Trichome Bases Research Articles

Uncovering the physiology and distribution of thallium in Tl-hyperaccumulating and Tl-sensitive populations of Biscutella laevigata L.

Thallium (Tl) is extremely toxic to all lifeforms and an emerging pollutant. Plants in the Brassicaceae family, including edible crops, have an enhanced capacity for Tl accumulation, even from soils with low thallium concentration. The most extreme Tl hyperaccumulator is Biscutella laevigata, capable of attaining >32,000 μg Tl g-1 DW in its leaves. Biscutella laevigata from a non-metallicolous accession (Feltre, Italy) and a metallicolous accession (Les Malines, France) were subjected to a dosing experiment in hydroponics (0, 5, 30 μM Tl), followed by synchrotron-based µXRF analysis to elucidate tissue and cellular-level Tl distribution. Flow cytometric data on the two used accessions showed the Feltre accession has a genome size twice of that of the Les Malines accession (256 and 125 pg/2C respectively), suggesting they are phylogenetically distant populations. The Feltre accession does not accumulate Tl (125 μg Tl g-1 DW on average in leaves) at the 5 µM Tl dose level, whereas the Les Malines accession had a mean of 1750 μg Tl g-1 DW, with peaks of 24,130 μg Tl g-1 DW at the 30 µM Tl dose level. At 30 µM Tl the non-metallicolous accession did not grow, and at 5 µM Tl showed reduced biomasss compared to the metallicolous one. In Les Malines accession, the synchrotron-based µXRF analysis revealed that Tl is localised in the vacuoles of epidermal cells, especially underneath trichomes and in trichome basal cells. Thallium also occurs in solid crystalline deposits (3-5 µm in size, ~40 wt% Tl) that are mainly found in foliar margins and under trichome bases. Biscutella laevigata is an attractive model for studying Tl hypertolerance and hyperaccumulation on account of the extreme expression of this trait, and its marked intraspecific variability.

Exploring the Pharmacognostic Characteristics, Antioxidant Potential, and Anticholinesterase Activity of Piliostigma thonningii (Schum.) Milne-Redh.: Implications for Neuroprotection and Cognitive Health

Aim: The aim of this research is to investigate the pharmacognostic characteristics, antioxidant potential, and anticholinesterase activity of Piliostigma thonningii (Schum.) Milne-Redh. This study seeks to evaluate its potential applications for neuroprotection and cognitive health enhancement. Place and Duration of Study: This study was carried out in Nigeria by the Department of Medicinal Plant Research and Traditional Medicine, National Institute for Pharmaceutical Research and Development, Idu – Abuja, Nigeria between January 2024 and March 2024. Methodology: Physicochemical studies, including total Ash value and moisture content, were assessed using the powdered leaf sample. Leaf microscopy was conducted to examine the epidermal layer of the leaves. Anti-oxidant assays (Total phenol, total flavonoid and 2,2- diphenyl-1-picrylhydrazyl [DPPH] free radical scavenging activity), as well as acetylcholinesterase (AchE) inhibition assay was carried out on the methanolic leaf extract of the plant. Results: The powdered leaves of P. thonningii contained a total ash of 5.00% ± 0.00 and 7.74% ± 0.01 moisture. The alcohol- and water-soluble extractive values were 8.51% ± 0.24 and 9.77% ± 0.31, respectively. Leaf microscopic analysis showed the presence of polygonal cell walls, unicellular multiseriate trichomes, trichome base, xylem vessels, rosette-type calcium oxalate crystals, parenchyma, and collenchyma cells. The methanolic leaf extract exhibited antioxidant capacity, inhibiting DPPH in a dose-dependent manner, with total phenolics and flavonoids of 53.74(GAE) ± 1.59 and 42.51mg QE/g ± 0.38, respectively. The methanolic extract of P. thonningii in this study showed an AchE inhibition of between 5.89 % at 10 mg/ml to 16.56 % at 20 mg/ml Conclusion: The study reveals significant pharmacognostic characteristics, robust antioxidant potential, and notable anticholinesterase activity of P. thonniingii, suggesting its promising role in neuroprotection. These findings highlight its potential application in enhancing cognitive health and preventing neurodegenerative diseases.

How and why do species break a developmental trade-off? Elucidating the association of trichomes and stomata across species.

