Helical Thickenings Research Articles

Towards a better understanding of xylem: Helical thickenings in vessels of woody angiosperms are associated with thinner cell walls and lower vessel diameter

Towards a better understanding of xylem: Helical thickenings in vessels of woody angiosperms are associated with thinner cell walls and lower vessel diameter

The coffin-reliquary of the holy Serbian king Stefan of Dečani (fourteenth century): wood, pigments and metal surfaces

The coffin-reliquary for the relics of the holy Serbian king Stefan Uroš III of Dečani has been made around 1343 as a rectangular chest with a gable cover. The present study aimed to identify the wood this coffin-reliquary was made, as well as the pigments and metals found on its surface. The combination of anatomical traits (diffuse-porosity, distinct helical thickenings in vessels, simple perforation plates, 3- to 4-seriate noded rays and diffuse-in-aggregates axial parenchyma) showed that the wood belongs to linden, i.e., to the botanical genus Tilia L. (Malvaceae). The linden is one of the sacred trees in Serbian culture, and its wood could also be used due to its ease for joinery. X-ray fluorescence spectroscopy (XRF analyzer) was used for in situ determination of the material chemistry of the pigments, as well as the metals on the wooden surfaces of the coffin. Their elemental composition showed that wooden coffin-reliquary was painted with vermilion, malachite or copper resinate, orpiment, and lead white, while metal surfaces were shown to be gold and silver. Unlike a commonly used palette of earthy pigments, these coloring matters belong to precious noble pigments.

A new species of Pseudotsuga (Pinaceae) from the lower Miocene of Lesvos, Greece, and its palaeogeographical and palaeoclimatic implications

Pseudotsuga Carrière is commonly known as Douglas-fir, a minor genus attributed to Pinaceae. Four extant species are included in this genus, with dispersed distribution in East Asia and western North America. Pseudotsuga possesses a number of fossil records of needled leaves, seed cones, and seeds. Nevertheless, few reliable fossil wood of this genus has been specifically investigated. Here, we describe some anatomically well-preserved petrified fossil wood from the lower Miocene of Lesvos Island, Greece, as Pseudotsuga lesvosensis n. sp. The studied fossil wood remains are characterized by the presence of normal axial and radial resin canals, piceoid cross-field pitting, along with distinctive helical thickenings in cell walls consistent with Pseudotsuga. The present fossil conifer further enriches the species diversity of the Miocene Petrified Forest in Lesvos. The first report of Pseudotsuga lesvosensis from the southern Europe in this study extends the tempo-spatial distribution patterns of Pseudotsuga and contributes to further understanding of its origin and evolutionary history. The occurrence of P. lesvosensis fossil wood, as well as other palaeontological macrofloral composition evidence, indicates a humid warm temperate to subtropical climatic condition during the early Miocene within the Lesvos, which differs significantly from the current Mediterranean climate.

Wood structural diversity in fynbos, chaparral, and maquis: a preliminary estimation

Summary Fynbos, a shrubland from the Cape Floristic Region in South Africa, is one of five Mediterranean-climate biomes alongside maquis in the Mediterranean Basin, chaparral in California, matorral in Central Chile and kwongan in Southwestern Australia. We compiled the available information on the wood anatomy of 226 species belonging to 65 genera of 14 families that occurred in fynbos and compared this dataset with the published data on wood diversity in Californian chaparral and Israeli maquis. “Carlquist’s Law”, i.e., the association between the ground tissue made of fibre tracheids and low vessel grouping, has been confirmed for the fynbos plants. The lack of ring porosity and very low incidence of semi-ring-porous woods is the most prominent difference of the fynbos from the other two vegetation types. These features are attributed to the paucity of deciduous plants in fynbos which is probably associated with the poor-nutrient soils in this biome. The fynbos differs from chaparral and maquis also in the greatest percentage of the species having no tracheids in their wood as well as with the lowest incidence of helical thickenings on the vessel walls. These differences could be explained by the lower tolerance of fynbos shrubs to seasonal drought due to the relatively mild dry season in this biome. We also found that some differences between fynbos, chaparral, and maquis in the incidences of fibre tracheids and vasicentric/vascular tracheids associated with large vessel groups can be at least partly explained by different systematic compositions of their floras. The higher percentage of distinct growth rings, greater vessel diameter, and lower vessel frequency in maquis compared with fynbos and chaparral can be attributed to a common occurrence of relatively tall trees in this vegetation.

