Electronic Flora of South Australia
Electronic Flora of South Australia
Census of SA Plants, Algae & Fungi
Identification tools

Electronic Flora of South Australia Genus Fact Sheet

Genus AMPHIROA Lamouroux 1812: 186

Phylum Rhodophyta – Class Florideophyceae – Order Corallinales – Family Corallinaceae – Subfamily Amphiroideae – Tribe Amphiroeae

Thallus with a crustose or endophytic base and erect to decumbent geniculate branches, with dichotomous, compressed branches or terete branches bearing clustered or whorled branches from the upper ends of many intergenicula; holdfast crustose or filamentous, endophytic, epilithic or epiphytic. Structure of branches with a 1- multi-tiered medulla of alternating short and one to several long-celled tiers, with lateral secondary pit-connections and a cortex several cells thick in both genicula and intergenicula, with epithallial cells; genicula formed by decalcification.

Reproduction: Conceptacles on the surfaces of intergenicula. Gametangial thalli usually dioecious, if monoecious with carpogonia and spermatangia in separate conceptacles. Carpogonial filaments usually 2-celled, arising on chamber floor, carposporangia terminating short gonimoblast filaments arising from a basal fusion cell. Spermatangia on short unbranched filaments on the chamber floor.

Tetrasporangia borne on separate thalli, with the roofs of the conceptacles connected to elongate cells from the floor which are interspersed among and peripheral to the zonately divided sporangia.

Life history triphasic with isomorphic gametophytes and tetrasporophytes.

Lectotype species: A. tribulus (Ellis & Solander) Lamouroux 1812: 186. (Hamel & Lemoine 1953: 40.)

Taxonomic notes: Amphiroa contains numerous species, mainly tropical - subtropical in distribution, with two species on southern Australian coasts.

While only one species, A. anceps, is common in southern Australia (from Cape Naturaliste south), another species, A. gracilis Harvey (1855a, p. 547), which was described from "King George's Sound and Rottnest", occurs in scattered localities.


HAMEL, G. & LEMOINE, P. (1953). Corallinacées de France et D'Afrique du Nord. Archs Mus. natn. d'Hist. Nat., Paris, 7 Sér, 1, 15–136, Plates 1–23.

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

LAMOUROUX, J.V.F. (1812). Sur la classification des Polypiers coralligenès non entièrement pierreux. Nouv. Bull. Sci. Soc. Philom. Paris 3, 181–188.

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

Author: H.B.S. Womersley & H.W. Johansen

Publication: Womersley, H.B.S. (28 June, 1996)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIB. Gracilarialse, Rhodymeniales, Corallinales and Bonnemaisoniales
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIB 1996, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.


1. Branches compressed, 1–3 (–4) mm broad except near the base

A. anceps

1. Branches terete, 1–2 mm in diameter near the base, 300–500 µm in diameter near the apices

A. gracilis

Disclaimer Copyright Disclaimer Copyright Email Contact:
State Herbarium of South Australia
Government of South Australia Government of South Australia Government of South Australia Department for Environment and Water