In situ morphometric study of the Diuris punctata species complex (Orchidaceae), with implications for conservation

2008 ◽  
Vol 21 (4) ◽  
pp. 289 ◽  
Author(s):  
Zoë F. Smith ◽  
Elizabeth A. James ◽  
Cassandra B. McLean
Keyword(s):  
Species Complex ◽  
Flower Colour ◽  
Population Level ◽  
Morphological Characters ◽  
Population Variation ◽  
Morphometric Study ◽  
Herbarium Specimens ◽  
Taxonomic Groups ◽  
Floral Characters

Taxa within the Diuris punctata species complex exhibit high levels of variation at both species and population level. Morphometric data collected in situ were used to investigate species boundaries of four Victorian Diuris species within the Diuris punctata species complex. Morphological characters and taxonomic groups identified in the present study were compared to those described under the current taxonomic treatment. Sixty-five multistate and continuous characters, including seven vegetative and 58 floral characters, were measured in situ across the range of each species within Victoria. The importance of flower colour in distinguishing taxa was highlighted but characters used were generally indiscrete. Certain characters used in current taxonomic descriptions, e.g. floral fragrance, were found to be uninformative. D. fragrantissima was confirmed as a separate taxon within the D. punctata group, justifying its recognition as a unique entity for conservation. Clustering of D. daltonii within D. punctata suggests that the recent elevation of the D. punctata var. daltonii to species level is not justified. The in situ measurement of morphological characters made it possible to incorporate sufficient sampling to encompass intra-specific and intra-population variation and is a feasible method to overcome sampling limitations encountered when herbarium specimens and limited destructive sampling are used.

Revision of the Calceolaria tripartita s. l. species complex (Calceolariaceae) using multivariate analyses of morphological characters

Phytotaxa ◽  
2014 ◽  
Vol 167 (1) ◽  
pp. 61
Author(s):  
PAMELA PUPPO
Keyword(s):  
Morphological Variation ◽  
Species Complex ◽  
Population Level ◽  
Morphological Characters ◽  
Herbarium Specimens ◽  
Key To Species ◽  
Quantitative Characters ◽  
Components Analysis ◽  
Morphological Differences ◽  
Floral Characters

The morphological variation of the Calceolaria tripartita species complex was evaluated using Principal Components Analysis (PCA) of morphological characters. Fourteen quantitative characters were measured on more than 250 herbarium specimens. The results suggest the recognition of three entities based on floral characters, especially stamen morphology. The distinction between C. mandoniana, C. chelidonioides and C. tripartita s.s. is not supported. The morphological differences between the closely related C. tripartita s.s. and C. chelidonioides were also analyzed using two characters previously used to differentiate them. Finally, the morphological variation of C. tripartita s.s. throughout its geographical range and at an intra-population level was also surveyed. Even though this species is highly variable, no further subdivision is supported morphologically. A taxonomic synopsis and a key to species of the Calceolaria tripartita species complex are provided.

Taxonomy of Echium (Boraginaceae) species from Cape Verde Islands

2008 ◽  
Vol 21 (1) ◽  
pp. 26 ◽  
Author(s):  
Maria M. Romeiras ◽  
Lia Ascensão ◽  
Maria C. Duarte ◽  
Maria A. Diniz ◽  
Maria S. Pais
Keyword(s):  
Morphological Variation ◽  
Cape Verde ◽  
General Context ◽  
Herbarium Specimens ◽  
Cape Verde Islands ◽  
Ecological Preferences ◽  
Macaronesian Islands ◽  
Pattern Of Variation ◽  
Taxonomic Groups

The morphological variation of endemic species from the Macaronesian Islands has long attracted attention of many taxonomists. The taxonomy of the endemic Echium L. species (E. hypertropicum Webb, E. stenosiphon Webb and E. vulcanorum A.Chev.) from Cape Verde Islands was revised, on the basis of in situ collected material and on herbarium specimens. Our results revealed that the patterns of morphological variation correspond closely to the geographic localisation of the islands groups, and that habit and floral morphology are important for distinguishing the two southern taxa, E. hypertropicum and E. vulcanorum, from the northern species, E. stenosiphon. This species has the same ecological preferences (e.g. altitude; exposition; soil type) in São Nicolau, São Vicente and Santo Antão Islands. However, the differences in indumentum observed among E. stenosiphon specimens account for the occurrence of different taxonomic groups distributed in these Northern Islands. The two southern species, E. hypertropicum and E. vulcanorum, are morphologically similar, but have different ecological preferences, a pattern of variation similar to other Macaronesian Echium species. Furthermore, the morphological variation observed among the three Cape Verde species, discussed within the general context of Echium taxonomy and closely related genera (e.g. Lobostemon, Echiostachys and Pontechium), suggests that the systematic relationships are beyond the actual circumscription of these genera.