Myrcianthes (Myrtaceae) revisited: a new species, a new synonym, a lectotypification and an overview of its wood anatomy

Myrcianthes is a New World genus of Myrtaceae (Tribe Myrteae) with 38 currently accepted species that was monographed in 1992. This paper proposes a new species, Myrcianthes cruciata from Northeastern Brazil (Bahia, Ceará and Sergipe), the synonymization of M. cavalcantei under M. fragrans and the lectotypification of the former name. Myrcianthes cruciata is similar to M. pseudomato but differs in the longer peduncles, 3.5–5 cm (2–4 cm in M. pseudomato) and greater number of ovules per locule, c. 15–30 (15–20 in M. pseudomato), as well as the morphology of the embryo, which is reniform in M. cruciata and strongly invaginated in the middle (almost V-shaped) in M. pseudomato and also emerged in different lineage in the phylogeny. The wood anatomy of the new species is similar to other species of the genus: diffuse porous, with exclusively solitary vessels with high density, no vessel arrangement, with simple perforation plates, vessel-ray pits with distinct borders, similar to the intervessel pits in size and shape, apotracheal parenchyma, rays 1–3 cells wide, with disjunctive ray cells; no helical thickenings were observed in the vessels, nor any mineral inclusions in the axial or ray parenchyma.

On the possible functions of helical thickenings in conductive cells in wood

Summary The career of Sherwin J. Carlquist was marked by numerous pioneering contributions to botany and especially to ecological and evolutionary wood anatomy. He developed some of the most important modern functional hypotheses for wood, including postulating a biomechanical and fluid dynamic role for helical thickenings (HT) in seasonally dry environments. Here we endeavor to honor Carlquist’s legacy by summarizing existing observations, explicitly acknowledging that HT represent a range of non-homologous and likely functionally disparate features, and exploring HT functional hypotheses in light of data from a pantropical genus, Croton, in which HT are associated with mesic rather than xeric conditions. This is noteworthy in part because HT are commonly associated with the flora of temperate mesic areas and seasonally dry areas, particularly in non-tropical regions. Based on observations in Croton, the distribution of HT around the world, and interesting advances in fluid dynamics, we propose that diversity in this feature may serve two related functions in addition to the potential mechanical role previously articulated, namely, vessel refilling after cavitation and increased hydraulic efficiency.

Water Transport Characteristics of Multiple Structures of Xylem Vessels in Magnolia

The multiple structures of xylem vessels in Magnolia provide stable and efficient water transport channels. The structural parameters of xylem vessels were studied in wood sections and in macerated materials. The results showed that the xylem vessels of Magnolia contained a helical thickening structure and a pit structure of a secondary wall, and the end walls had a scalariform perforation plate. The helical thickening and scalariform perforation plate increased the flow resistance of the vessel, and the pit structure decreased the flow resistance of the vessel. There was a close positive correlation between the flow resistance of the vessels and the helical width, the helical height, the thickness of the scalariform perforation plate, the number of holes in the scalariform perforation plate, the length of the pit canal, and the pit spacing. In addition, there was a negative correlation between the flow resistance of the vessels and the helical spacing, the pit vertical diameter, and the pit domain length. Among these structural parameters, the helical height, the number of holes, and the length of pit canal had a greater influence on the flow resistance. The pit structure caused the vessel to produce radial water transport. The radial transmission efficiency increased with the increase in the pit domain length. With no pit membrane in the pit structure of Magnolia, the radial transmission efficiency would be between 43.99% and 53.21%.

Longitudinal transmittance of visible and near-infrared light in the wood of 21 conifer species

Summary Light transmittance and reflectance were measured in 21 conifer species using a spectrophotometer equipped with an integrating sphere and light within a wavelength range of 500–1200 nm, to clarify the variety of longitudinal light transmitting properties among wood species. Transmittance values varied not only among different species but also between the sapwood and heartwood within certain species. Transmittance intensity increased from about 600–700 nm and showed peaks or shoulders in the ranges of 870–900 nm and 930–950 nm, and at around 1100 nm in all samples. The spectra tended to show similar patterns for 2 species within the same genus (Chamaecyparis, Abies, Picea, Pinus, Pseudotsuga and Tsuga). Light transmittance differed between the sapwood and the heartwood in several species, and, patterns of the difference differed among the different genera. Peaks at around 1100 nm were observed in both the sapwood and heartwood of all samples. Maximum conductivities of light at these peaks were relatively lower in wood species with helical thickenings (genera Pseudotsuga, Torreya and Taxus). Based on these results, it can be seen that the anatomical characteristics of wood influence the transmittance of light. The density of wood and secondary metabolites occurring in heartwood are also thought to influence the transmittance of light.

