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1.
A new species of the genus Hypnea Lamouroux, H. furnariana sp. nov., from the eastern coast of Sicily (Mediterranean Sea) is described. Plants form entangled mats with anastomosing branches. Branches and branchlets are subulate and much more slender than the main axes. In transverse section the axial cells are very small, while pericentral cells are quite larger and rounded or slightly oblong-shaped. Tetraspo-rangial swellings (annular or unilaterally exserted) and cystocarps are localized in the sub-apical or in the middle part of fertile branches. A comparison was made with the closely related species H. spinella and H. pannosa .  相似文献   

2.
Four species of Amansia Lamouroux were initially found in Natal. More Complete studies on these species revealed a new genus, Melanamansia, Which is described on the basis of presence of two dorsal pseudopericentral cells in two new species from Natal (M. seagriefii sp. nov. & M. fimbrifolia sp. nov.) in addition to other structural characters and features of pigmentation and reproduction. Pseudopericentral cells are not present in the type species of Amansia, A. multifida Lamouroux. The other two species of Amansia occurring in Natal, A. glomerata C. Agardh & A. loriformis sp. nov., have characters similar to the type species. Comparison of species from other regions of the world has shown that eight additional species, previously assigned to Amansia, belong to the new genus.  相似文献   

3.
In this paper a new species of Nitella, N. vermiformis, from Sichuan is reported. The new species is the similar to Nitella procera Han from Yunnan. But gametangia of the latter grow in every furcte, and fertile branchlets are similar to sterile ones. There are not central radial branchlets and accessory branchlets in first furcate branchlet; the membrane ofoospore is vermiform-processed.  相似文献   

4.
The first occurrence of Palisada maris-rubri (K.W. Nam et Saito) K.W. Nam (Ceramiales, Rhodomelaceae) from the Mediterranean Sea, is reported. To date the species was known only from tetrasporic specimens from the type locality (Ras Muhammed, Sinai, Egypt, Red Sea). Mediterranean thalli share nearly all vegetative and reproductive features with Red Sea specimens showing more robust thalli with axes to 3 mm broad and ultimate branchlets to 1000 µm broad, absence of intercellular spaces between medullary cells and epidermal cells in transverse section with a palisade arrangement. Male and cystocarpic thalli are recorded for the first time. Moreover, the analysis of characters of three species of Chondrophycus previously known from the Mediterranean Sea ( C. patentirameus (Montagne) K.W. Nam, C. tenerrimus (Cremades) G. Furnari et al. and C. thuyoides (Kützing) G. Furnari) led us to conclude that they belong to the genus Palisada . The following new combinations are formally proposed: P. patentiramea (Montagne) Serio et al., P. thuyoides (Kützing) Serio et al., P. tenerrima (Cremades) Serio et al.  相似文献   

5.
In cuttings of Chara vulgaris consisting of 3–4 internodal cells with whorls (branchlets) transport of photoassimilates was investigated by 14C-labelling. The distribution of radioactivity in different component parts of the plant was shown as percentage and calculated in relation to fresh weight. Sucrose was identified as the main transported carbohydrate. In fertile Ch. vulgaris plants, developing oogonia and antheridia were important sinks for transported carbohydrates. Polarity of transport in the internodal cells (nutrients and assimilates) remains constant, as the main characteristic, from base to apex in fertile as well as in sterile plants. In sterile plants, the branchlets being the main source for photoassimilates and the apex the sink, transport from branchlets is mainly in the direction of the internodes. In the case of fertile plants gametangia are additional sinks redirecting transport of assimilates into the branchlets.  相似文献   

6.
Osmundaria prolifera, kuetzingia natalensis, Halopythis pinastroïdes and Vidalia fimbriata contain C27 sterols as the major sterols. Six other species of the Amansieae, belonging to the genera Amansia, Vidalia, Lenormandia and Rythiphlaea, contain C28-sterols as the major sterols.  相似文献   

7.
Sphenopteris damesii (Stur), a rather frequentspecies from the Sarre-Lorraine Coalfield was only known till now as a typical sphenopteridian sterile foliage. The study of a lot of specimens from recent boreholes has allowed us to show the great polymorphism of this species whose foliage, usually deeply dissected, tends to be pecopteridian in the fertile stage.The organization of fructifications and the type of included spores are described for the first time. Moreover, the comparison of the fertile specimens of Sph. damesii with those from the same horizon described by P. Corsin as Pecopteris saraei has revealed similarity in limb morphology, in the organization of fructifications, in the type of spores which proves that P. saraei is the fertile form of Sp. damesii. Consequently, P. Corsin's species is a posterior synonym of Sphenopteris damesii (Stur).The generic attribution of this species sets a nomenclatural question: the features of the fructifications agree exactly with the diagnose of the genus AsterothecaPresl but this genus till now was reserved for sporangia born by typical pecopteridian foliage. Nevertheless, the species is temporarily refered to Asterotheca until further works allow to decide about the subordination of these different characters.  相似文献   

