Overlooked morphological variation and a proposal for a new taxonomic circumscription of Alyssum simplex (Brassicaceae)

Phytotaxa ◽  
2019 ◽  
Vol 416 (2) ◽  
pp. 149-166
Author(s):  
VERONIKA CETLOVÁ ◽  
JAVIER FUERTES-AGUILAR ◽  
DARIA IUDOVA ◽  
STANISLAV ŠPANIEL

A recent study of European annual taxa of Alyssum has revealed that A. simplex includes two cytotypes (diploid and tetraploid) which differ in genetic markers, evolutionary history, and monoploid relative genome size. In this paper we present a new taxonomic treatment of A. simplex in which we treat the two cytotypes as two separate species. We select and discuss suitable names for both taxa (diploid A. simplex and tetraploid A. collinum), examine their morphological differences and survey their geographic distribution. In addition, we compare both cytotypes with the morphologically similar and genetically related species A. strigosum and designate lectotypes and a neotype of several relevant names.

Phytotaxa ◽  
2021 ◽  
Vol 528 (2) ◽  
pp. 93-110
Author(s):  
JOSÉ SAID GUTIÉRREZ-ORTEGA ◽  
MIGUEL ANGEL PÉREZ-FARRERA ◽  
JEFFREY CHEMNICK ◽  
TIMOTHY J. GREGORY

The cycad genus Dioon comprises 17 species from Mexico and Honduras, all of them delimited based on their morphological variation and geographic distribution. A recent evaluation of the biological variation among Dioon populations from Oaxaca and Chiapas, Mexico, demonstrated that the concept of the species Dioon merolae actually consists of three lineages that should be recognized as different taxa. One lineage was already described as Dioon oaxacensis, leaving the concept of Dioon merolae comprising two lineages distributed on both sides of the Isthmus of Tehuantepec. However, there are conspicuous morphological differences between these two lineages. Here, we tested whether such a differentiation within the concept of Dioon merolae merits the differentiation of two different taxa. We evaluated the qualitative and morphometric variation among populations belonging to the Dioon merolae lineages, and compared it with the closely related species Dioon oaxacensis. Morphological observations and statistical tests demonstrated that the populations of southeastern Oaxaca, traditionally considered as part of Dioon merolae, represent a distinct species that we described as Dioon salas-moralesae. Identifying the diagnostic characters of this new species helps enable an understanding of the criteria that should be considered to delineate the boundaries between other cycad species.


1977 ◽  
Vol 109 (12) ◽  
pp. 1605-1618 ◽  
Author(s):  
D.A. Chant ◽  
R.I.C. Hansell ◽  
H.J. Rowell

AbstractMorphological variation between two closely related species in the genus Amblyseius Berlese was examined by numerical taxonomic methods. Multivariate tests indicated that A. canadensis Chant and Hansell and A. novaescotiae (Chant) represent two separate and distinct morphological groups. This supports their taxonomic retention as valid species. Intraspecific morphological variation was also examined and found to be correlated with climatic and host plant variables.


Phytotaxa ◽  
2018 ◽  
Vol 358 (2) ◽  
pp. 162
Author(s):  
STANISLAV ŠPANIEL ◽  
LÝDIA HABURAJOVÁ ◽  
VERONIKA CETLOVÁ