Mechanical properties of charcoal and its representativeness of vegetation in northern China.

The objective of this paper is to examine the representativeness of charcoal taxa at archeological sites in northern China. We carried out standardized laboratory compression tests on 168 samples representing 21 taxa charred at four different temperatures to characterize the mechanical properties of common taxa in temperate China. The results indicate that significant fragmentation differences occur between taxa. Ring-porous/semi-ring-porous taxa with a moderate density (>0.55 g/cm3) are overrepresented, while those with a very low to low density (<0.55 g/cm3) are moderately represented. Diffuse-porous taxa with slightly dense uniseriate rays, rare multiseriate rays and distinct helical thickenings are underrepresented, and those with slightly dense multiseriate rays are overrepresented, while those with rare to moderate multiseriate rays and helical thickening absence are moderately represented. Gymnosperm trees are generally well represented. Among the ubiquitous taxa at the archeological sites across northern China, Quercus and Ulmus may be overrepresented, and Pinus, Salix, Populus, and Acer may be underrepresented, while Betula may be moderately represented.

Distinctive wood anatomy of early-diverging Asteraceae: Barnadesioideae

Abstract Asteraceae subfamily Barnadesioideae (ten genera, c. 90 species), confined to South America, are sister to the remainder of the family. The relative antiquity of the barnadesioids might lead one to expect that they contain more wood features plesiomorphic for the family, but only one character clearly falls in that category. Pits on imperforate tracheary elements are bordered (except for annuals), whereas simple pits occur in two related families, Calyceraceae (part) and Stylidiaceae (all that have been examined); in Goodeniaceae bordered pits only occur. By attaining fully bordered pits in Chuquiraga, the imperforate tracheary elements qualify as an apomorphy, ‘neotracheids’, valuable for resisting embolism formation in dry and cold South American habitats. Neotracheids are found also in Loricaria (Asteraceae: Inuleae), also from these habitats. Neotracheids, like plesiomorphic tracheids, are conductive, unlike fibre tracheids and libriform fibres. Other barnadesioid wood characters adapted to cold and drought include grouping of vessels, high vessel density, shorter vessel elements and helical sculpture (including helical thickenings on lumen-facing walls) of secondary xylem vessels. In Chuquiraga and Dasyphyllum, these helical thickenings are bordered in some species (new report for angiosperms). Some of the barnadesioid adaptations to cold and drought can be found in North American Artemisia spp. (Asteraceae: Anthemideae), especially in montane and desert areas. Wood features of barnadesioids match their respective habits and habitats: a few trees; shrubs of humid, dry or desert areas; a distinctive rhizomatous succulent in the pampas (Schlechtendalia); a scree/gravel perennial (Huarpea) and two genera of annuals, one with succulent leaves (Duseniella) and one with rayless (at least at first) stems in arid and open soils (Doniophyton). Diversity is unusual considering the small size of the subfamily. Examples of endodermal crystals (Arnaldoa only), pith sclereids and primary xylem fibres are cited.

Case Presentation - Biventricular Hypertrophy and Valvular Pulmonary Stenosis in Adult Patient with Noonan Syndrome: A Rare Case

