Arrangement Of Vascular Bundles Research Articles

Utilization of Advanced Microscopy Techniques and Energy-dispersive X-ray Spectroscopy to Characterize Three Piper Species Related to Kava.

Macro- and microscopic techniques have long been used to describe plant materials and establish plant structural profiles. These techniques are commonly used in botanical authentication to identify the genuine and closely allied species used in botanical research. Advanced microscopic techniques were used in this study to differentiate three different Piper species used as kava or kava-kava. The genuine species is Piper methysticum and the other two species commonly called false-kava or kava-kava, are Piper auritum and Piper excelsum. Macroscopic characteristics, including a black-spotted stem and fibrous root, are characteristic of P. methysticum, whereas the stem of P. auritum is greenish with no spots, and the P. excelsum stem is purple-pink. Microscopic attributes include the characteristic collenchyma of stems and the pattern of arrangement of peripheral and medullary vascular bundles. The starch grains are smaller in P. excelsum than in the other two species. Energy-dispersive X-ray spectroscopy analysis of the crystals indicates the expected calcium, magnesium, and silica, along with lesser amounts of sodium, and potassium. The crystals present in the Piper species vary in shape, size, and elemental composition. Combining macro- and microscopical techniques and resulting characteristics are instrumental in differentiating the three Piper species.

A Modeling Approach to Studying the Influence of Grafting on the Anatomical Features and SAUR Gene Expression in Watermelons

Grafting alters the genetic and anatomical features of plants. Although grafting has been widely applied in plant propagation, the underlying processes that govern the effects of the procedure are not fully understood. Samples were collected to study the long-term influence of grafting on the leaf-shoot morphology, leaf-shoot anatomy, and genetic signature of the grafted plants. Citrulus lanatus (Thunb.) Matsum. & Nakai (cv. Lady) was used as the scion, and Lagenaria siceraria (Molina) Standl (cv. Argentario) as a rootstock. In grafted plants, leaf blades and petioles were 20.92% and 12.82% longer, respectively, while the midrib collenchyma was 35.68% thicker, and the diameter of the vessel member was 11.17% larger than in ungrafted plants. In the stem, grafting affected the arrangement and number of vascular bundles (from 1 to 2 rings). The thickness of the epidermis decreased by 69.79%, and the size of the external fascicular phloem decreased by 23.56%. The diameter of the vessel member of the grafted plants increased by 28.94%. Eight out of ten evaluated primers met the requirements (stability in both watermelons and bottle gourd, tissue-specific). In the genetic tests, we examined whether this change in the gene expression pattern is due to the grafting and, if so, to what extent. Seven out of eight tested Small Auxin Up-Regulated RNA (SAUR) genes were expressed in the ungrafted and grafted C. lanatus lines in four cases; the expression increased by more than 10% after grafting. The morpho-anatomical changes and genetic variation reported in this study for grafted lines of C. lanatus contribute to the understanding of the underlying mechanisms of plant growth observations resulting from grafting.

Panxianopteris taeniopteroides gen. et sp. nov., an anatomically preserved taeniopterid leaf from the upper Permian of Guizhou Province, China

Taeniopterid leaves with entire margins, prominent midribs and simple or bifurcate lateral veins are present in many Paleozoic and Mesozoic floras globally and were a typical and diverse element in the late Paleozoic equatorial Cathaysian flora. Most taeniopterid leaves are preserved as impression-compression fossils that reveal only information on their morphology and in some cases cuticle structure. Taeniopterid leaves preserved with anatomy are much rarer and have only previously been identified in the Mesozoic. Here we report a taeniopterid leaf from the upper Permian Xuanwei Formation in southwestern China that preserves morphology and anatomy. The leaf is over 18 cm long and 10 cm wide, with the lamina attached to the lateral sides of the midrib. Parallel lateral veins arise from the midrib which has longitudinal ridges on its adaxial surface and two distinct groups of vascular bundles. One group of bundles is adaxially located and arranged in a rough inverted Ω-shape, while the other is abaxially located and arranged in a ring. Individual bundles have endarch primary xylem and secondary xylem. Comparisons with other anatomically preserved taeniopterid leaves allow us to establish Panxianopteris taeniopteroides gen. et sp. nov. This vascular bundle arrangement is most comparable to the rachis of the Triassic Umkomasiales pteridosperm leaf Dicroidium fremouwensis from the Gondwanan flora. P. taeniopteroides is the first anatomically preserved taeniopterid leaf reported from the Paleozoic and the Cathaysian flora, and although its affinity remains enigmatic because it is only known from its isolated leaf, it is likely to be a pteridosperm allied with the Umkomasiales or their ancestral lineage.

