The family Polygonaceae in West Africa: Taxonomic significance of leaf epidermal characters

Ayodele, A. E.; Olowokudejo, J. D.

doi:10.1016/j.sajb.2005.12.009

Cited by 29 publications

(25 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Th ese structures are made of projections of the fundamental tissue of the vein, which form cavities or fi ssures with trichomes, and have already been described for the genus (Da Cunha & Vieira 1993/97; Quinteiro et al 2006). Epidermal characters have been used in studies on the relationship of taxa (e.g., Ayodele & Olowokudejo 2006;Erxu et al 2009). Some characteristics of the epidermis are infl uenced by environmental conditions, such as the outline of the anticlinal wall and the shape of the external periclinal wall of the epidermal cells.…”

Section: Discussionmentioning

confidence: 99%

Comparative leaf anatomy and micromorphology of Psychotria species (Rubiaceae) from the Atlantic Rainforest

et al. 2011

View full text Add to dashboard Cite

RESUMO(Anatomia e micromorfologia comparada da folha de espécies de Psychotria (Rubiaceae) da Floresta Atlân-tica). O gênero Psychotria compreende aproximadamente 2000 espécies, a maioria arbórea distribuídas em florestas tropicais e subtropicais. Dentro de Rubiaceae, o gênero é bem conhecido pelas espécies produtoras de alcalóides bioativos e taxonomia complexa. Os caracteres anatômicos e micromorfológicos de P. hoffmannseggiana, P. carthagenensis, P. deflexa, P. glaziovii, P. leiocarpa, P. racemosa e P. vellosiana foram investigados e descritos. A variação interespecífica foi avaliada, a fim de contribuir para a sistemática do gêwnero. A análise dos componentes principais (PCA) e a análise de agrupamento através das médias não ponderadas de grupos pareados (UPGMA) indicaram quatro grupos baseados na presença e ausência de algumas características estudadas. Mesofilo dorsiventral, folhas hipostomáticas, estômatos paracíticos, organização do sistema vascular do pecíolo e da nervura principal em arco e presença de feixes acessórios são comuns nas espécies examinadas e são características típicas de Rubiaceae. A presença de cristais estilóides e de alcalóides é considerada característica diagnóstica destas espécies de Psychotria. Outras características usadas para a distinção das espécies o gênero são: o contorno do pecíolo, a ornamentação da cutícula e a presença de tricomas. ABSTRACT(Comparative leaf anatomy and micromorphology of Psychotria species (Rubiaceae) from the Atlantic Rainforest). Th e genus Psychotria comprises approximately 2,000 species that are mostly shrubs distributed in forests of the tropics and subtropics. Within the Rubiaceae, Psychotria is well known for its species that produce bioactive alkaloids and for its taxonomic complexity. Th e anatomical and micromorphological characters of the leaves of P. hoff mannseggiana, P. carthagenensis, P. defl exa, P. glaziovii, P. leiocarpa, P. racemosa, and P. vellosiana were investigated and described to understand the interspecifi c variation of these species, which will contribute to the systematics of the genus. Principal component analysis (PCA) and unweighted pair group method analysis (UPGMA) indicated four groups based on the presence or absence of some of the characters studied. Dorsiventral mesophyll, hypostomatic leaves, paracytic stomata, organization of the vascular system of the petiole and midrib in an arc and the presence of accessory bundles are common in the species examined and are typical characteristics of the Rubiaceae. Th e presence of styloid crystals and alkaloids are considered diagnostic characters of Psychotria. Other characteristics used to separate species in the genus are the petiole contour, cuticle ornamentation, and presence of trichomes. Th e results of the UPGMA cluster analyses indicated that there is similarity between Psychotria (subg. Heteropsychotria) and Palicourea species.

show abstract

Section: Discussionmentioning

confidence: 99%

Comparative leaf anatomy and micromorphology of Psychotria species (Rubiaceae) from the Atlantic Rainforest

et al. 2011

View full text Add to dashboard Cite

show abstract

“…and Triplaris Loefl. [4]–[10]. Of these, Persicaria , Polygonum , Rheum and Rumex are more or less cosmopolitan, while the others are more restricted in their range, and a few have disjunct distributions across Australasia and South America as well as Africa and South America (e.g., Muehlenbeckia and Symmeria respectively).…”

Section: Introductionmentioning

confidence: 99%

Age Estimates for the Buckwheat Family Polygonaceae Based on Sequence Data Calibrated by Fossils and with a Focus on the Amphi-Pacific Muehlenbeckia

