SCHMITZIA EVANESCENS SP. NOV. (RHODOPHYTA,GIGARTINALES) A NEW SPECIES OF CALOSIPHONIACEAE FROM THE NORTHEASTERN NEW ZEALAND COAST1

A new red alga, Schmitzia evanescens sp. nov. (Gigartinales), is described from the northeastern coast of North I., New Zealand. Gametophytes are diminutive, delicate, mucilaginous spring annuals which grow subtidally on cobble substrata. The uniaxial construction and carposporophyte development place this new taxon in the Calosiphoniaceae, a family of only two genera, Calosiphonia H. M. Crouan et P. L. Crouan and Schmitzia P. C. Silva. This is the first report of this family in New Zealand. The new species has vegetative features of both these genera, but is assigned to Schmitzia on the basis of its unusual carposporophyte development in which the gonimoblast initial arises directly from the connecting filament at some distance from the undifferentiated intercalary auxiliary cell. Because recent investigators of other red algal genera with a similar carposporophyte development have questioned the validity of site of gonimoblast initiation as a generic criterion it is suggested that the separation of Schmitzia and Calosiphonia should be re-evaluated. These and several other genera in the Gymnophlaeaceae, Pseudoanemoniaceae, Dumontiaceae and Gloiosiphoniaceae, can be considered, on morphological and reproductive grounds, to be relatively simple and therefore perhaps primitive members of the Rhodophyta.     

MORPHOLOGY OF THE SUBANTARCTIC RED ALGA CENACRUM SUBSUTUM GEN. ET SP. NOV. (RHODYMENIALES) FROM MACQUARIE ISLAND1

The red alga Cenacrum subsutum gen. et sp. nov. is described from material collected at Macquarie Island in the subantarctic between November 1977 and February 1978. The habit and carposporophyte development are similar to members of the family Rhodymeniaceae (Rhodymeniales), but certain vegetative features are unique. The frond is a variously incised or lobed foliose blade with hollow apices above and a medulla which becomes progressively filled basipetally with ingrowing rhizoidal filaments. Details of carpogonial branch, auxiliary cell, connecting cell and gonimoblast anatomy are given, as well as observations on the habitats and distribution of the species.     

A NEW METHOD OF CYSTOCARP DEVELOPMENT IN THE RED ALGAL GENUS CALLOPHYLLIS (KALLYMENIACEAE) FROM CHILE1

Traditional studies suggest that the Kallymeniaceae can be divided into two major groups, a nonprocarpic Kallymenia group, in which carposporophyte formation involves an auxiliary cell branch system separate from the carpogonial branch system, and a procarpic Callophyllis group, in which the carpogonial branch system gives rise to the carposporophyte directly after fertilization. Based on our phylogenetic studies and unpublished observations, the two groups each contain both procarpic and nonprocarpic genera. Here, we describe a new method of reproductive development in Callophyllis concepcionensis Arakaki, Alveal et Ramírez from Chile. The carpogonial branch system consists of a supporting cell bearing both a three‐celled carpogonial branch with trichogyne and two‐lobed “subsidiary” cells. After fertilization, large numbers of secondary subcortical and medullary cells are produced. Lobes of the carpogonial branch system cut off connecting cells containing enlarged, presumably diploid nuclei that fuse with these secondary vegetative cells and deposit their nuclei. Derivative enlarged nuclei are transferred from one vegetative cell to another, which ultimately cut off gonimoblast initials that form filaments that surround the central primary medullary cells and produce carposporangia. The repeated involvement of vegetative cells in gonimoblast formation is a new observation, not only in Callophyllis, but in red algae generally. These results call for a revised classification of the Kallymeniaceae based on new morphological and molecular studies.     