Assessment of Density and Anatomical Features of Young and Old Bambusa vulgaris (Schrad. ex J.C. Wendl.) Culm Heights as Sustainable Structural Material in Ghana

This study sought to assess the density and anatomical features of young and old Bambusa vulgaris Schrad. ex JC Wendl. culm heights and, therefore, evaluate their influence on the utilization potential of the culm as a sustainable structural material. Bambusa vulgaris culm of 2-year and 4-year-old were harvested and prepared to the required length of 6 meters for the study. Basic density and anatomical features were carried out. The results showed that the basic density of old bamboo ranges from 652.91 kg/m³ to 729.06 kg/m³, while the young bamboo ranges from 342.33 kg/m³ to 509.52 kg/m³. The vascular bundle arrangement was found to be in Type III and Type IV for the culm heights of both young and old bamboo. The average vascular bundle radial diameter ranged from 761.13 μm to 890.78 μm for the old culm and 727.16 μm to 844.83 μm for the young culm. The average vascular bundle tangential diameter ranged from 499.44 μm to 533.49 μm for the old culm and 425.56 μm to 483.56 μm for the young culm. The radial diameter of the metaxylem vessel of the old culm ranged from 216.81 μm to 54.74 μm, while 214.23 μm to 73.86 μm were for the young culm. Parenchyma tissues ranged from 35%– to 70% for the old bamboo culm and 45% to 75% for the young bamboo culm. Vessel proportion ranged from 6%–12% for the old culm while the young culm ranged from 5%–11%. Fiber proportion ranged from 22% to 54% for the old culm and 19% to 44% for the young culm. Old bamboo had better vascular bundle properties than that of young bamboo. The density is significantly correlated positively to the anatomical properties. Old bamboo is more suitable to be used as the engineered composite material due to its better anatomical features across the culm wall thickness.

Anatomy of leaf blade, leaf sheath and pseudopetiole in Neotropical Bambusoideae (Poaceae): Insights into structure and taxonomic contributions

Anatomical investigations aiming to seek alternative characters for the taxonomy of bamboos are almost exclusively restricted to the leaf blade. Little is known about the anatomical structure of other parts of the leaf, such as the leaf sheath and pseudopetiole. The present paper analyzed the complete structure of foliage leaves, including the foliage leaf blade, foliage leaf sheath, and pseudopetiole of species belonging to the tribes Bambuseae (subtribes Guaduinae, Chusqueinae and Arthrostylidiinae) and Olyreae (subtribe Parianinae) to identify useful characters in the taxonomy of bamboos. We used scanning electron microscopy and light microscopy to describe micromorphological and anatomical features. All species sampled share the following features: foliage leaf blades with uniseriate epidermis; adaxial bulliform cells; mesophyll with arm cells, cavities, and collateral vascular bundles. Intercostal sclerenchyma associated to bulliform cells was observed only in Arthrostylidiinae. Micromorphologically, the shape and distribution of silica bodies, presence, type, and distribution of papillae on the long cells and subsidiary cells, and the presence and distribution of trichomes may be taxonomically informative in different taxonomic levels. We highlight the absence of papillae on the surfaces of foliage leaf blade of Guaduinae since the presence of papillae is considered a putative diagnosis feature supporting the sister relationship of this subtribe with Arthrostylidiinae. We describe the anatomical structure of foliage leaf sheath for the first time for Guaduinae, Chusqueinae and Parianinae. In Guaduinae, we found a unique distribution pattern of silica cells on the abaxial surface of the leaf sheath. Anatomical data about the pseudopetiole structure also were described for the first time in bamboos species; the arrangement of vascular bundles may be taxonomically informative, especially in Guaduinae.

Implications of stipe and midrib morpho-anatomy on the taxonomy of Polypodiaceous ferns

After decades of uncertainty, the current fern classification corroborates traditional morphology with molecular evidence and is widely accepted. However, in the complex family Polypodiaceae, some major generic recircumscriptions are still open. The present study aims to provide a comprehensive account of the stipe and midrib morpho-anatomical features of polypodiaceous ferns from the eastern Himalayan region. Fresh specimens belonging to 24 species were collected from the study area. Macro-morphological features like colour, size, and texture were observed in the field with the aid of a dissection microscope while micro-morphological traits like scales, indument, and anatomical details were observed under a compound microscope. The type of tissues, arrangement of vascular bundles, the shape of xylem, and circumendodermal band seem to be of taxonomic significance. The UPGMA reveals comparable correlations with previously published clades and relationships based on morphological as well as molecular data.

