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 ECHINOSPORANGIUM Kylin 1956: 537.

Phylum Rhodophyta – Family Rhodomelaceae – Tribe Polyzonieae

Thallus erect, irregularly branched, with robust perennial axes below; apices revolute, developing axes with a dorsal, membranous keel and 2 adjacent rows of flat, ventral, determinate laterals, arising 2 segments apart; older axes heavily corticated and covered with slender, branched appendages; holdfast massive, becoming branched. Structure. Indeterminate axes with 6 pericentral cells, ecorticate, dorsal and ventral ones and 2 lateral ones on each side; the dorsal ones form the largely monostromatic keel and the ventral lateral cells form the alternate determinate laterals, separated by a single unbranched cell; determinate laterals scalpelliform, with a posterior margin 3 cells thick, otherwise monostromatic apart from close to the indeterminate axis. Indeterminate branches arise endogenously. Trichoblasts arise from alternate lower to mid segments of the posterior margin of determinate laterals.

Reproduction: Gametophytes probably dioecious. Procarps on the second cell of the lower 1 (–3) trichoblasts on determinate laterals; carposporophytes with terminal carposporangia; cystocarps ovoid, pericarp heavily corticated. Spermatangia unknown.

Tetrasporangia in series in the midrib adjacent to the keel, cut off from the ventral pericentral cell, large and covered by corticating cells which develop outward prolongations 1–3 cells long, with rounded ends.

Type species: E. semipennatum (Lamouroux ex Poiret)Kylin 1956: 537.

Taxonomic notes: Echinosporangium contains only a single species, since C. imbricata J. Agardh is synonymous.

Echinosporangium is very similar to Cliftonaea in morphology, structure and reproduction, differing in having the determinate laterals flat rather than terete and arising from each second segment instead of every segment, and in having the corticating cells over the tetrasporangia producing short, 1–3 celled, filaments with rounded ends (not "echino"). They are clearly closely related and may be better placed within the one genus.


KYLIN, H. (1956). Die Gattungen der Rhodophyceen. (Gleerups: Lund.)

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

Publication: Womersley, H.B.S. (24 February, 2003)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIID. Ceramiales – Delesseriaceae, Sarcomeniaceae, Rhodomelaceae
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIID 2003, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.

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