A preliminary study on the distribution pattern of isoflavones in rhizomes of Iris from China and its systematic significance

A comparative isoflavonoid analysis of 22 species of Iris, representing almost all the subgenera, and one species of its allied genus Balamcanda, B. chinensis (L.) DC. was carried out by TLC, with iridin, tectoridin, irigenin, tectorigenin, irisfloretin, dichotomin, wogonin, rhamnazin, apocynin, androsin being used as authentic compounds. The results show that the isoflavones are the characteristic constituents of Iris and Belamcanda. According to the distribution pattern of isoflavones, the Iris species here studied can be divided into 2 groups; one contains isoflavonoid aglycons, while the other contains both glycosides and isoflavonoid aglycons. From the point view of chemosystematics, subgen. Limniris contains isoflavonoid aglycons only and might be a natural group; subgen. Crossiris might be also a natural group when Iris speculatrix Hance is excluded; subgen. Pardanthopsis is similar to B. chinensis in the chemical constituent might be a primitive group in Iris and has close relationship with subgen. Crossiris, subgen. Xyridion and subgen. Iris. Based on the evidence from phytochemistry, palynology and cytology, Iris cathayensis Migo and I. mandshurica Pall. are considered intermediate groups between subgen. Limniris and subgen. Iris and I. speculatrix Hance an intermediate group between subgen. Limniris and subgen.Crossiris, while I. confusa Sealy and I. wattii Baker might be conspecific.     

中国鸢尾属植物根茎中异黄酮类成分分布的初步研究及其系统学意义

本文对鸢尾属Iris 22个种(基本上包括了各个亚属的代表)及其近缘属植物射干属Belamcanda的 射干 B．chinensis(L．)DC．进行了根茎的异黄酮类成分的比较分析研究。结果表明,鸢尾属植物和射干 中普遍具有异黄酮类成分,这是它们的特征性成分之一。根据化学成分的特征,鸢尾属可以分为两大类 群：只含异黄酮甙元的类群和既含异黄酮甙又含甙元的类群。从化学成分的分布特征来看,无附属物亚 属subgen．Limniris只含异黄酮甙元,是一个比较自然的类群。鸡冠状附属物亚属subgen．Crossiris,除小 花鸢尾 I．speculatrix Hance外,是一个较自然的类群。野鸢尾亚属subgen．Pardanthopsis和射干属的成分 非常相似,有着密切的亲缘关系,是鸢尾属中原始的类群。从化学成分特征来看,野鸢尾亚属与琴瓣鸢 尾亚属subgen．Xyridion、鸡冠状附属物亚属、须毛状附属物亚属subgen．Iris都有着一定的联系。根据化 学成分、孢粉学、细胞学等特征,认为：华夏鸢尾I．cathayensis Migo和长白鸢尾I．mandshurica Maxim．为无附属物亚属与须毛状附属物亚属两亚属之间的过渡类型。小花鸢尾是无附属物亚属向鸡冠状附属物亚属过渡的中间类型。扁竹兰I．confusa Sealy和扇形鸢尾I．wattii Baker可能是同一个种。     

Molecular phylogeny and systematic in the genus Brachycaudus (Homoptera: Aphididae): insights from a combined analysis of nuclear and mitochondrial genes