8.
Phillips  L.E.  Nelson  W.A.  & Kraft  G.T. 《Journal of phycology》2000,36(S3):54-55
The genus Lenormandia is composed of nine species from Australia and New Zealand. Some of the these are well known, but others are rare, obscure and ill-defined. We have examined material of all described species and found that they fall into two discrete groups that differ in apex morphology and position of reproductive structures. Plants of the first group, containing the type species L. spectabilis , have a cleft apex and reproductive structures produced directly on the blade surface, whereas those of the second group have a strongly inrolled apex and produce reproductive structures dorsally on small branchlets which arise either from the margins or the midrib. The groups were also found to form discrete clades on analysis of 18S rRNA sequences. All the members of the first group are endemic to Australia, whereas the second group, designated by the new genus name Adamsiella , contains two previously described New Zealand species and a single Australian representative. In addition, two new species are described in this group from New Zealand. Members of the closely related genus Lenormandiopsis were also examined and the type species, L. latifolia , was found to conform in apex morphology and position of reproductive structures to the genus Lenormandia. Accordingly Lenormandiopsis has been subsumed within Lenormandia. The remaining three members of the former genus Lenormandiopsis , however, were found to differ from both the type species and the genus Lenormandia and consequently have been transferred to the separate genus Geraldia , along with a new species from Geraldton, Western Australia which is designated as the type.  相似文献   

9.
Three gelidialean species, Gelidiella pannosa (Feld‐mann) Feldmann et Hamel, Pterocladiella caerulescens (Kutzing) Santelices et Hommersand and Pterocladiella caloglossoides (Howe) Santelices, are newly reported from Japan, and their characteristic features are described. Monoecious plants of P. caerulescens produce spermatangial sori on: (i) fertile cystocarpic branchlets; (ii) special spermatangial branchlets on a cystocarpic axis; and (iii) branchlets of a special spermatangial axis. The latter two are newly reported in this species. Gelidiella pannosa has numerous unicellular independent points of attachment, whereas P. caerulescens and P. caloglossoides have the peg type of secondary rhizoidal anchorage. In the molecular phylogenetic study using small subunit ribosomal DNA sequences, G. pannosa is included in the Gelidiella clade with 100% bootstrap support in neighbor‐joining (NJ) analysis and 99% in maximum parsimony (MP) analysis. Pterocladiella caerulescens and P. caloglossoides are included in the Pterocladiella clade with 99.7% bootstrap support in NJ analysis and 100% in MP analysis. Each type of secondary rhizoidal attachment is completely consistent with the respective genus clade, which suggests that this morphological characteristic reflects phylogeny within the order Gelidiales.  相似文献   

10.
Material of the red alga Odonthalia floccosa (Esper) Fal-kenberg (Rhodomelaceae, Ceramiales), collected from California, was cultured in the laboratory and its life-history was completed. Tetraspores grew into bipolar sporelings that differentiated into a colorless rhizoidal portion and a pigmented upright shoot. The sporelings became compressed apically and formed lateral branches in a regularly distichous manner that were congenitally fused with the main axis. These tetraspore germlings grew into diecious gametophytes. Male ga-metophytes produced numerous spermatangia on modified fertile branchlets (male trichoblasts) that possessed three to four monosiphonous, proximal segments. Female gametophytes formed a single pro-carp on the suprabasal segment of unbranched female trichoblasts. Cystocarps developed on the female gametophytes cocultured with male gametophytes and released viable carpospores that developed into fertile te-trasporophytes. Tetrasporangia were produced from the third and fourth periaxial cells in each of 12–45 successive fertile segments and provided three (two lateral and one basal) cover cells. The occurrence of both spermatangia and procarps on fertile trichoblasts in O. floccosa suggests that the alga is the most derived in these two characters among the species of the genus Odonthalia. This species is distributed in cold temperate regions in the North Pacific, and it should be excluded from the North Atlantic marine algal flora.  相似文献   

11.
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   

12.
Reproductive allocation (the proportion of biomass allocated to reproductive tissue, RA) in Sargassum thunbergii was studied in Yantai, Shandong Peninsula, southern coast of Bohai Bay, China. Annual reproduction initiated in mid-June and peaked in mid-July (90 ± 8% fertile thalli and 75 ± 6% RA mean). Both RA and percentage of fertile thalli exhibited significant temporal variations during reproduction. Sterile thalli were only observed in small length hierarchies at peak reproduction and mean values of RA showed a significantly hierarchical variation, suggesting that the size of thalli played an important role in reproduction and RA were size-dependent. Numerous receptacles were produced along the lateral branches during the reproductive period. A distinct seasonal pattern was observed wherein the presence of lateral branches was followed by the onset of reproduction. RA was positively correlated with the number of lateral branches, as well as the total length of lateral branches. In addition, fertile thalli decayed quickly after peak reproduction. The probability of decay was evidently higher for fertile than for sterile thalli, because all surviving thalli were sterile and short during July–August. So, a trade-off between reproduction and survival may exist at individual levels in S. thunbergii.  相似文献   

