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1.
Habenaria sect.Macroceratitae from Brazil is revised, and seven species are recognized:H. bractescens, H. gourlieana, H. johannensis, H. longicauda, H. macronectar, H. nabucoi, and the newly describedH. paulistana. A main feature of these species is the presence of long, separated, involute stigmatic processes.Habenaria bractescens, H. gourlieana, H. johannensis, andH. macronectar are distributed mainly from central and southeastern Brazil to southern Brazil and southern South America, whereasH. longicauda andH. nabucoi are distributed mainly from west central, southeastern and northeastern Brazil to northern South America.Habenaria paulistana is restricted to the state of São Paulo.Habenaria bradei, H. juergensii, andH. sartoroides are lectotypified, andH. kleyi is neotypified. The identity ofH. fastor is discussed andH. nabucoi is recognized as the valid name for this species. Seven other species previously placed in sect.Macroceratitae are sufficiently distinct and are removed from the section.  相似文献   

2.
Three new species of Chrysobalanaceae from South America are described:Couepia bernardii, Hirtella barnebyi andH. confertiflora. TheCouepia guianensis complex is discussed, redefined and divided into three subspecies that include material previously recognized as separate species. Observations are also made on recent collections of three poorly known species ofHirtella, H. araguariensis,H. dorvalii andH. leonotis.  相似文献   

3.
Seventeen species ofHibiscus sectionFurcaria are native to the New World, of which 12 (one diploid, nine tetraploids, one octoploid and one decaploid) have been studied cytotaxonomically. New chromosome counts (2n=4x=72) are reported forH. cucurbitaceus, H. flagelliformis, H. kitaibelifolius, andH. laxiflorus. Seventeen types of tetraploid interspecific hybrids (seven new to this study) all showed complete meiotic chromosome homology (genome formulaGGPP) and normal floral development. That all hybrids were nevertheless almost completely sterile suggests a cytoplasmic component to the genetic differentiation of the species. The diversification of the tetraploid species in habits, habitats and geographical ranges is considerable, despite their similar genome constitutions. A key to 17 native and four introduced African species is presented.Hibiscus cerradoensis sp. nov. is described.  相似文献   

4.
J. M. Campbell 《ZooKeys》2014,(415):295-309
Two species, Hymenorus bifurcatus, and H. excavatus are described as new from Guatemala and the new species H. balli from both the state of Chiapas in southern Mexico and Guatemala. These three species are unique among the species of Hymenorus Mulsant, 1851 in the unusual and highly modified fifth ventrites of the male and the modified shape of the female ninth tergites. The unusual sexual characters of the males and females are illustrated with photographs. The usage of the generic names Hymenorus Mulsant versus Hymenophorus Mulsant is discussed.  相似文献   

5.
Study of herbarium specimens, crossing behavior, chromosome conjugation, and live populations has shown that the endemic North American species ofHibiscus sect.Trionum comprise two distinct genetic groups.Hibiscus militaris Cav. andH. coccineus Walt, crossed readily and yielded fertile Fi’s. Also,H. incanus Wendl.,H. moscheutos L., andH. lasiocarpos Cav. crossed freelyinter se, and the hybrids were all vigorous and fertile. However, crosses of these three forms with eitherH. militaris orH. coccineus gave lethal hybrids. Preliminary evidence suggests thatH. palustris L. is similar toH. moscheutos, H. incanus, andH. lasiocarpos in crossing behavior. These four forms were found to occur in distinct geographical areas. They may be considered as ecotypes of a single ecospecies.H. grandiflorus Michx. is morphologically related to this alliance, but yielded a viable fertile hybrid when crossed withH. coccineus. Further study of the affinities ofH. grandiflorus andH. palustris is in progress.  相似文献   

6.
Robert S. Irving 《Brittonia》1970,22(4):338-345
Hedeoma pilosum andH. microphyllum are described as new. The former, an endemic of western Texas, is closely related toH. pusillum andH. apiculatum; the latter is intermediate betweenH. costatum andH. nanum. H. oblongifolium var.mexicanum andH. drummondii var.crenulatum are presented as two new varieties, both of which may have originated as hybrids.Hedeoma crenulatum is proposed as a new name to replaceH. montanum (Brade) Epling & Játiva. Three new combinations are made in the genusHesperozygis, and new status is accorded to two species.  相似文献   