Phylogenetic relationships among members of the Aphid genus Brachycaudus (Homoptera: Aphididae) were inferred from partial sequences of mitochondrial cytochrome B oxidase (CytB), two partial fragments of mitochondrial cytochrome C oxidase subunit I (COI) and the internal transcribed spacer II (ITS2) of ribosomal DNA. Twenty-nine species, with several specimens per species, were included, representing all the historically recognized species-groups and subgenera used in the genus except the monospecific subgenus Mordvilkomemor. Results indicate that the genus Brachycaudus is a well-supported monophyletic group. While our results validate the monophyly of subgenera Thuleaphis , Appelia and Brachycaudus s. str. , they reveal two discrepancies in the classical taxonomy. First, the monotypic subgenus Nevskyaphis does not appear valid. Second, the traditionally defined Acaudus subgenus is not monophyletic. On the other hand, our phylogenetic trees corroborate Andreev's recent definition of Acaudus and Brachycaudina. However, they clearly show that the subgenera Prunaphis , Nevskyaphis and Scrophulaphis as defined by this author do not form monophyletic groups. Our results also highlight a highly supported clade that has not been discussed by previous authors; this clade could form a new subgenus, the subgenus Nevskyaphis . Finally, our study shows that molecular data and morphology meet the same limits in delimiting species groups and species themselves. Species groups in which taxonomic treatment is difficult are polytomous. Furthermore, except for one node clustering Brachycaudus s. str . and Appelia, intersubgeneric relationships remain poorly resolved even when several genes are added to the phylogenetic analysis. These results, together with previous studies in other aphid groups suggest that diversification might have been a rapid process in aphids.     

A cladistic study of Arillastrum, Angophora and Eucalyptus (Myrtaceae)

A cladistic study of Anllastrum, Angophora and Eucalyptus (Myrtaceae). Transformed cladistic; character compatibility; branch and bound, and Farris-Wagner methods gave similar solutions in a cladistic study of Arillastrum, Angophora and Eucalyptus. These analyses, based on morphological characters, indicate that Eucalyptus is a monophyletic group and that its sister taxon is Angophora.
Within Eucalyptus , subgenera Blakella and Corymbia are sister taxa to all other groups; subgenera Monocalyptus, Idiogenes and Gaubaea form a monophyletic group with subgenus Monocalyptus sister to subgenera Idiogenes and Gaubaea ; subgenera Symphyomyrtus and Telocalyptus together also form a monophyletic group and, with Eucalyptus similis (subgenus Eudesmia group 4), are sister to the Monocalyptus group. Eucalyptus subgenus Telocalyptus (4 species), Eucalyptus subgenus Idiogenes (1 species) and Eucalyptus subgenus Gaubaea (2 species) should not be recognized as subgenera and some individual species need further examination. Eucalyptus subgenus Eudesmia is a paraphyletic group.
Some characters are identified as parallelisms, e.g. axillary inflorescences, sepaline operculum, bristle glands, and clustered anthers. A more congruent interpretation of the single operculum of Eucalyptus subgenus Monocalyptus as at least partly petaline rather than solely sepaline in origin is suggested.
The area relationships for the taxa are concordant with those derived from geological and climatological information. New Caledonia is sister area to Australia, and within Australia southwestern Australia is sister area to south-eastern and north-eastern Australia.     

Phylogenetic relationships within Plantago (Plantaginaceae): evidence from nuclear ribosomal ITS and plastid trnL-F sequence data

A molecular phylogenetic study of Plantago L. (Plantaginaceae) analysed nucleotide variation in the internal transcribed spacers (ITS) of nuclear ribosomal and plastid trnL-F regions. Included are 57 Plantago species, with two Aragoa species as the ingroup and three Veronica species as the outgroup. Phylogenetic analysis using maximum parsimony identified five major clades, corresponding to the taxonomic groups Plantago subgenera Plantago, Coronopus, Psyllium, Littorella and Bougueria . Aragoa is sister to genus Plantago . Plantago subgenus Littorella is sister to the other subgenera of Plantago . The results are in general correlated with a morphological phylogenetic study and iridoid glucoside patterns, but Plantago subgenus Albicans is paraphyletic and should be included in Plantago subgenus Psyllium sensu lato to obtain a monophyletic clade with six sections. Plantago section Hymenopsyllium is more closely related to section Gnaphaloides than to section Albicans . Plantago subgenus Bougueria is sister to subgenus Psyllium s.l. section Coronopus in Plantago subgenus Coronopus is subdivided in two series. Only some of the sections can be resolved into series. DNA variation within genus Plantago is high, a result that would not have been predicted on the basis of morphology, which is relatively stereotyped. If we calibrate a molecular clock based on the divergence of P. stauntoni , endemic to New Amsterdam in the southern Indian Ocean, we calculate the time of the split between Plantago and Aragoa to be 7.1 million years ago, which is congruent with the fossil record.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 323–338.     

