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1.
Melastomataceae is a tropical family of 4500–5000 species divided into nine tribes. The largest tribe, Miconieae, is composed of approximately 2200 species in 30 genera and is found exclusively in the Neotropics. Previous phylogenetic analyses of the Miconieae have suggested that many of the genera are derived from a paraphyletic Miconia. However, these analyses only included six species of the large genus Leandra, so its phylogenetic affinities remained unclear. As currently defined Leandra is characterized by acute petals and terminal inflorescences, but some species of Miconia, Clidemia and Ossaea also have these characters. In this study, we present an analysis of nrITS sequence data for a sample of 63 species of Leandra. The genus is clearly resolved as polyphyletic, but some distinct and well‐supported clades exist. Some of these partially correspond to sections recognized in the nineteenth century by Cogniaux, or to geographic distribution. The distribution of seed structure characters is better correlated with the phylogeny than traditional characters, such as petal morphology. Seed appendages in Leandra have evolved independently at least four times. © The Willi Hennig Society 2007.  相似文献   

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The seed morphology of 79 species of neotropical Miconieae (Melastomataceae) is presented. These species have been chosen, in majority, from the polyphyletic genus Leandra. A few other species from the polyphyletic genera Miconia, Ossaea, and Clidemia were also sampled, because of potential similarities. Sixteen morphological seed types are defined after analysis through light microscopy and scanning electron microscopy. The seed morphology appears to possess a great deal of variability on the level of the overall shape as well as the structure and the surface of the testa. The different types defined here do not match with genera or sections, but rather are composed of species coming from different genera. In comparison with a preliminary molecular phylogeny study done on Leandra, some types of seeds are related to well supported clades. In some cases seed morphology corresponds with natural groups of species, thus being of high phylogenetic importance.  相似文献   

4.
As presently known, the genusSiphonoglossa can be divided into two “subgenera,” one of which is here divided into two sections,Pentaloba andSiphonoglossa. Two new species are described from a locality in Durango, Mexico :S. durangensis in sect.Siphonoglossa andS. linearifolia in sect.Pentaloba. Three other species are transferred intoSiphonoglossa:S. canbyi from northeastern Mexico;S. buchii from Haiti and the Dominican Republic andS. incerta from southern Baja California, Mexico.  相似文献   

5.
All neotropical genera previously included in the tribe Isertieae A. Rich. ex DC. are considered. The tribe Isertieae is here delimited by the following characters: absence of rhaphides, valvate aestivation of the corolla, cordiform or discoid placenta, fleshy indehiscent fruit, and seed coat cells with pitted walls. As so delimited, the tribe definitely includes the neotropical generaIsertia Schreb.,Gonzalagunia Ruiz & Pav.,Amphidasya Standl.,Raritebe Wernh.,Sabicea Aubl., andMussaenda L. as well as some paleotropical genera not here considered. The following neotropical genera are excluded from tribe Isertieae:Hippotis Ruiz & Pav.,Pentagonia Benth.,Sommera Schlecht.,Tammsia Karst.,Coccocypselum P. Browne,Schradera Vahl,Didymochlamys Hook, f., andXerococcus Oerst. The position of four genera,Striolaria Ducke,Patima Aubl.,Habroneuron Standl., andNeosabicea Wernh., remains uncertain due to a lack of material.  相似文献   

6.
Tetsuo Koyama 《Brittonia》1974,26(2):133-138
Described as new areSmilax biumbellata of the affinity ofS. nervomarginata,S. siamensis of the affinity of 5.perfoliata, and two others inSmilax sect.Macranthae:S. inversa andS. pachysandroides.Smilax inversa (characterized by strongly deflexed leaves and inflorescences on zigzag stems) andS. pachysandroides (with subsessile leaves on low simple stems) show no close resemblance to any previously known species of the section.  相似文献   