A MORPHOLOGICAL STUDY OF HOMMERSANDIA MAXIMICARPA GEN. ET SP. NOV. (KALLYMENIACEAE,RHODOPHYTA) FROM THE NORTH PACIFIC1

A new foliose red alga, common subtidally from British Columbia to the Aleutian Islands, is described and given the name Hommersandia maximicarpa. The lobed perennial thallus, which can reach a height of 23 cm, is distinguished by its vegetative structure and by its unique pattern of nonprocarpic carposporophyte development. In transverse section, the blades consist of a narrow filamentous medullary layer sandwiched on either side by large ellipsoidal subcortical cells and a thin outer cortex. The monocarpogonial branch and auxiliary cell systems of the female plants are typical of many members of the Kallymeniaceae. However, after the carpogonialfusion cell forms, a distinctive developmental pattern begins. The connecting filaments radiate outward into the surrounding tissue, branch abundantly, and become septate. They then contact, in addition to auxiliary cells, many small moniliform accessory branches. These branches appear to act as initiation points for the gonimoblast filaments. The large diffuse carposporophytes produced are unknown in any other member of the Cryptonemiales. The vegetative and reproductive anatomy of Hommersandia is compared to other Kallymeniaceae, and similar patterns of postfertilization development are examined in the Rhodophyta.     

VEGETATIVE AND REPRODUCTIVE MORPHOLOGY OF EUCHEUMA ISIFORME (SOLIERIACEAE,GIGARTINALES, RHODOPHYTA)1

Eucheuma isiforme (C. Agardh) J. Agardh exhibits a combination of vegetative and reproductive features that distinguish it from other critically studied genera in the Solieriaceae. The development of the multiaxial thallus, emphasizing the arrangement of periaxial cells around each axial file; presence of reproductive nemathecia that contain carpogonial branches and auxiliary cells; and post-diploidization stages, including gonimoblast and pericarp initiation, stages of fusion cell formation, and carposporophyte development are described and illustrated for the first time in this species. The vegetative and reproductive features observed in E. isiforme are not diagnostic of any of the recently erected tribes in the Solieriaceae. Eucheuma appears most closely related to the Indian Ocean genus, Sarconema.     

SYSTEMATIC REVISION OF THE GENERA LIAGORA AND IZZIELLA (LIAGORACEAE,RHODOPHYTA) FROM TAIWAN BASED ON MOLECULAR ANALYSES AND CARPOSPOROPHYTE DEVELOPMENT,WITH THE DESCRIPTION OF TWO NEW SPECIES1

Some Liagora and Izziella distributed in Taiwan display a wide range of morphological variation and can be difficult to distinguish. To clarify species concepts, we applied DNA sequence analyses and examined carposporophyte development in detail. These studies revealed two new species, which are described herein as Izziella hommersandii sp. nov. and Izziella kuroshioensis sp. nov. I. kuroshioensis superficially resembles Izziella formosana and Izziella orientalis in that its involucral filaments subtend rather than surround the lower portion of the gonimoblast mass (= Izziella type) and a fusion cell is formed from cells of the carpogonial branch, but it can be separated by differences in the cell numbers and branching pattern of the involucral filaments, as well as thallus morphology. In contrast to other species that also bear short lateral branchlets, I. hommersandii is unique in possessing a mixture of short and long involucral filaments, a phenomenon not reported before. The length of the involucral filaments is species specific among species of Izziella and contrasts to the behavior of the involucral filaments after fertilization in species such as “Liagora”setchellii [= Titanophycus setchellii comb. nov.], in which the filaments completely envelop the gonimoblast. In addition, the cells of the carpogonial branch in Titanophycus do not fuse after fertilization to form a fusion cell. Thus, a combination of characters with respect to the behavior of the carpogonial branch and the involucral filaments after fertilization is very useful for delineating species boundaries in Izziella and for separating Titanophycus from Izziella and Liagora.     