Molecular phylogeny of Incarvillea (Bignoniaceae) based on ITS and trnL-F sequences

Incarvillea is a herbaceous and temperate member of Bignoniaceae, previously divided into four subgenera, Niedzwedzkia, Amphicome, Incarvillea, and Pteroscleris. Niedzwedzkia and Amphicome have in the past been treated as independent genera. Different relationships have been proposed for the four subgenera. Here, maximum parsimony analysis using ITS and trnL-F sequences resulted in similar trees and showed that the genus is monophyletic. Analysis of the combined data resulted in a single tree with five major clades highly supported and well resolved. The relationships of the five major clades are (subgenus Niedzwedzkia (Incarvillea olgae (subgenus Amphicome (subgenus Incarvillea, subgenus Pteroscleris)))). All four subgenera are well supported for monophyly, with the exception of subgenus Incarvillea, represented here by I. sinensis and I. olgae. Incarvillea olgae is not closely related to I. sinensis, a conclusion supported by morphology. The two basal monotypic subgenera are found in Central Asia. The most species-rich subgenus, Pteroscleris, has 10 species in the Himalaya-Hengduan Mountains and may have dispersed early from central Asia to eastern Asia. Short branch lengths on the molecular trees within Pteroscleris suggest a recent and rapid radiation of this rosette-forming subgenus, perhaps connected with the uplift of the Himalaya-Hengduan massif.     

Phylogeny of Drosophila and related genera: conflict between molecular and anatomical analyses

Drosophila species are extensively used in biological research; yet, important phylogenetic relationships within the genus and with related genera remain unresolved. The combined data for three genes (Adh, Sod, and Gpdh) statistically resolves outstanding issues. We define the genus Drosophila inclusively so as to include Scaptomyza and Zaprionus (considered distinct genera in the taxonomy of Wheeler, 1981) but excluding Scaptodrosophila. The genus Drosophila so defined is monophyletic. The subgenus Sophophora (including the melanogaster, obscura, and willistoni groups) is monophyletic and the sister clade to all other Drosophila subgenera. The Hawaiian Drosophila (including Scaptomyza) is a monophyletic group, but the subgenus Drosophila is not monophyletic, because the immigrans group is more closely related to the subgenus Hirtodrosophila than to other species of the subgenus Drosophila, such as the virilis and repleta groups.     

Phylogeny of Geomydoecus and Thomomydoecus pocket gopher lice (Phthiraptera: Trichodectidae) inferred from cladistic analysis of adult and first instar morphology

The phylogeny for all 122 species and subspecies of chewing lice of the genera Geomydoecus and Thomomydoecus (Phthiraptera: Trichodectidae) hosted by pocket gophers (Rodentia: Geomyidae) is estimated by a cladistic analysis of fifty-eight morphological characters obtained from adults and first instars. The data set has considerable homoplasy, but still contains phylogenetic information. The phylogeny obtained is moderately resolved and, with some notable exceptions, supports the species complexes proposed by Hellenthal and Price over the the last two decades. The subgenera G. (Thaelerius) and T. (Thomomydoecus) are both shown to be monophyletic, but the monophly of subgenus T. (Jamespattonius) could not be confirmed, perhaps due to the lack of first-instar data for one of its component species. The nominate subgenus of Geomydoecus may be monophyletic, but our cladogram was insufficiently resolved to corroborate this. Mapping the pocket gopher hosts onto the phylogeny reveals a consistent pattern of louse clades being restricted to particular genera or subgenera of gophers, but the history of the host-parasite association appears complex and will require considerable effort to resolve.     

