首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Ongoing taxonomic work on Mezilaurus has revealed two new species of the genus in Brazil, which are here described and illustrated. The first one, Mezilaurus glabriantha, from the state of Espírito Santo, represents the third endemic species known from the Brazilian Atlantic Forest, and Mezilaurus microphylla occurs in seasonally dry forests from the central Brazilian state of Tocantins. A key to distinguish the extra-Amazonian species of Mezilaurus from Brazil is provided.  相似文献   

2.
Zamia lindosensis, a species of cycad from sandy soils of Amazonas, Colombia, is described and illustrated. It is compared to Zamia amazonum, which has similar habitat requirements, petiole morphology and prickles, leaflet margins, and strobili but with very narrow leaflets.  相似文献   

3.
Three new species of Schefflera (Araliaceae) from the “Calyptrate” clade of the Andean region in Colombia are described and illustrated. Schefflera bifurcata is similar to S. cicatricata, but it differs by presenting a smaller number of flowers per umbel and fewer carpels. Schefflers brevirama differs from S. elachistocephala by having an arboreal habit and smaller leaflets. Schefflera connata is related to S. quinduensis, but it differs in the inflorescence being a panicle of umbels and the style connate. These species are distributed to the north of the Cordillera Central in the department of Antioquia, and S. connata also occurs to the north of the Cordillera Occidental in the departments of Antioquia and Chocó.  相似文献   

4.
Myrcia incompleta, from the northern Brazilian states of Amazonas and Rondônia, is described and illustrated. This species is apparently related to Calyptranthes paniculata and C. speciosa, from which it is distinguished mainly by its narrower leaves with midvein strongly raised adaxially and shorter, pauciflorous inflorescences. Conservation status for the species is proposed.  相似文献   

5.

Key message

Although tree-ring chronologies of Cedrela fissilis and Cedrela angustifolia showed a common climatic signal, local conditions influence growth, suggesting that forest guidelines should be appropriate to the species and context.

Abstract

Cedrela species are highly valued because of the quality of their timber. Understanding the behaviour of each different Cedrela species and their ecology is of importance to ensuring that forest harvesting and management do not endanger the survival of natural populations. These species grow in a wide range of environmental gradients and different types of forests in Bolivia. This study used dendrochronological methods to analyse growth–precipitation relationships of two Cedrela species coming from three locations with different environmental conditions: dry Chiquitano (Concepción), Chiquitano transitional Amazonian (Guarayos), and Bolivian-Tucuman montane forests (Postrervalle). The rainy season in all locations runs from October to April and the dry season runs from May to September. Twelve Cedrela fissilis specimens were sampled from dry Chiquitano, 11 Cedrela fissilis specimens from Chiquitano transitional Amazonian, and 30 Cedrela angustifolia specimens from Bolivian-Tucuman montane forests. The samples were crossdated and exhibited a common signal between trees from three sites, despite tree rings from the Chiquitano transitional Amazonian forest being narrower and displaying blurred bands of parenchyma in the boundaries. Significant inter-series correlation was found for the C. fissilis species series from dry Chiquitano with r = 0.261 (p < 0.01) and Chiquitano transitional Amazonian forests with r = 0.284 (p < 0.01), and for Cedrela angustifolia from Bolivian-Tucuman montane forests with r = 0.374 (p < 0.01). Mean annual growth was 2.07, 1.92, and 2.82 mm year?1 at the three sites, respectively. Cedrela species from dry Chiquitano and Bolivian-Tucuman montane forests were sensitive to precipitation from October to April of the current growth year (wettest season) and to low temperatures from May to July of the current growth year (driest season). Samples from Chiquitano transitional Amazonian were more sensitive to precipitation during late rainy season (March, April, and May of the current growth year) and high temperatures during the rainy months (November–December). Growth differences between sites and species in response to climate variations and local conditions should be taken into account and handled with different forest management guidelines.
  相似文献   