LEACHIELLA PACIFICA,GEN. ET SP. NOV., A NEW PARASITIC RED ALGA FROM WASHINGTON AND CALIFORNIA

Leachiella pacifica, gen. et sp. nov., a marine alloparasitic red alga is described from Washington and California. Several species of Polysiphonia and Pterosiphonia are hosts for this parasite. The thallus is a white, multiaxial, unbranched pustule with rhizoidal filaments that ramify between host cells, forming numerous secondary pit connections with host cells. All reproductive structures develop from outer cortical cells. Tetrasporocytes, situated on stalk cells, undergo simultaneous, tetrahedral cleavage to form tetraspores. Spermatia are formed continuously by oblique cleavages of the elongate spermatial generating cells. This results in spermatial clusters consisting of 4–8 spermatia in an alternate arrangement. Carposporophyte development is procarpial. The carpogonium is part of a six-celled branch including a sterile cell that is formed by the basal cell. The carpogonial branch is attached laterally to an obovate supporting cell that also forms an auxiliary cell, presumably formed prior to fertilization. After fertilization the carpogonium temporarily fuses with the auxiliary cell apparently to transfer the diploid nucleus and initiate further fusion with the subtending supporting cell to form an incipient fusion cell. The auxiliary cell portion of this fusion cell divides to form gonimoblast initials that continue to divide, forming gonimoblast filaments whose terminal cells differentiate into carpospores. The remainder of the fusion cell enlarges by continual fusion with adjacent vegetative cells. The resultant carposporophyte consists of a basal, multinucleate fusion cell supporting a hemispherical cluster of gonimoblast filaments with terminally borne carpospores. Vegetatively, Leachiella resembles several other parasitic red algae but it is clearly separated by the procarp, carposporophyte development and structure, and tetrasporocyte cleavage.     

REPRODUCTIVE DEVELOPMENT OF THE PARASITIC RED ALGA GARDNERIELLA TUBERIFERA (SOLIERIACEAE,GIGARTINALES)1

Examination of the reproductive morphology of the adelphoparasitic red alga Gardneriella tuberifera Kylin reveals that this monotypic genus is correctly placed in the family Solieriaceae (Gigartinales), to which its host Agardhiella gaudichaudii (Montagne) Silva et Papenfuss also belongs. Gardneriella is multiaxial, nonprocarpic and has an inwardly directed, three-celled carpogonial branch. The large, reniform uninucleate auxiliary cell is distinct prior to and after fertilization. It is diploidized by an unbranched, multicellular connecting filament which lacks pit connections. One or two connecting filaments arise from each fertilized carpogonium. From the diploidized auxiliary cell, the gonimoblast initial is cut off obliquely toward the interior of the thallus. The cells of the gonimoblast fuse with adjacent unpigmented vegetative cells of Gardneriella and pigmented cells of the host. These cells become incorporated into the developing cystocarp and, from those of Gardneriella, additional short chains of gonimoblast cells arise. The mature cystocarp is placentate, radiately lobed, and lacks a surrounding involucre. Carposporangia are borne in short chains and the unpigmented carpospores are released upon the dissolution of outer vegetative cells. No ostiole is present. Gardneriella appears to be most closely related to the placentate solieriacean genera Agardhiella, Sarcodiotheca, and Meristiella and therefore this genus should be placed in the tribe recently erected for these taxa, the Agardhielleae.     

CHARACTERIZATION OF MYHOGRAMME LNIDA, MYRIOGRAMMEAE TRIB. NOV (DELESSEIUACEAE, FWODOPHYTA)

The Myriogramme group of Kylin was found to contain two distinct clusters of genera that merit recognition at the tribal level. In this paper, we establish the tribe Myriogrammae based on a study of the type species of Myriogramme, M. livida, from the Southern Hemisphere. The Myriogrammae is characterized by 1) marginal and diffuse intercalary meristems; 2) nuclei arranged in a ring bordering the side walls of vegetative cells; 3) microscopic veins absent; 4) procarps scattered, formed opposite one another on both sides of the blade posterior to one or more vegetative pericentral cells (cover cells) and consisting of a carpogonial branch, a one-/to two-celled lateral sterile group and a one-celled basal sterile group; 5) auxiliary cell diploidized by a connecting cell cut off posteriolaterally from the fertilized carpogonium; 6) gonimoblast initial cut off distally from the auxiliary cell, generating one distal and one to two lateral gonimoblast filaments that branch in the plane of the expanding cystocarp cavity and later fuse to from an extensive, branched fusion cell; 7) spermatangial and tatrasporangial sori formed inside the margin on both sides of the blade by resumption of meristematic activity; and 8) tetrasporangia produced primarily from the central cells. The Myriogrammae currently includes Myriogramme Kylin , Gonimocolax Kylin , Haraldiophyllum A. Zinova , Hideophyllum A. Zinova, and a possible undescribed genus from Pacific North and South America. Genera are separated based primarily on features of gonimoblast and carposporangial development .     