Phylogeny and infrageneric classification of Symplocos (Symplocaceae) inferred from DNA sequence data

Symplocos comprises ～300 species of woody flowering plants with a disjunct distribution between the warm-temperate to tropical regions of eastern Asia and the Americas. Phylogenetic analyses of 111 species of Symplocos based on the nuclear ribosomal internal transcribed spacer (ITS) region and the chloroplast genes rpl16, matK, and trnL-trnF yielded topologies in which only one of the four traditionally recognized subgenera (Epigenia; Neotropics) is monophyletic. Section Cordyloblaste (subgenus Symplocos; eastern Asia) is monophyletic and sister to a group comprising all other samples of Symplocos. Section Palura (subgenus Hopea; eastern Asia) is sister to a group comprising all other samples of Symplocos except those of section Cordyloblaste. Symplocos wikstroemiifolia (eastern Asia) and S. tinctoria (southeastern United States), both of subgenus Hopea, form a clade that groups with S. longipes (tropical North America) and the species of subgenus Epigenia. The remaining samples of subgenus Hopea (eastern Asia) form a clade. Section Neosymplocos (subgenus Microsymplocos; Neotropics) is well nested within a clade otherwise comprising the samples of section Symplocastrum (subgenus Symplocos; Neotropics). Section Urbaniocharis (subgenus Microsymplocos; Antilles) groups as sister to the clade comprising Symplocastrum and Neosymplocos. The data support the independent evolution of deciduousness among section Palura and S. tinctoria. The early initial divergence of sections Cordyloblaste and Palura from the main group warrants their recognition at taxonomic levels higher than those at which they are currently placed. An inferred eastern Asian origin for Symplocos with subsequent dispersal to the Americas is consistent with patterns from other phylogenetic studies of eastern Asian-American disjunct plant groups but contrary to a North American origin inferred from the earliest fossil occurrences of the genus.     

Phylogeny of Rubus (rosaceae) based on nuclear ribosomal DNA internal transcribed spacer region sequences

We used nuclear ribosomal DNA internal transcribed spacer region (ITS 1 - 5.8S - ITS 2; ITS) sequences to generate the first phylogeny of Rubus based on a large, molecular data set. We sampled 57 taxa including 20 species of subgenus Rubus (blackberries), one to seven species from each of the remaining 11 subgenera, and the monotypic and closely related Dalibarda. In Rubus, ITS sequences are most informative among subgenera, and variability is low between closely related species. Parsimony analysis indicates that Rubus plus Dalibarda form a strongly supported clade, and D. repens may nest within Rubus. Of the subgenera with more than one species sampled, only subgenus Orobatus appears monophyletic. Three large clades are strongly supported: one contains all sampled species of nine of the 12 subgenera; another includes extreme Southern Hemisphere species of subgenera Comaropsis, Dalibarda, and Lampobatus; and a third clade consists of subgenus Rubus plus R. alpinus of subgenus Lampobatus. Rubus ursinus appears to be a hybrid between a close relative of R. macraei (subgenus Idaeobatus, raspberries) and an unidentified subgenus Rubus species. ITS sequences are generally consistent with biogeography and ploidy, but traditionally important morphological characters, such as stem armature and leaf type, appear to have limited phylogenetic value in Rubus.     

Molecular phylogenetics of the genus Ceratitis (Diptera: Tephritidae)

The Afrotropical fruit fly genus Ceratitis MacLeay is an economically important group that comprises over 89 species, subdivided into six subgenera. Cladistic analyses of morphological and host use characters have produced several phylogenetic hypotheses for the genus. Only monophyly of the subgenera Pardalaspis and Ceratitis (sensu stricto) and polyphyly of the subgenus Ceratalaspis are common to all of these phylogenies. In this study, the hypotheses developed from morphological and host use characters are tested using gene trees produced from DNA sequence data of two mitochondrial genes (cytochrome oxidase I and NADH-dehydrogenase subunit 6) and a nuclear gene (period). Comparison of gene trees indicates the following relationships: the subgenus Pardalaspis is monophyletic, subsection A of the subgenus Pterandrus is monophyletic, the subgenus Pterandrus may be either paraphyletic or polyphyletic, the subgenus Ceratalaspis is polyphyletic, and the subgenus Ceratitis s. s. might not be monophyletic. In addition, the genera Ceratitis and Trirhithrum do not form reciprocally monophyletic clades in the gene trees. Although the data statistically reject monophyly for Trirhithrum under the Shimodaira-Hasegawa test, they do not reject monophyly of Ceratitis.     