13.
14.
Based on characters of the fertile fronds, two species of fossil ferns from the Lower Cretaceous Potomac Group of the U.S.A., originally described as species of Osmunda by Fontaine in 1889, are transferred to the genus Anemia. The two species display primitive characters for that genus. Analysis of these and other characters of Anemia and related species, using parsimony and compatibility programs, suggests possible phylogenetic arrangements and facilitates delimination of three taxonomic units within Anemia that were already distinct during Cretaceous time. The subgenera Coptophyllum and Anemia are shown to be paraphyletic in the suggested phylogenies and the schemes agree with the known stratigraphy of the fossil ferns.  相似文献   

15.
Abstract  The Australian genus Thoreauana Girault is revised: the three known species are redescribed and Thoreauana giraulti sp. n. is described. A new genus of Charipinae from Australia, Dilapothor n. gen., is described. The diagnostic characters for the tribe Charipini are discussed and a key to the Charipini genera is provided.  相似文献   

16.
Sterile and fertile shoots of a microphyllous vascular plant are described from the Lower Devonian Posongchong Formation (? upper Siegenian), Yunnan Province, southern China and placed in the new taxon Halleophyton zhichangense gen. et sp. nov. The sterile axes are characterized by conspicuous, contiguous swollen rhomboidal to hexagonal leaf bases and relatively broad spatulate laminae. The relief of the leaf bases is not so pronounced in the fertile areas, which bear numerous cauline sporangia with two equal valves. In vegetative characters the new fossils, although smaller and more fragmentary, resemble Drepanophycus gaspianus but in the absence of information on the fertile parts of the latter and because of the controversy surrounding the concept of the genus Drepanophycus, we decided to erect a new genus. Its relationship to the lycophytes sensu stricto is equivocal as exact details of the relationship of sporangium with leaf and sporangium vascularization remain unknown.  相似文献   

17.
Six new species of the Australian myrmecophilous ptinid genus Polyplocotes are described from South Australia. Three are from the deserts of central Australia, one from the Franklin Islands in the Great Australian Bight, one from Eyre Peninsula and one from the Riverland region. Morphologically, the majority of these new species are conventional Polyplocotes , but two are less typical. The characters uniting the genus are explored in the discussion, and comparisons are made to related genera. Although the six new species described here have not been observed in the field, the species of this genus are known to be myrmecophilous, and ant – beetle interactions similar to those seen in other spider beetles might occur between these new species and their host ants.  相似文献   

18.
Compressed specimens of the fern Osmunda are described from the Triassic of the Allan Hills, Antarctica. The specimens consist of a once pinnate, deeply pinnatifid fertile frond as well as several sterile specimens. Six pinnae are present on the partial fertile rachis, with two sterile pinnae above four fertile pinnae. Both sterile and fertile specimens are virtually identical to the modern species Osmunda claytoniana. Entire fronds are fragmentary; the longest is 21 cm in length. Sterile pinnae are alternate and deeply pinnatifid, with slightly toothed pinnules and dichotomous venation. Fertile pinnae are 1-1.3 cm long, once pinnate, and lack vegetative lamina. Sporangia are clustered, each 300-375 um in diameter, and possess a transverse annulus 6-8 cells long; dehiscence is by a vertical slit. Fronds arise from a rhizome 4 cm long by 1 cm wide; two croziers are present on the rhizome. Two frond segments up to 6 cm long and three deeply pinnatifid pinnae are present on the uppermost part of one rachis. Pinnules are ~4 mm long and 2-3 mm wide. The presence of this Osmunda species in the Triassic demonstrates stasis of frond morphology, both fertile and vegetative, for the genus.  相似文献   

19.
ABSTRACT

A new species of the genus Polysiphonia from the Mediterranean Sea is described. It is an ecorticate species, with 4 pericentral cells, showing prostrate axes from which erect axes arise. Rhizoids are formed by pericentral cells in a median position remaining in open connection with them. Erect axes are straight, simple throughout or pseudodichotomous at the base then simple or with one (rarely two-three) orders of branching; trichoblasts and scar cells not observed. Only tetrasporangial plants were found. They show ellipsoid tetrasporangia borne in short straight series, often interrupted by sterile segments. The new species is also characterized by a peculiar habit consisting of prostrate axes, adhering to lower faces of Peyssonnelia spp. by means of rhizoids growing upward, from which erect upright axes perforating thalli of the supporting species arise. A comparison with the related species of Polysiphonia was also carried out.  相似文献   

20.
Abstract  Four new species of the Australian ptinid genus Diplocotes are described. Two of these species are from the dry tropical and subtropical areas of northern and central Queensland, while the other two are from the arid areas of South Australia. While the four new species described here have not been observed with ants in the field, the species of this genus are known to be myrmecophilous, and similar interactions may occur between the new species and their host ants. Additionally, many characters are shared with other unrelated myrmecophilous species, and may be convergent adaptations to the ant-associated lifestyle.  相似文献   

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