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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.  相似文献   

2.
A new ceramiaceous alga, Sciurothamnion stegengae De Clerck et Kraft, gen. et sp. nov., is described from the western Indian Ocean and the Philippines. Sciurothamnion appears related to the tribe Callithamnieae on the basis of the position and composition of its procarps and by the majority of post‐fertilization events. It differs, however, from all current members of the tribe by the presence of two periaxial cells bearing determinate laterals per axial cell. Additionally, unlike any present representative of the subfamily Callithamnioideae, no intercalary foot cell is formed after diploidization of the paired auxiliary cells. The genus is characterized by a terminal foot cell (“disposal cell”), which segregates the haploid nuclei of the diploidized auxiliary cell from the diploid zygote nucleus. The nature of three types of foot cells reported in the Ceramiaceae (intercalary foot cells containing only haploid nuclei, intercalary foot cells containing haploid nuclei and a diploid nucleus, and terminal foot cells containing only haploid nuclei) is discussed.  相似文献   

3.
Dicroglossum gen. nov. (Delesseriaceae, Ceramiales) is a monotypic genus based on Delesseria crispatula, a species originally described by Harvey for plants collected from southwestern Western Australia. Distinctive features of the new genus include exogenous indeterminate branches; growth by means of a single transversely dividing, apical cell; absence of intercalary divisions in the primary, secondary, and tertiary cell rows; lateral pericentral cells not transversely divided; not all cells of the secondary cell rows producing tertiary cells rows; all tertiary initials reaching the thallus margin; midrib present but lateral nerves absent; determinate lateral bladelets arising endogenously; blades monostromatic, except, at the midrib; carpogonial branches restricted to primary cell rows, on both surfaces of unmodified blades; procarps produced on both blade surfaces, each procarp consisting of a supporting cell that bears two four-celled carpogonial branches and one sterile-cell group of three to four cells; and tetrasporangia borne in two layers, separated by a central row of sterile cells. The combination of exogenous indeterminate branching and bicarpogonial procarps is considered to warrant the recognition of a new tribe, the Dicroglosseae, within the subfamily Delesserioideae.  相似文献   

4.
Recent collections of Rhodocallis elegans Kützing from southeastern Australia have permitted detailed observations of vegetative and reproductive structures that reveal features not exhibited by any existing tribe of Ceramiaceae. As a consequence, we establish the new tribe Rhodocallideae based on the unispecific genus Rhodocallis. Defining characters include: 1) four periaxial cells cut off in an alternating (rhodomelaceous) sequence; 2) determinate branchlets of two types: a) persistent lateral branchlets produced from the first-formed periaxial cells, and b) deciduous transverse branchlets produced from the second and third periaxial cells, with cortical filaments issuing from all four periaxial cells; 3) first- and second-order determinate branchlets terminated by thick-walled spines; 4) indeterminate branches formed at the tips of directly converted determinate branchlets; 5) axial cells of indeterminate branches heavily corticated by a cylinder of descending rhizoidal filaments; 6) spermatangial parent cells borne directly on unmodified outer cortical cells; 7) carpogonial branches borne in series on second and third periaxial cells of modified indeterminate axes; 8) procarps lacking sterile-cell groups; 9) a single derivative of the zygote nucleus transferred from the carpogonium to the auxiliary cell directly through a tube rather than by means of a connecting cell; 10) gonimoblasts surrounded by a network of rhizoidal filaments through which the gonimolobes protrude, the carposporophyte subtended by an investment of determinate branchlets; and 11) tetrasporangia tetrahedrally divided, borne on surface cortical cells of special determinate branchlets and protruding outside the cuticular layer.  相似文献   

5.
The only member of the red algal family Solieriaceae known from New Zealand is the endemic Sarcodiotheca colensoi (Hook. & Harv.) Kylin. This study shows that it differs in several respects from the type S. furcata (Setch. & Gard.) Kylin; thus a new genus Placentophora is created for the New Zealand alga. Although P. colensoi nov. comb. is retained in the Solieriaceae on the basis of vegetative, spermatangial, tetrasporangial, carpogonial-branch and early gonimoblast features, it differs from typical members of that family in its pattern of later carposporophyte development. After a single gonimoblast initial is cut off from the auxiliary cell towards the center of the thallus, further gonimoblasts develop from the initial as ramifying, radiating filaments. These filaments enter an extensive “nutritive-cell” region surrounding the auxiliary cell, form, numerous connections to the “nutritive” cells, and incorporate most of them into a central placenta of interconnected, and variously-fused vegetative and gonimoblast cells. Carpo-sporangia then form in short chains around the periphery of the placenta. The cystocarp lacks both a central fusion cell and a sterile-celled investment, or “Faserhülle.” The distinctive carposporophyte of Placentophora is compared to patterns of gonimoblast development, known in other members of the Solieriaceae.  相似文献   