Phylogeny of Oriental voles (Rodentia: Muridae: Arvicolinae): molecular and morphological evidence

The systematics of Oriental voles remains controversial despite numerous previous studies. In this study, we explore the systematics of all species of Oriental voles, except Eothenomys wardi, using a combination of DNA sequences and morphological data. Our molecular phylogeny, based on two mitochondrial genes (COI and cyt b), resolves the Oriental voles as a monophyletic group with strong support. Four distinct lineages are resolved: Eothenomys, Anteliomys, Caryomys, and the new subgenus Ermites. Based on morphology, we consider Caryomys and Eothenomys to be valid genera. Eothenomys, Anteliomys, and Ermites are subgenera of Eothenomys. The molecular phylogeny resolves subgenera Anteliomys and Ermites as sister taxa. Subgenus Eothenomys is sister to the clade Anteliomys + Ermites. Caryomys is the sister group to genus Eothenomys. Further, the subspecies E. custos hintoni and E. chinensis tarquinius do not cluster with E. custos custos and E. chinensis chinensis, respectively, and the former two taxa are elevated to species level and assigned to the new subgenus Ermites.     

Molecular phylogeny of the palm genus Chamaedorea, based on the low-copy nuclear genes PRK and RPB2

Sequence data from the low-copy nuclear genes encoding phosphoribulokinase (PRK) and the second largest subunit of RNA polymerase II (RPB2) are used to generate the first phylogenetic analysis of Chamaedorea (Arecaceae: Arecoideae: Chamaedoreeae), the largest neotropical genus of palms. The prevailing current taxonomy of Chamaedorea recognizes approximately 100 species in eight subgenera, all delimited using floral characters, which provide a useful starting point to explore species-level systematics. Sequence data from 63 species, including representatives of all eight subgenera, were analyzed using maximum parsimony and Bayesian inference optimality criteria. Genus Chamaedorea is resolved as monophyletic with strong support in all separate and combined analyses. The less species-rich subgenera are convincingly monophyletic and can be diagnosed using morphological synapomorphies. In contrast, the two largest subgenera, Chamaedorea and Chamaedoropsis, which are supposedly distinguishable from each other by the degree of connation in the staminate petals, are both resolved as highly polyphyletic. Several well supported monophyletic groups resolved by these gene regions have never before been proposed within Chamaedorea and are challenging to delimit using morphological criteria. Although PRK proved more informative than RPB2, both regions have strong utility for interpreting species-level relationships among the palms, which are notoriously recalcitrant subjects for molecular phylogenetic studies. In addition, a paralog of the target copy of PRK identified during the analysis represents a potentially valuable source of phylogenetic information for future studies.     

Phylogenetic relationships among Bactrocera species (Diptera: Tephritidae) inferred from mitochondrial DNA sequences