Previous studies have suggested a trade-off between trichome density (Dt) and stomatal density (Ds) due to shared cell precursors. We clarified how, when, and why this developmental trade-off may be overcome across species. We derived equations to determine the developmental basis for Dt and Ds in trichome and stomatal indices (it and is) and the sizes of epidermal pavement cells (e), trichome bases (t), and stomata (s) and quantified the importance of these determinants of Dt and Ds for 78 California species. We compiled 17 previous studies of Dt-Ds relationships to determine the commonness of Dt-Ds associations. We modeled the consequences of different Dt-Ds associations for plant carbon balance. Our analyses showed that higher Dt was determined by higher it and lower e, and higher Ds by higher is and lower e. Across California species, positive Dt-Ds coordination arose due to it-is coordination and impacts of the variation in e. A Dt-Ds trade-off was found in only 30% of studies. Heuristic modeling showed that species sets would have the highest carbon balance with a positive or negative relationship or decoupling of Dt and Ds, depending on environmental conditions. Shared precursor cells of trichomes and stomata do not limit higher numbers of both cell types or drive a general Dt-Ds trade-off across species. This developmental flexibility across diverse species enables different Dt-Ds associations according to environmental pressures. Developmental trait analysis can clarify how contrasting trait associations would arise within and across species.

The CsTM alters multicellular trichome morphology and enhances resistance against aphid by interacting with CsTIP1;1 in cucumber

The multicellular trichomes of cucumber (Cucumis sativus L.) serve as the primary defense barrier against external factors, whose impact extends beyond plant growth and development to include commercial characteristics of fruits. The aphid (Aphis gossypii Glover) is one of prominent pests in cucumber cultivation. However, the relationship between physical properties of trichomes and the aphid resistance at molecular level remains largely unexplored. Here, a spontaneous mutant trichome morphology (tm) was characterized by increased susceptibility towards aphid. Further observations showed the tm exhibited a higher and narrower trichome base, which was significantly distinguishable from that in wild-type (WT). We conducted map-based cloning and identified the candidate, CsTM, encoding a C-lectin receptor-like kinase. The knockout mutant demonstrated the role of CsTM in trichome morphogenesis. The presence of SNP does not regulate the relative expression of CsTM, but diminishes the CsTM abundance of membrane proteins in tm. Interestingly, CsTM was found to interact with CsTIP1;1, which encodes an aquaporin with extensive reports in plant resistance and growth development. The subsequent aphid resistance experiments revealed that both CsTM and CsTIP1;1 regulated the development of trichomes and conferred resistance against aphid by affecting cytoplasmic H2O2 contents. Transcriptome analysis revealed a significant enrichment of genes associated with pathogenesis, calcium binding and cellulose synthase. Overall, our study elucidates an unidentified mechanism that CsTM-CsTIP1;1 alters multicellular trichome morphology and enhances resistance against aphid, thus providing a wholly new perspective for trichome morphogenesis in cucumber.

Characterization of Microbotryum lychnidis-dioicae Secreted Effector Proteins, Their Potential Host Targets, and Localization in a Heterologous Host Plant.

Microbotryum lychnidis-dioicae is an obligate fungal species colonizing the plant host, Silene latifolia. The fungus synthesizes and secretes effector proteins into the plant host during infection to manipulate the host for completion of the fungal lifecycle. The goal of this study was to continue functional characterization of such M. lychnidis-dioicae effectors. Here, we identified three putative effectors and their putative host-plant target proteins. MVLG_02245 is highly upregulated in M. lychnidis-dioicae during infection; yeast two-hybrid analysis suggests it targets a tubulin α-1 chain protein ortholog in the host, Silene latifolia. A potential plant protein interacting with MVLG_06175 was identified as CASP-like protein 2C1 (CASPL2C1), which facilitates the polymerization of the Casparian strip at the endodermal cells. Proteins interacting with MVLG_05122 were identified as CSN5a or 5b, involved in protein turnover. Fluorescently labelled MVLG_06175 and MVLG_05122 were expressed in the heterologous plant, Arabidopsis thaliana. MVLG_06175 formed clustered granules at the tips of trichomes on leaves and in root caps, while MVLG_05122 formed a band structure at the base of leaf trichomes. Plants expressing MVLG_05122 alone were more resistant to infection with Fusarium oxysporum. These results indicate that the fungus might affect the formation of the Casparian strip in the roots and the development of trichomes during infection as well as alter plant innate immunity.

