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1.
Scanning electron microscope and light microscope examination of seed-coat features of 26 species of Orthocarpus have allowed recognition of many species-level differences (summarized in a key) and of three seed-coat types that parallel taxonomic subgroups but support realignments at generic and infrageneric levels. Type 1 seeds (subg. Orthocarpus, sect. Orthocarpus) have a lateral hilum, sculptured inner tangential seed-coat walls, and a tightly fitting outer seed coat. They are very similar to seeds of Cordylanthus. Seeds of Types 2 and 3 have a terminal hilum and membranous inner tangential cell walls. Type 2 seeds (subg. Orthocarpus, sects. Castillejoides and Cordylanthoides, with one exception) have a net-like, loosely fitting outer seed coat that shows close relationship to seeds of Castilleja. Inner tangential walls of Type 2 seeds normally rupture. Type 3 seeds (subg. Triphysaria, with two exceptions) have a tightly fitting outer seed coat and inner tangential walls are always retained. Seed features support evidence from floral morphology and chromosome numbers that Orthocarpus as currently recognized is not a monophyletic lineage. 相似文献
2.
Jan Kirschner Lázaro J. Novara Vladimir S. Novikov Sven Snogerup Zdeněk Kaplan 《Folia Geobotanica》1999,34(3):377-390
A new classification of the genusJuncus (Juncaceae) is presented. The genus is divided into two subgenera, characterized by the presence/absence of bracteoles and the structure of inflorescence. Lower rank subdivisions, sections, generally correspond to the traditionally recognized subgenera introduced by Buchenau. A new name is introduced for what has been called subg. (sect.)Ensifolii, Juncus sect.Iridifolii. A checklist of supraspecific names inJuncus, with typification and references to the sectional names accepted, is presented in the Appendix. 相似文献
3.
The systematics of the aquatic fern genusAzolla
Lam. is revised at the supraspecific level. Published morphological data are reviewed, and cytological and cladistic analyses of the genus conducted, enabling a discussion of the putative evolutionary trends in the genus, and a revision of the current taxonomy. A phylogenetically more acceptable subgeneric and sectional classification is proposed, viz. subg.Azolla sect.Azolla (comprisingA. filiculoides
Lam.,A. rubra
R. Br.,A caroliniana auct. nonWilld.,A. microphylla auct. nonKaulf. andA. mexicana
Presl), subg.Azolla sect.Rhizosperma (Mey.)Mett. (comprisingA. pinnata
R. Br.), and subg.Tetrasporocarpia subg. nov. (comprisingA. nilotica
Decne. exMett.). 相似文献
4.
Pollen morphology of 14 species of Collomia (Polemoniaceae) was examined by light microscopy, and by both scanning and transmission electron microscopy. Four distinct pollen types were observed which are based principally upon 1) shape, number and distribution of apertures, and 2) surface sculpturing: Type 1—zonocolporate with striate ridges; Type 2—zonocolporate with striato-reticulate ridges; Type 3—pantoporate with radiate ridges; Type 4—pantoporate with irregularly reticulate ridges. Evaluation of pollen morphology reveals considerable discrepancy with respect to presently accepted sectional classification. Collomia grandiflora of sect. Collomia has a pollen type similar to that of members of sect. Collomiastrum and is now interpreted as representing an independent evolutionary line derived from the latter section. Collomia diversifolia of sect. Courtoisia has a pollen morphology similar to that of sect. Collomia. whereas C. heterophylla of the same section possesses pollen unique within the genus. This last pollen type shows close similarity to the pollen of members of Polemonium, Gilia, Leptodactylon, and Ipomopsis. Pollen of C. tinctoria and C. tracyi of sect. Collomia are anomalous within Polemoniaceae. No significant difference in exine stratification was discernible among the four pollen types. 相似文献
5.
Phylogenetic relationships within Euphorbiinae were inferred from our analysis of the 3′; end of the chloroplast gene ndhF.
A sampling of that subtribe covered 88 species; 3 closely related species from the subtribes Anthosteminae and Neoguillauminiinae
and the tiribe Hippomaneae were included as outgroups. A phylogenetic assessment was carried out using the parsimony approach.
