Electronic Flora of South Australia Genus Fact Sheet

Genus PORPHYRA C. Agardh 1824: XXXII, 190, nom. cons.

Phylum Rhodophyta – Class Bangiophyceae – Order Bangiales – Family Bangiaceae

Thallus (gametophytic macrothallus) foliose, membranous, erect but flaccid, branched from the base but rarely above, one or two cells thick, attached by a small holdfast of interwoven rhizoids from numerous suprabasal cells; cell divisions diffuse or partly marginal; pit-connections absent. Rhodoplasts more or less stellate with a central pyrenoid.

Reproduction: Reproduction of the gametophyte by monospores or aplanospores, with sexual reproduction by spermatangia formed in packets of 64–256, usually marginally, and by vegetative cells becoming carpogonia with short prototrichogynes; the zygote divides directly into packets of 4–32 carposporangia, each with a single deeply-pigmented
carpospore.

Conchocelis phase (sporophyte) minute, filamentous, branched, with pit-connections, usually embedded within shells.

Lectotype species: P. purpurea (Roth) C. Agardh 1824: 191 [= P. umbilicalis (L.)Kützing].

Taxonomic notes: Conchocelis phase (sporophyte) reproducing by monospores and by conchosporangia (meiosporangia) formed in fertile cell rows (Conway & Cole 1977).

A genus of numerous species, often forming conspicuous communities in the mid and upper eulittoral on cool temperate coasts. Many studies on their reproduction are reviewed by Cole & Conway (1980) and sexual reproduction has been established by Hawkes (1978). The southern Australian species are reasonably clear-cut with mature, fertile specimens, but further studies (similar to Kornmann & Sahling 1991) are needed on their variation and life-histories.

References:

AGARDH, C.A. (1824). Systema Algarum. (Berling: Lund.)

COLE, K. & CONWAY, E. (1980). Studies in the Bangiaceae: Reproductive modes. Bot. Mar. 23, 545–553.

CONWAY, E. & COLE, K. (1977). Studies in the Bangiaceae: structure and reproduction of the conchocelis of Porphyra and Bangia in culture (Bangiales, Rhodophyceae). Phycologia 16, 205–216.

HAWKES, M.W. (1978). Sexual reproduction in Porphyra gardneri (Smith et Hollenberg)Hawkes (Bangiales, Rhodophyta). Phycologia 17, 329–353.

KORNMANN, P. & SAHLING, P.-H. (1991). The Porphyra species of Helgoland (Bangiales, Rhodophyta). Helgoländer Meeresunters. 45, 1–38.

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

Author: H.B.S. Womersley

Publication: 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 PORPHYRA

1. Blades delicate, rose-pink, ovate to lanceolate, epiphytic on certain brown (or red) algae in the upper sublittoral

P. woolhousiae

1. Blades lanceolate or ribbon shaped, becoming umbilicate and often broader than long, grey to red or dark purple, growing on rock or hard substrates

2

2. Thallus fairly tough, retaining its form when old, shrinking on drying and not adhering strongly to paper; usually over 45 µm thick; carposporangial groups prominent, scattered, with vegetative cells among the groups; spermatangia occurring irregularly around the margin

P. columbina

2. Thallus usually delicate, disintegrating when old, adhering closely to paper and not markedly shrinking on drying; usually 20–30 µm thick; carposporangial groups usually not prominent; spermatangia occurring in (usually) narrow, elongate strips, extending inwards from the apical and side margins of the thallus

P. lucasii


Disclaimer Copyright Disclaimer Email Contact:
State Herbarium of South Australia
Government of South Australia Government of South Australia Department of Environment, Water and Natural Resources