Introduction: Noonan syndrome (NS) is a genetic disorder often accompanied by multiple congenital abnormalities. The prevalence of NS at live birth has been reported as one in 1000-2500 individuals. About 80% of patients with Noonan syndrome have abnormalities in the cardiovascular system.Case presentation:41-year-old Javanese male presented with chief complaint shortness of breath. His Body Mass Index (BMI) was 18,3. He had an oval-shaped face with a short neck, thin hair, and prominent nasolabial fold. Echocardiography showed biventricular hypertrophy alongside pulmonary valve stenosis, pulmonary regurgitation and minimal pericardial effusion. Discussion: In 1962, Jacqueline Noonan, a pediatric cardiologist, identified 9 patients whose faces were very similar, had short stature, significant chest deformities, and with pulmonary stenosis. Noonan syndrome is a relatively common non-chromosomal syndrome that is similar to the phenotype of Turner's syndrome and presents with cardiovascular malformations. Adult with NS has distinctive facial features such as ptosis, wide eyes, low posterior rotation of ears and helical thickening, and a wide neck.Pulmonary stenosis is the most common heartdefect found in NS, besides HCM isalsoquitecommon inabout20% of patients. We reported a case of a patient with typical characteristics of NS such as pulmonary valve stenosis accompanied by biventricular ventricular hypertrophyand its typical face who survived through adulthood.Conclusion: Syndrome Noonan in the adult is quite rare and difficult to diagnose. We reported a case of an adult man with facial appearance and echocardiographic findings identical with Noonan Syndrome.

Stem and Leaf Anatomy of Aragoa (Plantaginaceae): In Search of Lost Rays.

Aragoa is a shrubby genus endemic to páramo in the northern Andes representing the sister group to Plantago and Limosella. Stem and leaf structure of Aragoa corrugatifolia were studied to clarify the evolutionary pathways and ecological significance of their anatomical traits. Aragoa and Plantago share a non-fascicular primary vascular system, rayless wood and secondary phloem, and anomocytic stomata. Aragoa is distinctive from most Plantaginaceae in the presence of cortical aerenchyma and of helical thickenings in vessels. Its procambium emerges in the primary meristem ring as a continuous cylinder. The view on the ring meristem and procambial strands as developmental stages in the formation of a primary vascular system is not relevant for Aragoa, and probably for other Plantaginaceae. The raylessness is synapomorphic for the crown clade of Plantaginaceae comprising Aragoa, Littorella, Plantago, Veronica, Picrorhiza, Wulfenia, and Veronicastrum. The loss of rays is thought to be predetermined by procambium rather than by the vascular cambium. The extremely narrow vessels with helical thickenings are presumably adaptive to hydric and thermic conditions of páramo. Cortical aerenchyma is thought to be a response to the local hypoxia caused by the water retained by ericoid leaves. Trichomes on juvenile leaves are expected to be the traits of considerable taxonomic importance.

Earliest fossil record of the genus Tetradium (Rutaceae) in Asia: implications for its evolution and palaeoecology

AbstractA new species, Tetradium nanningense sp. nov. (Rutaceae), is described on the basis of well‐preserved mummified wood from the upper Oligocene Yongning Formation of Nanning Basin, Guangxi Province, South China. This species represents the most ancient fossil evidence of the genus Tetradium in Asia, the region of its modern distribution. Its occurrence in the late Oligocene is consistent with the diversification age of the modern Asian species within this genus as estimated by molecular dating: T. nanningense could be closely related to an ancestor of extant Tetradium species. The fossil record of Tetradium suggests that this genus migrated from North America to eastern Asia in the Oligocene. The presence of (semi‐)ring‐porous wood and helical thickenings on vessel walls in T. nanningense provides new evidence for the independent gains of these traits in the course of evolution among different plant groups from eastern and south‐eastern Asia in the Oligocene. These wood features might have arisen in response to the increase in climate seasonality following the abrupt climate cooling across the Eocene–Oligocene boundary.

Case Study of Anatomy, Physical and Mechanical Properties of the Sapwood and Heartwood of Random Tree Platycladus orientalis (L.) Franco from South-Eastern Poland

Oriental arborvitae is not fully characterized in terms of its microscopic structure or physical or mechanical properties. Moreover, there is a lot of contradictory information in the literature about oriental arborvitae, especially in terms of microscopic structure. Therefore, the sapwood (S) and heartwood (H) of Platycladus orientalis (L.) Franco from Central Europe were subjected to examinations. The presence of helical thickenings was found in earlywood tracheids (E). Latewood tracheids (L) were characterized by a similar thickness of radial and tangential walls and a similar diameter in the tangential direction in the sapwood and heartwood zones. In the case of earlywood tracheids, such a similarity was found only in the thickness of the tangential walls. The volume swelling (VS) of sapwood and heartwood after reaching maximum moisture content (MMC) was 12.8% (±0.5%) and 11.2% (±0.5%), respectively. The average velocity of ultrasonic waves along the fibers (υ) for a frequency of 40 kHz was about 6% lower in the heartwood zone than in the sapwood zone. The dynamic modulus of elasticity (MOED) was about 8% lower in the heartwood zone than in the sapwood zone. These differences, both in the case of υ and MOED, were statistically significant. However, no statistically significant differences were found for the static bending strength (MOR, approx. 90 MPa), modulus of elasticity at static bending (MOE, approx. 4800 MPa), or compression strength parallel to the grain (CS, approx. 47 MPa) in relation to the wood zone (sapwood, heartwood).