Analysis of mechanical and anatomical properties of two bamboo species – Thyrostachys siamensis Gamble and Dendrocalamus strictus (Roxb.) Nees (Poaceae)

Bamboos are treated to boost their shelf life from the degrading activity of fungal microbes and other insects and to increase their longevity in use and durability by using various chemicals. The present study is vis-a-vis the standardization of two bamboo species Dendrocalamus strictus and Thyrostachys siamensis for a comparative analysis of the mechanical and anatomical properties of samples treated with CCB (Copper Chrome Boron), and BBA (Borax Boric Acid) as well as untreated samples.Samples were tested for both bending and compression; and the parameters such as MOE (Modulus of Elasticity), MOI (Moment of Inertia), Maximum compressive strength, and ultimate strength were analyzed. The anatomical variations arising in the top and bottom sections were also investigated and it has found that the mechanical properties of the species treated with CCB solutions yield a better result in maximum compressive strength and high value of MOI as compared to BBA whereas the samples treated with BBA provides superior performance with respect to MOE. Anatomical examination revealed that the cellular structure and arrangement of vascular bundles are responsible for the increase in time taken for the rate of penetration of chemicals in D.strictus i.e one-half hour as compared to T.siamensis which got treated in 20 minutes. In D.strictus the density of vascular bundles is high so it takes time to get it treated completely as compared to T. siamensis.

Taxonomic Significance of Foliar and Stem Anatomy in the Delimitation of Piptadeniastrum africanum (Hook.F.) Brenan and Cathormion altissimum (Hook.F.) Hutch. & Dandy

The current monotypic status of the genus Piptadeniastrum Brenan is reasonably challenged as Cathormion altissimum is claimed to be closely related to Piptadeniastrum africanum – the only species in the genus – by some indigenous people of Bayelsa State. This work systematically examines this claim by studying some aspects of the foliar and stem anatomy of P. africanum and C. altissimum. Leaf peels and stem sections were made and analyzed according to standard procedures. Anatomical characteristics considered include stomata distribution, stomatal Index, type of stomata, the shape of leaf epidermal cells and anticlinal walls, the outline of the stem, and the arrangement of vascular bundles. Results showed that stomatal distribution in both plants was hypostomatic. Stomatal index and stomata type was 21.5% and mainly anomocytic, respectively, for P. africanum and 14.4% and primarily paracytic, respectively, for C. altissimum. Epidermal cell shape is irregular with undulating anticlinal walls in P. africanum, while epidermal cell shape is rectangular to polygonal with curved or straight anticlinal walls in C. altissimum. The outline of the stem is angular with four pronounced ridges and furrows in P. africanum, while the stem outline is wavy with very mild protrusions in C. altissimum. The differences in anatomical characteristics may justify the placement of these plants in different genera. Piptadeniastrum Brenan is monotypic.

Micromorphological study of Cordia sinensis Lam. from the Northern Western Ghats, India

The genus Cordia L. is a medicinally important taxon. Cordia sinensis Lam., which is endemic to the Western Ghats of India, is a potential medicinal plant and is presumed to have similar biochemical activities. Since the species is consumed mainly in crude form, it is difficult to establish the identity based on only mature leaf and stem characters. A significant study has been carried out to authenticate the identity of the Cordia genus based on foliar anatomical characters. The anatomical sections of a leaf transverse section and petiole transverse section of the species were observed under the bright-field compound microscope, and observations were documented. Though the diagrammatic outline of the leaf sections is similar, detailed anatomical characters are significantly different. The structure and number of the trichomes are observed abaxial and adaxial sides of the leaves. The trichomes were also found to be valuable characters for identification. In the case of leaf, the number and arrangement of vascular bundles, arrangement of collenchyma at the lower epidermis, palisade cells, and distribution of storage cells are the major characteristics to differentiate other species of Cordia. During the study, we also observed the detailed characters of the cuticular layer, trichomes, and stomatal characters. Rananculious type stomata and the presence of cystoliths in the basal cell of the trichome are the common characteristics observed in the studied species. Based on the preliminary study, the species can be differentiated based only on foliar anatomical characters.