6.
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 .  相似文献   

7.
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.  相似文献   

8.
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.  相似文献   

9.
The taxonomic distinctiveness of the crustose red algal genus Polystrata Heydrich (Peyssonneliaceae) is confirmed on the basis of morphological and molecular data. The vegetative and reproductive morphology of the type species Polystrata dura Heydrich is newly described. Polystrata thalli are thick multi‐layered crusts, each crust of which is composed of a mesothallus, a superior perithallus, and an inferior perithallus. P. dura is characterized by a poorly developed inferior perithallus consisting of single‐celled perithallial filaments and each layer of multi‐layered crusts being closely adherent to the parental layer. This Polystrata species is identical to Peyssonnelia species, the type genus of the Peyssonneliaceae in the morphology of sexual reproductive organs: a carpogonial branch and an auxiliary cell branch are formed laterally on respective nemathecial filaments; the gonimoblasts are developed from connecting filaments and auxiliary cells; the spermatangia are produced in male and female nemathecia; and the spermatangial filament produces a series of one to four paired spermatangia that form a whorl surrounding each central cell (the Peyssonnelia dubyi‐type development). Polystrata fosliei (Weber‐van Bosse) Denizot is clearly distinguished from P. dura by an inferior perithallus as well‐developed as the superior perithallus, and each layer of multi‐layered crusts being loosely adherent to the parental layer. In our small subunit rDNA trees of the Peyssonneliaceae, these Polystrata species formed a clade with low to medium supports, although the phylogenetic position of Polystrata was unresolved in this family. Therefore, the thallus structure of Polystrata may be regarded as an important taxonomic character at the genus rank.  相似文献   

10.
Mazoyerella gen. nov., based on Corynospora arachnoidea Harvey from Tasmania, is placed provisionally in the Compsothamnieae tribe of the Ceramiaceae. All plants can produce elongate-ovoid monosporangia which reproduce the same phase. Sporophytes also bear polysporangia and sexual plants are dioecious, bearing either spermatangial heads or subterminal procarps followed by carposporophytes with nearly all gonimoblast cells becoming carposporangia and an involucrum of sterile filaments developing from sterile cells associated with the procarp. The life-history has been followed through successive generations in culture.  相似文献   

11.
Two species of the crustose red algal genus Peyssonnelia (Gigartinales, Peyssonneliaceae) are reported from Japanese waters for the first time. These species share the following combination of vegetative and reproductive features: thalli with appressed margins, perithallial filaments arising from the whole upper surface of each hypothallial cell (the Peyssonnelia rubra‐type anatomy), unicellular rhizoids, hypobasal calcification and spermatangia that are produced in double chains (the Peyssonnelia harveyana‐type spermatangial filament). However, they differ obviously from each other in the hypothallus orientation as seen from below, the perithallus structure in relation to the consistency of the crust, the origin of gonimoblasts and the elevation of the nemathecia. Peyssonnelia armorica is characterized by: (i) hypothallial filaments comprising a polyflabellate layer; (ii) easily separable perithallial filaments in a gelatinous matrix; (iii) gonimoblasts originating exclusively from the auxiliary cell; and (iv) semi‐immersed (slightly elevated) nemathecia. Peyssonnelia harveyana is characterized by: (i) hypothallial filaments arranged in parallel rows; (ii) closely packed perithallial filaments in a firm matrix; (iii) gonimoblsts originating from both the auxiliary cell and the connecting filament; and (iv) conspicuously elevated nemathecia.  相似文献   

