Taxonomic significance of macro and micro-morphology of Geranium L. species Using Scanning Electron Microscopy.

Macro and micromorphology of different parts that is, sepals, petals, flowers, indumentum, and leaf shape of 22 Geranium L. taxa from Iran were studied. These taxa representing the eight sections of the genus as sect. Dissecta, sect. Geranium, and sect. Tuberosa (of subgen. Geranium); sect. Batrachioidea, sect. Divaricata, sect. Lucida, sect. Ruberta and sect. Trilopha (of subgen. Robertium), that were collected from different geographical habitats of Iran. The biometric study involved 27 quantitative and 33 qualitative characters which were studied by use of stereomicroscopy and scanning electron microscopy (SEM). Statistical analyses were done by use of PAST software. Principal Component Analysis defined the most variable characters. Results showed that the diagnostic features were; length, width, apex of sepals, petals, trichomes type in pedicles and sepals along with their density, the shape length and width of leaves. In general, the present study revealed that the species could be differentiated by macro and micro-morphological characters. Taxa of two subgenera were clearly separated based on selected characters. These characters were found useful for the taxonomic identification and species delimitation in almost all taxa studied at the sub generic level, although some species of section Geranium and section Dissecta are mixed and nested in both subgenea.

Contrasting Patterns of Nucleotide Substitution Rates Provide Insight into Dynamic Evolution of Plastid and Mitochondrial Genomes of Geranium.

Geraniaceae have emerged as a model system for investigating the causes and consequences of variation in plastid and mitochondrial genomes. Incredible structural variation in plastid genomes (plastomes) and highly accelerated evolutionary rates have been reported in selected lineages and functional groups of genes in both plastomes and mitochondrial genomes (mitogenomes), and these phenomena have been implicated in cytonuclear incompatibility. Previous organelle genome studies have included limited sampling of Geranium, the largest genus in the family with over 400 species. This study reports on rates and patterns of nucleotide substitutions in plastomes and mitogenomes of 17 species of Geranium and representatives of other Geraniaceae. As detected across other angiosperms, substitution rates in the plastome are 3.5 times higher than the mitogenome in most Geranium. However, in the branch leading to Geranium brycei/Geranium incanum mitochondrial genes experienced significantly higher dN and dS than plastid genes, a pattern that has only been detected in one other angiosperm. Furthermore, rate accelerations differ in the two organelle genomes with plastomes having increased dN and mitogenomes with increased dS. In the Geranium phaeum/Geranium reflexum clade, duplicate copies of clpP and rpoA genes that experienced asymmetric rate divergence were detected in the single copy region of the plastome. In the case of rpoA, the branch leading to G. phaeum/G. reflexum experienced positive selection or relaxation of purifying selection. Finally, the evolution of acetyl-CoA carboxylase is unusual in Geraniaceae because it is only the second angiosperm family where both prokaryotic and eukaryotic ACCases functionally coexist in the plastid.

Genetic structuring, dispersal and taxonomy of the high-alpine populations of the Geranium arabicum/kilimandscharicum complex in tropical eastern Africa.

The scattered eastern African high mountains harbor a renowned and highly endemic flora, but the taxonomy and phylogeographic history of many plant groups are still insufficiently known. The high-alpine populations of the Geranium arabicum/kilimandscharicum complex present intricate morphological variation and have recently been suggested to comprise two new endemic taxa. Here we aim to contribute to a clarification of the taxonomy of these populations by analyzing genetic (AFLP) variation in range-wide high-alpine samples, and we address whether hybridization has contributed to taxonomic problems. We identified only two genetic groups. One corresponded to G. kilimandscharicum, which has been reported as exclusively high-alpine and confined to the eastern Rift mountains in East Africa. The other corresponded to G. arabicum, reported from lower altitudes on the same mountains as well as from a wide altitudinal span in Ethiopia and on the western Rift mountains in East Africa. The four populations analyzed of a recently described species from the Bale Mts in Ethiopia were admixed, indicating that they result from recent long-distance dispersal of G. kilimandscharicum from East Africa followed by hybridization with local G. arabicum in naturally disturbed habitats. Some admixture between the two genetic groups was also inferred on other mountains, supporting earlier suggestions of introgression based on morphology. We did not find support for recognition of the recently suggested new subspecies of G. arabicum in Ethiopia. Interestingly, the high-alpine G. kilimandscharicum lacked clear geographic structuring, suggesting a recent history of colonization of the different mountains or extensive intermountain gene flow.