Comparison of chloroplast genomes and phylogenetic analysis of four species in Quercus section Cyclobalanopsis

The identification in Quercus L. species was considered to be difficult all the time. The fundamental phylogenies of Quercus have already been discussed by morphological and molecular means. However, the morphological characteristics of some Quercus groups may not be consistent with the molecular results (such as the group Helferiana), which may lead to blurring of species relationships and prevent further evolutionary researches. To understand the interspecific relationships and phylogenetic positions, we sequenced and assembled the CPGs (160,715 bp-160842 bp) of four Quercus section Cyclobalanopsis species by Illumina pair-end sequencing. The genomic structure, GC content, and IR/SC boundaries exhibited significant conservatism. Six highly variable hotspots were detected in comparison analysis, among which rpoC1, clpP and ycf1 could be used as molecular markers. Besides, two genes (petA, ycf2) were detected to be under positive selection pressure. The phylogenetic analysis showed: Trigonobalanus genus and Fagus genus located at the base of the phylogeny tree; The Quercus genus species were distincted to two clades, including five sections. All Compound Trichome Base species clustered into a single branch, which was in accordance with the results of the morphological studies. But neither of group Gilva nor group Helferiana had formed a monophyly. Six Compound Trichome Base species gathered together in pairs to form three branch respectively (Quercus kerrii and Quercus chungii; Quercus austrocochinchinensis with Quercus gilva; Quercus helferiana and Quercus rex). Due to a low support rate (0.338) in the phylogeny tree, the interspecies relationship between the two branches differentiated by this node remained unclear. We believe that Q. helferiana and Q. kerrii can exist as independent species due to their distance in the phylogeny tree. Our study provided genetic information in Quercus genus, which could be applied to further studies in taxonomy and phylogenetics.

Lophiolepis (=Cirsium Epitrachys seksiyonu) cinsine ait Türkiye’den yeni bir melez kaydı (Asteraceae, Carduinae)

Lophiolepis Cass., belonging to the tribe Cardueae of the family Asteraceae (subtribe Carduinae) is newly separated from the genus Cirsium Miller in the light of recent molecular studies. It has a high affinity to form interspecific and intersubspecific hybrids under certain circumstances. In the present study, one hybrid combination, Lophiolepis x trifurca (Petr.) Bureš, Del Guacchio, Iamonico &P. Caputo which was previously described as Cirsium x trifurcum Petrak by Petrak in 1914 is newly recorded for Turkish Flora. The hybrid specimens have intermediate characters with parental species; Lophiolepis kosmelii (Adams) Bureš, Del Guacchio, Iamonico & P. Caputo and L. caucasica (Adams) Bureš, Del Guacchio, Iamonico & P. Caputo. Plant samples including parental species were collected from Şavşat district of Artvin province in sympatric populations. These specimens were carefully examined and compared with the putative parents, and morphological character measurements of hybrid plants, as well as parental species were carried out. The samples’ natural habits were photographed, cauline leaf drawings were supplied using a stereomicroscope, leaf micromorphological characters were determined and anatomical characteristics were compared with parents, in detail. In conclusion, intermediate morphological characteristics between L. x trifurca and its parents were determined in terms of features such as cauline leaves, phyllaries, capitula and corolla. It has spines on adaxial sides, and uniseriate multicellular tomentose trichomes in abaxial ones. Cuticle has striate appearance near to the stomata/ trichome bases in the abaxial surface and scale/granules are shown in adaxial parts. This taxon has amphistomatic leaves and dorsiventral mesophyll as in the parental species.

Fossil leaves of Populus L. (Salicaceae Mirb.) from the upper Pliocene of Tengchong, Yunnan, southwestern China

Fossil leaves of Populus L. (Salicaceae Mirb.) were widely reported in the North Hemisphere during the Cenozoic. However, most of them are leaf impressions without details of cuticles or only preserved as tiny cuticle fragments. Here, we describe several fossil leaves of Populus with fine cuticular structures from the upper Pliocene of Tengchong, western Yunnan, China. The leaves have ovate, rhombic-ovate to orbicular leaf shape with long petioles, pinnate venation, rounded to cuneate bases, acuminate apices and serrate margins. They are pilose bilaterally with multicellular trichome bases and hypostomatic with paracytic stomata. According to the gross morphology and cuticle structures, the present fossils mostly resemble the extant species P. rotundifolia Griff. except that the fossils have denser trichome bases, and are therefore tentatively assigned to Populus cf. rotundifolia Griff. Nowadays, P. rotundifolia is distributed at mountain slopes above an elevation of 2000 m a.s.l. The present new finding indicates that western Yunnan might have approached its present height at least by the late Pliocene. Recent phylogenetic study proposed that the divergence of P. rotundifolia from P. davidiana Dode occurred at the Pleistocene (Calabrian, ca. 0.88 Ma). However, our fossil occurrence implies that such a divergence might have occurred at least by the late Pliocene (3.3–2.8 Ma), much earlier than the molecular estimation. In addition, the Hengduan Mountainous Region might be the species differentiation center of P. rotundifolia from P. davidiana based on their modern distributions and the present fossil occurrence.