The relationships revealed via these ndhF data supported the monophyly of subg.Esula, subg.Chamaesyce, subg.Euphorbia, and subg.Lacanthis. However, the polyphyly of subg.Agaloma, subg.Lyciopsis, and subg.Eremophyton also was strongly suggested. The African succulent Euphorbiinae can be divided into primarily two independent groups: 1)
spiny succulents, which form a strongly supported clade with three subclades (subg.Euphorbia, subg.Lacanthis, andMonadenium+Synadenium); and 2) non-spiny succulents, which consist of sect.Meleuphorbia, sect.Medusae, sect.Anthacantha, sect.Trichadenia, sect.Pseudeuphorbium, sect.Treisia, and sect.Pseudacalypha. In the ndhF tree, the subg.Esula clade is placed as a sister to the rest of the Euphorbiinae. Thus, the origin of theEuphorbia s.I. should be sought within the herbaceous species of subg.Esula. The core North American endemicEuphorbia groups --Agaloma, Chamaesyce, andPoinsettia — are monophyletic and independent of the South American subg.Agaloma. Instead, they are derived from the AfricanEuphorbia subg.Lyciopsis andEremophyton. The Eurasian subg.Esula clade forms two subclades, which are concordant to sect.Esula and sect.Tithymalus. 相似文献
6.
Chloroplast DNA restriction site variation was studied in 31 New World species ofIpomoea, representing a majority of the New World sections and series within the genus. Using 14 endonucleases, a total of 124 phylogenetically informative restriction sites was detected. Dollo parsimony, Wagner parsimony, and bootstrap methods were employed to construct phylogenetic trees and evaluate confidence intervals of monophyletic groups. With a few exceptions, groups circumscribed on the basis of morphological variation are in agreement with groupings based on restriction site variation. Relationships between subgeneric groupings, however, disagree substantially with those proposed in the past. Although conflicting hypotheses for some intersectional relationships are not presently resolvable, cpDNA restriction site analyses propose the following refinements of existing classification schemes.Ipomoea ser.Setosae is divided into distantly related groups, as is sect.Pharbitis. SeriesTyrianthinae, a proposed segregate of sect.Pharbitis, is associated with sect.Calonyction and the Tricolor complex (subg.Quamoclit).Ipomoea sect.Batatas is segregated from other herbaceous groups of the heterogeneous subg.Quamoclit sensu lato and aligned as a derivative ofI. setosa, subg.Eriospermum. To test for homology of key characters weighted in traditional schemes, morphological features were studied with respect to their distribution on lineages defined by restriction site data. Characters such as setose sepals, foliose-pubescent sepals, and erect growth habit, among others, are interpreted as having multiple origins, while 3-locular ovaries, 4-locular ovaries, and long-haired seeds have evolved only once. 相似文献
7.
AbstractAllium is taxonomically a difficult genus with blurred taxonomic borders at all taxonomic ranks. In this research, anatomy and morphology of bulb tunics in 42 species of the genus representing its 16 currently recognized sections and 6 subgenera (Allium, Cepa, Reticulatobulbosa, Amerallium, Polyprason and Melanocrommyum) were investigated. Our results indicated the following characters to be most informative at sectional and subgeneric levels: features of calcium oxalate crystals and subepidermal cell layer of the outermost bulb tunic, type of tracheids, and bulbils presence. Three main types of crystals, i.e. prismatic, sand and druses, were fairly common among the investigated species except for the members of A. sect. Acanthoprason (A. subg. Melanocrommyum) that often lack crystals. The subepidermal layers of outer tunics were mostly composed of hexagonal, rectangular, or elongated cells but A. paradoxum (A. subg. Amerallium, sect. Briseis) showed the pentagonal type and A. longisepalum (A. subg. Amerallium, sect. Molium) the elliptic type of subepidermal cells. The members of A. sub. Melanocrommyum showed various types of tunic cells and crystals. 相似文献
8.
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
9.
