| 1. |
|
|
| 2. |
- Andriamihajarivo, Tefy H., et al.
(författare)
-
Phyllopentas flava (Rubiaceae), a New Morphologically Heterodistylous and Functionally Dioecious Species from Madagascar
- 2011
-
Ingår i: Systematic Botany. - 0363-6445 .- 1548-2324. ; 36:4, s. 1024-1027
-
Tidskriftsartikel (refereegranskat)abstract
- A new species of the Afro-Malagasy genus Phyllopentas Karehed & B. Bremer, Phyllopentas flava Razafim., T. Andriam. et Karehed, is described and illustrated. This plant is restricted to the Itremo region in southeastern Madagascar and is distinct morphologically from the other species of the genus by its pubescent, narrowly ovate to narrowly elliptic leaves, grey-whitish and thickly hairy midribs and secondary veins on the lower surfaces of leaves, and functionally dioecious and heterodistylous flowers. Summaries of distribution, phenology, habitat, and ecology are given and a conservation assessment is also provided.
|
|
| 3. |
- Chazot, Nicolas
(författare)
-
Phylogenomics of the Palm Tribe Lepidocaryeae (Calamoideae: Arecaceae) and Description of a New Species of Mauritiella
- 2021
-
Ingår i: Systematic Botany. - 0363-6445 .- 1548-2324. ; 46, s. 863-874
-
Tidskriftsartikel (refereegranskat)abstract
- The palm tribe Lepidocaryeae (Arecaceae) comprises seven genera and 51 currently accepted species that are distributed in lowland tropical forests and savannas across Africa and the Americas. Subtribal relationships within Lepidocaryeae have been a persistent challenge, limiting our understanding of its systematics, morphology, and biogeography. Several aspects make the tribe an ideal system to study plant evolution and diversity: it is well-represented in the fossil record as a prolific pollen producer, its continental diversity contradicts common biodiversity patterns of lower species richness in Africa in comparison to South America, and it contains one of the most abundant Amazonian tree species, Mauritia flexuosa. Here, we investigated the systematics of the tribe by sampling 122 individuals representing 42 species (82% of the tribe), using target sequence capture. We recovered nearly 10,000 single nucleotide polymorphisms from nuclear and plastid DNA across 146 target sequences to separately infer a phylogenomic tree. Our results strongly support inter-generic and inter-specific relationships, where a majority of nodes were resolved with over 90% bootstrap support. We also identify strong phylogenetic support for the recognition of a new species from central and south Amazonia, Mauritiella disticha. The distichous phyllotaxy is diagnostic of the species within the genus. Rare and currently only known from the middle-lower Madeira River basin in the state of Amazonas, Brazil, M. disticha is restricted to open vegetation and forest edges growing in white sand habitats with saturated or well-drained soils. Our preliminary red list assessment suggests its threatened status to be vulnerable (VU). We use our phylogenomic inference to define and contextualize systematic relationships in the tribe, and present a formal species description.
|
|
| 4. |
- Daniel, Thomas F., et al.
