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1.
The taxonomy of the Polygonum douglasii complex is revised. A summary of relevant taxonomic information is provided, along with a key to the species and subspecies,
plus typification, synonymy, discussion, distribution, and ecology. Morphology and micromorphology of stems, leaves, perianth,
pollen, and achenes are analyzed and illustrated. Based on these data, 12 species and two subspecies are recognized. A new
species, P. gabrielae, is described and illustrated from Oregon. 相似文献
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3.
A new genus,Goodmania, is described for the species currently known asOxytheca luteola Parry of central and southern California. A member of Polygonaceae, subfamily Eriogonoideae,Goodmania is an isolated genus, distinct fromEriogonum by the awned bracts, and fromOxytheca by its involucral bracts not forming a distinct tube, yellow flowers, non-glandular pubescence, and small, paired cauline leaves.Goodmania is seemingly related to the Death Valley endemic,Gilmania, but differs in having a whorl of five involucral bracts subtending the cluster of short-pedicellate flowers. 相似文献
4.
A new genus and species,Dedeckera eurekensis, are described from the Last Chance Mountains, Inyo Co., California, from an area just south of the Eureka Valley sand dunes. A member of Polygonaceae, it is most closely related toEriogonum, differing from that genus in lacking a tubular involucre, and fromStenogonum, Hollisteria, Nemacaulis, andGilmania in being a shrubby perennial. It differs from all other members of the subfamily Eriogonoideae in having (1) a head of subsessile or sessile flowers borne on a slender peduncle and subtended by 2 to 5 foliaceous bracts, and (2) a single short-pedicellate axillary flower at the base of each peduncle. The numerous yellow-flowered heads are arranged in open cymose inflorescences that terminate short annually produced branches with alternately arranged exstipulate foliage leaves.Eriogonum flexum is transferred to the genusStenogonum. A key to the genera of subfamily Eriogonoideae is included. 相似文献
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6.
Eriogonum soliceps, a new species of subg.Eucycla sect.Capitata, is described. It may be readily distinguished from all other taxa of the subgenus by its reduced inflorescence. From its
presumed nearest relative,E. mancum, this new species differs in its solitary (vs. 2–5) involucre, presence of a peduncle but no scape, lack of bracts at the
base of the involucre, and distinctly pustulose midribs of the mature flowers. 相似文献
7.
The two closely related speciesLycopsis variegata andAnchusa cretica, formerly placed inAnchusa subg.Rivinia, were compared with the type species ofLycopsis andAnchusa, on the basis of a set of macro and microcharacters. The presence of only two fertile stamens as well as other peculiar characters in flower structure, androecium, gynoecium, pollen and fruit, supports the institution of the new genusAnchusella, consisting ofA. variegata andA. cretica. Karyological and eco-chorological aspects are consistent with morphological data in pointing to the autonomy of this genus, which appears characterized by autapomorphic, advanced traits. 相似文献
8.
Piero G. Delprete 《Brittonia》1999,51(1):15-23
The genusRiodocea is here described from material collected in the várzea forest of the Rio Doce Valley, northern Espírito Santo.Riodocea is a monotypic genus probably related to the Amazonian endemicKutchubaea. A line drawing shows general morphology and photomicrographs show pollen morphology ofRiodocea pulcherrima. Distribution maps ofRiodocea andKutchubaea are included.
The valley of the Rio Doce is here included in the Bahian Hylaea, defined as a subregion of the Brazilian Atlantic forest.
The connections between the Amazonian Hylaea and the Bahian Hylaea are discussed. 相似文献
9.
U. Meve 《Plant Systematics and Evolution》1995,197(1-4):233-242
A comparison of the West AfricanNeoschumannia
Schltr. and the East AfricanSwynnertonia
S. Moore reveals that the two monotypic genera must be united.Swynnertonia is sunk into synonymy ofNeoschumannia and the new combinationNeoschumannia cardinea (S. Moore)Meve is made for the East African species.Neoschumannia is shown to belong to the tribeStapelieae. The taxon exhibits a very unusual character combination: the growth form of a woody liana is combined with a tripartite corona unique within theAsclepiadaceae. The morphology of the corona suggests a position ofNeoschumannia close to the base of theStapelieae —Ceropegiinae alliance. 相似文献
10.
Redefinition of the neotropical genus Anthopterus (Ericaceae: Vaccinieae), including one new species
James L. Luteyn 《Brittonia》1996,48(4):605-610
The taxonomic history of Anthopterus as it relates to Themistoclesia is briefly reviewed. Anthopterus is redefined to include several species formerly placed in Themistoclesia. Two subgenera are established within Anthopterus. Anthopterus costaricensis Luteyn is described as new, and the new combination Anthopterus pterotus (A. C. Sm.) Luteyn is made. A key to the genus, a list of the species currently accepted, and brief notes on distribution
and frequency are provided. Most species of Anthopterus are rare and their habitats are endangered. 相似文献
11.