Odontarrhena tortuosa is a herbaceous species occurring in steppe and rocky habitats of Eurasia. The present study is focused on the cytogeography and morphological variation of the species’ populations growing in the Pannonian basin (Central Europe), which represents the westernmost part of its distribution area. Flow cytometric analyses have revealed the existence of tetraploid populations, which are reported here for the first time for Central Europe. We analysed the morphological variation of 329 individuals from Slovakia, Hungary and Serbia by multivariate morphometric methods to evaluate morphological differences between two cytotypes (diploids and tetraploids), between the subspecies (O. tortuosa subsp. tortuosa and O. tortuosa subsp. heterophylla) and between populations growing in three regions differing in the type of substrate (rocks, sand dunes and sandy and rocky screes). Although we have not found any clear morphological differences between the cytotypes, we have confirmed several previously reported morphological differences between the two subspecies, which occur in regions differing in the type of substrate. Flow cytometric data also indicate certain differences in monoploid genome size between all groups of populations under comparison. Populations from Serbia differ from other populations of O. tortuosa subsp. tortuosa in morphology and genome size, but due to a lack of data on the genetic variation of the species we suggest no change in taxonomy. For the identification of the two subspecies, we present an updated determination key.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243310
Author(s):  
Rostislav Linda ◽  
Ivan Kuneš ◽  
Martin Baláš

Birches are generally known for their high genetic and morphological variability, which has resulted in the description of many species. Ojców birch was described in 1809 by Willibald Suibert Joseph Gottlieb Besser in Poland. Since then, several studies assessing its taxonomy were conducted. Today, various authors present Ojców birch at different taxonomic ranks. In Czechia, the Ojców birch is classified a critically endangered taxon and confirmed at one locality consisting of several tens of individuals. However, before a strategy for its conservation can be applied, we consider it necessary to assess the taxonomic position of the endangered Czech population and to evaluate its relationship to the original Polish population. This study aimed to evaluate the morphometric and genetic variability between populations of B. ×oycoviensis in Poland and the Czechia and their relationship to regional populations of B. pendula, one of the putative parental species of the Ojców birch. Altogether, 106 individuals were sampled, including the holotype of B. szaferi, the second putative parental species of B. ×oycoviensis, received from the herbarium of W. Szafer, which is deposited at the Institute of Botany in Kraków. Morphological analyses identified differences in leaves between B. ×oycoviensis and B. pendula. However, no significant differences were found in genome size between selected taxa/working units except for B. pendula sampled in Czechia. The identified difference of the Czech population of B. pendula is probably caused by population variability. Genetic variability between all the taxa under comparison, regardless of their origin, was also very low; only the benchmark taxa (B. nana and B. humilis) clearly differed from all samples analyzed. The results indicate minute morphological and negligible genetic variability between the Czech and Polish populations of B. ×oycoviensis. In light of our results, the classification of B. ×oycoviensis as B. pendula var. oycoviensis seems more accurate than all hitherto presented alternatives (e.g. B. ×oycoviensis as a separate species).


Zootaxa ◽  
2019 ◽  
Vol 2713 (1) ◽  
pp. 52 ◽  
Author(s):  
BASTIAN BENTLAGE

Numerous nominal species have been considered synonymous with Carybdea alata Reynaud, 1830 (cf. Gershwin 2005). A recent revision concluded that several of the species collectively referred to as C. alata are valid and indeed separate species (Gershwin 2005; but see also Bentlage et al. 2010). Additionally, these species (including C. alata) were moved into the genus Alatina Gershwin 2005 (family Alatinidae Gershwin, 2005) because of stark morphological differences they display compared to the other species of Carybdea. In particular, Alatina species possess crescentic phacellae and a rhopaliar niche ostium that is covered by a single upper and two lateral scales (t-shaped sensu Gershwin 2005; cf. Bigelow 1938) compared to a single upper covering scale (heart-shaped sensu Gershwin 2005; cf. Bigelow 1938) and epaulette-like or linear phacellae in the corners of the stomach in Carybdea species. Recent molecular phylogenetic analyses support the separation of Carybdea and Alatina (Bentlage et al. 2010). Alatina grandis posed a problem in Gershwin's (2005) revision, as the type of this species appeared to be lost to science, preventing a closer investigation of its identity. I located a type specimen of the species in the collections of the National Museum of Natural History, Smithsonian Institution (USNM). The purpose of this letter is to draw attention to this important specimen, and highlight directions for future studies on the evolutionary history of the genus Alatina.