6.
Two new species of Miconia from northern Amazonia area described. Miconia amapaënsis has been collected in the Brazilian state of Amapá and in nearby locations in northern Pará and southern French Guiana. It has remarkable seeds, with both the appendix and seed coat covered with long papillae. Miconia forzzae has been collected on the Brazilian side of the Neblina Massif, in the Brazilian state of Amazonas, close to the border with Venezuela. It has 4-merous flowers, with a terete hypanthium, yellow stamens, the ovary apex with unbranched trichomes, and a punctiform stigma. This species may be endangered, considering its narrow distribution, and the fact that it was collected between 2000 and 2100 m elevation in an isolated mountain range with no neighboring mountains with similar height, but we assess its conservation status as “data deficient”, due to a lack of knowledge on the situation of the populations and the number of individuals.  相似文献   

7.
Three new species from Brazil are described and illustrated. Passiflora cervii, P. jiboiaensis, and P. transversalis all belong to Passiflora subg. Decaloba.  相似文献   

8.
Three new species of Davilla (Davilla sessilifolia, Davilla minutifolia and Davilla aymardii) from Bahia, Brazil, are described and illustrated. Affinities and diagnostic characteristics of each species are discussed. The new species belong to Davilla sect. Homalochlaena.  相似文献   

9.
A new species of Bignoniaceae from Brazilian cerrado and caatinga is described and illustrated: Xylophragma tenue. The species is characterized by its slightly bullate leaves, lateral leaflets with asymmetrical base, loosely branched inflorescence, flowers with tubular calyx with a shortly 5-cuspidate and frequently bilabiate rim, infundibuliform corolla, and capsules flat, woody, smooth, and with raised margins. Comments on distribution, phylogenetic affinities, and comparisons with morphologically similar species are also presented. Resumo Uma nova espécie de Bignoniaceae ocorrente no cerrado e caatinga é descrita e ilustrada: Xylophragma tenue. A espécie é caracterizada pelas folhas levemente buladas, folíolos laterais com base fortemente assimétrica, inflorescência laxa, flores com cálice tubular e margem curto-5-cuspidada e frequentemente bilabiada, corola infundibuliforme e cápsulas planas, lenhosas, lisas e com margens elevadas. São fornecidos comentários sobre a distribuição geográfica, posicionamento filogenético e comparações com espécies morfologicamente próximas.  相似文献   

10.
The Burseraceae are known to comprise one of the most important tree families in Amazonia, but examination of Burseraceae diversity indicates that this importance is achieved differently in different parts of the Amazon, generally showing greater relative density compared to relative diversity in the east and greater relative diversity compared to relative density in the west, but both high relative density and diversity in central Amazonia. The patterns of relative density may be explained by current climates and by soils, but those of diversity are more likely a function of historical events. Revision of the Burseraceae for two projects near Manaus, Brazil revealed four new taxa. Protium hebetatum is widespread in western Amazonia, but it is one of the most common trees in central and west-central Amazonia; it resembles P. grandifolium. Protium tonyanum is a distinctive new species in poorly resolved sect. Sarcoprotium. Protium paniculatum var. modestum is known thus far only from the vicinity of Manaus plus several localities in the state of Amazonas, Venezuela; a key to the varieties is provided. Dacryodes hopkinsii is one of a group of four species in that genus from Amazonia and the Venezuelan Guayana with relatively large and fleshy flowers that are functionally bisexual. The discovery of these new taxa underscores the biological importance of Manaus and vicinity as a center of diversity for many taxa and exemplifies the synergy between well-designed floristic projects and systematics.  相似文献   

11.
12.
Syneches from Brazilian biome of Caatinga were studied, two new species are described, Syneches atratus sp. nov. and Syneches limeirai sp. nov., and three species, Syneches annulipes Bezzi, 1909, Syneches moraballi Smith, 1963, and Syneches rafaeli Ale-Rocha & Vieira, 2008, are recorded for the biome. An identification key for the species of Syneches from Caatinga biome is provided.  相似文献   

