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31.
HENDRIK J. T. VENTER FLS RUDOLF L. VERHOEVEN 《Botanical journal of the Linnean Society. Linnean Society of London》1999,131(4):417-422
A new species of Cryptolepis from Yemen, Arabian Peninsula, C. yemenensis is described and figured. It is recognized by the glabrous appearance of the plant, oblong-elliptic to narrowly obovate leaves, small flowers, small follicles and ridged seed. The new species resembles Cryptolepis gillettii Hutch. & E.A. Bruce and C. volubilis (Balf f.) Schwartz to some extent. Their flowers are die, except for size and different corona shapes. However, they differ with regard to the shape and size of the follicles, the texture of the seed coat and the absence or presence of vesture on the plants. 相似文献
32.
ALEXEY V. F. Ch. BOBROV JOHN DRANSFIELD FLS MIKHAIL S. ROMANOV EKATERINA S. ROMANOVA 《Botanical journal of the Linnean Society. Linnean Society of London》2012,168(4):377-394
The Malesian genus Eugeissona, with six species, is sister to all other Calamoideae, which are in turn sister to all other Arecaceae. The structure of its gynoecium and fruit is thus potentially of great interest in understanding gynoecium evolution in calamoid palms and in Arecaceae as a whole. The wall of the incompletely trilocular gynoecium of Eugeissona is thick and differentiated into several topographic zones, with a well‐developed vascular system even before pollination. During gynoecium and fruit development, the outer and inner epidermises are little specialized and form the exocarp and endocarp (obliterated in the mature fruit), respectively. In contrast, the mesophyll of the carpels differentiates strongly and is markedly specialized: four massive topographic zones are easily distinguished within the mesocarp. The peripheral zone of the mesocarp forms the body of the scales (a synapomorphy for Calamoideae). The second and the fourth zones are multilayered and parenchymatous with a massive derived vascular system in the former. The third zone of the mesocarp comprises a stout sclerenchymatous pyrene, made of fibre‐like sclereids, the innermost bundles of the derived vascular system and dorsal, ventral and lateral vascular bundles. The fruits of all other Calamoideae lack the sclerenchymatous pyrene and thus differ dramatically from Eugeissona fruits. The similarity of the processes of histogenesis during gynoecium and fruit development in Eugeissona with those in Nypa and borassoid palms, suggests these features could be plesiomorphic for the family. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 168 , 377–394. 相似文献
33.
Samuli Lehtonen Niklas Wahlberg Maarten J. M. Christenhusz FLS 《Botanical journal of the Linnean Society. Linnean Society of London》2012,170(4):489-503
We analysed one nuclear gene (18S) and seven plastid markers [five protein coding (atpA, atpB, rbcL, rpoC1, rps4) and two non‐coding (trnH‐psbA, trnL‐trnF] for 31 members of Polypodiales and four outgroup taxa. We focused our sampling on the lindsaeoids and associated ferns in order to obtain a better understanding of the diversification of the early polypods. However, the exact phylogenetic position of Saccoloma and Cystodium remained uncertain. Based on relaxed molecular clock analyses, it appears that the crown group lindsaeoids diversified in the Caenozoic, more or less simultaneously with the main radiation of other Polypodiales, even though the original divergence between the lindsaeoid and non‐lindsaeoid polypods occurred before the end of the Jurassic. The current pantropical distribution of lindsaeoids can be explained by either long‐distance dispersal across the oceans or vicariance caused by the retreat of previously widely distributed tropical forests from higher to lower latitudes. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170 , 489–503. 相似文献
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35.
The interrelationships of all major groups of Platyhelminthes: phylogenetic evidence from morphology and molecules 总被引:10,自引:0,他引:10
D. T.J. LITTLEWOOD FLS K. ROHDE K. A. CLOUGH 《Biological journal of the Linnean Society. Linnean Society of London》1999,66(1):75-114
We used a data matrix of 65 morphological characters from 25 ingroup and 6 outgroup taxa, and an alignment comprising complete 18S rDNA sequences from 82 species of parasitic and free-living Platyhelminthes and from 19 species of lower invertebrates to analyse phylogenetic relationships of various platyhelminth taxa. Of the 1358 unambiguously alignablc molecular positions, 995 were variable and 757 were phylogenctically informative (parsimony criterion); complete 18S rDNA sequences ranged in length from 1755 to 2873 bp. Main conclusions are: Ncodermata are monophylctic, and the Trematoda, Monogenca and Cestoda within them are monophylctic as well. The sister group of the Ncodermata is all the other Ncoophora; the Kalyptorhynchia, Typhloplanida, Dalyelliida and Tcmnocephalida form one clade, and the last three another. Monophyly of the Seriata is rejected, but Polycladida/ Macrostomida/Haplopharyngida are monophylctic, as arc the last two taxa. As a consequence, validity of the taxon Trepaxonemata is rejected. Further studies must show the correct position of the Acocla and Nemertodermatida. It is stressed that morphological and molecular data in some respects lead to contradictory results, for instance concerning the position of the Fecampiidac/ Urastoma/Ichthyophaga and the relative position of the Lccithoepitheliata. Denser sampling of taxa for molecular data, complementary sequences from independent genes, and inclusion of additional morphological data are necessary to resolve these contradictions. 相似文献
36.