Comparative anatomy of five species of Campyloneurum (Polypodiaceae) from South America

Anatomical characters of the sporophyte of five Campyloneurum species are presented: C. aglaolepis, C. angustifolium, C. angustipaletum, C. lorentzii, and C. tucumanense, to evaluate anatomical characters with a taxonomic value. Histological sections of the root, rhizome, and petiole were made in three sections (basal, middle, and distal) and lamina, using specimens of herbarium and material collected for this purpose. Observations were made with a light microscope and a scanning electron microscope. The anatomical characters, such as the type of helical thickening in parenchymal cells in outer cortex and the number of layers in the inner cortex of the root; diameter, presence of prurine, number of meristeles and sclereid nests in the rhizome; adaxial groove and the number of vascular bundles in the petiole; and mesophyll, stomata and hairs types in the lamina, shows a highly significant in taxonomic value for the separation between the five studied species. For the first time, hydathodes, nectaries, diacytic stomatal types and homogeneous mesophyll are described in Campyloneurum, and the anatomy of C. tucumanense is presented.

Wood Anatomy of Argophyllaceae (Asterales): Adaptation in a Small Clade

Argophyllaceae (Argophyllum, 14 spp.; Corokia, 6 spp.; Lautea, 1 sp.), are shrubs that occur in the southwestern Pacific and eastern Australia. They occur in habitats where moisture is relatively common but dry days and mild frost may occur. The woods of these genera show enough distinctive features to justify their grouping in a single family: perforation plates with 10–20 bars, vessel elements narrow and numerous per mm2, imperforate tracheary elements about 50% longer than the vessel elements, axial parenchyma scarce, diffuse, multiseriate rays narrow and heterocellular (upright cells common in uniseriate rays), crystals absent, gum deposits common. These features group the genera of Argophyllaceae more closely with each other than with the nearest families in Asterales (Alseuosmiaceae, Phellinaceae). Probable apomorphies of the genera include helical thickenings in vessels and tracheids, together with abundant tracheids and rare septate fiber-tracheids (Corokia); almost total absence of axial parenchyma and tracheids combined with maximal abundance of septate fiber-tracheids and no helical thickenings (Argophyllum, Lautea). Lautea, formerly included within Corokia, has floral and foliar distinctions and is endemic to a single island, Rapa Iti. Woods of Argophyllaceae are alike in their ecological adaptations (perforation plates, vessel diameter and density) but the presence of tracheids and helical thickenings in Corokia suggest adaptations to frost and mild drought. As expected, vessels group more prominently in the tracheid-free species (Argophyllum, Lautea) but very little in the tracheid-rich genus Corokia.

Wood identification of an ancient Greek coffin from the Bosporan Kingdom

Abstract Wood identification of 13 samples is made for the first time for the well-preserved coffin from the Bosporan Kingdom exhibited in the State Hermitage Museum. Due to the decay state, observation was carried out with Scanning Electron Microscopy. Additional information was obtained from macerated material. The samples studied show a complex of characteristics common to the Cupressaceae family: axial tracheids without helical thickenings, presence of axial parenchyma, homogeneous rays, cupressoid cross-field pits, and absence of resin canals. The presence of dark-stained content in the ray cells and the structure of its end walls, as well as the size of the rays, allow the determination of the wood samples as Cupressus sp. and Juniperus sp. The supporting parts of the coffin construction are made from cypress, while the decorative details and an inner bed are from juniper. These results support the dating of the coffin and the known information about different usage of timbers in the production of coffins in the Bosporan Kingdom.