(författare)
-
The "Tetramerium Lineage" (Acanthaceae : Acanthoideae : Justicieae) : Delimitation and intra-lineage relationships based on cp and nrITS sequence data
- 2008
-
Ingår i: Systematic Botany. - 0363-6445 .- 1548-2324. ; 33:2, s. 416-436
-
Tidskriftsartikel (refereegranskat)abstract
- We used DNA sequence data from five genic regions (nrITS; chloroplast trnL-F, trnT-L, rps16, trnS-G) to study phylogenetic relationships of the Tetramerium lineage (Acanthaceae: Justicieae). From a sample of 70 species (representing 25 genera) previously affiliated with the Tetramerium lineage, 68 are included therein. Our analyses excluded Papuasian Calycacanthus and Neotropical Streblacanthus monospermus from the Tetramerium lineage; however, two species described in Justicia (J. gonzalezii and J. medranoi) and a Malagasy species of uncertain generic affinities are nested within the lineage. A monophyletic Tetramerium lineage consists of 23 currently recognized genera with at least 168 species, more than 70% of which occur in the New World. Old World Chlamydocardia and Clinacanthus are serially sister to all other members of the lineage. Other Old World taxa consist of: Ecbolium clade (all sampled species of Ecbolium plus Malagasy Populina richardii), Megalochlamys clade (Megalochlamys, Trichaulax and the unidentified Malagasy species), and two isolated taxa (Angkalanthus and Chorisochora). All analyses strongly support monophyly of the New World Tetramerium lineage. The basal clades of New World plants, all with nototribic flowers, are: 1) the taxonomically heterogeneous but palynologically consistent Mirandea clade, and 2) the Pachystachys clade + the South American Anisacanthus clade. The second is sister to all other NW plants, referred to here as the core Tetramerium lineage. We recognize five clades within the core Tetramerium lineage related as follows: (Henrya clade (Carlowrightia parviflora clade (North American Anisacanthus clade (core Carlowrightia clade + Tetramerium)))). Macromorphological synapomorphies are unknown for the Tetramerium lineage and for many of its constituent clades. However, we propose sternotribic flowers as synapomorphic for the core Tetramerium lineage, and flowers with the lower-central lobe of the corolla modified into a keel as a synapomorphy for a lineage consisting of Tetramerium and the core Carlowrightia clade. Palynological characters provide putative synapomorphies for some clades (e.g. Ecbolium clade, Mirandea clade) and autapomorphies for several species (e.g. Mexacanthus mcvaughii, Trichalux mwasumbii). An Old World origin is postulated for the Tetramerium lineage, and we posit a single dispersal event to America and subsequent extensive radiation there, especially in arid zones of Mexico and adjacent regions. Taxonomic implications of our results are extensive. Notably, many traditionally recognized genera (e.g. Anisacanthus, Carlowrightia, Mirandea) are not monophyletic and emphasis on floral form often has been phylogenetically misleading; for example, floral adaptations to pollination by hummingbirds have evolved at least eight times in the New World Tetramerium lineage.
|
|
| 5. |
- Ekenäs, Catarina, et al.
(författare)
-
A molecular phylogenetic study of Arnica (Asteraceae) : Low chloroplast DNA variation and problematic subgeneric classification
- 2007
-
Ingår i: Systematic Botany. - 0363-6445 .- 1548-2324. ; 32:4, s. 917-928
-
Tidskriftsartikel (refereegranskat)abstract
- DNA sequences from five chloroplast DNA regions (the rpl16 and rps16 introns and the psbA-trnH, ycf4-cemA, and trnT-L spacers), and the nuclear ribosomal internal and external transcribed spacer (ITS and ETS) regions, were analyzed using maximum parsimony and Bayesian methods to explore the putatively complicated history of the mainly North American genus Arnica. The chloroplast regions were found to contain minimal variation in Arnica. Of 3710 nucleotides, only 119 were variable and 45 informative. However, combined with the ribosomal DNA data, the analysis yielded a number of well-supported clades. Strong support for the monophyly of Arnica was found in both the separate and combined analyses but none of the five currently recognized subgenera was resolved as monophyletic in any of the analyses. Arnica (Whitneya) dealbata and A. mallotopus (Mallotopus japonicus), two species that were previously placed outside Arnica, were confidently confirmed as members of the genus. The analyses revealed that A. nevadensis (subg. Austromontana) is most closely related to A. dealbata and that A. mallotopus forms a strongly supported clade with A. unalaschcensis (subg. Andropurpurea). Earlier biogeographical hypotheses that suggested an arctic origin and southward spread of the genus are not supported by our analyses. Hybridization, homoplasy, and rapid evolution are possible explanations for conflicts between the chloroplast and nuclear ribosomal data sets and for low support of the deeper nodes.
|
|
| 6. |
- Ferm, Julia, et al.