7.
Ten kinds of interspecific hybrids were obtained involving the following species: H. surattensis L. (2x, genome constitution BB), H. sudanensis Hochr. (2x, GG), and H. rostellatus Guill. and Perr. (4x, GGHH) from Africa; H. furcatus Roxb. non Willd. (8x) from India and Ceylon; H. furcellatus Lam. and H. bifurcatus Cav. (both 4x, PPQQ) from South America; and H. heterophyllus Vent. (6x) from Australia. Chromosome pairing in pollen mother cells (PMC's) at metaphase I in the 4x hybrids H. bifurcatus-rostellatus and H. furcellatus-rostellatus indicated that the parents have one genome in common (Q = G or H). Hibiscus furcatus was shown earlier to have a B genome; hybrids of H. surattensis-sudanensis F1 X furcatus were hexaploid, having received an unreduced gamete from their hybrid parent, and had approximately 36 II, 36 I in PMC's. The genome formula of H. furcatus may therefore be designated BBGGWWZZ. The hybrid H. rostellatus-furcatus (BGGHWZ) confirmed that H. furcatus has a G genome in common with H. rostellatus; pairing of the other three genomes was inconsistent, as was that in H. rostellatus-heterophyllus. Some samples of the latter approached 36 II, 36 I, expected if H. heterophyllus were GGHHJJ; other samples had less pairing. Hibiscus furcatus-heterophyllus hybrids apparently arose from unreduced gametes of H. heterophyllus and originated as decaploids rather than heptaploids; chromosome number was unstable in PMC's. Nevertheless, multivalents, especially trivalents, were frequent enough to suggest that H. furcatus and H. heterophyllus share G genomes. On the other hand, an 8x H. bifurcatus-furcatus hybrid, which apparently arose from an unreduced gamete of H. bifurcatus, had a low multivalent frequency. Hybrids were obtained of H. heterophyllus X sudanensis and H. surattensis-sudanensis X heterophyllus, but the plants were weak and were not analyzed cytologically. We suggest that the New World, African, Indian, and Australian genomes which retain a considerable degree of homology (G or H or both) were distributed by land prior to separation of the southern continents by continental drift.  相似文献   

8.
The aphid predator Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is an invasive alien species in Europe and North America with negative effects on non-target species (including a decline of native ladybird populations), as well as fruit production, and human health. It is, therefore, important to find out which natural enemies could be used to reduce their numbers. Knowledge of H. axyridis’ natural enemies is summarised and data collected from the Netherlands over the past ten years are presented. Beetles were sampled from winter aggregations and from spring through to autumn with illuminated screens at night. Natural enemies were not found in samples of H. axyridis from 2003–2007. From 2008 onward H. axyridis adults were infested by: Hesperomyces virescens Thaxt. fungi (summer and winter), Parasitylenchus bifurcatus Poinar and Steenberg nematodes (winter), Coccipolipus hippodamiae (McDaniel and Morrill) mites (winter), and Dinocampus coccinellae (Schrank) parasitoids (summer and winter). Our results indicate that these natural enemies are starting to use H. axyridis as a host, but are as yet not sufficiently abundant to control the population.  相似文献   

9.
Hybos bifurcatus sp. n. and H. mengqingae sp. n. are described. The two new species are closely related with Hybos trfurcatus Yang et Yang and H. caesariatus Yang et Yang.  相似文献   

10.
Blepharidachne is a disjunct American genus with four species:B. kingii (S. Wats.) Hackel (Great Basin of western U.S.A.) andB. bigelovii (S. Wats.) Hackel (Coahuila, Mexico and Texas, U.S.A.) in North America;B. benthamiana (Hackel) A. S. Hitchc. andB. hitchcockii Lahitte, both in central and western Argentina.Blepharidachne kingii is the only species with perfect flowers, the other three being monoecious as a result of a series of reductive processes. After a discussion of these morphological peculiarities, heretofore overlooked, the article is completed with a brief taxonomic synopsis of the genus.  相似文献   

11.
Morphological, cytological, and paper Chromatographic studies of populations from northern Michigan and examination of herbarium specimens from throughout North America were used to clarify the relationships ofGoodyera oblongifolia, G. repens var.ophioides, andG. tesselata. A canonical analysis of morphological data from mixed populations of these three species depictsG. tesselata as intermediate betweenG. oblongifolia andG. repens var.ophioides. The latter two species are diploid (2n = 30) andG. tesselata is tetraploid (2n = 60). Triploids (2n = ca. 45) were found in two mixed-species populations in northern Michigan.Goodyera tesselata produces three phenolic compounds present inG. oblongifolia and five different compounds present inG. repens var.ophioides. The range ofG. tesselata is confined to glaciated territory (except for two stations) in northeastern North America where the postglacially produced ranges ofG. oblongifolia andG. repens var.ophioides overlap. However,G. tesselata is quite abundant in areas outside the region of sympatry of the other two species. Based on this evidence, it is postulated thatG. tesselata is an allotetraploid species which resulted from hybridization betweenG. oblongifolia andG. repens var.ophioides during early post-Pleistocene. The slightly earlier blooming season ofG. tesselata may have been selected for to provide a measure of reproductive isolation between the tetraploid and its parents and to adapt the new species to the rather short growing season of northeastern North America.  相似文献   