Comparative wood anatomy of Atraphaxis taxa in Turkey

The wood anatomy of four Atraphaxis taxa that have natural distribution in Turkey—Atraphaxis billardieri Jaub. &amp; Spach, Atraphaxis billardieri subsp. tournefortii (Jaup. &amp; Spach) Lovelius, Atraphaxis spinosa L., and endemic Atraphaxis grandiflora (Willd.)—were compared in this study. The wood samples were sectioned according to standard techniques. Samples were macerated with Schultze’s method. Tangential and radial vessel diameters, intervessel pit diameters, vessel wall thickness, vessel elements length, dimensions of libriform fibres (lengths, widths, cell wall thickness and, lumen diameter), and uniseriate and biseriate ray heights were measured, and the number of vessels per mm2, number of rays per mm, and number of vessels per group were counted. The qualitative features such as growth rings, vessel grouping, presence of helical thickening and storied structure, vestured pits, type of perforation plate, and arrangement of axial parenchyma were determined. These four species of Atraphaxis shrubs differ in some wood characteristics such as growth rings, vessel grouping, vestured pits, height and density of rays, number of vessels per mm2, and the dimensions of the vessel.

Using Lenses Attached to a Smartphone as a Macroscopic Early Warning Tool in the Illegal Timber Trade, in Particular for CITES-Listed Species

Wood anatomy is a key discipline as a tool for monitoring the global timber trade, particularly for wood listed in protected species conventions such as Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES). One of the main barriers to reducing illegal trafficking of protected species is ensuring that customs officials with appropriate training in wood anatomy are equipped with simple tools, at both the origin and destination of shipments, so they can raise an early warning about wood suspected of contravening international treaties and immediately send samples to a specialised laboratory. This work explains how lenses attached to a smartphone, capable of achieving up to 400× magnification using the phone digital zoom, can be used to distinguish features that are not visible with traditional 10× or 12× lenses, enhancing the capacity to view features not typically observable in the field. In softwoods, for example, this method permits determination of the type of axial parenchyma arrangement, whether there are helical thickenings in axial tracheids and whether axial tracheids have organic deposits or contain alternate polygonal pits, and in the rays, if the tracheids are smooth-walled or dentate and if the cross-field pits are window-like. In hardwoods, it allows verification of the presence of tyloses and deposits in vessels, the type of perforation plates and whether the intervascular pitting is scalariform; in the rays it is possible to differentiate the types of ray cells; and in the axial parenchyma, to determine the presence of oil cells. In addition, unlike macroscopic analysis with a conventional magnifying lens, this type of lens can be used with the appropriate mobile application for the biometry of important elements such as ray height and vessel diameter.

Stem and leaf structure of Searsia erosa (Thunb.) Moffett (Anacardiaceae) with systematic, ecological and ethnobotanical implications

The anatomy of stems and leaves of the southern African evergreen shrub Searsia erosa (Anacardiaceae) was studied. This species shows the suite of typical traits of Anacardiaceae, such as the presence of secretory canals in the cortex, secondary phloem, wood rays and vascular bundle of leaf midrib, pericyclic fibres in nearly continuous bands, compound sieve plates on oblique walls, simple perforation plates, alternate intervessel pitting, and septate libriform fibres. Like other Searsia species, S. erosa has abundant sclereids in non-conducting secondary phloem, multicellular peltate glandular trichomes on leaf epidermis, short vessel elements and minute intervessel pits; two latter characters are thought to be diagnostic for this genus. Unlike Asian species of Searsia, S. erosa lacks marginal axial parenchyma as well as prismatic crystals in axial parenchyma and in libriform fibres, but it shows the helical thickenings on vessel walls. The presence of the last trait in a southern African species agrees with association of helical thickenings with the regions that experience water stress. The tangential expansion of secondary phloem in S. erosa and probably in other Searsia species is mainly performed by considerable increase in volume of its cells by their sclerification. Such a way of bark growth in girth is out of scope of bark anatomists. Searsia erosa is distinctive from other congeneric species in its hypostomatous leaves with abundant glandular trichomes on adaxial side. This condition demonstrates a labor division between the adaxial side with glandular trichomes that may contribute to leaf protection, and the stomata-bearing abaxial side providing the gas exchange. Unlike most members of Anacardiaceae, the secretory canals of S. erosa produce the oleoresin containing terpenoids (essential oils) and lipids, but lack polysaccharides. The abundance of glandular trichomes and secretory canals producing terpenoids is a presumable reason of the use of S. erosa in traditional medicine by the Basotho people.