Several members of the dipteran family Tephritdae are serious pests because females lay eggs in ripening fruit. The genus Bactrocera is one of the largest within the family with over 500 described species arranged in 28 subgenera. The phylogenetic relationships among the various species and subgenera, and the monophyly of specific groups have not been examined using a rigorous phylogenetic analysis. Therefore, phylogenetic relationships among 24 Bactrocera species belonging to 9 subgenera were inferred from DNA sequence of portions of the mitochondrial 16S rRNA, cytochrome oxidase II, tRNA(Lys), and tRNA(Asp) genes. Two morphological characters that traditionally have been used to define the four groups within the subgenus Bactrocera were evaluated in a phylogenetic context by mapping the character states onto the parsimony tree. In addition, the evolutionary trend in male-lure response was evaluated in a phylogenetic context. Maximum parsimony analyses suggested the following relationships: (1) the genus Bactrocera is monophyletic, (2) the subgenus B. (Zeugodacus) is paraphyletic, (3) the subgenus B. (Daculus) is a sister group to subgenus B. (Bactrocera), and (4) the subgenus B. (Bactrocera) is monophyletic. The mapping analyses suggested that the morphological characters exhibit a simple evolutionary transition from one character state to another. Male-lure response was identified as being a labile behavior that has been lost on multiple occasions. Cue-lure response was plesiomorphic to methyl-eugenol response, and the latter has evolved independently within the Bactrocera and Zeugodacus groups of subgenera. The implications of our results for devising a coherent, consolidated classification for Bactrocera is discussed.     

Chloroplast-DNA restriction site analysis in the genus Bromus (Poaceae)

Chloroplast DNA (cpDNA) restriction site variation was examined in 32 species, representing five subgenera, of Bromus (Poaceae). Thirty-seven phylogenetically informative restriction sites were detected. Cladistic analysis of the restriction site data produced a single most-parsimonious tree of 50 steps. The cladogram indicated two major clades within the genus. One clade included B. trinii of subgenus Neobromus and species of subgenus Ceratochloa. The other was composed of subgenera Festucaria, Stenobromus, and Bromus. Within the second clade, species of subgenus Festucaria appeared in three lineages. The second clade also contained an assemblage of species belonging to subgenera Stenobromus and Bromus in a separate lineage. There was very little resolution of relationships in this assemblage since several species appeared individually in separate lineages. The cpDNA phylogenetic hypothesis did not separate species of subgenera Stenobromus and Bromus into well-defined clades as circumscribed by morphology and cytogenetics. The cpDNA tree is in agreement with the phylogenetic scheme based on traditional data in that: 1) subgenera Neobromus and Ceratochloa were the first to diverge, while Bromus and Stenobromus diverged later; 2) within the genus Bromus species with small chromosomes are ancestral; and 3) subgenera Bromus and Stenobromus probably originated from similar ancestors as Festucaria. The tree based on cpDNA data does not support that: 1) subgenera Neobromus and Ceratochloa did not have a common origin; 2) subgenus Festucaria is monophyletic; and 3) subgenera Stenobromus and Bromus are distinct entities. The mean nucleotide sequence divergence values between pairs of subgenera ranged from p = 0.0 to 0.9. These values suggest that cpDNA evolution in Bromus is slow.     

Molecular phylogeny of the snubnose darters, subgenus Ulocentra (genus Etheostoma, family Percidae)

Snubnose darters comprise one of the largest subgenera of the percid genus Etheostoma. Many species are described based on differences in male breeding coloration. Few morphological synapomorphies have been proposed for the subgenus and their relatives, making it difficult to delineate monophyletic clades. The phylogenetic relationships of the 20 snubnose darter species of the subgenus Ulocentra and 11 members of its proposed sister subgenus Etheostoma were investigated with partial mitochondrial DNA sequences including 1033 bp encompassing the entire mitochondrial control region, the tRNA-Phe gene, and part of the 12S rRNA gene. Two hypotheses on the relationship and monophyly of the two subgenera were evaluated. Both maximum-parsimony and neighbor-joining analyses supported monophyly of the subgenus Ulocentra and resolved some species-level relationships. The banded darter, E. zonale, and its sister taxon, E. lynceum, were not closely related to the snubnose darters and appear to be diverged from the other members of the subgenus Etheostoma, fitting their former distinction as the recognized subgenus Nanostoma. The sister group to Ulocentra appears to be a restricted species assemblage within the subgenus Etheostoma containing E. blennioides, E. rupestre, E. blennius, and the E. thalassinum species group. The placement of the harlequin darter, E. histrio, is problematic, and it may represent a basal member of Ulocentra or of the restricted subgenus Etheostoma. Despite recent estimates of divergence times between nominal Ulocentra taxa, each species exhibits its own unique set of mtDNA haplotypes, providing no direct evidence for current genetic exchange between species. The nominal taxa of snubnose darters thus appear to be evolving independently from each other and therefore constitute valid species under the Phylogenetic Species Concept.     