Dry shrinkage of Moso bamboo in relation to vascular bundle structure

Abstract Bamboo is susceptible to moisture-induced dimensional instability and cracking. Combining traditional methods with vascular bundle detection, the coordinates and fiber sheath area of each vascular bundle was determined accurately. Based on data fitting, the change in the shape of cross-section was quantified and analyzed based on parameters such as radius, radian, and arc length. The changes in the total area and the areas of different types of fiber sheath, as well as the changes in the arrangement of vascular bundles were studied. The results showed that when the moisture content was reduced from 64% to 0%, the radius of the cross section was increased by 21%, while the radian and arc length decreased by 22% and 6%, respectively. The fibers shrunk by 15%, which was greater than that of the other tissues except bamboo fibers (9%). The gradient distribution of the fiber volume fraction contributed to its asynchronous dry shrinkage. Significant radial and tangential displacements were found in vascular bundles. This work further elucidated the dry shrinkage mechanism of bamboo, and was of great significance for the quantitative analysis of changes in bamboo structure from a combination of micro and macro perspectives.

Dandelion pappus morphing is actuated by radially patterned material swelling.

Plants generate motion by absorbing and releasing water. Many Asteraceae plants, such as the dandelion, have a hairy pappus that can close depending on moisture levels to modify dispersal. Here we demonstrate the relationship between structure and function of the underlying hygroscopic actuator. By investigating the structure and properties of the actuator cell walls, we identify the mechanism by which the dandelion pappus closes. We developed a structural computational model that can capture observed pappus closing and used it to explore the critical design features. We find that the actuator relies on the radial arrangement of vascular bundles and surrounding tissues around a central cavity. This allows heterogeneous swelling in a radially symmetric manner to co-ordinate movements of the hairs attached at the upper flank. This actuator is a derivative of bilayer structures, which is radial and can synchronise the movement of a planar or lateral attachment. The simple, material-based mechanism presents a promising biomimetic potential in robotics and functional materials.

Root system growth and anatomy of cotton seedlings under suboptimal temperature

AbstractRoot morphology and anatomy are important plant traits that could potentially influence seedling vigour, resource acquisition and susceptibility to early‐season stress. Therefore, the objective of the current experiment was to evaluate the effects of cultivar and growth temperature on seedling root growth and anatomical characteristics in cotton. To address this objective, experiments were conducted with six modern cotton cultivars, expected to have differences in seedling vigour, grown under optimal (30/20°C) and suboptimal (20/15°C) day/night temperature regimes. Root morphology and taproot cross‐sectional anatomy were evaluated two weeks after planting. Cultivars with the most vigorously growing root systems produced 73% more secondary roots, 68% more total root length, 74% more surface area and 72% higher total root volume than the least vigorous cultivars. The cultivar with the greatest production of secondary roots also exhibited a somewhat uncommon hexarch arrangement of vascular bundles in taproot cross sections. Thus, we suggest that this difference in root anatomy may be a determinant of genotypic differences in lateral root development. In response to low temperature, taproot length, total root length, secondary root formation, root surface area and root volume declined substantially relative to optimal temperature conditions (35%–75% declines). This reinforces the need to ensure optimal temperature conditions at planting or to identify cultivars with improved performance under suboptimal early‐season conditions. Conversely, root diameter responded positively to low growth temperatures, and cold‐induced increases in root thickness were associated with increases in the number and cross‐sectional area of root cells.

Comparative leaf anatomy of ten Nepenthes L. species (Nepenthaceae) from Peninsular Malaysia

The genus Nepenthes (Nepenthaceae) in Peninsular Malaysia includes fourteen species that can be found from the sea-level to over 1000 m in the mountains. Our observation indicated that Nepenthes can be found in five major habitat types: specifically in tropical lowland evergreen rain forest, heath forest, peat swamp forest, montane forest, and limestone forest. Their leaves have several anatomical characters that remain underexplored. There were specific differences between species that could be potential identification characters. The following anatomical characteristics were explored for their diagnostic value and comprised of ten distinct anatomical characteristics in Nepenthes, viz., density and stomatal index (SI), hypodermis cell – cell layers, occurrence of fiber groups mixed with the hypodermis cells, adaxial cuticle thickness, vascular bundle arrangement, midrib outline shape, venation plasticity, druses appearance and appendage/trichome type.

