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1.
报道了秦岭植物分布3新记录属:鹿蹄草科(Pyrolaceae)的沙晶兰属(Monotropastrum Andres)、列当科(Orobanchaceae)的藨寄生属(Gleadovia Gamble et Prain)和爵床科(Acanthaceae)的十万错属(Asystasia Blume)。相应的新记录种或变种为无毛沙晶兰[M.humile(D.Don)H.Hara var.glaberrimum H.Hara]、藨寄生(G.ruborum Gamble et Prain)和白接骨[A.neesiana(Wallich)Nees]。  相似文献   

2.
首次报道中国爵床科(Acanthaceae)一新记录种:大叶可爱花(Eranthemum macrophyllum Wall.ex Nees)。该种原记载分布于缅甸,在中国仅见于云南省铜壁关省级自然保护区。为名称Eranthemum macrophullus指定了后选模式。  相似文献   

3.
4.
We compared the organization of genetic variability in Aletes humilis, a species restricted to seven populations in north-central Colorado, with A. acaulis, a closely related widespread species. Genetic variability was scored at 11 electrophoretically detectable protein loci. Nine of these loci were polymorphic (i.e., P > 0.95) in both taxa, and were used for interpopulation and interspecific comparisons. Levels of genetic variability and patterns of organization of this variability are very comparable in both species. In contrast to many other narrow endemics, A. humilis is not genetically depauperate when compared to its presumed progenitor. Both biochemical and morphological evidence suggest that A. humilis is derived from A. acaulis; the comparable levels of variability in the two species suggest that A. humilis was derived from a source containing a substantial portion of the original A. acaulis genome, because there is no evidence of a genetic bottleneck or appreciable loss of allelic variability.  相似文献   

5.
本研究首次发现西藏新记录属云实属(Caesalpinia Linn.)植物——见血飞(Caesalpinia cucullata Roxb.),另外报道了11个新记录种和2个变种:瓶尔小草科(Ophioglossaceae)薄叶阴地蕨(Botrychium daucifolium Wall.),凤尾蕨科(Pteridaceae)华中凤尾蕨(Pteris kiuschiuensis var.centrochinensis ChingS.H.Wu),毛茛科(Ranunculaceae)尾叶铁线莲(Clematis urophylla Franch.),椴树科(Tiliaceae)刺蒴麻(Triumfetta rhomboidea Jacq.),锦葵科(Malvaceae)拔毒散(Sida szechuensis Matsuda),中华地桃花[Urena lobata var.chinensis(Osbeck)S.Y.Hu],柳叶菜科(Onagraceae)草龙[Ludwigia hyssopifolia(G.Don)Exell]、卵叶丁香蓼(Ludwigia ovalis Miq.),唇形科(Lamiaceae)小鱼仙草[Mosla dianthera(Buch.-Ham.)Maxim.],玄参科(Scrophulariaceae)石龙尾[Limnophila sessiliflora(Vahl)Bl.],爵床科(Acanthaceae)白接骨[Asystasia neesiana(Wall.)Nees],桔梗科(Campanulaceae)卵叶半边莲(Lobelia zeylanica Linn.),天南星科(Araceae)百足藤[Pothos repens(Loureiro)Druce]。研究结果进一步丰富了西藏的植物区系,并为研究与相邻地区植物区系的联系增加了新内容。  相似文献   

6.
7.
We used sequence data from the intron and spacer of the trnL-trnF chloroplast region to study phylogenetic relationships among Acanthaceae. This region is more variable than other chloroplast loci that have been sequenced for members of Acanthaceae (rbcL and ndhF), is more prone to length mutations, and is less homoplasious than these genes. Our results indicate that this region is likely to be useful in addressing phylogenetic questions among but not within genera in these and related plants. In terms of phylogenetic relationships, Elytraria (representing Nelsonioideae) is more distantly related to Acanthaceae sensu stricto (s.s.) than Thunbergia and Mendoncia. These last two genera are strongly supported as sister taxa. Molecular evidence does not support monophyly of Acanthaceae s.s., although there is strong morphological evidence for this relationship. There is strong support for monophyly of four major lineages within Acanthaceae s.s.: the Acanthus, Barleria, Ruellia, and Justicia lineages as here defined. The last three of these comprise a strongly supported monophyletic group, and there is weaker evidence linking the Ruellia and Justicia lineages as closest relatives. Within the Acanthus lineage, our results confirm the existence of monophyletic lineages representing Aphelandreae and Acantheae. Lastly, within the Justicia lineage, we develop initial hypotheses regarding the definition of sublineages; some of these correspond to earlier ideas, whereas others do not. All of these hypotheses need to be tested against more data.  相似文献   

8.
Riassunto

L'A. ha studiato i cariogrammi di 6 specie italiane del genere Carlina L. (C. gummifera Less. var. Fontanesii (DC.) Fiori, C. acaulis L. var. alpina (Jacq.) Fiori, C. acanthifolia All., C. lanata L., C. vulgaris L., C. carymbosa L.).