The pollen of 30 taxa (27 species, one subspecies and two varieties) in two genera, viz Polygonum s. str. and Polygonella was investigated with LM and SEM, and some selected taxa with TEM. In all genera investigated the pollen is prolate to spheroidal, and the aperture is mostly tricolporate, rarely panto-hexacolporate (especially Polygonum section Polygonum). The exine sculpturing pattern is the most variable feature. Three types of exine can be recognized. Type 1 (Avicularia-Type, sensu Hedberg) - All species of section Polygonum and section Tephis share the smooth tectate exine with spinules, sometimes the surface is more or less rough (Polygonum afromontanum in section Tephis). Type 2 (Pseudomollia-Type, sensu Hong) - Pollen of Polygonum molliaeforme (section Pseudomollia) has the exine, which is verrucose on both poles and nearby the mesocolpium, and mostly psilate around the ectoaperture. Type 3 (Duravia-Type, sensu Hedberg) - Pollen grains of Polygonum section Duravia and Polygonella have the exine which is semitectate-reticulate at the mesocolpium and the poles, and rugulate/reticulate or sometimes foveolate with microspinules around the ectoapertures. The pollen grains in four taxa (viz Polygonum section Pseudomollia, P. section Duravia and genus Polygonella) have a well-marked dimorphism of the ektexine, which is considered to be a synapomorphic condition. The differences of pollen grain between the genus Polygonella and Polygonum section Duravia are almost non existent and clearly interrelated. It is therefore postulated that the similarity in pollen of both taxa is not the result of convergency, but is interpreted as a homology. It is noteworthy that the pollen of Polygonum molliaeforme (section Pseudomollia) appears as intermediate between the Avicularia-type and the Duravia-type, and is well supported the value of separated section for its own. Additionally, in TEM, some exine ultrastructures (e.g. columellae, foot layer, endexine) appear to be valuable characters for comparison between/among taxa. The systematic potentialities of the pollen data of the studied taxa at various systematic levels are also discussed. 相似文献
12.
OAKLEY SHIELDS JAMES L. REVEAL F.L.S. 《Biological journal of the Linnean Society. Linnean Society of London》1988,33(1):51-93
The relationship between the butterfly genus Euphilotes and their host plant genus Eriogonum in western North America is suggested to be one of sequential evolution rather than coevolution. Eriogonum, a genus of nearly 250 species, probably had a Miocene origin, but has had its modern distribution significantly influenced by recent Pleistocene glaciation. The evolution of Euphilotes, as a distinct genus of four sibling species, apparently postdates the establishment and recent proliferation of Eriogonum. Successful speciation in Euphilotes has been accomplished mainly through modifications in genitalia of those butterflies using a single species of Eriogonum. The subsequent proliferation of Euphilotes subspecies has been the result of host switching coupled with geographic isolation onto individual species of Eriogonum acting as restricted biogeographic islands. In the first instance, direct evolutionary competition for a limited resource (one species of Eriogonum) leads to partitioning of that resource by the butterflies whose entire life cycle is associated with that plant species. In the second instance, host switching and isolation have permitted establishment of minor subspecies without significant interaction with other subspecies of the same species. In instances where interspecific subspecies competition exists, resource partitioning, coupled with more pronounced genetic isolation, seem to have occurred resulting in more readily distinct subspecies. We speculate that the success of subspeciation in Euphilotes is dependent upon the numeric size and geographic extent of the host species. Euphilotes subspecies on plants of restricted distributions are themselves seemingly limited in their evolutionary potential as the most dynamic evolution of Euphilotes subspecies is that associated with widespread and variable Eriogonum species. In all instances, the tempo and mode of evolution in Euphilotes appears to be sequential as it follows and is seemingly dependent upon what has already occurred in Eriogonum. 相似文献
13.
D. J. Goyder 《Kew Bulletin》2008,63(3):467-469
Summary Tylophora tridactylata Goyder (Apocynaceae: Asclepiadoideae) is described from the Eastern Arc mountains of southern Tanzania and illustrated. Its conservation status is assessed. 相似文献
14.
Summary
Teucrium scabrum (Lamiaceae), a new species from the western part of Thailand, related to T. quadrifarium Buch.-Ham. and T. viscidum Blume is described and illustrated, and a distribution map is provided. 相似文献
15.
To more confidently assess phylogenetic relationships among astome ciliates, we obtained small subunit (SSU) rRNA sequences from nine species distributed in six genera and three families: Almophrya bivacuolata, Eudrilophrya complanata, Metaracoelophrya sp. 1, Metaracoelophrya sp. 2, Metaracoelophrya intermedia, Metaradiophrya sp., Njinella prolifera, Paraclausilocola constricta n. gen., n. sp., and Paraclausilocola elongata n. sp. The two new species in the proposed new clausilocolid genus Paraclausilocola n. gen. are astomes with no attachment apparatus, two files of contractile vacuoles, and an arc-like anterior suture that has differentiations of thigmotactic ciliature on the anterior ends of the left kineties of the upper surface. Phylogenetic analyses were undertaken using neighbor-joining, Bayesian inference, maximum likelihood, and maximum parsimony. The nine species of astomes formed a strongly supported clade, showing the subclass Astomatia to be monophyletic and a weakly supported sister clade to the scuticociliates. There were two strongly supported clades within the astomes. However, genera assigned to the same family were found in different clades, and genera assigned to the same order were found in both clades. Thus, astome taxa appear to be paraphyletic when morphology is used to assign species to genera. 相似文献
16.
