Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

http://amborella.net/2010PlantSystematics/DATA/3-24-APG%202003%20Bot%20J%20Linn%20Soc%20APGII.pdf

An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II

An updated inventory of the vascular flora alien to Italy, providing details on the occurrence at regional level, is presented. The checklist includes 1597 species, subspecies, and hybrids, distributed in 725 genera and 152 families; 2 taxa are lycophytes, 11 ferns and fern allies, 33 gymnosperms, and 1551 angiosperms. 157 taxa are archaeophytes and 1440 neophytes. The alien taxa currently established in Italy are 791 (570 naturalized and 221 invasive), while 705 taxa are casual aliens, 4 are not assessed, 7 are of unknown regional distribution, 47 have not been confirmed in recent times, 3 are considered extinct or possibly extinct in the country, and 40 are doubtfully occurring in Italy. This checklist allows to establish an up-to-date number (9792) of taxa constituting the whole (native and alien) Italian flora.

/pdf/an-updated-checklist-of-the-vascular-flora-native-to-italy-2tuf9mb3d4.pdf

An updated checklist of the vascular flora native to Italy

Geographic Variation, Speciation, and Clines.

The carnivorous habit in flowering plants represents a grade of structural organization. Different morphological features associated with the attraction, trapping, and digestion of prey characterize a diversity of specialized forms, including the familiar pitcher and flypaper traps. Phylogenetic analysis of nucleotide sequence data from the plastic rbcL gene indicates that both carnivory and stereotyped trap forms have arisen independently in different lineages of angiosperms. Furthermore, these results demonstrate that flypaper traps share close common ancestry with all other trap forms. Recognition of these patterns of diversification may provide ideal, naturally occurring systems for studies of developmental processes underlying macromorphological evolution in angiosperms.

Carnivorous plants: Phylogeny and structural evolution

Correct species identification is critical for studies on biodiversity, ecology, and conservation. Determining Opuntia s.s. species is difficult because they have similar traits and are phenotypically plastic. Taxonomic keys are based on vegetative traits, rather than reproductive ones such as flowers, because they are assumed to be too similar. We analyzed morphometric characteristics of flowers and cladodes over 6 years to determine which of these is most useful for differentiating Opuntia species from the Chihuahuan Desert. For each species (Opuntia robusta, O. cantabrigiensis, O. tomentosa, and O. streptacantha),we tagged 20 hermaphroditic and 40 dioecious plants (totaling 100) from 2014-2020, to complete the sample size of flowers and cladodes. Seventeen morphometric characters were measured for new cladodes and 15 for flowers, and discriminant analysis was applied to determine which traits enabled species delimitation. Six of the 17 cladode characteristics combined explained 89% of the variation, while nine floral characteristics combined explained 94% of the variation. Floral morphometrics proved to be very useful to accurately differentiate species and should be included, in addition to cladodes, in future taxonomic studies. Here, we provide the first taxonomic key that includes floral traits to identify Opuntia and a new description of each studied species.

Complex taxonomy in opuntioideae: is floral morphometry essential to identify opuntia species?

The phylogenetic relationships of Peniocereus (Cactaceae) species were studied using parsimony analyses of DNA sequence data. The plastid rpl16 and trnL-F regions were sequenced for 98 taxa including 17 species of Penio- cereus, representatives from all genera of tribe Pachycer- eeae, four genera of tribe Hylocereeae, as well as from three additional outgroup genera of tribes Calymmantheae, Notocacteae, and Trichocereeae. Phylogenetic analyses sup- port neither the monophyly of Peniocereus as currently cir- cumscribed, nor the monophyly of tribe Pachycereeae since species of Peniocereus subgenus Pseudoacanthocereus are embedded within tribe Hylocereeae. Furthermore, these results show that the eight species of Peniocereus subgenus Peniocereus (Peniocereus sensu stricto) form a well- supported clade within subtribe Pachycereinae; P. serpenti- nus is also a member of this subtribe, but is sister to Bergerocactus. Moreover, Nyctocereus should be resur- rected as a monotypic genus. Species of Peniocereus subge- nus Pseudoacanthocereus are positioned among species of Acanthocereus within tribe Hylocereeae, indicating that they may be better classified within that genus. A number of morphological and anatomical characters, especially related to the presence or absence of dimorphic branches, are discussed to support these relationships.

Monserrat Vázquez-SánchezKenneth M. Cameron

Figure A1 from: Sánchez D, Vázquez-Benítez B, Vázquez-Sánchez M, Aquino D, Arias S (2022) ﻿Phylogenetic relationships in Coryphantha and implications on Pelecyphora and Escobaria (Cacteae, Cactoideae, Cactaceae). PhytoKeys 188: 115-165. https://doi.org/10.3897/phytokeys.188.75739

Salvador Arias

Papers

Complex taxonomy in opuntioideae: is floral morphometry essential to identify opuntia species?

Monserrat Vázquez-SánchezKenneth M. Cameron

Figure A1 from: Sánchez D, Vázquez-Benítez B, Vázquez-Sánchez M, Aquino D, Arias S (2022) Phylogenetic relationships in Coryphantha and implications on Pelecyphora and Escobaria (Cacteae, Cactoideae, Cactaceae). PhytoKeys 188: 115-165. https://doi.org/10.3897/phytokeys.188.75739

Salvador Arias

Papers

Complex taxonomy in opuntioideae: is floral morphometry essential to identify opuntia species?

Monserrat Vázquez-SánchezKenneth M. Cameron

Figure A1 from: Sánchez D, Vázquez-Benítez B, Vázquez-Sánchez M, Aquino D, Arias S (2022) ﻿Phylogenetic relationships in Coryphantha and implications on Pelecyphora and Escobaria (Cacteae, Cactoideae, Cactaceae). PhytoKeys 188: 115-165. https://doi.org/10.3897/phytokeys.188.75739

Figure A1 from: Sánchez D, Vázquez-Benítez B, Vázquez-Sánchez M, Aquino D, Arias S (2022) Phylogenetic relationships in Coryphantha and implications on Pelecyphora and Escobaria (Cacteae, Cactoideae, Cactaceae). PhytoKeys 188: 115-165. https://doi.org/10.3897/phytokeys.188.75739