(författare)
-
A Revised Subgeneric Classification of the Neotropical Genus Zapoteca (Caesalpinioideae; Fabaceae)
- 2022
-
Ingår i: Systematic Botany. - : American Society of Plant Taxonomists. - 0363-6445 .- 1548-2324. ; 47:1, s. 208-214
-
Tidskriftsartikel (refereegranskat)abstract
- The subgeneric classification of the neotropical legume genus Zapoteca is revised based on an analysis of the nuclear ETS and ITS, and the plastid trnL-trnF DNA regions. Zapoteca subgenus Ravenia is included in Z. subgenus Zapoteca, Z. quichoi is transferred from Z. subgenus Amazonica to Z. subgenus Zapoteca, Z. sousae is included in Z. subgenus Zapoteca, and the new subgenus Zapoteca subgenus Subamazonica is described to accommodate the species Z. filipes and Z. scutellifera. A key to the subgenera is presented.
|
|
| 7. |
- Fritsch, Peter W., et al.
(författare)
-
Taxonomic Implications of Morphological Variation in Cercis canadensis (Fabaceae) from Mexico and Adjacent Parts of Texas
- 2009
-
Ingår i: Systematic Botany. - : American Society of Plant Taxonomists. - 0363-6445 .- 1548-2324. ; 34:3, s. 510-520
-
Tidskriftsartikel (refereegranskat)abstract
- Taxonomic treatments recognize three varieties of Cercis canadensis: with variety canadensis, widespread throughout the eastern United States, and varieties texensis and mexicana, found east and west of the Pecos River in Texas, respectively. The distribution of Cercis continues southward into northeastern Mexico, but complex variation in leaf shape has confounded straightforward application of varietal names to the Mexican plants. To clarify the taxonomy of Cercis in Mexico, we conducted a morphometric analysis with 281 herbarium specimens, including a representative set of samples from Texas. Correlation and principal component analysis of 12 characters recovered two groups that correspond to the presence versus absence of branchlet pubescence. These groups are geographically distinct at the northern and southern extremes of the focus area but exhibit a large central region of overlap. No other discontinuities in character states were discovered to corroborate this division. Leaf shape varies continuously from ovate-acuminate at the northern and southern extremes to subreniform in the central region, suggesting clinal adaptation to the mesic versus xeric environments in which the plants occur. Based on our data, we apply the varietal epithets mexicana and, provisionally, texensis to Mexican C. canadensis with pubescent and glabrous branchlets, respectively, the latter based on geographic proximity to plants in Texas in the absence of definitive evidence on the phenotypic distinction between varieties canadensis and texensis.
|
|
| 8. |
- Havran, J. Christopher, et al.
(författare)
-
Taxonomic Reevaluation of Endemic Hawaiian Planchonella (Sapotaceae)
- 2021
-
Ingår i: Systematic Botany. - 0363-6445 .- 1548-2324. ; 46, s. 875-888
-
Tidskriftsartikel (refereegranskat)abstract
- Planchonella (Sapotaceae) in Hawaii has a complicated taxonomic history that has resulted in considerable confusion among bota- nists and conservation practitioners. Up to seven different species and several varieties have been described in Hawaii, with the most recent taxonomic evaluation recognizing one species, P. sandwicensis. We have conducted a phylogenetic study of Hawaiian Planchonella using molec- ular (ETS, ITS, and RPB2) and morphological data to infer whether one or several species can be distinguished. In line with earlier research based on molecular data, we find that Planchonella in Hawaii is comprised of two well-supported clades distinguished by fruit color: yellow or purple. The purple-fruited clade contains individuals with flat leaf blades, long pedicels, and greenish corollas, a species corresponding to P. sandwicensis, distributed on all Hawaiian Islands except the island of Hawaii. The yellow-fruited clade possesses leaves that are frequently longitudinally rolled, wavy or distally deflexed, short pedicels, and yellow or cream (rarely greenish) corollas, a species corresponding to P. spathulata that is distributed on all Hawaiian Islands but is believed rare in Kauai. Both species can set fruit with aborted ovules, resulting in small fruits that look dissimilar to well-developed fruit. The species can occur in sympatry, where P. sandwicensis seems to be better adapted to slightly wetter forests and higher altitudes, whereas P. spathulata usually occurs at lower elevations in mesic to dry forests. Both species exhibit large morphological variation and overlap, resulting in many previous collections with inadequate label information, which has impeded correct taxonomic determinations. We refrain from recognizing infraspecific taxa because there is no morphological coherence, no molecular support, and it is unhelpful for species conservation. Five lectotypes are here designated. Both species are assessed for conservation status according to IUCN guidelines and are tentatively proposed as species of Least Concern.