Effect of high-intensity light on the photosynthetic activity, pigment content and expression of light-dependent genes of photomorphogenetic Solanum lycopersicum hp mutants

The relationship between photosynthesis, pigment accumulation, and the expression of key light-regulated genes in Solanum lycopersicum hp-1, hp-2 and hp-1.2 photomorphogenetic mutants under conditions of high-intensity light (2000 μm (photons) m−2s−1) was studied.The hp-2 mutant (LA3006) and the hp-1 mutants (LA4012 and LA3538) are deficient in DET1 (De-etiolated 1 and DDB1 (DNA DAMAGE-BINDING PROTEIN 1), respectively, which are components of the CDD complex (COP10, DDB1, DET1). HP mutants are superproducers of various pigments and are sensitive to light. We have shown that HIL (high-intensity light) causes a decrease in PSII activity after 24 and 72 h of irradiation, which was partially restored after 72 h in the WT. The photosynthetic rate noticeably decreased only in LA4012 and LA3538 after 24 h of irradiation. After 72 h, the photosynthetic rate decreased in all mutants, with the exception of hp-1.2 LA0279, but the decrease was most noticeable in LA4012, yet significant changes in the respiration rate were absent. The LA0279 mutant was more capable of accumulating anthocyanin in the cells of the subepidermal parenchyma and chlorenchyma, as well as in the cells at the base of large multicellular glandular trichomes and in the mesophyll. Another important difference was the accumulation of increased amounts of antheraxanthin and phenolic compounds in the leaves of LA0279 after 72 h of HIL irradiation. Unlike LA4012, LA3006, LA0279, and LA3538 sowed a significantincrease in the expression levels of CHS, HY5, and FLS genes after 24 h, which may be one of the reasons for the higher adaptive potential of those three mutants. In addition to that in LA3538, strong light-induced stress led to an increased level of flavonol synthase (FLS) expression in the LA3006, LA0279, and LA4012 mutants.We hypothesize that the photosynthetic apparatus (PA) of the LA0279 mutant, which is deficient in the DET1 and DDB1 genes, is most adapted to prolonged HIL. Most likely, the resistance of PA mutants to HIL is due to a variety of factors, which, in addition to the redistribution of carotenoids, may include morphological features associated with the accumulation of anthocyanin in the epidermis, subepidermal layer, mesophyll and trichomes of leaves and with an increase in leaf thickness.

New genus for megaphyllous leaves from the Upper Paleozoic of Mexico Velascoa pueblensis gen. nov

The paleoflora of the Matzitzi Formation has been studied since the beginning of the last century. Recent surveys have allowed the collection of abundant unregistered material, within which there is a notable group of leaves with a morphology similar to Ginkgophyta. The morphological analysis of more than 100 specimens resulted in the identification of large laminae with a long petiole, fan-shaped leaves with dichotomous venation and a characteristic constant segmentation that occurs up to three times and ends at the apex with 12 segments. It exhibits epidermal cells with sinuous to crenulated walls on the abaxial side, where anomocytic stomata and trichome bases can be observed. Given the absence of reproductive structures and the age of the material, its affinity to the order Ginkgoales is not possible; the comparisons were thus made with genera of the artificial group Ginkgophyta from different localities of the Upper Paleozoic. The results show significant morphological differences that support the proposal of a new genus and species, denominated Velascoa pueblensis. We also identified 10 orders and 27 genera that update the floristic lists created over 50 years ago. This information is important since it will allow to resolve future taxonomic, distributional, and/or environmental aspects that allowed the establishment of the taxa mentioned above.