Il corredo cromosomico è 2n = 20 per tutte le specie. Per la presenza di un gruppo di cromosomi della lunghezza superiore a 4 μ nelle specie a grossi capolini, si rende possibile distinguere auche cariologicamente nel genere Carlina L. due sezioni, corrispondenti alla possibile distinzione morfologica delle Carline in Macrocefale (C. gummifera Less. var. Fontanesii (DC) Fiori, C. acaulis L. var. alpina (Jacq.) Fiori, C. acanthifolia All., C. latana L.) e Microcefale (C. vulgaris L. e C. eorymbosa L.).  相似文献   

9.
该文报道了我国樟科新樟属的一个新变种——大果滇新樟[Neocinnamomum caudatum(Nees)Merr.var.macrocarpum Wenbin Xu et B.S.Xia],该变种与原变种区别在于果实宽椭圆形,长近3 cm,宽达2cm,叶具明显离基三出脉(三出脉距叶基0.5 cm或更长),产自广西壮族自治区德保县东凌乡。  相似文献   

10.
Mohan Ram , H. Y. (U. Delhi, India.) The development of the seed in Andrographis serpyllifolia. Amer. Jour. Bot. 47(3) : 215—219. Illus. 1960.–Andrographis serpyllifolia, a member of the Acanthaceae, has an embryo sac with a bifurcated chalazal part. At the time of fertilization both synergids and antipodal cells disintegrate. Early in its development the endosperm is composed of 3 distinct parts: (1) a binucleate densely cytoplasmic chalazal haustorium; (2) a large binucleate micropylar haustorium; and (3) a central chamber which develops into the endosperm proper. The divisions in the central endosperm chamber are ab initio cellular. A few of the endosperm cells elongate enormously, ramify into the integument and destroy the surrounding cells. These cells have been termed secondary haustoria. Due to the unequal destruction of the integument, the endosperm assumes a ruminate condition. The mature seed is nearly naked because the seed coat is almost completely digested. The embryo has a long suspensor. The micropylar cells of the suspensor are hypertrophied and multinucleate. Contrary to Mauritzon's (1934) belief, the course of endosperm development is markedly different from that observed in Thunbergia. So far, albuminous seeds have been reported only in the subfamily Nelsonioideae. The present investigation provides a case of its occurrence in the Acanthoideae also.  相似文献   

11.
In the course of reconstructing the Brazilian herbarium of Prince Maximilian of Wied, several species were found in the literature which need either correction or clarification. Problems include priority considerations, authority of species names, conflicting typifications and other errors. This paper reports 12 currently accepted species collected by Prince Maximilian in Brazil, commenting on their taxonomic status and nomenclature. Included are type specimens of Andromeda ambigua Schrad. (lecto and isolectotypes; = Agarista revoluta (Spreng.) Hook. f. ex Nied.), Andromeda crassifolia Nees (lecto and isolectotypes; = Agarista revoluta), Aphelandra marginata Nees & Mart. (lecto and isolectotypes), Aphelandra maximiliana (Nees) Benth. (lecto and isolectotypes), Ceiba ventricosa (Nees & Mart.) Ravenna (lectotype), Cinnamodendron axillare (Nees) Endl. ex Walp. (lecto and isolectotypes), Croton gnaphaloides Schrad. (lecto and isolectotype), C. klaenzei Müll. Arg. (holotype), Geissomeria nitida (Nees & Mart.) Nees & Mart. (lecto and isolectotypes), Nectandra squarrosa Nees var. pyrifolia Nees (lecto and isolectotypes; = Ocotea squarrosa (Nees) Mez), Ocotea squarrosa (lecto and isolectotypes), Pavonia semiserrata (Schrad.) Steud. (lecto and isolectotypes), Stenandrium serpens Nees (lecto and isolectotypes), Zollernia falcata Wied-Neuw. & Nees (lecto and isolectotypes; = Z. glabra (Spreng.) Yakovlev) and Z. splendens Wied-Neuw. & Nees (lectotype; = Z. glabra). Additionally, a new name, Aphelandra verrugensis P. L. R. Moraes, is proposed to replace Synandra amoena Schrad., which is the oldest name of the taxon currently known as Aphelandra ignea Nees.  相似文献   