CHARACTERIZATION OF SCHIZOSERIS CONDENSATA,SCHIZOSERIDEAE TRIB. NOV. (DELESSERIACEAE,RHODOPHYTA)1

The Myriogramme group of Kylin contains two distinct clusters of genera that merit recognition at the tribal level. We previously established the tribe Myriogrammeae, and in this paper we erect the Schizoserideae based on a study of the type species of Schizoseris, S. laciniata (=S. condensata), from the southern hemisphere. The Schizoserideae is characterized by 1) marginal and diffuse intercalary meristems; 2) nuclei initially arranged in a plate in the median plane in meristematic and mature cells; 3) chloroplasts one to few, lobed or dissected; 4) microscopic veins absent; 5) procarps scattered, formed singly on either side of the blade with cover cells absent and consisting of a one- to two-celled lateral sterile group, a one- to two-celled basal sterile group, and a four-celled carpogonial branch in which the trichogyne passes beneath the lateral sterile group and emerges anterior to it; 6) auxiliary cell diploidized by a connecting cell cut off posteriolaterally from the fertilized carpogonium; 7) gonimoblast initial cut off laterally from one side of the auxiliary cell and giving rise to unilaterally branched gonimoblast filaments bearing carposporangia in branched chains; 8) gonimoblast fusion cell highly branched, candelabra-like, incorporating all but the basalmost cells of the carposporangial chains and radiating through the central cells in the floor of the cystocarp; 9) spermatangial and tetrasporangial sori formed from surface cells in both monostromatic and polystromatic portions on both sides of the blade; and 10) tetrasporangia formed primarily from cortical rather than from central cells. The Schizoserideae presently includes Schizoseris Kylin, Neuroglossum Kützing, Abroteia J. Agardh, and Polycoryne Skottsberg in Kylin and Skottsberg.     

THE MORPHOLOGY OF CUBICULOSPORUM KORONICARPIS GEN. ET SP. NOV., REPRESENTING A NEW FAMILY IN THE GIGARTINALES (RHODOPHYTA)

The red alga Cubiculosporum koronicarpis gen. et sp. nov. is described from material collected during 1968 in the Philippines. The species differs substantially in regard to its carposporophyte development from other red algae in the order Gigartinales, and a new family is created based on its unique combination of reproductive features. A single, short, connecting filament is formed between the fertilized carpogonium and a nearby auxiliary cell. The latter produces several ramifying gonimoblast filaments towards the interior of the thallus. No fusion cell is formed and the gonimoblast filaments grow inward among the cells of the central axis, form secondary connections to them, and give rise to outwardly directed carposporangial filaments that develop within peripheral chambers formed between elongating inner cortical cells. The alga is a low, clump-forming species of well-washed intertidal reef platforms at the one Philippine locality where it has been found. There it contributed a uniform but very minor amount to the wet weight of the standing crops that were studied during two separate seasons of the year.     