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Antibody systems were produced in rabbits by immunization with antigen systems from seed ofZea mays, Z. mexicana andTripsacum dactyloides. Antigen systems were generally ranked in the following order using Zeaantibody systems: Zea > Tripsacum > Elyonurus ≈ Bothriochloa > Coix ≈ Manisuris > Andro-pogon ? Triticum. Tripsacum antibody systems also ranked these antigen systems in a similar order except that Tripsacum > Zea, and Manisuris ≈ Bothriochloa ≈ Elyonurus. Some Tripsacum species produced anomalous results. Serology suggests that Zea and Tripsacum should be placed together in the subtribe Tripsacinae of the tribe Andropogoneae: the tribe Maydeae is probably an unnatural assemblage. Tripsacum and Zea have probably evolved from ancestors with affinities to the subtribes Rottboellinae and Bothriochloeae of the tribe Andropogoneae. The high degree of serological correspondence shown by Elyonurus to Zea suggests a close common ancestry, but Manisuris appears no more similar to Tripsacum than do other genera of the Rottboellinae and Bothriochloeae. By polyacrylamide gel electrophoresis, no differences were found between maize and teosinte from Mexico and north Guatemala. Teosinte from south Guatemala consistently lacked bands present in both maize and Mexican teosinte but shared no greater similarity to Tripsacum and cannot therefore be considered as tripsacoid. The high degree of band homology between maize and Mexican teosinte supports a parental relationship and it is suggested that Mexican teosinte represents the germ plasm from which maize was domesticated. Neither electro-phoretic nor serological results supported the hypothesized hybrid (viz. Zea x Manisuris) origin of Tripsacum.  相似文献   

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Morphological variation ofPotentilla norvegica L.,P. heidenreichii Zimmeter andP. supina L. usually treated within the sectionRivales Wolf,P. recta L. (sect.Rectae Wolf),P. canescens Bess.,P. argentea L. s.l.,P. collina Wibel (sect.Argenteae Wolf) andP. goldbachii Rupr. (sect.Chrysanthae Wolf) was studied using multivariate statistical methods. According to k-means clustering,P. canescens stands closer toP. heidenreichii of the sect.Rivales than toP. argentea. P. collina, the other representative of sect.Argenteae, is not connected withP. canescens at all. Therefore,P. canescens should belong to sect.Rivales and not to sect.Argenteae. InPotentilla argentea s.l.,P. impolita Wahlenb.,P. argentea L. var.argentea, var.decumbens (Jord.)Lehm., var.demissa (Jord.) Lehm., var.grandiceps (Zimmeter) Rouy etE.G. Camus and var.tenerrima (Velen.) Wolf were identified.P. impolita specimens did not cluster out into a separate cluster as didP. collina, P. canescens andP. heidenreichii, but formed mixed clusters with different varieties ofP. argentea s.str. Therefore,P. impolita is not worthy of the rank of species and evidently not even that of subspecies, and should be treated as a variety—P. argentea var.incanescens (Opiz) Focke.  相似文献   

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Three species of lepidopterous larvae were collected fromAmaranthus hybridus L. growing in field corn during 1975 and 1976 at Hastings, Florida.Spodoptera exigua (Hubner) was the predominant species in May.Spodoptera eridania (Cramer) was predominant in June andHerpetogramma bipunctalis (F.) in July and August. Nine native species of parasites, representing theBraconidae, Eulophidae, Ichneumonidae andTachinidae, emerged from these larvae.Meteorus autographae Muesebeck emerged from bothS. exigua andS. eridania. TheTachinidae, Winthemia rufopicta (Bigot),Eucelatori rubentis (Coquillett) andLespensia sp., emerged from mixtures ofS. exigua andS. eridania. Apanteles marginiventris (Cresson),Temelucha sp., andChelonus texanus Cresson emerged from bothS. exigua andH. bipunctalis larvae, andEuplectrus platyhypenae Howard andOphion sp. emerged fromS. eridania. All the species of parasites from the lepidopterous larvae that feed onAmaranthus hybridus are also reported as parasites ofS. frugiperda, a serious pest of corn. Therefore these larvae onA. hybridus may be a source of the parasites found attackingS. frugiperda.  相似文献   