|
|
| 9. |
- Kårehed, Jesper, et al.
(författare)
-
Evolution of the Australasian families Alseuosmiaceae, Argophyllaceae, and Phellinaceae
- 1999
-
Ingår i: Systematic Botany. - 0363-6445 .- 1548-2324. ; 24:4, s. 660-682
-
Tidskriftsartikel (refereegranskat)abstract
- Based on results from cladistic analyses of morphology and DNA sequences (the two chloroplast genes rbcL and ndhF), the three Australasian families Alseuosmiaceae, Argophyllaceae, and Phellinaceae are each monophyletic, belong within Asterales, and together form a monophyletic group. Two new rbcL sequences and thirteen new ndhF sequences were obtained. Congruence tests did not reveal any significant incongruence between the two molecular data sets or between the molecular and morphological data. The character evolution of the Alseuosmiaceae-Argophyllaceae-Phellinaceae group is discussed. The Australasian ancestor of this group was probably a woody plant with simple, alternate, serrate leaves and regular, choripetalous, epigynous flowers borne in panicles. All tree families should be retained in line with the "principle of ease of identification."
|
|
| 10. |
- Löfstrand, Stefan D., et al.
(författare)
-
Phylogeny and Generic Delimitations in the Sister Tribes Hymenodictyeae and Naucleeae (Rubiaceae)
- 2014
-
Ingår i: Systematic Botany. - 0363-6445 .- 1548-2324. ; 39:1, s. 304-315
-
Tidskriftsartikel (refereegranskat)abstract
- The Hymenodicteae-Naudeeae clade is a predominantly Paleotropical group with 220 species in 28 genera. The phylogertetic relationships and generic limits within Naucleeae have previously been assessed using combined molecular-morphological data, however the status of some genera remains questionable. The evolutionary relationships within Hymenodictyeae have never been investigated before. We performed phylogenetic analyses of the Hymenodictyeae-Naucleeae clade using nuclear [nrETS; nrITS] and chloroplast [ndhF; rbcL; rps16; trnT-F] data and a large sampling of both tribes. Our study supports the monophyly of the tribes, all subtribes of Naucleeae (Adininae, Breoniinae, Cephalanthinae, Corynantheinae, Mitragyninae, Naucleinae, and Uncariinae), and the Hymenodictyeae genera Hymenodictyon and Paracorynanthe. In Naucleeae, the monotypic genera Adinauclea, Metadina, and Pertusadina are nested within Adina, Mitragyna within Fleroya, Ludekia, Myrmeconauclea, and Ochreinauclea within Neonauclea, and Burttdavya and Sarcocephalus within Nauclea. Corynanthe and Pausinystalia are mutually paraphyletic. We provisionally maintain the current generic status of Neonauclea and its allied genera, pending further study. In sum, we recognize 17 genera in Naucleeae: Adina s. l., Breonadia, Breonia, Cephalanthus, Corynanthe s. l., Diyaminauclea, Gyrostipula, Janotia, Khasiaclunea, Ludekia, Mitragyna s. l., Myrmeconauclea, Nauclea s. l., Neolamarckia, Neonauclea, Ochreinauclea, and Uncaria. Five new combinations were made: Adina euryncha, Adina malaccensis, Corynanthe lane-poolei subsp. iturense, Corynanthe talbotii, and Nauclea nyasica.
|
|