2013

View full text Add to dashboard Cite

The buckwheat family Polygonaceae is a diverse group of plants and is a good model for investigating biogeography, breeding systems, coevolution with symbionts such as ants and fungi, functional trait evolution, hybridization, invasiveness, morphological plasticity, pollen morphology and wood anatomy. The main goal of this study was to obtain age estimates for Polygonaceae by calibrating a Bayesian phylogenetic analysis, using a relaxed molecular clock with fossil data. Based on the age estimates, we also develop hypotheses about the historical biogeography of the Southern Hemisphere group Muehlenbeckia. We are interested in addressing whether vicariance or dispersal could account for the diversification of Muehlenbeckia, which has a “Gondwanan” distribution.Eighty-one species of Polygonaceae were analysed with MrBayes to infer species relationships. One nuclear (nrITS) and three chloroplast markers (the trnL-trnF spacer region, matK and ndhF genes) were used. The molecular data were also analysed with Beast to estimate divergence times. Seven calibration points including fossil pollen and a leaf fossil of Muehlenbeckia were used to infer node ages.Results of the Beast analyses indicate an age of 110.9 (exponential/lognormal priors)/118.7 (uniform priors) million years (Myr) with an uncertainty interval of (90.7–125.0) Myr for the stem age of Polygonaceae. This age is older than previously thought (Maastrichtian, approximately 65.5–70.6 Myr). The estimated divergence time for Muehlenbeckia is 41.0/41.6 (39.6–47.8) Myr and its crown clade is 20.5/22.3 (14.2–33.5) Myr old. Because the breakup of Gondwana occurred from 95–30 Myr ago, diversification of Muehlenbeckia is best explained by oceanic long-distance and maybe stepping-stone dispersal rather than vicariance. This study is the first to give age estimates for clades of Polygonaceae and functions as a jumping-off point for future studies on the historical biogeography of the family.

show abstract

“…However, the lowest epidermal cell diameter on the adaxial surface of D. dewevrei is the characteristic of the species. The usefulness of leaf epidermal characters in solving taxonomic problems has been reported by many authors (Ayodele & Olowokudejo 2006;Kadiri & Ayodele 2003;Ogundipe & Ayodele 2000). The highest number of cell/mm 2 and cell thickness on both surfaces separates D. chrysochlamy from the others.…”

Section: Discussionmentioning

confidence: 91%

A preliminary leaf epidermal and pollen morphology of some West African species of <i>Desplatsia</i> Bocq

Shokefun

Ayodele

Orijemie

2017

JOMPED

View full text Add to dashboard Cite

Desplatsia is a genus made up of about four to eight species which are mostly trees native to tropical Africa. The leaf and pollen characters of three West African species of Desplatsia were investigated using light microscopy. The study was aimed at investigating the leaf epidermis and pollen morphology of the species to further enhance the understanding of the taxonomic relationships in the genus. The epidermal cells were isodiametric, polygonal to irregular with straight, curved to wavy anticlinal cell walls. The species were hypostomatic with anisocytic and staurocytic stomata types. The adaxial and abaxial walls of Desplatsia chrysochlamywere characterised by three-celled head multicellular glandular trichomes with highest number of cells and stomata and striated adaxial surface. The four-armed branched and stellate trichomes with the largest stomata size of 19.5 µm × 15.6 µm distinguished D. dewevrei from D. subericarpa in which the largest cells, lowest number of stomata and size were recorded. The pollen grains were medium in size 26.5 µm–47.5 µm, tricolporate with long colpi. However, the subprolate, baculate exine surface, small ora and lumen width separated D. chrysochlamy from D. dewevrei and D. subericarpa in which prolate, perforated exine surface and colpi margo were recorded. A key is provided for the identification of the species. Therefore, the ora size, lumen width, number of epidermal cell and stomata are additional taxonomic characters that can be used for species delimitation in the genus.

show abstract

The family Polygonaceae in West Africa: Taxonomic significance of leaf epidermal characters

Cited by 29 publications

References 8 publications

Comparative leaf anatomy and micromorphology of Psychotria species (Rubiaceae) from the Atlantic Rainforest

Comparative leaf anatomy and micromorphology of Psychotria species (Rubiaceae) from the Atlantic Rainforest

Age Estimates for the Buckwheat Family Polygonaceae Based on Sequence Data Calibrated by Fossils and with a Focus on the Amphi-Pacific Muehlenbeckia

A preliminary leaf epidermal and pollen morphology of some West African species of <i>Desplatsia</i> Bocq

Contact Info

Product

Resources

About