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Acacia guilandinae DC. is recognized asMimosa guilandinae (DC.) Barneby, endemic to French Guiana and adjoining Amapá, Brazil;M. pseudo-obovata is subordinated as a Brazilian var.pseudo-obovata (Taub.) Barneby to CaribbeanM. ceratonia L.; andM. laticifera is found synonymous withM. obovata Benth. Diagnostic morphological characters of each taxon are presented in key form.  相似文献   

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Notes on the taxonomy and distribution of various species of Labiatae of Mexico, and Central and South America, are presented, as part of a continuing series of supplements to the authors’ earlier monographs. Eight new species are described in the generaHyptis, Salvia, Satureja, andScutellaria. Two new combinations are made, one each inHarlanlewisia andSatureja. A key and revision are given for the six species ofLepechinia sect.Parviflorae.  相似文献   

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Walter S. Judd 《Brittonia》1986,38(3):238-242
Calycogonium squamulosum Cogn., a Puerto Rican endemic, is shown properly to be placed inHenriettea DC, (includingHenriettella Naud.), and this transfer is made. The species is allied to several other lepidote taxa ofHenriettea, e.g.,H. squamata (Alain) Alain andH. acunae (Alain) Alain (all endemic to the Oriente region of Cuba).Calycogonium squamulosum is also compared to the Hispaniolan endemic,Henriettea barkeri (Urban & Ekman) Alain [syn.H. elliptica (Urban) Alain], a species with stellate to stellate-strigose hairs.  相似文献   

16.
David M. Bates 《Brittonia》1967,19(3):227-236
Reevaluation of the generic limits ofMalvastrum A. Gray requires the transfer of several species. Among these,M. lacteum (Ait.) Garcke andM. subtriflorum (Lag.) Hemsley of Central America and Colombia form a natural alliance differing fromMalvastrum in morphological, cytological, and ecological characteristics and are recognized as a new genus,Kearnemalvastrum. The affinities ofKearnemalvastrum within the tribe Malveae are uncertain. Despite the fact thatK. lacteum andK. subtriflorum occupy similar ecological situations, are fully interfertile, and apparently hybridize to some degree in nature, they do maintain their identity and, therefore, are recognized as species.  相似文献   

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Microautoradiography was used to screen natural phytoplankton populations from Lake Kinneret for their ability to take up radioactive organic substrates (glucose, acetic acid, amino acids, and glycollic acid. Several of the important Chlorophyta (Pediastrum spp.,Actinastrum hantzschii, Kirchncriella spp.,Coelastrum spp.,Scenedesmus spp., andTetraëdron spp.) and Cyanophyta (Microcystis spp.,Merismopedia sp.,Chroococcus spp., andAnabaena spp.) showed consistent organic uptake. However, the principal bloom former, the dinoflagellatePeridinium cinctum fawestii and most of the pelagic algae observed, never assimilated any of the above substrates. Autoradiographic surveys permit rapid screening of algal populations for species which are capable of taking up organic matter and can indicate potential facultative heterotrophs.  相似文献   

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InCallithrix, Saguinus, Aotus, andCallicebus other group members than the mother participate in infant care. Differences among these species are obvious in respect to the time of being off any caregiver, and in respect to the carrying position (Aotus andCallicebus). Alloparental care, a basic behaviour pattern in these species, has evolved from the parking behaviour of the prosimians. The infants are «parked» at other group members.  相似文献   

20.
Barbara Ertter 《Brittonia》1980,32(1):70-102
The genusOxytheca of western North America and temperate South America consists of seven species which are keyed, described, discussed, illustrated, and mapped. They are divided among sect.Oxytheca, sect.Acanthoscyphus stat. & comb. nov., and sect.Neoxytheca sect. nov.Oxytheca dendroidea subsp.chilensis is given as a new combination, whileO. parishii var.cienegensis andO. parishii var.goodmaniana are described as new. The history and relationships of the genus are discussed. It is retained as distinct fromEriogonum and is thought to have arisen from the larger genus nearE. spergulinum, E. parishii, andE. apiculatum in subgenusGanysma. Cytological data indicatedn= 20.  相似文献   

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