THE ATLANTIC SPECIES OF SOLIERIA (GIGARTINALES,RHODOPHYTA): THEIR MORPHOLOGY,DISTRIBUTION AND AFFINITIES1

Solieria chordalis (C. Agardh) J. Agardh and S. tenera (J. Agardh) Wynne et Taylor exhibit multiaxial growth from a cluster of four to eight obconical apical cells. A single periaxial cell is cut off from each axial cell and successive periaxial cells are rotated 120° in a zig-zag pattern along each axial filament. Periaxial cells produce branched, laterally diverging filaments which form the cortex. The medulla is composed of axial cells, elongate cells of lateral filaments, stretched interconnecting cells, and secondary rhizoids. The two species are nonprocarpic. Carpogonial branches are 3-celled, inwardly directed, with a reflexed trichogyne. The auxiliary cell together with associated darkly-staining inner cortical cells form an association, the auxiliary cell complex, that is recognizable prior to diploidization. A single, unbranched, non-septate connecting filament issues from the fertilized carpogonium and fuses with the inner, lateral side of an auxiliary cell. Production of an involucre from surrounding vegetative cells is stimulated and a gonimoblast initial is cut off toward the interior of the thallus which divides to form a compact cluster of gonimoblast cells. A fusion cell is produced through fusion of inner gonimoblast cells with the auxiliary cell that, in turn, fuses progressively with cells of the lateral file bearing the auxiliary cell. Mature cystocarps have terminal carposporangia cut off from gonimoblast cells at the periphery of the fusion cell and are surrounded by an involucre with a distinct ostiole. Tetrasporangia are cut off laterally from surface cortical cells which then cut off one or two additional derivatives toward the outside. A lectotype is designated for Solieria chordalis, but the lectotypification of S. tenera is questioned. We conclude that Solieria is closely related to Rhabdonia and place the Rhabdoniaceae in synonomy with the Solieriaceae.     

Comparative morphology and systematics of Chondrymenia lobata from the Mediterranean Sea and a phylogeny of the Chondrymeniaceae fam. nov. (Rhodophyta) based on rbcL sequence analyses

The Chondrymeniaceae Rodríguez-Prieto, G. Sartoni, S.-M. Lin & Hommersand, fam. nov., is proposed for Chondrymenia lobata. Analyses of rbcL sequences place the new family in a large gigartinalean assemblage that comprises the Cystocloniaceae–Solieriaceae complex. Plants are decumbent and growth takes place by division of multiple apical cells at the margin of the blade. Thalli consist of an outer cortex of subspherical to elongate cortical cells arranged in anticlinal rows, a subcortex of cells cross-linked by lateral arms, and a large central medulla composed of primary medullary filaments intermixed with numerous rhizoidal filaments. Male stages are reported in monoecious individuals. Inactive carpogonial branches consist of a two-celled filament that is directed inwards from the supporting cell. Functional carpogonial branches are oriented outwardly, with the carpogonia and trichogynes pointed towards the thallus surface. After presumed fertilization, the carpogonium fuses with the hypogynous cell and transfers the zygote nucleus. The hypogynous cell, in turn, fuses with the supporting cell which contains many haploid nuclei. The resulting fusion cell functions as an auxiliary cell that cuts off a single gonimoblast initial, which produces the gonimoblast filaments. Gametophytic cells close to the auxiliary cell unite with it to form a placental fusion network of variable size and outline, and a placental fusion cell. Proximal gonimoblast cells fuse with the placental fusion cell, while the distal cells differentiate into branched chains of subspherical carposporangia. The superficial similarity of the outwardly developed osteolate cystocarp is responsible for Kylin's (1956) placement of Chondrymenia in his family Sarcodiaceae; however, the manner in which the placenta is formed is more like that seen in the Cystocloniaceae–Solieriaceae complex.     

The morphology and ecology of Nemastoma and Predaea species (Nemastomataceae,Rhodophyta) from Ghana

Two members of the family Nemastomataceae (Gigartinales, Rhodophyta) are described from subtidal habitats in Ghana. Nemastoma confusum sp. nov. is a plant of irregularly lobed, thick gelatinous blades with subacute marginal projections and surface proliferations. It is composed of a lax medulla and submoniliform cortical filaments with prominent intercalary gland cells. Carposporophytes are one to three spherical lobes of carposporangia borne on gonimoblast initials arising directly from auxiliary cells contacted by connecting filaments. A rudimentary involucre is formed around the gonimoblast by elongating vegetative cortical cells borne on the auxiliary cell. The genus Predaea is recorded for the first time from Africa, and P. feldmannii Boerg. is described in morphological detail together with some observations on its ecology in Ghana. Distinctive features of connecting filament formation, nutritive cell production and gonimoblast initiation and development are illustrated and compared to other species of the genus. A second species, P. masonii (Setch. & Gardn.) De Toni fil., is represented by a single specimen in the collections and appears to be distinct from P. feldmannii on cortical and gland cell features.     