12.
The cell of Caloglossa leprieurli is a polycaryon. The sexual thalli are usually dioecious. Its life cycle involves the alternation of three generations. In the reproductive season, the appearance of tetrasporophyte and female and male gametophyte shows evident difference. The tetrasporophyte is big and flat. The branches are sparse. Many small red spots, i.e. tetrasporogial groups, can be seen with the naked eyes in the upper part of the branch. The terminal part of the female gametophyte is a little twisted with thick branches. The cystocarps are spherical and most of them are located in ventral side of the upper branch points. The male gametophyte is smaller with less branches. Its terminal part is a little twisted with pale colour. The pit connections of the vegetative cells of every thallus are all well developed. The carpogonial branch consists of four cells. Generally, it is formed by the division of the pericentral cell. After fertilization of the carpogonium, an auxiliary cell is formed by the division of supporting cell. Usually five to seven, even more than ten young procarps can be formed at the apical part of the reproductive branch. The procarps often occur on consecutive segments of pericentral ceils. But among most of them only a carpogonium is fertilized and developes into cystocarp. When a carpogonium is fertilized, the other one on this branch usually cease further development. The spermatangia are formed on the lateral wing cells of both sides of the upper part midrib of a reproductive branch and distributed on both dorsal and ventral surfaces. A vegetative cell is divided into three cells in parallel to the surface of the thallus. The cortical cells under the two outer surfaces forms three to four permatangial mother cells. Each spermatangial mother cell divides into two to four spermatangia. After the sperm dispersal of the mature spermatangia, the spermatangial mother cells are still retained on both sides of the middle discoid cells.  相似文献   

13.
Ossiella pacifica gen. et sp. nov. is described from sub tidal habitats (5–19 m) in the central (Hawaiian Islands) and southwestern (Norfolk Island) Pacific Ocean. Plants consist of limited prostrate axes that rapidly become erect and form ecorticate, subdichotomously branched axes bearing up to seven (mostly six) di-/to trichotomously branched, pigmented, determinate, quickly caducous whorled laterals from subapical axial cells. Two to five tetrasporangza are borne directly on the inflated basal cells of pigmented determinate laterals. One to two spermatangial fascicles are similarly placed in male plants. Subapical procarps are borne on a three-celled fertile axis, which occupies the same position as an indeterminate branch, being itself displaced laterally by the continued growth of the indeterminate axis. Procarps are bicarpogonial, the sterile cell normally associated with the supporting cell in procarps of the Griffithsieae being converted into a functional four-celled carpogonial branch . Ossiella is compared with the other membus of the tribe, and a dichotomous key to the genera is offered. On morphological grounds , Ossiella seemingly forms a perfect intermediary link along the phylogenetic lineage between the eastern Australian genus Baldockia A. Millar, the eastern American genus Calliclavula G. W. Schneid, and the widespread Anotrichium Nägeli .  相似文献   

14.
Three new species of the genus Balliella Itono & Tanaka are described from eastern Australia. Balliella amphiglanda from Lord Howe I. and Port Hacking, N.S.W., is distinctive in producing either abaxial or adaxial gland cells from the basal cells of lateral branches and in having tetrasporangia restricted to short branches. Balliella repens, from Tryon I., Heron I and Wistari Reef Qld., and Lord Howe I., N.S.W., is distinguished from the other species of the genus by its regularly developed prostrate systems and clustered tetrasporangia. Balliella grandis, from Wistari Reef, North West I. and One Tree I., Qld., is the largest recorded species of Balliella. It has correspondingly large gland cells and abaxial as well as adaxial tetrasporangia. Our work supports the placement of Balliella in the tribe Antithamnieae, a move which necessitates emending Wollaston's definition of the tribe to include species with procarps that form at successive levels along main axes rather than at only one or two points behind the apices.  相似文献   

15.
A minute parasite of Neosiphonia poko (Hollenberg) Abbott from a shallow lagoon on the central-Pacific Johnston Atoll is described as Neotenophycus ichthyosteus Kraft et Abbott, gen. et sp. nov. The infective parasite cell first connects to a central-axial cell of the host, then emerges from between host pericentral cells at a node before dividing into a three- or four-celled primary axis. Epibasal cells of the parasite divide to form three pericentral cells whose derivatives produce a globular head on the basal cell and on which reproductive structures differentiate almost immediately. Trichoblasts on any life-history stage are completely lacking. Spermatangia are borne on mother cells across the whole thallus surface. Procarps consist of four pericentral cells that encircle a subapical fertile-axial cell in an ampullar configuration, one of the pericentral cells serving as the supporting cell and bearing a four-celled carpogonial branch and a single sterile cell. Diploidization results in a longitudinal/concave division of the auxiliary cell and formation of an arching linear series of inner gonimoblast cells, each dividing toward the thallus surface into gonimoblast filaments of very narrow, horizontally aligned cells terminated by initially monopodial, later by sympodial, carposporangia, the whole of the mature female gametophyte consisting of an amalgam of several cystocarps within a lax jacket of sterile gametophytic tissue. Tetrasporophytes are composed of lobes of pericentral-cell-derived filaments, each axial cell of which is ringed by three pericentral cells producing tetrahedral tetrasporangia enclosed by two pre-sporangial cover cells. Affinities of the new genus are discussed and comparison is made particularly to the enigmatic parasite Episporium centroceratis Möbius. It is concluded that relationships with any previously described tribe are so remote or obscure that the new tribe Neotenophyceae should be proposed for it.  相似文献   

