Electronic Flora of South Australia Genus Fact Sheet

Genus CALLOPHYLLIS Kützing 1843: 400

Phylum Rhodophyta – Class Florideophyceae – Order Gigartinales – Family Kallymeniaceae

Thallus much divided into flat, subdichotomous to irregular branches lying essentially in one plane, often flabellate in habit. Structure. Medulla of large ovoid cells separated by filaments of small cells, and a smaller-celled cortex; stellate and refractive cells absent.

Reproduction: Carpogonial branch systems mono- or polycarpogonial, usually with lobed supporting cell, first cell of the carpogonial branch, and subsidiary cells. Separate auxiliary cell systems absent, with the carpogonial branch system after fertilization developing into a fusion cell from which gonimoblast filaments develop directly.

Lectotype species: C. variegata (Bory) Kützing 1843: 401.

Taxonomic notes: Carposporophyte of dense groups of carposporangia separated by intermixed filaments and large medullary cells, forming a sunken (but often becoming protuberant) cystocarp, with or without an ostiole. Spermatangia cut off from outer cortical cells.

Tetrasporangia cruciately divided, scattered in the outer cortex on the branches.

Callophyllis is the only Australian genus of the Kallymeniaceae which lacks separate auxiliary cell systems and so can be regarded as procarpic. The fusion cell can sometimes be recognised in the centre of relatively young carposporophytes. Reproductive cells in Callophyllis are relatively uniform and, as Abbott & Norris (1965) found for species of this genus in Pacific North America, it has not been possible to separate the Australian species on reproductive features. All Australian species are monocarpogonial with lobed cells, the degree of lobing depending largely on the age of the system. Cystocarps of C. rangiferina in particular vary considerably in size, degree of protrusion, and development of the ostiole, depending largely on the maturity of the carposporophyte.

Carpogonial branch systems are often profusely developed close to the apices in female plants. In the absence of fertilization, the cells of the systems enlarge, become lighter staining, and are usually digested by vegetative filaments from the medulla. In the Australian species no carpogonial branch systems have been observed more than a few millimetres from the apices. Cytocarps are also found only within a few millimetres of the apices; those formed on short branches are probably lost when the branch is lost, but it seems likely that carposporophyte tissue, after loss of the carposporangia, may be similarly digested by vegetative filaments.

Considerable variation in form occurs in both C. lambertii and C. rangiferina, probably depending on the ecological habitat and on the age of the plant. In particular, some plants of both species apparently last for a second season and show prominent proliferous growth from the older axes which have been largely denuded following the first season growth.

Only three Australian species of Callophyllis are recognised here. Two of these, C. rangiferina and C. lambertii, are very common on coasts with moderate to strong wave action and they are both variable species with intergrades in form betweeen those considered typical of each species. The specimens placed under the third species, C. cervicornis, are relatively few, and, though apparently distinct, small plants approach forms of C. rangiferina in habit. Further studies of variation within the genus are desirable.

In determining species of Callophyllis, relatively mature plants are necessary. Young plants may often be fertile, but the characteristic form of the apices is best seen in larger and older plants.

References:

ABBOTT, I.A. & NORRIS, R.E. (1965). Studies on Callophyllis (Rhodophyceae) from the Pacific Coast of North America. Nova Hedwigia 10, 67–84, Plates 6–19.

KÜTZING, F.T. (1843). Phycologia generalis. (Leipzig.)

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 AUSTRALIAN SPECIES OF CALLOPHYLL1S

1. Thallus margins above smooth, with few if any spinous or proliferous laterals; terminal segments lanceolate and basally narrower, often apically furcate; normal laterals often 1 cm or more apart, lower axes usually under 3 mm broad

C. cervicornis

1. Thallus margins often irregular with short and often spinous, or long, laterals; terminal segments slender and lanceolate but usually not basally constricted, or broad and spathulate; normal laterals usually less than 1 cm apart; lower axes often over 3 mm broad

2

2. Thallus robust, commonly over 15 cm high; apices not lanceolate, usually broad and basally narrower, often spathulate with upper, marginal prongs, usually over 1 mm and commonly over 2 mm broad close to apices

C. lambertii

2. Thallus slender, usually less than 20 cm high; apices profusely branched, terminal segments lanceolate, usually acute and less than 1 mm broad for some millimetres from apex

C. rangiferina


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