Evolutionary variation of aspartate aminotransferase and superoxide dismutase isoenzymes in 14 wild and cultivated species ofPhaseolus andVigna has been studied by electrophoresis and isoelectric focusing in polyacrylamide gel. The American cultivated beans of the genusPhaseolus s. str.,P. vulgaris, P. coccineus, P. lunatus andP. acutifolius, form a homogeneous group with only minor isoenzyme variation. The genusVigna, on the contrary, proves to be heterogeneous in isozyme characters. Several clusters of taxa can be distinguished in close correspondence with modern treatments of the genus. The isoenzyme data support the inclusion of the Asian Azuki beans of subg.Ceratotropis inVigna, but argue against the transfer of the S. American speciesP. adenantha. The cowpea complexV. unguiculata s. lato of sect.Catiang forms an uniform and isolated group, distinct from other sections of subg.Vigna, and shows affinity toPhaseolus s. str. by some isoenzymes. It is suggested to removeV. unguiculata s. lato from subg.Vigna and to recognize it as a separate subg.Catiang (DC.)Jaaska & Jaaska, stat. nov. 相似文献
10.
Elvira Hörandl Khatere Emadzade 《Perspectives in Plant Ecology, Evolution and Systematics》2012,14(4):310-324
Evolutionary classification attempts to integrate information on shared ancestry, evolutionary process and phenetic information into the taxonomic concept. Here we exemplify this concept on the monophyletic, species-rich and cosmopolitan plant genus Ranunculus. Previous classifications have rendered almost all traditional sections as polyphyletic, and a modern revision based on phylogenetic principles was so far lacking. Maximum parsimony and Bayesian inference analysis of a combined nuclear (ITS of nrDNA) and plastid DNA dataset (matK/trnK, and psbJ–petA) provided a phylogenetic framework for the genus with nine well-supported subclades. Neighbor Net analysis revealed a reticulate data structure within two subclades with frequent polyploidy and/or hybridization. Character evolution was studied by McClade reconstructions of morphological data mapped on to the molecular tree topology. Morphological characters show a mosaic-like distribution, but express several shared states congruent to molecular clades. A total evidence approach (TE) based on the combined morphological and molecular dataset suggests a subdivision of Ranunculus into a paraphyletic, temperate to arctic group of five subclades (subg. Auricomus), and a temperate to subtropical clade with four subclades (subg. Ranunculus). Infrageneric classification of two subgenera and 17 sections is based on both monophyly s.l. as evident from TE and a minimum of shared morphological characters. Six subclades have shared morphological or karyological features (sects. Auricomus, Flammula, Oreophili, Polyanthemos, Ranunculus, Thora, and Trisecti). One subclade was subdivided into three smaller clades according to morphological data (sects. Epirotes, Leucoranunculus, Ranuncella, Aconitifolii). In the case of reticulate evolution and uncertain ancestry we accept well-supported genetic clusters with shared morphological features, as revealed by Neighbor Net analysis (sections Batrachium, Hecatonia, Pseudadonis). Character evolution connected to ecological shifts characterizes the paraphyletic section Ranunculastrum, the holophyletic section Euromontani (sect. nov.), and the monotypic sect. Echinella. The information content of our classification is compared to alternative concepts. 相似文献
11.
Felipe Wartchow 《Plant biosystems》2020,154(5):700-704
AbstractAmanita is a well established genus corresponding one to the major groups of Agaricales having with a rich systematic story. Several species belonging to this genus were recently reported from Brazil. Recent studies changed drastically its infrageneric classification, recognizing the subgenera Amanita, Amanitina and Lepidella. Within the subg. Amanitina, the ectomycorrhizal species with amyloid basidiospores, appendiculate pileus and stipe base with more globose to subglobose bulb belong to sect. Roanokenses. Amanita xenokommosis belongs to this section and is described here a new species from the Brazilian Coastal Sand Dune. It is characterized by elongate to cylindrical amyloid basidiospores, brown pileus with sharp floccose appendiculate remnants and bulb covered by a large limbate/saccate universal veil. Amanita caojizong, A. manginiana, A. modesta, A. pseudomanginiana and A. pseudoporphyria are similar species, but differ in many aspects, such as basidiospores size, shape of bulb and characteristics of the universal veil. 相似文献
12.