16.
鹧鸪菜[Caloglossa leprieurii(Mont)J.Ag.]细胞含多核。在生殖季节,孢子体、雌、雄配子体在外形上有明显的差异:四分孢子体大而平展,分枝的上部肉眼可见有红色小斑点,即为四分孢子囊群。雌配子体顶部略蜷曲,分枝密,囊果呈球状,多位于分枝上部分枝点的腹面。雄配子体个体较小,枝顶蜷曲,颜色淡,特别生有精子囊的部分更淡。每种藻体的营养细胞的纹孔连结非常发达,每个细胞都具有4-5条,多者达7-8条。果胞枝由四个细胞组成,一般由围轴细胞分裂形成,果胞受精后,由支持细胞分裂形成辅助细胞,一个生育小枝上,可以连续形成5-7个甚至10个以上幼果胞系,但多数仅有一个果胞受精发育成囊果。当一个果胞受精时,其他果胞系就停止发育。精于囊位于分枝上部中肋的两侧,背腹面均有分布。一个营养细胞沿着叶面平行方向平周分裂成三个细胞,在两个外侧细胞各形成3-4个精子囊母细胞,每个精子囊母细胞斜壁分裂产生2-4个精子囊,放散后,余下的精子囊母细胞仍留在中间盘状细胞上。  相似文献   

17.
Vegetative and reproductive development of Neosiphonia flavimarina gen. et sp. nov. (Rhodomelaceae, Ceramiales) from Bangpo on the western coast of Korea was investigated. This species is superficially similar to Polysiphonia, but differs distinctly from the latter in vegetative and reproductive structures. The plants attach by a solid disk composed of a dense cluster of rhizoids cut off from the pericentral cell wall, and bear erect indeterminate branches producing the lateral-branch initials from successive segments in a spiral arrangement. The procarps have a three-celled carpo-gonial branch. Spermatangial branches are formed on a primary branch of the trichoblasts, terminating in a single or occasionally two large, sterile cells. Tetra-sporangia are produced from the second pericentral cell adjacent to the trichoblast basal cell on indeterminate branches, and arranged spirally. Comparing several taxonomic characters among related genera, Neosiphonia occupies an independent phylogenetic position from Polysiphonia and leads to the conclusion that the genus may have a strong link with Fernandosiphonia which has a unilateral branching system. Relevant nomenclatural changes for several Polysiphonia species are also proposed.  相似文献   

18.
Gymnoderma, which has been considered a monotypic genus, is composed of three species. G. insulare is described from Japan and differs from G. coccocarpum of southeastern Asia in being smaller and having a thicker cortex with didymic acid present. G. lineare from the Southern Appalachians is transferred from Cladonia because the podetia lack symbiotic algae, are solid, and are located on the marginal lower side of the thallus. Gymnoderma, including three species and possibly representing an ancestral form of Cladonia, is disjunctively distributed in eastern Asia and the Southern Appalachians. G. coccocarpum is reported from Thailand and Borneo for the first time.  相似文献   

19.
Womersleya monanthos (J. Agardh) Papenfuss is typically an epiphyte of larger brown and red algae that are common in drift along the southeastern coasts of Australia. A hitherto little-known member of the Phycodrys group of the Nitophylloideae, its reproductive features have been studied in detail and its taxonomic position clarified. Blades are polystromatic throughout and lack veins or nerves, with blades originating from apical cells of primary and second-order cell rows. Intercalary cell divisions take place in primary cell rows and all other branch orders, with third-order laterals arising both abaxially and adaxially on cells of second-order rows. Fertile central cells bear procarps on pericentral cells on both sides of the blade, the procarps consisting of two 4-celled carpogonial branches and a single central group of sterile cells that enlarge and persist at the distal end of a bicampanulate fusion cell at maturity. Spermatangia and tetrasporangia form in circular subapical sori on both sides of the blade or in marginal lobes or proliferations. After comparing it to other members of the Phycodrys group, we conclude that Womersleya is a monotypic genus well distinguished from other genera and with probable closest affinities to the Northern Hemisphere Polyneura, Erythroglossum and Sorella, as well as the Australian endemic, Crassilingua.  相似文献   

20.
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.  相似文献   

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