Anatomy of two species of Plumbago : a traditional medicinal plant and its relevance for taxonomy

Plumbago is a traditional medicinal plant in Ayurveda. The paper presents anatomical study of leaf, petiole, stem and root of two species of Plumbago namely P. zeylanica, P. auriculata and, its relevance in discrimination of these two species. Anatomical features of leaf which are of diagnostic value in delimitation of both taxa are outline of T. S.,shape and size of epidermal cells, presence of sclerenchyma surrounding the vascular bundles, number of tannins cells. Characters of taxonomic significance in petiole anatomy are outline of T. S, presence of trichomes, shape and size of epidermal cells, abundance of collenchyma, arrangement and number of vascular bundles, presence of sclerenchyma surrounding vascular bundles, number of tannin cells. The diagnostically useful anatomical features of stem to discriminate both taxa of Plumbago are degree of elevation of stem ridges, occurrence of double layered epidermis, size of epidermal cells, distinctness of endodermis, abundance and distribution of pericyclicsclerenchyama, number of vascular bundles. Anatomical features of taxonomic significance in root are width of cortex and abundance of starch grains in cortex cells, abundance and distribution of pericyclics clerenchyama, amount of vascularization, distribution, diameter and density of vessels, width of medullary ray.

Türkiye'den Alysseae Tribusunun (Brassicaceae) 21 Temsilcisinin Petiyol Anatomisi

This paper presents in detail petiole anatomy of 21 representatives of tribe Alysseae, 5 of which are endemic from Turkey. In the examined taxa, differences have found in the petiole shape, arrangement and number of vascular bundles, and the presence of collenchyma. Petiole shapes are in sulcate, circular, or flat types. The most common type is sulcate with blunt or acute margins. The epidermises are in 1, 2 or more layer. The number of vascular bundles in the examined taxa varies between 1 (Berteroa mutabilis) and 9 (Alyssum strictum and A. strigosum subsp. strigosum) in total. In addition, vascular bundles in the middle are broadly or narrowly arc-shaped with 1-5 lobed. These results display that the compared petiole anatomical characteristics among the examined taxa are somewhat suitable to their delimitation in traditional rank in the Flora of Turkey.

Key distinguishing characters (KDCs) of official (Boerhaavia diffusa L.) and commonly mistaken (Trianthema portulacastrum L.) sources of Mukkirattai of Siddha

Boerhaavia diffusa L. has been used extensively in Siddha system of medicine and is often confused with Trianthema portulacastrum L. due to morphological similarities. This particular study compares, analyses and identifies the key distinguishing features of the two whole plant drugs based on pharmacognostical and phytochemical aspects. The samples were studied for macroscopy, microscopy, physicochemical analysis, preliminary phytochemical analysis and HPTLC following standard procedures. Macroscopic studies showed few notable differences in macro-microscopy of root, stem, leaves and flowers of both the plants. Microscopically root, stem, leaf and petiole of both the plants showed differences in layers of cork, presence of crystals and medullary rays (in root), the thickness of cuticle, cortex and arrangement of vascular bundles (stem), presence of characteristic type of trichomes (leaf) and shape of the petiole. Powder microscopy showed differences in epidermis, crystal types and shape of pollen. Preliminary phytochemical analysis showed the presence of phenol, saponins and coumarins in B. diffusa and was not detected in T. portulacastrum. There were significant differences in the values of quantitative microscopy, physicochemical parameters and HPTLC of both the whole plant samples. The finding of this study will be helpful for the correct identification of the plant.

Leaf architecture and petiole anatomy of Philippine Dipterocarpus species (Dipterocarpaceae)

The study investigated the leaf architecture and petiole anatomy of eight Dipterocarpus (Dipterocarpaceae) species growing in Mount Makiling Forest Reserve (MMFR) in the Philippines to delineate the species, especially during their non-flowering phase. Leaf and petiole samples from MMFR were examined following the manual on leaf architecture studies. Freehand technique was used to examine the stomata and petiole characters. A UPGMA phenogram was then generated to determine the relationships among Dipterocarpus species using 26 leaf and petiole characters. The most useful characters to delineate Dipterocarpus species are the presence of trichomes, the arrangement of vascular bundles (medullary and outer vascular bundles), areolation, fimbrial vein, and leaf size. Other characters viz., the laminar ratio, blade class, laminar shape, base shape, margin type, and intersecondary, and layers and shape of parenchyma and collenchyma cells were useful as unifying characters. Therefore, certain characters of the leaf architecture and petiole anatomy may be used as taxonomic markers to delineate and correlate the Dipterocarpus species in the Philippines particularly during the nonflowering phase of the species. However, further investigations using samples from the wild populations of the species and molecular techniques may be done to elucidate the taxonomic use of the characters presented in this study.
 Bangladesh J. Plant Taxon. 27(1): 1-14, 2020 (June)