Seed-coat morphology of 14 species of Collomia (Polemoniaceae) was examined with light microscopy and scanning electron microscopy. Two seed types were observed based on surface sulpturing: Type 1—hexagonal epidermal cells forming a shallow reticulum with well-defined cell boundaries; Type 2—longitudinally ridged and irregularly arranged crater-like depressions with inconspicuous cell boundaries. Only two species, C. debilis and C. larsenii of sect. Collomiastrum have seed-coat Type 1. Seed-coat Type 2 is characteristic of all species of sect. Collomia, sect. Courtoisia, and C. mazama, C. rawsoniana of sect. Collomiastrum. The present investigation reveals a fairly homogeneous seed-coat pattern in the genus and does not offer significant information for realignment of infrageneric classification. Anatomical studies with light microscopy show that a mucilaginous seed coat develops from the outermost layer of integument in which each epidermal cell develops spiral secondary wall thickenings. Mucilaginous seeds of most Collomia species probably provide adaptive significance in that adherence of seeds to ground prohibits further dispersal to unfavorable habitats, or epizoochoric dispersal. 相似文献
13.
We examined the phylogeny of the genusRubus in Korea using an internal transcribed spacer (ITS) of the nuclear ribosomal DNA and a trnL-trnF (trnL/F) intergenic region
of the chloroplast DNA. In all, 21 ingroup species (1.2 kb for each species) were analyzed using parsimony, resulting in 672
aligned sequences from ITS, and 502 bases with trnL/F. Individual and combined analysis of ITS and trnL/F data proved that
the genusRubus is a monophyletic group. This phylogeny also substantiated a previous sectional classification scheme rather than a subgerius
classification scheme. However, our results did not support the earlier sectional classification by Focke (sect.Corchorifolii), but did support the sectional classification of Nakai: sect.Crataegifolii (R. crataegifolius, R. takesimensis andR. trifidus), and sect.Villosii (R. corchorifolius). Most of these species, which are found in Korea and belong to subg.Idaeobatus, appeared in two different groups in all data sets. This suggests that this subgenus is a polyphyletic group that has gone
through at least two independent evolutionary processes. The taxa, when mapped onto the combined tree, showed that the occurrence
of their morphological characters of simple and compound leaves was concurrent in KoreanRubus. ITS sequence data were consistent overall with the geographical distribution of each species. Furthermore, the trnL/F sequence
data provided phylogenetic information within closely related species. 相似文献
14.
M. MENDUM P. LASSNIG A. WEBER F. CHRISTIE 《Botanical journal of the Linnean Society. Linnean Society of London》2001,135(3):195-213
The current sectional classification of the genus Aeschynanthus Jack, essentially based on seed morphology, presents some problems of species placement. A comparative SEM survey of seed and seed appendages was undertaken in order to assess the value of this classification. Seeds of 99 taxa (that is about two‐thirds of the estimated total) were examined and found to fall into two types, A and B. Type A has spiral testa cell orientation, papillae formed from a single cell and short smooth appendages. Type B is recognized by the straight orientation of the testa cells, combined with the presence of papillae formed from the raised ends of two adjacent cells on the long hair‐like appendages and usually on the testa. Only six of the investigated species did not fall into either category. Three have straight testa cell orientation combined with single‐cell papillae and short smooth appendages; the papillae and appendage characters place them in type A. Three have spiral testa cell orientation and short smooth appendages but the testa cells have slightly raised ends; these are also placed in Type A. The three subtypes in Type A are equivalent to the sections Haplotrichium s.s., Microtrichium and Aeschynanthus, but the divisions are less clear than those within Type B. However, other morphological characters support sectional separation. Type B subdivides into three: two subtypes equivalent to sections Polytrichium and Diplotrichium, and a third encompassing section Xanthanthos together with part of the current sect. Haplotrichium, and here referred to as sect. X. There is sufficient morphological correlation with seed type to make the sectional position of many species clear without recourse to seed, particularly in sects Polytrichium, Diplotrichium, Haplotrichium S.S. and Aeschynanthus. There is strong correlation between seed type and geographical distribution. Sects. Microtrichium and Aeschynanthus, with Type A seed, are essentially Malesian. Groups with Type B seed are largely confined to mainland south and south‐east Asia, except for sect. Polytrichium which is more widespread, possibly due to the greater effectiveness of a coma of hairs in wind dispersal. It is suggested that Type A seed, probably sect. Microtrichium, is the least determined and Type B sect. Polytrichium the most derived seed type. Based on these findings a revised key to the sections is provided. 相似文献
15.