A distribution and taxonomic reference dataset of Geranium in the New World.

Geranium L. is a genus of over 350 species distributed throughout most of the world, except in lowland tropical areas. It is the largest genus of the Geraniaceae and is represented in the New World by 137 species. This dataset includes 8,937 records that covers the genus Geranium the New World, providing an updated, taxonomically consistent and a sound geographical distribution of the 137 species of Geranium in America. Specimens from 128 herbaria were reviewed. These were supplemented by others collected during nine field trips, which allowed better knowledge of the variability of characters within populations, and refining species distribution ranges. Each record represents a specimen that has been reviewed and in some cases collected by C. Aedo. Accepted scientific name, locality details, distribution status (introduced, native, naturalized, uncertain), geographic coordinates are given for 8,538 (95%) records, and habitat information for 3,952 (44%). All data have been released under a CC-BY license in a standardized format, which enables easy integration with other data, for example through GBIF.org.

Species-level phylogeny, fruit evolution and diversification history of Geranium (Geraniaceae).

The cosmopolitan genus Geranium L. (Geraniaceae) consists of c. 350 species distributed in temperate habitats worldwide, with most of its diversity concentrated in the Mediterranean region. Unlike other genera in Geraniaceae, the species of Geranium present contrasting seed discharge syndromes, i.e. the 'Erodium-type' (ET), the 'carpel-projection type' (CP), the 'seed-ejection type' (SE), and the 'inoperative type' (IT), which have been used to delimit major groups within the genus. However, phylogenetic relationships within Geranium are unknown and so is the evolution of the different seed discharge mechanisms. Here, we used a calibrated multispecies coalescent approach to infer the species-level phylogeny and divergence times of the genus based on chloroplast (rbcL, trnL-trnF) and nuclear (ITS) DNA sequences. Our sampling represents most of the morphological variation described in the genus. We reconstruct the evolution of the seed discharge mechanism using ancestral state reconstruction (ASR) techniques on the multispecies coalescent tree, and assess the association between fruit type evolution and species diversification using stochastic birth-death and trait-dependent diversification models. Finally, we reconstruct the early biogeographic history of the genus using discrete and continuous biogeographic analyses of species distribution centroids, including fossil evidence and tip dates. Our results show that fruit type is homoplasious and that the classification based on fruit type in Geranium is artificial. The taxonomy and putative apomorphic characters for Geranium are discussed. ASR of the fruit characters suggests that ET may represent the ancestral state in Geranium and from which CP originated twice, IT presumably once, and SE twice. The independent appearance of the SE syndrome is in both cases associated with increases in diversification rates in the genus. The biogeographic analysis centers the origin and early 10Ma diversification of Geranium on the Mediterranean region. The evolution of seed discharge mechanism about 5Ma might have allowed the species of Geranium to increase in geographic range and to ultimately, diversify.

Volatiles of Geranium purpureum Vill. and Geranium phaeum L.: chemotaxonomy of balkan Geranium and Erodium species (Geraniaceae).

The essential oils obtained by hydrodistillation of Geranium purpureum and G. phaeum were characterized by GC-FID and GC/MS analyses (the former for the first time in general). In total, 154 constituents were identified, accounting for 89.0-95.8% of the detected GC peak areas. The investigated essential oils consisted mainly of fatty acids and fatty-acid-derived compounds (45.4-81.3%), with hexadecanoic acid and (E)-phytol as the major components. The chemotaxonomic significance of the variations in the essential-oil composition/production of the presently and previously investigated Geranium and highly related Erodium taxa from Serbia and Macedonia was assessed by multivariate statistical analyses. The main conclusions drawn from the high chemical similarity of the two genera, visible from the obtained dendrograms and biplots, confirm the close phylogenetic relationship between the investigated Geranium and Erodium taxa, i.e., that there is no great intergeneric oil-composition variability. Changes in the composition and production of essential oils of the herein investigated taxa and 60 other randomly chosen species belonging to different plant genera were also statistically analyzed. The results put forward pro arguments for the oil-yield-oil-composition correlation hypothesis.

Identification and characterization of the water gap in physically dormant seeds of Geraniaceae, with special reference to Geranium carolinianum.