The complete chloroplast genome sequence of Quercus chungii (Fagaceae)

Quercus chungii F.P.Metcalf, a rare oak with endemic to southern China, belongs to the compound trichome base (CTB) lineage in the Cyclobalanopsis section. The complete chloroplast genome of the species was assembled and annotated in this study. The circular genome was 160,731 bp in size, presenting a typical quadripartite structure including one large single-copy region (LSC, 90,140 bp), one small single-copy region (SSC, 18,911 bp), and two copies of inverted repeat regions (IRs, 25,840 bp). It encoded a total of 113 unique genes, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. The maximum-likelihood (ML) phylogenetic tree reconstructed by IQ-TREE indicated that Q. chungii was more closely related to Q. myrsinifolia and Q. sichourensis.

Aquatic ferns (Salviniaceae) in the Holocene sediments from the Bermejo River, Eastern Chaco, Argentina

The Gran Chaco Americano is a large subtropical plain and one of the major biogeographic and morphostructural territories of South-America. Eastern Chaco is the wettest sector of the Gran Chaco and has heterogeneous environments. It includes different types of woodlands and forests together with savannahs, grasslands and wetlands. These vegetation patterns have been proposed to be the result of the Quaternary alluvial plain dynamics and the intensive migration of the Chacoan main rivers. Fossil records-that show change-are scarce and most of them come from the Fidelidad Formation (late Holocene). This Formation is located on the Bermejo River natural levees near the Villa Escolar Town (Formosa Province, Argentina). Fern fossils discovered in this Formation correspond to heterosporous aquatic ferns (Salviniaceae). The impressions were assigned to Salvinia cf. minima Baker 1886. These correspond with orbicular to elliptical leaves, with a smooth margin, and both the apex and the base are rounded. The base bears a slightly developed petiole. The venation pattern is dichotomous with anastomoses forming areolas. Generally, four tubercles (trichome bases) per areola are observed. The massulae and spores correspond to Azolla cristata Kaulfuss 1824. The massulae are rounded, oval or kidney-shaped and have septate glochidia. Spores are trilete and spheroidal. The floating ferns Salvinia and Azolla are good indicators of open fresh-water or wetlands paleo-environments. Hence, the lower levels of the Fidelidad Formation are associated with mostly calm freshwater bodies such as rivers, streams or wetlands, which are closely related to the activity of the Bermejo River during the late Holocene. These aquatic fern fossils provide new insights into paleoenvironmental conditions and increase the paleontological richness of the Eastern Chaco.

Arabidopsis thaliana zinc accumulation in leaf trichomes is correlated with zinc concentration in leaves

Zinc (Zn) is a key micronutrient for plants and animals, and understanding Zn homeostasis in plants can improve both agriculture and human health. While root Zn transporters in plant model species have been characterized in detail, comparatively little is known about shoot processes controlling Zn concentrations and spatial distribution. Previous work showed that Zn hyperaccumulator species such as Arabidopsis halleri accumulate Zn and other metals in leaf trichomes. To date there is no systematic study regarding Zn accumulation in the trichomes of the non-accumulating, genetic model species A. thaliana. Here, we used Synchrotron X-Ray Fluorescence mapping to show that Zn accumulates at the base of trichomes of A. thaliana. Using transgenic and natural accessions of A thaliana that vary in bulk leaf Zn concentration, we demonstrate that higher leaf Zn increases total Zn found at the base of trichome cells. Our data indicates that Zn accumulation in trichomes is a function of the Zn status of the plant, and provides the basis for future studies on a genetically tractable plant species to understand the molecular steps involved in Zn spatial distribution in leaves.

Cellular autofluorescence and browning in trichomes of Chinese cabbage (Brassica campestris) in response to mechanical stimulation and senescence.

There is limited information concerning the formation of dot-like browning appearing at the base of trichomes on mature leaves on the Chinese cabbage (Brassica campestris L. ssp. pekinensis). This study confirmed for the first time that enhanced autofluorescence can be induced in the base of trichomes when pressure stimuli is applied to trichomes; the enhanced autofluorescence gradually moves to the top of trichomes and the neighbouring mesophyll tissue within 15min. The excitation of autofluorescence in trichomes was found to be more effective in mature leaves compared to newly emergent leaves. Increased polyphenol oxidase (PPO) activities and reactive oxygen species (ROS) accumulation were also detected in the basal region of trichomes that were subjected to mechanical stimuli. Enhanced fluorescence was observed at the top of the trichomes in senescencing leaves. A browning in the base of the trichomes during leaf senescence was observed. In contrast, no browning occurred at the base of the trichomes in leaves that were subject to pressure stimuli. The blue fluorescence in the trichomes in senescent leaves arises mainly from the condensed cytoplasm. No direct evidence was able to prove that the enhanced autofluorescent substances in the trichomes during leaf senescence are the cause of the browning at the early growth stages.