Molecular phylogeny of the genus Ceanothus (Rhamnaceae) using rbc L and ndh F sequences

 Intrageneric phylogeny among ten representative Ceanothus species was investigated using DNA sequences of the chloroplast encoded ndhF and rbcL genes. Parsimony analysis of the ndhF sequences identified two main clades corresponding to two subgenera Ceanothus and Cerastes. The phylogenetic results suggest that three monophyletic clades within the subgenus Ceanothus can be delimited on the basis of (1) evergreen or (2) deciduous leaves and (3) thorn presence within the evergreen clade. The estimated divergence time based on rbcL sequences suggests that the two subgenera diverged 18–39 million years ago whereas species within each subgenus diverged more recently. Taken together, the results support the division of Ceanothus into two monophyletic subgenera and are consistent with the postulated recent divergence of many species within each subgenus. Received: 25 September 1996/Accepted: 8 November 1996     

Phylogenetic relationships among bumble bees (Bombus, latreille) inferred from mitochondrial cytochrome b and cytochrome oxidase I sequences

We conducted a molecular study intending to derive an estimate of the relationships within the genus Bombus (bumble bees) by comparing the mitochondrial cytochrome b and cytochrome oxidase I (COI) genes from 19 species, spanning 10 of approximately 16 European subgenera and 3 subgenera from North and South America. Our trees differ from the most recent classifications of bumble bees. Although bootstrap values for deep branches are low, our sequences show significant data structure and low homoplasy, and all trees share some groups and patterns. In all cases, the subgenus Bombus s. str. clusters among the most derived bumble bees, contrary to other molecular studies. In all trees, B. funebris is the sister taxon of B. robustus, and in five of the six trees, B. wurflenii is the sister taxon to this clade. B. nevadensis is basal to the other species in the analysis of the cytochrome b gene, but appears to be among the most derived according to the analysis of the COI region. The species representing the subgenera Thoracobombus and Fervidobombus are consistently among the earliest diverged. Species that appear in very different positions in different trees are B. nevadensis, B. mesomelas, B. balteatus, and B. hyperboreus. All subgenera with two representatives in our analysis are apparently monophyletic except Fervidobombus, Melanobombus, and Pyrobombus. The groups formed by pocket makers and non-pocket makers within Bombus also appear to be paraphyletic, and therefore some subgenera may not accurately reflect phylogeny.     

Molecular phylogenetics of Acacia (Fabaceae: Mimosoideae) based on the chloroplast MATK coding sequence and flanking TRNK intron spacer regions

The tribe Acacieae (Fabaceae: Mimosoideae) contains two genera, the monotypic African Faidherbia and the pantropical Acacia, which comprise about 1200 species with over 950 confined to Australia. As currently recognized, the genus Acacia is subdivided into three subgenera: subg. Acacia, subg. Aculeiferum, and the predominantly Australian subg. Phyllodineae. Morphological studies have suggested the tribe Acacieae and genus Acacia are artificial and have a close affinity to the tribe Ingeae. Based on available data there is no consensus on whether Acacia should be subdivided. Sequence analysis of the chloroplast trnK intron, including the matK coding region and flanking noncoding regions, indicate that neither the tribe Acacieae nor the genus Acacia are monophyletic. Two subgenera are monophyletic; section Filicinae of subgenus Aculeiferum does not group with taxa of the subgenus. Section Filicinae, eight Ingeae genera, and Faidherbia form a weakly supported paraphyletic grade with respect to subg. Phyllodineae. Acacia subg. Aculeiferum (s. s.) is sister to the grade. These data suggest that characters currently used to differentiate taxa at the tribal, generic, and subgeneric levels are polymorphic and homoplasious in cladistic analyses.