Electronic Flora of South Australia Genus Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Gigartinales – Family Phyllophoraceae
Thallus erect, 5–20 cm high, subdichotomously branched, occasionally marginally proliferous, branches flat, 2–12 mm broad, more or less linear with rounded axils and apices. Structure of ovoid cells throughout, medulla large-celled, cortex small-celled. Cells with numerous rhodoplasts.
Reproduction: Sexual thalli dioecious. Female thalli with a medial line along the branches of procarps and carposporophytes, carpogonial branches 3–4-celled with the supporting cell becoming the auxiliary cell. Carposporophytes embedded, with clusters of carposporangia; ostioles absent but specialised pores (carpostomes) often present. Spermatangia borne in pockets within surface sori.
Tetrasporophytes with scattered nemathecia of numerous, adjacent, catenate chains of cruciately divided tetrasporangia.
Life history triphasic with isomorphic gametophytes and tetrasporophytes.
Type species: S. californica Harvey 1840: 408 [= S. interrupta (C. Agardh) Montagnel.
Taxonomic notes: A genus of 4 species, characterised by the medial lines of procarps and carposporangia on female plants. S. phyllophoroides (J. Agardh) Millar (1990, p. 354, fig. 24B, C) is known from northern N.S.W.
Steno gramme was spelled with a terminal 'a' in Harvey's original description, but with a terminal 'e' in Harvey 1848, pl. 157, then reverting to 'a' in 1853 and an 'e' in 1863. The derivation was from -gramme (a line) rather than -gramma (a written character), and most authors have used Harvey's later spelling of Steno gramme.
HARVEY, W.H. (1840). Algae. In Hooker, W.J. & Arnott, G.A.W., The Botany of Captain Beechey's Voyage, pp. 406–409. (London.)
HARVEY, W.H. (1848). Phycologia Britannica. Plates 145–216. (Reeve: London.)
MILLAR, A.J.K. (1990). Marine Red Algae of the Coffs Harbour Region, northern New South Wales. Aust. Syst. Bot. 3, 293–593.
The Marine Benthic Flora of Southern Australia Part IIIA complete list of references.
Womersley, H.B.S. (14 January, 1994)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIA, Bangiophyceae and Florideophyceae (to Gigartinales)
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIA 1994, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.
KEY TO SPECIES OF STENOGRAMME
1. Thallus branches (3–)
1. Thallus branches
State Herbarium of South Australia