M. E. OLSON S. CARLQUIST FLS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,135(4):315-348
Four life forms (habits) are identified in the 13 species of Moringa (bottle trees, sarcorhizal trees, slender trees, and tuberous shrubs) which are examined for wood anatomical correlations with habit, ecology, and systematic. Wood anatomy is similar within habit classes except for the sarcorhizal trees. The four bottle tree species and M. arborea (one of the sarcorhizal trees) are characterized by bands of confluent paratracheal parenchyma alternating with bands of libriform fibres, some of which may be parenchyma-like. The other sarcorhizal tree, M. ruspoliana , is characterized by alternating bands of parenchyma-like and long, slender libriform fibres. Root secondary xylem of all these species is characterized by bands of parenchyma and fibres. Slender trees do not show bands of fibres of different shapes and have fibrous roots with less parenchyma than the other species. Tuberous shrubs have stems mostly composed of long, slender fibres and large underground tubers mostly composed of parenchyma. Quantitative trends between ecologically different localities include wider vessel elements and higher conductive area in moister localities. Wood anatomy provides characters that are of potential phylogenetic utility at a variety of levels of relationship. Based on wood anatomy and geography, the most likely sister taxon to Moringa is Cylicomorpha (Caricaceae). 相似文献
37.
Cheilostomatous Bryozoa from Vanuatu 总被引:1,自引:0,他引:1
KEVIN J. TILBROOK FLS P. J. HAYWARD FLS D. P. GORDON FLS 《Zoological Journal of the Linnean Society》2001,131(1):35-109
The present account of some Bryozoa from Vanuatu is the first study of reef-flat species from the eastern Coral Sea. Based on samples collected from several shallow water localities on the island of Efate, a total of 92 species is described, including a new family, three new genera and 20 new species. Some of the newly recognized species are the result of taxonomic revision stimulated by these new samples, while others are entirely new to science. Of the new taxa described here, 16 are presently known only from Vanuatu. The total number of species recorded does not accurately represent the true taxonomic diversity of the Cheilostomatida of Vanuatu, and further sampling, at other localities and in other habitats, is needed before it can be reasonably estimated. The fauna is predominantly Indo-West Pacific in character with a high proportion of species apparently known only in the Southwest Pacific. 相似文献
38.
ANGELA C. MILNER FLS WILLIAM LINDSAY 《Zoological Journal of the Linnean Society》1998,122(1-2):211-235
The first unequivocal postcranial remains of baphetids (= loxommatids) associated with skull roof and lower jaw material are reported from a specimen of Baphetes from the English Upper Carboniferous, Duckmantian. Characters of the mandible, including the incorporation in the symphysis of paired parasymphysial plates, permit the identification of a previously indeterminate jaw from the Langsettian (Westphalian A) of Nova Scotia, as baphetid. The postcranial remains include vertebrae, pectoral and pelvic limb and limb girdle elements that present a combination of unique characters extending the diagnosis of the family Baphetidae, together with plesiomophic and derived characters which suggest that baphetids are primitive stem group tetrapods. 相似文献
39.
40.
Systematic significance of tepal surface morphology in tribes Persicarieae and Polygoneae (Polygonaceae) 总被引:7,自引:0,他引:7
SUK-PYO HONG FLS L. P. RONSE DECRAENE FLS E. SMETS FLS 《Botanical journal of the Linnean Society. Linnean Society of London》1998,127(2):91-116
In order to improve understanding of the systematic relationships between taxa and of tepal-pollinator and tepal-habitat relationships, a detailed scanning electron microscopy (SEW study of the adaxial tepal surface of 135 taxa belonging to c. 14 genera in the tribes Persicarieae and Polygoneae (Polygonoideae-Polygonaceae) was carried out. The tepal surfaces have revealed some striking differences among the genera studied. Three main patterns of sculpturing and cell shape can be recognized. Type I: mostly rectangular to elongate cells with straight or undulating anticlinal walls; the cuticles smooth or striate in longitudinal direction and often continuous (Persicaria, Bistortu, Aconogonon, Koenigia and some species of Fagopyrum). Type II: irregular tesselated to elongated cells, rarely rectangular with mostly sinuate anticlinal walls; the cuticles rarely with longitudinal striation, but with strong orthogonal to reticulate ridges or striae, often without correlation between cells (Polygonum s.s., Polygonella, Fallopia, Parapteropyrum, Pteropyrum, Atraphaxis and Calligonum). Type III: mostly irregular, mammilliform, papillose cells with either longitudinal tightly pressed or randomly ridged cuticles (some species of Fagotyrum and Oxygonum). The present data generally support the division of Polygoneae and Persicarieae by Ronse Decraene & Akeroyd. The mammilliform, papillate epidermis of tepals in Oxygonum and some Fagopyrum is probably well-adapted to entomophily either as a foothold or even as a light-trap, and also shows some correlation with heterostyly. It is noteworthy that the tepal structure of Polygonella (tesselated form) is highly similar to that of Polygonum s. s. (especially P. sect. Duravia). Cuticular striation alone does not appear to have much systematic value, but has a mechanical function in affording extra strength to the cell walls. Some correlations between the degree/shape of cuticles and the pollination mechanisms or the habitat of each taxon are also briefly discussed. It is concluded that the studied tepal characters can be useful in improving the classification of tribes Persicarieae and Polygoneae, arid give additional support at the infrageneric level. 相似文献