STRUCTURE AND DEVELOPMENT OF THE CARPOSPOROPHYTE OF NEMALION HELMINTHOIDES (NEMALIONALES,RHODOPHYTA)1

Following fertilization, the carposporophyte of Nemalion helminthoides (Velley in With.) Batters differentiates into four distinct regions: the fusion cell, the sterile gonimoblast cells, the carposporangial mother cells and the carposporangia. The gonimoblast is formed by apically dividing, monopodial filaments of limited growth which may later become pseudodichotomous. Upon differentiation of a terminal carposporangium, a gonimoblast filament may continue to grow sympodially. A single carposporangial mother cell may produce carposporangia in several different directions as well as proliferate successive carposporangia within the sporangial walls that remain after carpospore liberation. As the carposporophyte matures, the gonimoblast initial, the stalk cell, the hypogynous and subhypogynous cells fuse. Except for the fusion cell, all cells of the carposporophyte show organelle polarity and contain a distally located, lobed chloroplast and proximal nucleus.     

A phylogenetic re‐appraisal of the family Liagoraceae sensu lato (Nemaliales,Rhodophyta) based on sequence analyses of two plastid genes and postfertilization development

The marine red algal family Liagoraceae sensu lato is shown to be polyphyletic based on analyses of a combined rbcL and psaA data set and the pattern of carposporophyte development. Fifteen of eighteen genera analyzed formed a monophyletic lineage that included the genus Liagora. Nemalion did not cluster with Liagoraceae sensu stricto, and Nemaliaceae is reinstated, characterized morphologically by the formation of the primary gonimolobes by longitudinal divisions of the gonimoblast initial. Yamadaella and Liagoropsis, previously placed in the Dermonemataceae, are shown to be independent lineages and are recognized as two new families Yamadaellaceae and Liagoropsidaceae. Yamadaellaceae is characterized by two gonimoblast initials cut off bilaterally from the fertilized carpogonium and diffusely spreading gonimoblast filaments. Liagoropsidaceae is characterized by at least three gonimoblast initials cut off by longitudinal septa from the fertilized carpogonium. In contrast, Liagoraceae sensu stricto is characterized by a single gonimoblast initial cut off transversely or diagonally from the fertilized carpogonium. Reproductive features, such as diffuse gonimoblasts and unfused carpogonial branches following postfertilization, appear to have evolved on more than one occasion in the Nemaliales and are therefore not taxonomically diagnostic at the family level, although they may be useful in recognizing genera.     

Consideration of the order Cryptonemiales and the families Nemastomataceae and Furcellariaceae (Gigartinales,Rhodophyta) in light of the morphology of Adelophyton corneum (J. Agardh) gen. et comb. nov. from southern Australia

A new red algal genus is described, based on the southern Australian Chaetangium corneum J. Agardh. It is reproductively unique in that while the auxiliary cell is intercalary in an adventitious filament, a defining character of the order Cryptonemiales, the vegetative structure, carpogonial branches, connecting filaments and gonimoblast development seem strongly allied to lower families of the Gigartinales. Although its predominantly thallus-inward gonimoblast development is characteristic of the gigartinalian family Furcellariaceae, it is suggested that the new alga should be placed in the Nemastomataceae and that this family exhibits features which, in an ancient algal stock, could theoretically have given rise to the lower cryptonemialian and higher gigartinalian lines. The possible relationships between the Nemastomataceae, Furcellariaceae and Solieriaceae are discussed, and some seemingly primitive features of the Nemastomataceae are enumcrated.     