12.
Questions: The formerly overgrazed Inner Mongolia steppe was subject to retrogressive succession. Today, Artemisia frigida and Potentilla acaulis are two dominant species in different phases of successive degradation. To investigate the impact of grazing intensity on spatial community structure, we investigated the small‐scale spatial association between A. frigida and P. acaulis at zero, light, medium and heavy sheep grazing, and proposed factors involved in the spatial associations between these two species along a grazing intensity gradient. Location: The Inner Mongolia Grassland Ecosystem Research Station of the Chinese Academy of Sciences. Methods: Four grazing intensities were selected: zero, light (1.33 sheep/ha), medium (4.0 sheep/ha) and heavy (6.7 sheep/ha). After 13 years of grazing three 2 m × 2 m quadrats with 100 × 100 cells of size 2 cm × 2 cm were randomly selected in each treatment in July and August 2002. The presence of A. frigida and P. acaulis in each cell was recorded and the positions of the individuals were mapped using Cartesian coordinates in each quadrat. The small‐scale spatial associations between A. frigida or P. acaulis were quantified with the L12(d), J12(d) functions (both derived from K12(d), the former indicating the type of the spatial association, the latter indicating the strength of the spatial association), using Monte Carlo simulations. Results: A. frigida was negatively associated with P. acaulis at short distances (0–100 cm) under zero and light grazing, and negatively or independently under medium and heavy grazing. Increasing grazing intensities suppressed the peak negative associations. More intense grazing enhanced the tendency towards independent distribution of these two species. Conclusions: The small‐scale spatial associations between A. frigida and P. acaulis were significantly different at four different intensities of sheep grazing. Grazing disturbance, clonal growth habit of species, and interspecific competition are the main factors leading to a difference of spatial associations between these two species at different grazing intensities.  相似文献   

13.

Background

The stress‐gradient hypothesis predicts a shift from facilitative to competitive plant interactions with decreasing abiotic stress. This has been supported by studies along elevation and temperature gradients, but also challenged by the hypothesis of a facilitation collapse at extremely harsh sites. Although facilitation is known to be important in primary succession, few studies have examined these hypotheses along primary succession gradients.

Aim

To examine whether there is a relationship between the presence of the circumpolar cushion plant Silene acaulis and other species, and if so, whether there is a shift between positive and negative interactions along a primary succession gradient in a glacier foreland.

Location

Finse, southern Norway.

Methods

We examined the performance of the common alpine forb Bistorta vivipara, species richness of vascular plants, bryophytes and lichens, and the number of seedlings and fertile vascular plants in S. acaulis cushions, and control plots without S. acaulis, along a succession gradient with increasing distance from a glacier front, and thus decreasing abiotic stress. To examine if S. acaulis cushions modify the abiotic environment, we recorded soil temperature, moisture, organic content and pH in cushions and control plots.

Results

Bistorta vivipara performed better, as shown by bigger leaves in S. acaulis cushions compared to control plots in the harshest part of the gradient close to the glacier. There were few differences in B. vivipara performance between cushion and control plots in the more benign environment further away from the glacier. This suggests a shift from facilitative to mainly neutral interactions by S. acaulis on the performance of B. vivipara with decreasing abiotic stress. A trend, although not significant, of higher vascular species richness and fertility inside S. acaulis cushions along the whole gradient, suggests that S. acaulis also facilitates community‐level species richness. The causal mechanism of this facilitation is likely that the cushions buffer extreme temperatures.