Effect of gene mutation of plants on their mechano-sensibility: the mutant of EXO70H4 influences the buckling of Arabidopsis trichomes.

With the development of molecular biology, more and more mutants of plants have been constructed, where gene mutants have been found to influence not only the biological processes but also biophysical behaviors of plant cells. Trichomes are an important appendage, which has been found to act as an active mechanosensory switch transducing mechanical signals into physiology changes, where the mechanical property of trichomes is vital for such functions. Up to now, over 40 different genes have been found with the function of regulating trichome cell morphogenesis; however, the effect of gene mutants on trichome mechanosensory function remains elusive. In this study, we found that EXO70H4, one of the most up-regulated genes in the mature trichome, not only affects the thickness of the trichome cell wall but also the mechanical property (i.e., the Young's modulus) of trichomes. Finite element method simulation results show that the buckling instability and stress concentration (e.g., exerted by insects) cannot occur on the base of the mutant exo70H4 trichome, which might further interrupt the mechanical signal transduction from branches to the base of trichomes. These results indicated that the mutant exo70H4 trichome might lack the ability to act as an active mechanosensory switch against chewing insect herbivores. Our findings provide new information about the effect of gene mutation (like crop mutants) on the mechano-sensibility and capability to resist the agricultural pests or lodging, which could be of great significance to the development of agriculture.

Comprehensive observation of trichome development in Micro-tom tomato

Trichomes help plants defend against various stresses by formation of a protective barrier. Although the unicellular trichomes in <i>Arabidopsis</i> have been well studied, little is known of the development of multicellular trichomes in tomato. With seven morphologically and functionally different types, tomato trichomes are more complex than the unicellular trichomes in <i>Arabidopsis</i>. Here, we comprehensively analyzed the spatiotemporal pattern of tomato trichome development. Our observations show that the gradual reduction of type I/IV trichomes during leaf development is accompanied by an increase of other trichome types. We further examined the gland development of type I/IV trichomes by constructing a marker reporter, pSlAT2: GUS-YFP which is specifically expressed in the top cell of the trichomes. Interestingly, we found the multicellular base of trichomes is initiated as early as the two-cell stage. Through tracking a nuclear marker, H2B-GFP in tomato trichomes, we found the correlation between stalk cell length and nuclear size, suggesting that cell ploidy level could affect trichome cell size. Finally, we found type VII glandular trichomes exhibit two morphologically distinct forms, with the majority covered by a wax-like substance, which could help to form extra storage space for secretory metabolites. Our results provide the basis for further mechanistic study of trichome development in tomato.

Morphology and epidermal anatomy of Tricalycites, a winged propagule from the Cretaceous of North America

Tricalycites Hollick is a distinctive winged propagule that has served as a stratigraphic marker in North American Cretaceous floras. However, its affinities have long been uncertain since the original description of this genus in 1895. Our recent re-examination of specimens from major museum collections and from recent fieldwork has allowed for a revised concept of the morphology and the addition of new details of epidermal anatomy. Twenty three specimens were studied from numerous sites, ranging over a broad area of eastern North America including New Jersey, New York, Massachusetts, Rhode Island, Alabama, and Texas. Tricalycites disseminules have often been called winged fruits, but we cannot eliminate the possibility of them being gymnospermous seeds with a wing derived from an associated envelope or cupule. The type species, T. papyraceus, was previously described by Newberry as having one wing with three lobes or three wings, but we observed only one wing with three prominent lobes. Cuticles of Tricalycites were examined for the first time. The wings lack trichome bases and have paracytic to tetracytic stomata. The new observations facilitate a revised circumscription of the genus Tricalycites but still leave the affinities of this plant open for discussion.

