Studies on southern Australian taxa of Solieriaceae, Rhobdoniaceae and Rhodophyllidaceae (Rhodophyta)

Abstract

The morphology, reproduction, and relationships of the southern Australian species of three closely related families of the Gigartinales (Solieriaceae, Rhabdoniaceae and Rhodophyllidaceae) are described. In the multiaxial Solieriaceae, most genera of which are non-Australian, Solieria robusta (Greville) Kylin and five species of Callophycus Trevisan have been studied. Apart from Sarconema filiforme (Sonder) Kylin, these are the only southern Australian taxa retained in the family. In the uniaxial and non-procarpic Rhabdoniaceae, Rhabdonia Hooker and Harvey (three species), Catenella nipae Zanardini, Areschougia Harvey (three species), and Erythroclonium Sonder (four species) have been studied. A species previously placed in Areschougia, A. dumosa Harvey, is found to be procarpic and is described as a new genus, Melanema. In all other vegetative and reproductive features it is similar to Areschougia, and it is provisionally retained in the Rhabdoniaceae. In the uniaxial and procarpic Rhodophyllidaceae the following are studied: Rhodophyllis Kuetzing (four species), Craspedocarpus Schmitz (four species, previously placed in Rhodophyllis), Gloiophyllis barkeriae (Harvey) J . Agardh, Calliblepharis planicaulis (Harvey) Kylin, and a new genus Austroclonium, based on Rhabdonia charoides Harvey.The main features used by Kylin in separating and characterizing these families and genera are considered generally satisfactory, but there appear to be cases where they cannot be rigidly applied. Such cases include the direction of gonimoblast development, and in the case of Melanema it is suggested that procarpy has arisen, by loss of ability to form connecting filament, from a non- procarpic ancestor such as Areschougia.

New features in the vegetative and reproductive morphology ofCystoclonium purpureum(Cystocloniaceae, Rhodophyta) from the North Atlantic Ocean

“…The core reproductive characters that Kylin (1923Kylin ( , 1932Kylin ( , 1956) identified in Cystoclonium purpureum apply equally well to other genera in his Rhodophyllidaceae, as well as to some members of the Rhodophyllidaceae recognized by Schmitz & Hauptfleisch (1897) and those investigated by Min-Thein & Womersley (1976) in their treatment of the families Solieriaceae, Rhizophyllidaceae and Rhodophyllaceae from southern Australia. In most instances the auxiliary cell is an intercalary cell in an otherwise normal cortical filament.…”

“…Fredericq et al (1992) demonstrated that secondary gametophytic filaments unite with the supporting cell of the carpogonial branch directly below the auxiliary cell, but not with the gonimoblast filaments themselves, in Acanthococcus antarcticus. Secondary filaments are produced in the thallus interior to which sterile gonimoblast filaments later fuse in several species of Rhodophyllis (Min-Thein & Womersley, 1976;Thrainsson, 1986), and a small cluster of tightly packed secondary gametophytic filaments are formed towards the thallus interior in Craspedocarpus and Calliblepharis that are approached by basal sterile gonimoblast filaments that fuse with them (Min-Thein & Womersley, 1976;Thrainsson, 1986). Several non-procarpic genera have cystocarps in which the fusion cell extends throughout the length of a cortical filament almost to the central axis.…”

“…The Cystocloniaceae was established (as the family 'Cystocloneae') by Ku¨tzing (1843, p. 404) for the genus Cystoclonium, which has long been considered (Kylin, 1932(Kylin, , 1956Min-Thein & Womersley, 1976) to be a member of the Rhodophyllidaceae Schmitz (1892, p. 19). As pointed out by Guiry (1978), however, according to Principal IV and Article 11 of the ICBN, the Cystocloniaceae (orth.…”

Cell Wall Polysaccharides from Australian Red Algae of the Family Solieriaceae (Gigartinales, Rhodophyta): Highly Methylated Carrageenans from the Genus Rhabdonia

“…Areschougia and Erythroclonium are currently also members of the Solieriaceae (Gabrielson and Hommersand 1982). Rhabdonia was at one time the type genus of the family Rhabdoniaceae (Kylin 1956, Min-Thein andWomersley 1976). It was transferred with the genera Areschougia, Erythroclonium, and Melanema from the Rhabdoniaceae (now Caulacanthaceae) to the family Solieriaceae on the basis of homologous reproductive structures and processes (Gabrielson and Hommersand 1982).…”

Studies onMetamastophora(Corallinaceae, Rhodophyta). I.M. flabellata(Sonder) Setchell: Morphology and anatomy

“…Growth of gonimoblast filaments does not stop when open contact between ceils occurs and no new filaments bearing sporangia develop from the partially fused cells. The fusion of gonimoblast filament ceils with other ceils prior to carpospore formation is not unique to Clathromorphum, Melobesia and Mesophyllum but occurs in a diversity of other Rhodophyta, including members of the Acrotylaceae (Kraft, 1977a), the Dicranemaceae (Kraft, 1977b), the Mychodeaceae and Mychodeophyllaceae (Kraft, 1978), the Nizymeniaceae (Searles, 1968;Womersley, 1971), the Rhodophyllidaceae (Min-Thein & Womersley, 1976) and the Solieriaceae (Kraft, 1975;Min-Thein & Womersley, 1976). Because of this and because the carpospore bearing filaments emanate from the fusion cell, it is difficult to accept Lebednik's (1977, p. 391 Lebednik (1977) are procarpic with supporting cells functioning as auxiliary cells in a manner similar to that in Metamastophoraflabellata.…”