Phylogenetic relationships in Magnoliaceae subfam. Magnolioideae: a morphological cladistic analysis
Relationships within Magnolioideae have been the subject of persistent debate; the main point at issue mostly being the disposition of tribes, genera and sections. A morphological cladistic analysis of the subfamily using Liriodendron as the out-group showed that Magnolioideae consisted of a large basal polytomy, but with five resolved and variously supported clades. Manglietia constituted a clade with sect. Rytidospermum of Magnolia subg. Magnolia. Kmeria and Woonyoungia formed a pair. Pachylarnax, Parakmeria and Manglietiastrum were grouped together, and sect. Splendentes and Dugandiodendron also formed a pair. The largest and best supported clade consisted of Magnolia subg. Magnolia sects. Oyama and Maingola, Magnolia subg. Yulania, Michelia, Aromadendron, Alcimandra, Elmerrillia, Paramichelia and Tsoongiodendron, with sect. Oyama of Magnolia subg. Magnolia is sister to the remainder. Although Magnolia sect. Maingola, Aromadendron, Alcimandra and Elmerrillia constituted a poorly resolved subclade, Aromadendron formed a monophyletic clade with Alcimandra. Within the Michelia/Magnolia subgen. Yulania subclade, Paramichelia was sister to Tsoongiodendron. These results are supported by similar placement of taxa within various molecular analyses of the family, but the low level of resolution indicates that more morphological data are needed to improve phylogenetic signal. Our results support the molecular analyses in suggesting that Magnolia is best considered to be a large and diverse genus, but that the relationships between the taxa within it require more detailed clarification, with more extensive sampling and a combined molecular and morphological approach being needed. 相似文献
16.
Wolfgang Spethmann 《Plant Systematics and Evolution》1987,157(1-2):9-31
Recent studies have improved the infrageneric classification ofRhododendron, including my own investigations on flavonoids and anthocyanins as chemosystematic markers. From a synoptical comparison of morphological, anatomical and phytochemical characters a new system for the genus is proposed. Phylogenetic character progressions and relationships among subgenera, sections and subsections are discussed and illustrated. Key positions for subg.Candidastrum between chori subgenerumRhododendron andNomazalea, and for subg.Choniastrum between chori subgenerumHymenanthes andNomazalea are suggested. 相似文献
17.
In the present study, seeds of 13 Oxytropis DC. species (including two latest synonyms) classified in subg. Oxytropis (sect. Dolichocarpon, sect. Chrysantha and sect. Eumorpha), subg. Euoxytropis (sect. Orobia) and subg. Phacoxytropis (sect. Protoxytropis, sect. Janthina and sect. Mesogaea) from Turkey were examined using light and scanning electron microscopy to evaluate the taxonomic relevance of macro- and micro-morphological seed characters. As a result of the study, species-specific characters have been determined. Seeds exhibit variation in size, shape, surface sculpturing pattern, hilum position and weight. Seeds ranged from 1.61 to 4.04 mm in length and from 1.02 to 2.56 mm in width. Five different seed shapes were recognised, as prolonged semielliptic, reniform, prolonged reniform, quadratic and cardiform, with a length to width ratio ranging from 1.02 ± 0.08 to 1.75 ± 0.27. Rugulate, rugulate–reticulate and lophate sculpturing patterns were observed in the studied species. According to the results, seed characters, such as the size (length, width and the length/width ratio), the shape, the surface sculpturing and the weight appear to have low taxonomic value in distinguishing subgenera, sections and species. 相似文献
18.