Coccoloba P. Browne (Polygonaceae): Taxonomic value of new leaf anatomical and micromorphological characters in Brazilian species

Coccoloba P. Browne (Polygonaceae, Eriogonoideae) is a large and complex genus with high morphological homogeneity and difficult species identification. In order to highlight informative characters for potential use in taxonomy, leaf anatomy of 11 species of Coccoloba was investigated. Leaves were studied using light and scanning electron microscopy. It confirmed that multicellular peltate glandular trichomes, unicellular or multicellular non-glandular trichomes, mucilaginous epidermis, crystal idioblasts and collateral vascular bundles are shared by all Coccoloba species here investigated. Scleromorphic features such as fibers in subepidermal layer associated with vascular system, abundance of phenols and druses in mesophyll were found too. Information about wax micromorphology, trichome types, stomatal types, presence of papillae, presence of hypodermis, type of mesophyll and arrangement of vascular bundles in petiole can be used as diagnostic characters.

Survey of wheat straw stem characteristics for enhanced resistance to lodging

Lodging is one of the major constraints that threaten crop productivity. Although the relationship between cell walls and straw strength has been well recognized, little relevant research has been done in wheat, particularly on the monomer composition and structural characteristics of cell wall polymers and the arrangement of vascular bundles. In this study, we systematically investigated cell wall- and straw-related traits in a range of wheat germplasm resources and culm mutants using a high-throughput platform for cell wall analysis. We found that varieties with higher breaking force exhibited higher levels of crystalline cellulose but fewer hemicellulose components than other varieties. The lignin content was not consistent with the breaking force; instead, the lignin monomer constitution might be important because a significantly higher proportion of p-hydroxyphenyl (H) and guaiacyl (G) but a lower proportion of syringyl (S) monomers of lignin was found in the higher breaking force group. The crystallinity detected by X-ray diffraction was positively correlated with breaking force, indicating that the physical/chemical properties of polysaccharides also deserve attention. In terms of anatomical characteristics, the varieties with higher breaking force had a lower number and area of smaller vascular bundles in the peripheral sclerenchyma than other varieties. These results, together with the finding of a highly significant correlation between stem breaking force and straw fresh weight, 2nd internode width, flag leaf width and SiO2 content, should provide systematic information for breeding for lodging resistance.

Leaf anatomical characters of four epiphytic orchids of Sempu Island, East Java, Indonesia: The importance in identification and ecological adaptation

Rindyastuti R, Nurfadilah S, Rahadiantoro A, Hapsari L, Abywijaya IK. 2018. Leaf anatomical characters of four epiphytic orchids of Sempu Island, East Java, Indonesia: The importance in identification and ecological adaptation. Biodiversitas 19: 1906-1918. Leaf anatomy features are important characters to support species identification and classification, and they are related to ecological adaptation of species. The aims of the present study were: (i) to investigate leaf anatomical characters of four epiphytic orchids of Sempu Island (Ascochilus emarginatus, Dendrobium subulatum, Thrixspermum subulatum, and Thrixspermum acuminatissimum) in relation to the significance in species identification and ecological adaptation in coastal habitats of Sempu Island, (ii) to compare the adaptive ability of the four species in coastal habitats based on adaptive anatomical characters. The procedure of leaf anatomical studies as follows: orchid leaves were fixed in ethanol 70% and sliced into thin pieces with a microtome, and stained with 1% Safranin. The leaf anatomical organization of orchids (stomata, epidermis, mesophyll, vascular bundles, and other characters such as hypodermis, fibre bundles, raphide bundles, and spiral thickenings) was observed under light microscope. The results showed the comparable data of leaf anatomical characters among the orchids. There was distinct variation in the anatomical characters of the orchids including stomata anomocytic, tetracytic, and cyclocytic; the presence or absence of hypodermis, spiral thickenings, fibre bundles, raphide bundles, and bundle sheaths; homogenous and heterogenous mesophyll; and variation in vascular bundle arrangement. Detailed leaf anatomical characters can be used to distinguish a species from others, which are important to support species identification. The similarity of anatomical characters among these orchids were they possessed relatively thick cuticle and other specific anatomical characters as a structural adaptation to coastal habitat with high irradiation to reduce leaf transpiration. D. subulatum can be considered as the most adaptive orchid species to coastal habitats based on adaptive anatomical characters as it possessed the largest number of adaptive anatomical characters. The implication of this study is the importance of leaf anatomical features to support species identification and to increase understanding of orchid biology and ecology which are important in orchid conservation.