12.
Lynn Bohs 《Economic botany》1989,43(2):143-163
Plants of the genusCyphomandra (Solanaceae) have long been utilized for their edible fruits in their native Latin America. The best-known species is the domesticated tree tomato or tamarillo,Cyphomandra betacea. This species, popular as a raw or cooked fruit, is widely cultivated in Andean South America and is now dispersed worldwide in subtropical areas. Its origin and wild relatives are still unknown, but there are tentative reports of wild populations ofC. betacea in southern Bolivia and northwestern Argentina. Wild species ofCyphomandra such asC. hartwegii, C. sibundoyensis, andC. cajanumensis also produce edible fruits. Other species ofCyphomandra are used in medicinal preparations and as dyes. This group of plants is of increasing economic importance and may have considerable potential for future exploitation.  相似文献   

13.
14.
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   

15.
16.
Two species are recognized within the genus,H. monogyra Torr. & Grayex Gray andH. salsola Torr. & Grayex Gray. Of these, the fall-floweringH. monogyra is monomorphic and unambiguous. The springfloweringH. salsola, however, is polymorphic and contains elements that have often been segregated as distinct species. Examination of character intergradation and interpretation of morphological variation against the evolution and distributional backgrounds indicate that the latter complex is best treated within three varietal taxa:H. salsola var.fasciculata, with wings of the fruiting involucres appressed and spirally arranged;H. salsola var.salsola, with wings emergent and spirally arranged; andH. salsola var.pentalepis, with wings strongly emergent and whorled.  相似文献   

17.
H(Tla) system: Identification of two new loci,H-31 andH-32, and alleles   总被引:2,自引:2,他引:0  
Skin and tumor grafting experiments performed on F1 hybrid mice indicate that theH(Tla) histocompatibility system is composed of at least two genetic loci,H(Tla-1) andH(Tla-2), and that one of these loci,H(Tla-1), has at least three alleles. We suggest thatH(Tla-1) andH(Tla-2) be renamedH-31 andH-32, respectively.  相似文献   

18.
John T. Mickel 《Brittonia》1993,45(3):213-218
The fern genusElaphoglossum is well represented in wet, mountainous regions of Latin America, from which many species have recently been described. Six more new species ofElaphoglossum are reported:E. bryogenes from Ecuador andE. caudulatum, E. diminutum, E. delasotae, E. lellingeri, E. subcordatum, andE. xiphiophorum from Colombia.  相似文献   

19.
The life cycle of the moth,Meskea horor Dyar and its host specificity toSida acuta andS. rhombifolia were investigated. Moths emerge early in the morning and are usually inactive during the day. Feeding by the adults in the field was not observed. However, those in the laboratory fed on flowers ofS. acuta, S. rhombifolia andHibiscus sabdariffa, and drank water or dilute honey solution. Eggs are mainly laid on the underside of leaves. Larvae ofM. horor form galls in the stems ofS. acuta andS. rhombifolia which retard plant growth and flowering. Pupation occurs within the gall. The development time from egg to adult was 192 days and the adults lived for 11 to 14 days. Forty-eight plant species were tested to determine the host range ofM. horor. Adults emerged from seven species of plants in the family Malvaceae and larvae formed galls but died before pupating on a further 17 species.M. horor is considered to have too broad a host range to be used as a biological control agent forS. acuta andS. rhombifolia.  相似文献   

20.
Two African Ceratodontiformes are determined as Lepidosirenidae and they are referred toProtopterus Owen;Protopterus protopteroides (Tabaste) is strictly Cretaceous in age andProtopterus humei (Priem) is recorded in the Cretaceous and in the Paleocene. On the basis of toothplates of intermediate morphology it is assumed that the sisterspecies ofP. humei isP. protopteroides. Some other toothplates indicate that the ancestor of P.humei could beNeoceratodus africanus (Haug). These two Lepidosirenidae were probably living in freshwater, which suggests that the extension of this family to the South America occurred during the Early Cretaceous, before the separation of the two continents.  相似文献   

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