The goal of this study was to review the impact of DNA sequence analyses on our understanding of Cariceae phylogeny, classification
and evolution. To explore character evolution, 105 taxa from four different studies were included in an nrDNA ITS + ETS 1f
analysis of all recognized genera (Carex, Cymophyllus, Kobresia, Schoenoxiphium, Uncinia) and Carex subgenera (Carex, Psyllophora, Vignea, Vigneastra). As in previous analyses, four major Cariceae clades were recovered: (1) a “Core Carex Clade” (subg. Carex, Vigneastra, Psyllophora p.p); (2) A “Vignea Clade” (subg. Vignea, Psyllophora p.p.); (3) a “Schoenoxiphium Clade” (Schoenoxiphium, subg. Psyllophora p.p.), and (4) a “Core Unispicate Clade” (Uncinia, Kobresia, subg. Psyllophora p.p.). All studies provide strong support (86–100% BS) for the Core Carex and Vignea Clades, but only weak to moderate support (<50%–78% BS) for the Core Unispicate and Schoenoxiphium Clades. The relationships of these groups are unresolved. Studies suggest that Carex is either paraphyletic with respect to all Cariceae genera or to all genera except Schoenoxiphium. Kobresia is a grade, but Uncinia and possibly Schoenoxiphium are monophyletic. The monotypic Cymophyllus is indistinct from Carex subg. Psyllophora species. Character analyses indicate that inflorescence proliferation and reduction have occurred in all major clades, and
that the Cariceae’s unisexual flowers have evolved from perfect flowers. The ancestor to Cariceae possessed a multispicate
inflorescence with cladoprophylls and female spikelets with tristigmatic gynoecia and closed utricles. This morphology is
most similar to extant Carex subg. Carex species, which contradicts the nearly unanimous assumption that the highly compound inflorescences of Schoenoxiphium are primitive. Since taxonomic sampling and statistical support for phylogenies have generally been poor, we advocate the
temporary maintenance of the four traditional Carex subgenera with androgynous unispicate species placed within subg. Psyllophora and dioecious and gynaecandrous unispicate species distributed amongst subgenera Carex and Vignea. A collective effort focused on developing new nuclear markers, on increasing taxonomic and geographic sampling, and on studying
development within the context of phylogeny, is needed to develop a phylogenetic classification of Cariceae. 相似文献
19.
Analysis of phylogenetic relationships in the genus Solanum (Solanaceae) as revealed by RAPD markers
Phylogenetic relationships and genetic variation were examined in the genus Solanum based on the random amplified polymorphic DNA (RAPD) technique. Genetic distances were estimated for 42 accessions from five subgenera [Archaesolanum, Minon (Syn. Brevantherum), Leptostemonum, Potatoe, and Solanum]. This investigation provided new information and reinforced some suggestions from previous phylogenetic studies. Analysis with random markers from the total genome clearly separated Solanum sect. Dulcamara, from the other members of Solanum subg. Potatoe, and indicated that among the analysed Solanum subgenera subg. Solanum is most closely related to it. The results suggest that Solanum sect. Dulcamara should be excluded from Solanum subg. Potatoe. The subclusters formed by S. rostratum and S. citrullifolium appear to be distinct from the subcluster formed by the two accessions of S. sisymbriifolium. This topology indicates that Solanum sect. Androceras and Solanum sect. Cryptocarpum are fairly closely related, although the data suggest that the two sections should not be maintained. 相似文献
20.
《Journal of bryology》2013,35(4):465-474
AbstractThe distinguishing features of Lophozia subg. Protolophozia are enumerated. A key is provided for the eleven species of this primarily cool antipodal and subantarctic subgenus. Lophozia gymnocoleopsis Schust. & Engel from southern Chile is described as new. This species and L. crispata, also of southern South America, are the only representatives of subg. Protolophozia in South America. Protolophozia sect. Notolophozia and sect. Gymnocoleopsis Schust. are described as new. 相似文献