scholarly journals A taxonomic evaluation of the Thesium confine species complex (Santalaceae)

Bothalia ◽  
2018 ◽  
Vol 48 (1) ◽  
Author(s):  
Kagiso S. Mashego ◽  
M. Marianne Le Roux
Keyword(s):  
Species Complex ◽  
Growth Form ◽  
Taxonomic Revision ◽  
Morphological Characters ◽  
Research Strategy ◽  
Herbarium Specimens ◽  
African Species ◽  
Separate Species ◽  
Distribution Ranges ◽  
The Family

Background: Thesium L. is the largest genus in the family Santalaceae (sandalwood family). The last taxonomic revision of the southern African species dates back to 1925. An urgent revision of the genus is required as indicated in a recent national biosystematics research strategy for South Africa.Objectives: To revise the Thesium confine species complex (Thesium durum, T. confine and Thesium spartioides) and to update the typification, nomenclature, descriptions and distribution ranges.Method: Morphological characters were studied using own field collections as well as herbarium specimens from K, NU, PRE and PRU and images on Global Plants (JSTOR). Distribution ranges of the studied species were updated.Results: An examination of morphological characters revealed great similarity between T. spartioides and T. confine. Both species have an herbaceous habit, decumbent growth form, terminal (or less frequently axillary) inflorescences and a sympatric northern distribution in South Africa. Thesium durum differs from T. spartioides and T. confine in having a shrubby habit, erect growth form and axillary inflorescences and occurs in the southern part of South Africa.Conclusion: Thesium spartioides is synonymised under T. confine, and T. durum is retained as a separate species.

scholarly journals Estimating flowering transition dates from status-based phenological observations: a test of methods

2019 ◽  
Author(s):  
Shawn D Taylor
Keyword(s):  
Monte Carlo ◽  
Weibull Distribution ◽  
Population Level ◽  
Monte Carlo Analysis ◽  
Sampling Frequency ◽  
Herbarium Specimens ◽  
Echinacea Angustifolia ◽  
Final Sample ◽  
Growth And Reproduction

The scale of phenological research has expanded due to the digitization of herbarium specimens and volunteer based contributions. These data are status-based, representing the presence or absence of a specific phenophase. Modelling the progress of plant dormancy to growth and reproduction and back to dormancy requires estimating the transition dates from these status-based observations. There are several methods available for this ranging from statistical moments using the day of year to newly introduced methods using concepts from other fields. Comparing the proficiency of different estimators is difficult since true transition dates are rarely known. Here I use a recently released dataset of in-situ flowering observations of the perennial forb *Echinacea angustifolia*. In this dataset, due to high sampling frequency and unique physiology, the transition dates of onset, peak, and end of flowering are known to within 3 days. I used a Monte Carlo analysis to test eight different estimators across two scales using a range of sample sizes and proportion of flowering presence observations. I evaluated the estimators accuracy in predicting the onset, peak, and end of flowering at the population level, and predicting onset and end of flowering for individual plants. Overall a method using a Weibull distribution performed the best for population level onset and end estimates, but other estimators may be more appropriate when there is a large amount of absence observations relative to presence observations. For individual estimates a method using the midway point between the first flower presence and most prior flower absence, within 7 days, is the best option as long as the restriction does not limit the final sample size. Otherwise the Weibull method is adequate for individual estimates as well. These methods allow practitioners to effectively utilize the large amount of status-based phenological observations currently available.

scholarly journals Estimating flowering transition dates from status-based phenological observations: a test of methods

2019 ◽  
Author(s):  
Shawn D Taylor
Keyword(s):  
Monte Carlo ◽  
Weibull Distribution ◽  
Population Level ◽  
Monte Carlo Analysis ◽  
Sampling Frequency ◽  
Herbarium Specimens ◽  
Echinacea Angustifolia ◽  
Final Sample ◽  
Growth And Reproduction