2017 ◽  
Vol 154 (6) ◽  
pp. 1334-1343 ◽  
Author(s):  
XINGLIAN YANG ◽  
YUANLONG ZHAO ◽  
LOREN E. BABCOCK ◽  
JIN PENG

AbstractThe skeleton of a new vauxiid sponge (Order Verongida), Angulosuspongia sinensis gen. et sp. nov., described on the basis of material from calcareous mudstones of the Kaili Formation (Cambrian Stage 5), Jianhe area, Guizhou, South China, is composed of two layers of fused spicules outlining hexagonal or polygonal openings. These vauxiid remains are the first reported from outside Laurentia, and represent only the second genus attributed to the family. Its age is close to but still slightly older than the Burgess Shale Biota, and it appears to be a primitive relative of other members of the Vauxiidae. The morphological differences between Chinese and Laurentian vauxiid sponges may be a result of vicariance. These specimens not only extend the geographic distribution of vauxiids, but also help to fill a chronostratigraphical gap between North Greenland and North American material and provide additional evidence for understanding the evolutionary history of the Demospongiae.


Phytotaxa ◽  
2018 ◽  
Vol 336 (2) ◽  
pp. 101
Author(s):  
JULIÁN AGUIRRE-SANTORO

A taxonomic revision of the 17 Caribbean-endemic species of Wittmackia (Bromeliaceae) is presented. This group is a monophyletic lineage previously circumscribed as Hohenbergia subg. Wittmackiopsis but later transferred to Wittmackia based on phylogenetic and morphological evidence. This taxonomic treatment includes a complete overview of the morphological variation of the species, their geographical distribution and habitat, and notes on their ecology and conservation. A taxonomic key for the identification of the species is provided. Finally, complete descriptions with comments on the taxonomy, geographic distribution and habitat are presented.


2019 ◽  
pp. 23-36
Author(s):  
Mario. R. Cabrera

Formerly Cnemidophorus was thought to be the most speciose genus of Teiidae. This genus comprised four morphological groups that were later defined as four different genera, Ameivula, Aurivela, Cnemidophorus and Contomastix. The last appears as paraphyletic in a recent phylogenetic reconstruction based on morphology, but monophyletic in a reconstruction using molecular characters. Six species are allocated to Contomastix. One of them, C. lacertoides, having an extensive and disjunct geographic distribution in Argentina, Uruguay and Brazil. Preliminary analyses revealed morphological differences among its populations, suggesting that it is actually a complex of species. Here, we describe a new species corresponding to the Argentinian populations hitherto regarded as C. lacertoides, by integrating morphological and molecular evidence. Furthermore, we demonstrate that the presence of notched proximal margin of the tongue is a character that defines the genus Contomastix.


Phytotaxa ◽  
2016 ◽  
Vol 255 (2) ◽  
pp. 160 ◽  
Author(s):  
FANG WU ◽  
LI-WEI ZHOU ◽  
XIAO-HONG JI ◽  
XUE-MEI TIAN ◽  
SHUANG-HUI HE

Grammothele and Theleporus have a shallow pore surface, which makes them morphologically close to corticioid fungi. However, from a phylogenetic perspective, they are polyphyletic genera within the core polyporoid clade of the Polyporales. Eight specimens with a shallow pore surface from Hainan, southern China, were morphologically and phylogenetically studied. Among them, one was determined as Grammothele denticulata, four were identified as Theleporus membranaceus, and three are described as Grammothele hainanensis. G. hainanensis is characterized by the annual and resupinate basidiocarps with poroid to irpicoid hymenophore, a dimitic hyphal system with clamped generative hyphae and weakly dextrinoid skeletal hyphae, the presence of cystidioles, hyphal pegs and dendrohyphidia, and cylindrical, hyaline and thin-walled basidiospores. It is closely related to G. quercina in phylogeny. Morphologically, G. quercina differs in producing perennial basidiocarps with cream to pale greyish and larger pores. The morphological differences among the new species and other species were analyzed.


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