Recent systematic studies ofBartsia andOdontites showed the necessity to exclude the closely related perennial speciesBartsia aspera (Portugal and northern Morocco) andBartsia spicata (Central Pyrenees) from the genusBartsia as a segregate genus namedNothobartsia. Morphologically this new genus combines characteristic features ofBartsia and ofOdontites. Its autonomous systematic position is supported by the cladistic analysis, showing thatNothobartsia represents a relatively primitive genus standing close to the common ancestral root ofBartsia, Euphrasia, andOdontites. 相似文献
17.
Ogweno Midiwo J. Yenesew A. Juma B.F. Derese S. Ayoo J.A. Aluoch A.O. Guchu S. 《Phytochemistry Reviews》2002,1(3):311-323
There are several described medicinal plants in Kenya from a flora of approximately 10,000 members. Strong cross-medical information
from the 42 ethnic groups points to the high potential of some of these species. The Myrsinaceae are well established ethno-anthelmintics
and anti-bacterials. They are harbingers of long alkyl side chain benzoquinones which clearly have a protective function from
their histochemical disposition. The main benzoquinone in the sub-family Myrsinodae is embelin while for the Maesodae it is
maesaquinone together with its 5-acetyl derivative; the distribution of these benzoquinones by their alkyl side chain length
or the presence/absence of a 6-methyl group is in accord with morphological sub-family de-limitation. The benzoquinones showed
anti-feedant, anti-microbial, phytotoxic, acaricidal, insecticidal and nematicidal activity. Many other benzoquinones of medium
and minor concentration were also isolated and characterised. Some plants belonging to the Polygonaceae which are widely used
as ethno-anthelmintics have been studied. The common anthelmintic anthraquinones were obtained from all five Rumex species
while the naphthalenic acetogenin derivative, nepodin was more selectively distributed. The leaf of Polygonum senegalense is up to 17% surface exudate; about thirteen non polar flavonoid derivatives (chalcones, dihydrochalcones, flavanones and
a flavone) have been isolated from it. From the internal aerial tissues of this plant, the major flavonoids were common flavonoids,
quercetin, kaempferol, luteolin and their glycosides. The only unique compound isolated from this plant was 2′-glucosyl-6′-hydroxy-4′-methoxydihydrochalcone
whose aglycone, uvangolatin is part of the exudate mixture. Other leaf exudate plants studied include the stomach-ache medicine,
Psiadia punctulata (Compositae) from which novel methylated flavonoids, kaurene and trachyloban diterpenes have been found.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
18.
Suk-Pyo Hong 《Plant Systematics and Evolution》1991,176(1-2):125-131
Heterostyly is clearly confirmed inAconogonon campanulatum. This distylous species is dimorphic for tepals, styles, stigma surface, stamens, pollen grain size, and pollen sexine ornamentation. The floral shape is campanulate and thrum flowers are slightly larger than pin flowers. Small solitary bees were observed as flower visitors and probably effected pollination. The possible evolution of dioecy via heterostyly within the genusAconogonon is discussed. 相似文献
19.
Three marine scuticociliates, Falcicyclidium fangi nov. gen., nov. spec., Falcicyclidium atractodes nov. spec., and Cristigera media Kahl, 1928 were investigated using live observation and silver impregnation methods. The genus Falcicyclidium is distinguished by the combination of: (i) dorsoventrally flattened body, (ii) hook-like (falciform) paroral membrane, (iii) anterior end of paroral membrane posterior to anterior end of membranelle 1, and (iv) multiple caudal cilia. Falcicyclidium fangi nov. spec., the type of the new genus, can be recognized by the combination of its large size, extremely dorsoventrally flattened (3:1) body, consistently 10 somatic kineties, and the broad, elongate buccal area occupying 60% of the body length. Falcicyclidium atractodes nov. spec. is mainly characterized by a unique spine projecting from both the anterior and posterior end. The uncommon form, Cristigera media is redescribed based on the population from Qingdao, the statistic data and additional features, especially the morphology of the living cells, are documented. 相似文献
20.
In the course of monographic work in Myrtaceae it has become evident thatEugenia prismatica cannot be accommodated within any existing genus in the family. Therefore, a new genus,Curitiba, is described to contain it and the new combinationCuritiba prismatica is made.Curitiba is diagnosed by a combination of 4-angled hypanthia and fruits, ovules radiating from a central protruding placenta, and
seed coats with wavy rows of papillae. A key is provided to distinguishCuritiba from the Caribbean and Mesoamerican genusMosiera, where the species also had been placed before this transfer, and from other 4-merous genera in Brazil of subtribe Myrtinae.
In the Atlantic Forest of Brazil where the family Myrtaceae is one of the most species rich and ecologically important plant
families, the discovery ofCuritiba reveals a unique evolutionary lineage, highlights the endemism present in the Atlantic Forest, and underscores, the urgent
need for conservation of this rapidly disappearing and highly endangered biome. 相似文献