BACKGROUND AND AIMS: Physical dormancy in seeds of species of Geraniaceae is caused by a water-impermeable palisade layer in the outer integument of the seed coat and a closed chalaza. The chalazal cleft has been reported to be the water gap (i.e. location of initial water entry) in innately permeable seeds of Geraniaceae. The primary aim of this study was to re-evaluate the location of the water gap and to characterize its morphology and anatomy in physically dormant seeds of Geraniaceae, with particular reference to G. carolinianum. METHODS: Length, width, mass, anatomy and germination of two seed types (light brown and dark brown) of G. carolinianum were compared. Location, anatomy and morphology of the water gap were characterized using free-hand and microtome tissue sectioning, light microscopy, scanning electron microscopy, dye tracking, blocking and seed-burial experiments. KEY RESULTS: Treatment with dry heat caused a colour change in the palisade cells adjacent to the micropyle. When placed in water, the 'hinged valve' (blister) erupted at the site of the colour change, exposing the water gap. The morphology and anatomy in the water-gap region differs from those of the rest of the seed coat. the morphology of the seed coat of the water-gap region is similar in G. carolinianum, G. columbinum, G. molle and G. pusillum and differs from that of the closely related species Erodium cicutarium. CONCLUSIONS: Dislodgment of swollen 'hinged valve' palisade cells adjacent to the micropyle caused the water gap to open in physically dormant seeds of G. carolinianum, and it was clear that initial water uptake takes place through this gap and not via the chalazal opening as previously reported. This water gap ('hinged valve gap') differs from water gaps previously described for other families in morphology, anatomy and location in the seed coat.

A historical, scientific and commercial perspective on the medicinal use of Pelargonium sidoides (Geraniaceae).

UNLABELLED: ETHNOPHARMACOLOGICAL CONTEXT: A detailed review of the ethnobotany and commercial history of Pelargonium sidoides is presented, together with a brief summary of pre-clinical and clinical scientific results that support the use of the plant in modern, evidence-based phytomedicines. The aim is to identify the main factors responsible for the success in product development. MATERIALS AND METHODS: The literature studied includes all modern scientific papers and also old documents and books that are no longer readily accessible. RESULTS: Available ethnobotanical information shows that several tuberous Pelargonium species (including Pelargonium sidoides) are important traditional medicines with a rich ethnobotanical history. A summary of the interesting history of the commercial development of Stevens' Cure or Umckaloabo in Europe is presented. Scientific evidence for the efficacy of the product, mainly as a treatment for acute bronchitis, is reviewed. These include numerous in vitro studies as well as 18 clinical studies. The botanical identity of the plant and its complex mixture of coumarins and other chemical constituents are summarised. CONCLUSIONS: The use of Pelargonium stems or tubers for a variety of ailments (including the complications of dysentery) is an important but hitherto under-estimated part of traditional medicine in southern Africa. Key elements in the successful development of Pelargonium sidoides from a profound traditional remedy to a highly successful phytomedicine include the choice of species, a favourable cost-benefit ratio, innovative marketing over many years, good scientific evidence of the botanical and chemical identity of the product and convincing proof of concept.

[Identification on Geranium by X-ray diffraction fourier fingerprint patterns and similarity degree of different fingerprint patterns].

OBJECTIVE: To provide a X-ray diffraction (XRD) new method to identify different of herbal drugs of Geranium. METHODS: Analyse X-ray diffraction Fourier pattern of 1 plants of Geranium, 7 kinds substitute, and degree of different fingerprint patterns was calculated and analyzed according to the position (2 theta value) of peaks searched. RESULTS: Obtain the different X-ray diffraction Fourier pattern of 1 kinds plants of Geranium and 7 kinds substitutes of Geranium. CONCLUSION: This method can be used for indentification on different medicinal material of Geranium.

[Study on morphology of the pollen of 4 species from Geranium in Heilongjiang Province].

Morphology of the pollen of 4 species from Geranium in Heilongjiang province which are G. wilfordii Maxim., G. sibiricum L., G. platyanthum Duthie. and G. dahuricum DC. were observed with optical microscope and scanning electron microscope. The results showed pollen grains of the four species were nearly spherical, with short clavate-shaped, net-shaped and cave-shaped veins on the outer walls and three short-furrow germ pores. Both the clava size and number of clava per unit surface area were different. This paper provided evidences for palynology classification of Geranium.