Comparative foliar epidermal morphology of Isolona Engl. (Annonaceae)

A qualitative micromorphological assessment of the seven species of Isolona occurring in Nigeria and the Cameroons was undertaken with the aid of light microscope. The stomatal cells are particularly useful, providing stable characters which can be reliably employed in distinguishing the species. Hypostomatic leaves and paracytic stomatal type are generic constant. Possession of only paracytic stomata is characteristic of I. dewevrei whereas other species may have in addition another type such as 1+2 laterocytic stomatal type found only in I. zenkeri and presence of brachyparacytic stomata which shows relatedness of I. campanulata, I. congolana, I. hexaloba, I. pleurocarpus and I. thonneri. The epidermal surfaces appeared glabrous but an indication of hairs is shown by the presence of a glandular trichome base only in I. hexaloba. The epidermal cell characters such as epidermal cell shapes and anticlinal wall patterns seem to intergrade and they are not as definite as the stomatal cells. However, a combination of these features will be helpful in defining the species better and their leaf fragments can be differentiated based on the various characters studied for effective utilization in herbal medicinal research.

Adpression of medullosan prepollen-producing organs, their prepollen and cuticles (Westphalian, Intrasudetic Basin, Czech Republic)

The adpression fossil record from the Westphalian of the Intrasudetic Basin (Czech Republic) contains diversified medullosan prepollen organs. Langsettian bell-shaped prepollen organs were found in the Lampertice Member in the Žacléř area: Whittleseya elegans Newberry, W. delphinae Stockmans et Willière, W. silesiaca Pacyna et Zdebska and Givesia media (Stockmans) Stockmans et Willière. These fructifications may have been produced by plants with fronds of the fossil-genera Neuralethopteris Cremer and Alethopteris Sternberg. Parent plants of small Langsettian Aulacotheca sp. are uncertain. Duckmantian medullosan male fructifications from the Malé Svatoňovice area are elongated capsules described as Aulacotheca idae Šimůnek sp. nov. and were produced by plants with Alethopteris idae Šimůnek fronds. The prepollen grains and cuticles were isolated from Whittleseya elegans, W. delphinae, Givesia media and Aulacotheca idae. All prepollen grains are oval with two longitudinal grooves and a monolete suture, and are classified as Monoletes ovatus Schopf. There is great overlap in the dimensions of the prepollen of Whittleseya elegans, W. delphinae and Givesia media – 155–230 μm long and 100–180 μm wide. Prepollen of Aulacotheca idae are much bigger – 330–375 μm long and 190–245 μm wide. The inner cuticular layer is gently cutinised with polygonal cells. Cuticles from the prepollen organ surface has elongated cells in Whittleseya elegans (with stomata) and Givesia media (with trichome bases), and has polygonal cells in Whittleseya delphinae (with periclinal cell wall thickenings) and Aulacotheca idae (with hollow papillae on periclinal cell walls). The question, as to whether Whittleseya elegans and W. delphinae are conspecific is discussed.

Pharmacognostic Standardization and Physicochemical Analysis of Clerodendrum Wallichii (Merr.) Leaves

Background: Presently, the use of herbal medicines is expanding rapidly across the world. While considering source materials, authentication and standardization are prerequisites for herbal formulation in any system of medicine. The plant Clerodendrum Wallichii Merr. (Family: Lamiaceae) has been used for various ailments in traditional systems of medicines, particularly in the treatment of diarrhea, skin infection, inflammation and fever.&#x0D; Objectives: The present study was designed to establish the pharmacognostic standards and perform the physicochemical analysis of C. wallichii leaves. Macroscopic and microscopic studies were performed using the simple and trinocular microscope, respectively.&#x0D; Methods: The World Health Organization guidelines were followed for the physicochemical analysis of the plant. Fluorescence analysis was observed at daylight, short UV light, and long UV light. The leaves of C. wallichii were found dark green on the upper surface and light green in the lower surface which is odorless and bitter. The leaves are oblong to oblong-lanceolate with a smooth surface. The size of leaves varies from 11 to 18 cm in length and 2.5 to 4 cm in diameter.&#x0D; Results: Powdered microscopy showed the various characters like rare multicellular covering trichome, xylem vessels (reticulate), fiber, trichome base, stellate trichome, adaxial epidermal cell (rectangular), abaxial epidermal cell (irregular), vessels, stomata (anisocytic), calcium oxalate crystals (square and cubic). Physicochemical parameters like moisture content of dry powder of the plant was determined 9.3% W/W. The total ash, acid-insoluble, and water-soluble ash values were calculated as 10.48%, 1.08%, and 8.17%, respectively. The loss on drying was calculated as 9.3% W/W.&#x0D; Conclusion: Extractive values by cold and hot maceration method were also determined. Our obtained data help to authenticate the plant and establish its pharmacopoeial standards.