13.
14.
Five new compounds were isolated from Penicillium sp. Y-5-2 including an austin derivative 4, four isocoumarins 9, 11, 12, and 13, together with two known isocoumarins 8 and 10, and six known austin derivatives 1, 2, 3, 5, 6, and 7 and one phenol 14. Their structures and relative configurations were established by spectroscopic means. The absolute configurations of 4, 11, and 13 were defined mainly by comparison of quantum chemical TDDFT calculated and experimental ECD spectra. The cyclization of the pentan-2-ol pendant at C-3 in compound 13 allowed the assignment of a new 2,3,4,4a,6,10b-hexahydro-1H-benzo[c]chromene isocoumarin skeleton. New compounds 9, 11, and 13 revealed inhibitory activities against E. coli at MIC values around 32 μg/mL. The known compound 14 showed potent antibiotic activity against Staphylococcus aureus and Bacillus subtilis with MIC values 8 and 2 μg/mL, respectively, with no cytotoxicity when tested in vitro. A rapid and efficient technique for selecting antibiotic fungal strain among eight marine-derived fungi was also described.  相似文献   

15.
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.  相似文献   

16.
17.
The plants of the genus Salvia L. are important medicinal herbs of the Lamiaceae family and some of them such as S. officinalis (sage), S. miltiorrhiza (red sage, Danshen) and S. sclarea (clary sage) have been used as medicinal plants in the folk medicine of several countries. In this review, we discuss the reports that have examined Salvia species with the aim of isolation of pure compounds with different biological activities. The phytochemical analyses of various sage plants have reported 10 monoterpenoids (110), 1 sesquiterpenoid (11), 8 labdane (1320), 15 ent-kaurane (2135), 82 abietane, rearranged abietane and tanshinone (36117), 3 icetexane (118120), 43 clerodane (121163), and 3 pimarane (164166) diterpenoids with cytotoxic and antimicrobial, antiprotozoal, antioxidant, phytotoxic and insecticide effects. The other heavier terpenoids, including 3 sesterterpenes (167169), 10 triterpenoids and β-sitosterol (170180) have been introduced as minor bioactive compounds in the sage plants. Sahandinone (107), 6,7-dehydroroyleanone, 7-α-acetoxyroyleanone (40), and tanshinone like diterpenoids have been isolated from the roots’ extracts of different Salvia species. On the other hand, several radical scavenger phenolic compounds like simple phenolics and caffeic acid derivatives (181201) including rosmarinic acid, flavonoids (202217) as well as phenolic diterpenoids, such as carnosol and carnosic acid have been isolated from the aerial parts of these plants. One pyrrole (218) and 3 antimicrobial oxylipins (219221) are among the other less detected constituents in the members of Salvias. Furthermore, sages also synthesize antifungal, antileishmanial and antimalarial phytochemicals in their roots and shoots, which are reviewed in this paper. We also examine the allelopathic phenomena and the ecologically important phytochemicals identified in different parts of the sage plants. Finally, antifeedant and insecticide phenomena, which are due to the presence of volatile monoterpenes and clerodane diterpenes in these plants, are discussed. Considering the presence of diverse biologically active phytochemicals in the sage plants, they can be suggested as suitable candidates for the formulation of valuable natural medicines.  相似文献   

18.
A review of Astronium s.l. revealed a new species in section Astronium that is unusual because of its dwarf habit, presence of foliose bracts on the inflorescence, and sub-basal ovule placentation. Currently available collections suggest a disjunct distribution between the Brazilian states of Goiás and Rondônia and the northeastern part of the Bolivian department of Santa Cruz, but all on the Brazilian Shield. The new species is formally described and named as Astronium pumilum. The generic limits and morphological attributes of the sections of the genus are discussed, and a key to the known species is presented. A synopsis or revision of the genus is being prepared pending results from molecular systematic studies.  相似文献   

19.
Gustavia johnclarkii and G. hubbardiorum, two new species from the wet forests of northwestern and Amazonian Ecuador, are described and illustrated. In addition, the two subspecies of both G. speciosa and G. macarenensis are elevated to species, and the new combination Gustavia paucisperma is provided. A justification for these changes is presented.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号