Conclusions

Our results support the stress‐gradient hypothesis for the relationship between the cushion plant S. acaulis and the performance of a single species along a primary succession gradient in a glacier foreland. S. acaulis also tended to increase vascular plant species richness and fertility regardless of stress level along the gradient, suggesting facilitation at the community level. We found no collapse of facilitation at the most stressful end of the gradient in this alpine glacier foreland.  相似文献   

14.
报道了国产爵床科Acanthaceae山牵牛属Thunbergia(山牵牛亚科Thunbergioideae)6种、叉柱花属Staurogyne(瘤子草亚科Nelsonioideae)和老鼠簕属Acanthus(老鼠簕亚科Acanthoideae)各1种植物在扫描电镜下的花粉形态。山牵牛属植物的花粉粒为圆球形,均具螺旋状萌发孔,外壁纹饰以光滑或颗粒状为主,偶具棒状突起。具螺旋状萌发孔被认为是该科独特而较原始的花粉特征。叉柱花属的花粉粒为圆球形,具3孔沟,外壁平滑。老鼠簕属的花粉粒为长球形,具3沟,外壁具细网状纹饰或具小穿孔。花粉形态特征支持传统上将上述3属置于3个不同亚科的处理。  相似文献   

15.
The genus Tribolium Desv. consists of nine species, i.e., T. utriculosum (Nees) Renv., T. ciliare (Stapf) Renv., T. echinatum (Thunb.) Desv., T. hispidum (Thunb.) Desv., T. acutiflorum (Nees) Renv., T. obliterum sensu Davidse, T. glomeratum sensu Davidse, T. uniolae (L.f.) Renv., and T. brachystachyum (Nees) Renv. The genus has a basic chromosome number of 6, and from diploid to hexaploid specimens have been examined. Precocious segregation of metaphase I bivalents were observed in four species. Multivalent formation results in unequal chromosome segregation during anaphase I, and several cells with an 11–13 chromosome distribution have been observed. The presence of univalents and anaphase I bridges in all T. brachystachyum specimens suggests a hybrid origin for the species. B-chromosomes were present in specimens from four species. The B-chromosomes are similar to the euchromosomes with the exception that they do not participate in meiosis. The B-chromosomes have a possible isochromosome origin. The cytogenetic evidence presented supports the combination of Plagiochloa and Lasiochloa into Tribolium and indicates that the genus is closely related to Urochlaena, whereas it is not closely related to Prionanthium.  相似文献   

16.
An increase in the dose of the Su(var)3-7 locus of Drosophila augments heterochromatin-promoted variegated silencing. The deduced protein sequence of Su(var)3-7 reveals seven widely spaced zinc fingers. We found that Su(var)3-7 has affinity for DNA in vitro and that the minimal protein sequence requirement for DNA binding is any module containing two zinc fingers and the interval between them. As Su(var)3-7 is a heterochromatin-associated protein, we tested its affinity for various satellite DNA sequences in vitro. The AATAT and 353-bp elements have the highest affinity. If affinity for satellite DNAs contributes to the presence of Su(var)3-7 in heterochromatin, a general affinity for DNA, or sequences yet to be determined, suggests a function in the genomic silencing of position-effect variegation: expansion of heterochromatin, whether continuous by spreading or discontinuous by pairing with sequence elements scattered through euchromatin, could use the affinity of Su(var)3-7 for DNA.  相似文献   

17.
尾叶纤穗爵床(Leptostachya caudatiflora H. S.Lo D.Fang)的花药下方一室基部具距,应为爵床属植物,提出1个新组合——尾叶爵床(Justicia caudatifolia (H.S.Lo D.Fang) Z.P.Hao,Y.F.Deng T.Daniel),而纤穗爵床属仍为单种属。  相似文献   

18.
Phylloscirpus acaulis and Trichophorum rigidum (Cyperaceae) are widely distributed in the Andes of South America. A study of the taxonomy, vegetative architecture and inflorescence structure showed the existence of two subspecies, Phylloscirpus acaulis subsp. pachycaulis and Trichophorum rigidum subsp. ecuadoriense.  相似文献   

19.
Strobilanthes attenuata (Nees) Nees is described and illustrated. Its extensive synonomy is discussed and its principal characteristics are highlighted. Its introduction to countries with a temperate climate is chronicled and successful experience of its cultivation in England is described.  相似文献   

20.
Adhatoda vasica Nees, belonging to family Acanthaceae, is a well-known medicinal plant. It is endorsed for its pyrroloquinazoline alkaloids and its derivatives, such as vasicine and vasicinone. Germinating A. vasica seeds is a tedious task; on that account, vegetative propagation is the preferred method for its multiplication. For rapid and large-scale multiplication, germplasm conservation as well as secondary metabolites production, in vitro culture of A. vasica was preferred over conventional propagation by several researchers; however, some major applications of this tissue culture technique are still awaiting to undergo extensive research. The present review, for the first time, illustrates all the major achievements associated with in vitro regeneration of A. vasica, reported till date and highlights the future prospects.  相似文献   

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