womersley Part II, 1997: FIGS 39D, 41E,F.

Figure 39 image

Figure 39   enlarge

Fig. 39. A. Stilophora rhizodes (ADU, A44097). B. Nemacystis novae-zelandiae (ADU, Al2770). C. Spermatochnus paradoxus (ADU, A38153). D. Stilopsis harveyana (ADU, Al2872).

Figure 41 image

Figure 41   enlarge

Fig. 41. A–D. Spermatochnus paradoxus (ADU, A38153). A. Transverse section of branch showing single medullary filament with five laterals, cortex, primary cortical filaments and a phaeophycean hair. B. Longitudinal section showing medullary filament, cortex and four groups of cortical filaments, with phaeophycean hairs (above or below the section). C. Cortical cells with phaeoplasts, pyrenoids and physodes. D. Tuft of secondary cortical filaments with phaeophycean hairs and unilocular sporangia. E,F. Stilopsis harveyana (ADU, Al2872). E. Longitudinal section showing single medullary filament, cortex, papillose cortical filaments and phaeophycean hairs. F. Longitudinal section of a cortical tuft with longer cortical filaments, unilocular sporangia and a phaeophycean hair.


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