AUGOPHYLLUM,A NEW GENUS OF THE DELESSERIACEAE (RHODOPHYTA) BASED ON rbcL SEQUENCE ANALYSIS AND CYSTOCARP DEVELOPMENT1

A new genus, Augophyllum Lin, Fredericq et Hommersand gen. nov. related to Nitophyllum, tribe Nitophylleae, subfam. Nitophylloideae of the Delesseriaceae, is established to contain the type species Augophyllum wysorii Lin, Fredericq et Hommersand sp. nov. from Caribbean Panama; Augophyllum kentingii Lin, Fredericq et Hommersand sp. nov. from Taiwan; Augophyllum marginifructum (R. E. Norris et Wynne) Lin, Fredericq et Hommersand comb. nov. (Myriogramme marginifructa R. E. Norris et Wynne 1987) from South Africa, Tanzania, and the Sultanate of Oman; and Augophyllum delicatum (Millar) Lin, Fredericq et Hommersand comb. nov. (Nitophyllum delicatum Millar 1990 ) from southeastern Australia. Like Nitophyllum, Augophyllum is characterized by a diffuse meristematic region, the absence of macro‐ and microscopic veins, procarps consisting of a supporting cell bearing a slightly curved four‐celled carpogonial branch flanked laterally by a cover cell and a sterile cell, a branched multicellular sterile group after fertilization, absence of cell fusions between gonimoblast cells, and tetrasporangia transformed from multinucleate surface cells. Augophyllum differs from Nitophyllum by the blades becoming polystromatic inside the margins, often with a stipitate cylindrical base, the possession of aggregated discoid plastids neither linked by fine strands nor forming bead‐like branched chains, spermatangia and procarps initiated at the margins of blades, not diffuse, and a cystocarp composed of densely branched gonimoblast filaments borne on a conspicuous persistent auxiliary cell with an enlarged nucleus. Analyses of the rbcL gene support the separation of Augophyllum from Nitophyllum. An investigation of species attributed to Nitophyllum around the world is expected to reveal other taxa referable to Augophyllum.     

ULTRASTRUCTURE OF THE CARPOSPOROPHYTE AND CARPOSPOROGENESIS IN THE PARASITIC RED ALGA PLOCAMIOCOLAX PULVINATA SETCH, (GIGARTINALES,PLOCAMIACEAE) 1

The ultrastructure of the carposporophyte and carposporogenesis is described for the parasitic red alga Plocamiocolax pulvinata Setch. After presumed fertilization the zygote nucleus is apparently transferred to the auxiliary cell which initiates gonimoblast cell production. These gonimoblast cells differentiate into storage or generative cells. Storage gonimoblast cells (SGC) are large and multinucleate, contain large quantities of starch and are located nearest the auxiliary cell, when compared to the smaller uninucleate, devoid of starch, generative gonimoblast cells (GGC) that form terminal lobes of carpospores. In addition, compressed membrane bodies and annulate lamellae are common in these cells. During carposporophyte maturation the amount of starch in the SGC's decreases and eventually the auxiliary cell, as well as SGC's, degenerate. Generative gonimoblast cells (GGC's) cleave repeatedly to form carpospores which are interconnected by small pit connections. Stage one-carpospores are recognized by their elongated shape, the formation of small     

New Insights in the Cryptonemiales–Rhodymeniales Complex and Resurrection of the Allied Red Algal Order Nemastomatales Kylin 1925 as Inferred From rbcL Sequence Analysis and Comparative Reproductive Morphology

In a global molecular phylogeny of florideophycean red algae inferred from chloroplast‐encoded rbcL sequence analysis, a major monophyletic assemblage comprises the Cryptonemiales (=Halymeniales), the Rhodymeniales, the Schizymeniaceae (Schizymenia, Titanophora, Platoma) and the Nemastomataceae (Nemastoma, Predaea). The phylogenetic significance of the auxiliary cell and its interaction with the fertilized egg cell in this assemblage is discussed in relation to established and newly proposed classification schemes. The order Nemastomatales Kylin 1925 is reinstated and emended to contain the nonprocarpic Schizymeniaceae and Nemastomataceae. Unifying characters of the Nemastomatales include fertilized carpogonia that may establish fusions with carpogonial nutritive cells prior to the formation of septate connecting filaments, and simple gonimoblasts developing outwardly from auxiliary cells or from connecting filaments in their vicinity. The auxiliary cell is a transformed vegetative intercalary cell (Sebdeniaceae), that becomes surrounded by either clusters of nutritive cells (Nemastomataceae), involucral filaments (Schizymeniaceae) or by three‐dimensional ampullary filaments (Halymeniaceae including the Corynomorphaceae), or is part of a procarp (Rhodymeniales). The homology of outward gonimoblast initiation and maturation into a simple ball of carposporangia in the Cryptonemiales, Rhodymeniales and Nemastomatales will be illustrated.