The scale of phenological research has expanded due to the digitization of herbarium specimens and volunteer based contributions. These data are status-based, representing the presence or absence of a specific phenophase. Modelling the progress of plant dormancy to growth and reproduction and back to dormancy requires estimating the transition dates from these status-based observations. There are several methods available for this ranging from statistical moments using the day of year to newly introduced methods using concepts from other fields. Comparing the proficiency of different estimators is difficult since true transition dates are rarely known. Here I use a recently released dataset of in-situ flowering observations of the perennial forb *Echinacea angustifolia*. In this dataset, due to high sampling frequency and unique physiology, the transition dates of onset, peak, and end of flowering are known to within 3 days. I used a Monte Carlo analysis to test eight different estimators across two scales using a range of sample sizes and proportion of flowering presence observations. I evaluated the estimators accuracy in predicting the onset, peak, and end of flowering at the population level, and predicting onset and end of flowering for individual plants. Overall a method using a Weibull distribution performed the best for population level onset and end estimates, but other estimators may be more appropriate when there is a large amount of absence observations relative to presence observations. For individual estimates a method using the midway point between the first flower presence and most prior flower absence, within 7 days, is the best option as long as the restriction does not limit the final sample size. Otherwise the Weibull method is adequate for individual estimates as well. These methods allow practitioners to effectively utilize the large amount of status-based phenological observations currently available.

Qualitative and quantitative morphological evidence for recognition of a new species within Ceratozamia (Zamiaceae) from Mexico

Phytotaxa ◽  
2017 ◽  
Vol 317 (1) ◽  
pp. 17 ◽  
Author(s):  
LILÍ MARTÍNEZ-DOMÍNGUEZ ◽  
FERNANDO NICOLALDE-MOREJÓN ◽  
DENNIS WM. STEVENSON
Keyword(s):  
New Species ◽  
Population Level ◽  
Morphological Characters ◽  
Morphological Evidence ◽  
Herbarium Specimens ◽  
Qualitative And Quantitative ◽  
Leaf Emergence ◽  
Taxonomic History ◽  
History Of ◽  
A New Species

Several Ceratozamia populations from the “Carso Huasteco” region in Mexico have a controversial circumscription and have been historically identified as Ceratozamia fuscoviridis. In this paper, we present a review of the taxonomic history of this species and provide taxa circumscriptions based on analyses of herbarium specimens from this region and supplemented with fieldwork. For this, we have studied qualitative and quantitative morphological variation at population level. We recognize two species in this group: C. fuscoviridis and a new species, C. chamberlainii. Here, we provide two lines of qualitative and quantitative morphological evidence showing that plants of C. chamberlainii from southern San Luis Potosí to northern Hidalgo are distinct from C. fuscoviridis of central Hidalgo east of Veracruz. These species can be identified by leaflet form, leaf emergence color, color of the ovulate strobilus, and form of the megasporophyll, along with a combination of quantitative morphological characters.

scholarly journals Taxonomic status of Pelargonium reniforme Curt.

Bothalia ◽  
2014 ◽  
Vol 44 (1) ◽  
Author(s):  
Janine E. Victor ◽  
Mmamphe Aphane
Keyword(s):  
Conservation Status ◽  
Leaf Shape ◽  
Flower Colour ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
Herbarium Specimens ◽  
Current Investigation ◽  
Petiole Length ◽  
Pelargonium Sidoides ◽  
Variable Species

Background: Pelargonium reniforme Curt. is a morphologically variable species that many authors have attempted to split or combine. Confusion relating to the differences between the two subspecies currently included under P. reniforme has impeded attempts to assess their conservation status.  Pelargonium reniforme is closely related to  Pelargonium sidoides;  the two species are indistinguishable when not flowering and their distributions overlap in some areas.Objectives: With this study, we aimed to clarify the taxonomic status of the two subspecies of P. reniforme, which has relevance in terms of their conservation status.Method: Leaf shape, petiole length, internode length and flower colour were assessed by studying herbarium specimens of the two subspecies of  P. reniforme and specimens of P. sidoides. Living specimens of the two subspecies were also examined in their natural habitat.Results: The current investigation showed that the morphological characters used to distinguish the two subspecies of P. reniforme are too variable to separate them. Variation in some morphological characters may be related to environmental conditions.Conclusion: The recognition of the two subspecies of P. reniforme as distinct taxa is no longer justified.

scholarly journals Evolution and biodiversity of Antarctic organisms: a molecular perspective

2007 ◽  
Vol 362 (1488) ◽  
pp. 2191-2214 ◽  
Author(s):  
Alex David Rogers
Keyword(s):  
Continental Drift ◽  
Population Level ◽  
Extreme Environment ◽  
Morphological Characters ◽  
Secondary Contact ◽  
Genetic Studies ◽  
Antarctic Species ◽  
Taxonomic Groups ◽  
Climatic Cooling ◽  
The Antarctic

The Antarctic biota is highly endemic, and the diversity and abundance of taxonomic groups differ from elsewhere in the world. Such characteristics have resulted from evolution in isolation in an increasingly extreme environment over the last 100 Myr. Studies on Antarctic species represent some of the best examples of natural selection at the molecular, structural and physiological levels. Analyses of molecular genetics data are consistent with the diversity and distribution of marine and terrestrial taxa having been strongly influenced by geological and climatic cooling events over the last 70 Myr. Such events have resulted in vicariance driven by continental drift and thermal isolation of the Antarctic, and in pulses of species range contraction into refugia and subsequent expansion and secondary contact of genetically distinct populations or sister species during cycles of glaciation. Limited habitat availability has played a major role in structuring populations of species both in the past and in the present day. For these reasons, despite the apparent simplicity or homogeneity of Antarctic terrestrial and marine environments, populations of species are often geographically structured into genetically distinct lineages. In some cases, genetic studies have revealed that species defined by morphological characters are complexes of cryptic or sibling species. Climate change will cause changes in the distribution of many Antarctic and sub-Antarctic species through affecting population-level processes such as life history and dispersal.

scholarly journals Species delimitation and hybridisation history of a hazel species complex

2021 ◽  
Author(s):  
Zhiqiang Lu ◽  
Yongshuai Sun ◽  
Ying Li ◽  
Yongzhi Yang ◽  
Gaini Wang ◽  
...  
Keyword(s):  
Species Delimitation ◽  
Species Complex ◽  
Population Level ◽  
Flowering Phenology ◽  
The Other ◽  
Genetic Composition ◽  
Ssr Loci ◽  
History Of ◽  
Taxonomic Groups ◽  
Taxonomic Studies

Abstract Background and Aims Hybridisation increases species adaptation and biodiversity but also obscures species boundaries. In this study, species delimitation and hybridisation history were examined within one Chinese hazel species complex (Corylus chinensis–Corylus fargesii). Two species including four varieties have already been described for this complex, with overlapping distributions. Methods A total of 322 trees from 44 populations of these four varieties across their ranges were sampled for morphological and molecular analyses. Climatic datasets based on 108 geographical locations were used to evaluate their niche differentiations. Flowering phenology was also observed for two co-occurring species or varieties. Key Results Four statistically different phenotypic clusters were revealed, but these clusters were highly inconsistent with the traditional taxonomic groups. All the clusters showed statistically distinct niches, with complete or partial geographic isolation. Only two clusters displayed a distributional overlap, but they had distinct flowering phenologies at the site where they co-occurred. Population-level evidence based on the genotypes of 10 simple sequence repeat (SSR) loci supported four phenotypic clusters. In addition, one cluster was shown to have an admixed genetic composition derived from the other three clusters through repeated historical hybridisations. Conclusions Based on our new evidence, it is better to treat the four clusters identified here as four independent species. One of them was shown to have an admixed genetic composition derived from the other threes through repeated historical hybridisations. This study highlights the importance of applying integrative and statistical methods to infer species delimitations and hybridisation history. Such a protocol should be adopted widely for future taxonomic studies.

scholarly journals Morphometric study of Euchiton traversii complex (Gnaphalieae: Asteraceae)

2008 ◽  
Vol 21 (3) ◽  
pp. 178 ◽  
Author(s):  
Christina Flann ◽  
Ilse Breitwieser ◽  
Josephine M. Ward ◽  
Neville G. Walsh ◽  
Pauline Y. Ladiges
Keyword(s):  
New Zealand ◽  
Species Complex ◽  
Distinct Species ◽  
Morphometric Study ◽  
Herbarium Specimens ◽  
Phenetic Analysis ◽  
South Eastern ◽  
Alpine Regions ◽  
Eastern Australia ◽  
South Eastern Australia

A morphometric study was undertaken into alpine and subalpine species of Euchiton Cass. (Gnaphalieae: Asteraceae) in the Euchiton traversii species complex in south-eastern Australia and New Zealand. Phenetic analysis of both field-collected and herbarium specimens resolved the following six taxa included: Euchiton traversii (Hook.f.) Holub, Euchiton argentifolius (N.A.Wakef.) Anderb., Euchiton lateralis (C.J.Webb) Breitw. & J.M.Ward, Argyrotegium mackayi (Buchanan) J.M.Ward & Breitw., Argyrotegium fordianum (M.Gray) J.M.Ward & Breitw. and Argyrotegium poliochlorum (N.G.Walsh) J.M.Ward & Breitw. The results support the segregation of the genus Argyrotegium J.M.Ward & Breitw. from Euchiton. E. argentifolius is distinct from E. traversii, but conspecific with A. mackayi. E. lateralis is present in Tasmania as well as New Zealand. The distribution of Australian E. traversii is redefined to mainland alpine regions with a few rare occurrences in Tasmania. Australian E. traversii was shown to be similar to its New Zealand counterparts. Differences between E. lateralis and E. traversii were clarified. A. fordianum and A. poliochlorum are distinct species and their transfer to Argyrotegium is supported.

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