Leaf Indumentum Research Articles

Boea cavernarum Zich & B.Gray (Gesneriaceae), a remarkable new species from north Queensland, Australia

Boea cavernarum, restricted to near limestone crevices and caves in NE Queensland, is described. Images of whole plants, flowers, fruit and leaf indumentum, a distribution map, and a key to all species of Boea in Australia are provided. Thirteen species are now recognised in Boea.

Comparative Analysis of the Chloroplast Genomes of Eight Species of the Genus Lirianthe Spach with Its Generic Delimitation Implications.

Based on Sima and Lu's system of the family Magnoliaceae, the genus Lirianthe Spach s. l. includes approximately 25 species, each with exceptional landscaping and horticultural or medical worth. Many of these plants are considered rare and are protected due to their endangered status. The limited knowledge of species within this genus and the absence of research on its chloroplast genome have greatly impeded studies on the relationship between its evolution and systematics. In this study, the chloroplast genomes of eight species from the genus Lirianthe were sequenced and analyzed, and their phylogenetic relationships with other genera of the family Magnoliaceae were also elucidated. The results showed that the chloroplast genome sizes of the eight Lirianthe species ranged from 159,548 to 159,833 bp. The genomes consisted of a large single-copy region, a small single-copy region, and a pair of inverted repeat sequences. The GC content was very similar across species. Gene annotation revealed that the chloroplast genomes contained 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes, totaling 130 genes. Codon usage analysis indicated that codon usage was highly conserved among the eight Lirianthe species. Repeat sequence analysis identified 42-49 microsatellite sequences, 16-18 tandem repeats, and 50 dispersed repeats, with microsatellite sequences being predominantly single-nucleotide repeats. DNA polymorphism analysis revealed 10 highly variable regions located in the large single-copy and small single-copy regions, among which rpl32-trnL, petA-psbJ, and trnH-psbA were the recommended candidate DNA barcodes for the genus Lirianthe species. The inverted repeat boundary regions show little variation between species and are generally conserved. The result of phylogenetic analysis confirmed that the genus Lirianthe s. l. is a monophyletic taxon and the most affinal to the genera, Talauma and Dugandiodendron, in Sima and Lu's system and revealed that the genus Lirianthe s. s. is paraphyletic and the genus Talauma s. l. polyphyletic in Xia's system, while Magnolia subsection Gwillimia is paraphyletic and subsection Blumiana polyphyletic in Figlar and Nooteboom's system. Morphological studies found noticeable differences between Lirianthe species in aspects including leaf indumentum, stipule scars, floral orientation, tepal number, tepal texture, and fruit dehiscence. In summary, this study elucidated the chloroplast genome evolution within Lirianthe and laid a foundation for further systematic and taxonomic research on this genus.

Molecular phylogeny and character-mapping support the synonymy of Cordobia and Gallardoa in Mionandra (Malpighiaceae)

Background and aims – Cordobia, Gallardoa, Mionandra, and Peixotoa (Stigmaphylloid clade, Malpighiaceae) are four small, closely related genera comprising shrubs or lianas endemic to South American savannas, dry forests, and temperate steppes. Their generic limits have significantly changed in the last century, and past molecular phylogenetic studies of Malpighiaceae have not tested the morphological characters of this group to identify synapomorphies supporting these clades/genera. Material and methods – We sampled the monospecific Cordobia and Gallardoa, one species of Mionandra (out of 2 spp.), nine species of Peixotoa (out of 29 spp.), and a single species of Camarea and Janusia as outgroups. Bayesian and Maximum Likelihood analyses were carried out for this clade based on five molecular markers (i.e. ETS, ITS, PHYC, matK, and ndhF). A set of 16 macromorphological characters was scored and coded for identifying synapomorphies under the Maximum Likelihood criteria. Key results – Our molecular phylogeny recovered Peixotoa as monophyletic and sister to the clade comprising Cordobia + Gallardoa + Mionandra, strongly corroborating previous phylogenetic studies of Malpighiaceae. The character-mapping analyses recovered two synapomorphies supporting the Cordobia + Gallardoa + Mionandra + Peixotoa clade, six supporting Mionandra s.l. (i.e. Cordobia + Gallardoa + Mionandra), and five supporting Peixotoa. Cordobia and Gallardoa are proposed as synonyms of Mionandra, alongside the necessary combinations, typifications, and identification keys. Conclusions – Morphological characters related to the degree of connation of the stipules, leaf indumentum type, petiole length, inflorescence architecture, number of flowers per inflorescence, presence of a peduncle in the 1-flowered cincinni, sepal connation, posture and texture, petal width and margin integrity, staminode presence, shape and size, and the shape of the apex of styles were key in circumscribing these lineages. Mionandra s.l. is proposed and characterised, including a new combination, an identification key to distinguish its species, a distribution map, and taxonomy notes.

Staurantherafloribunda, a new species of Gesneriaceae from Yunnan, China.

Staurantherafloribunda F.Su, C.Y.Hao & K.Tan, a new species of Gesneriaceae from Yunnan, China, is described and illustrated here. It is morphologically similar to S.grandifolia Benth. in the shape of corolla, stigma, leaves and the number of stamens. However, it can be readily distinguished from the compared species by its dense cymes, leaf indumentum, lack of a corolla spur, calyx colour and stamen shape. The description of the new species, photographs, detailed descriptions, notes on etymology, distribution and habitat, as well as comparisons with morphologically similar species, are provided.

The Foliar Anatomy and Micromorphology of Cyphostemma hypoleucum (Vitaceae).

Cyphostemma hypoleucum (Harv.) Desc. ex Wild & R.B. Drumm is a perennial climber, indigenous to Southern Africa, and belongs to the Vitaceae. Although there have been many studies of Vitaceae micromorphology, only a few taxa have been described in detail. This study aimed to characterize the micro-morphology of the leaf indumentum and determining its possible functions. Stereo microscope, scanning electron microscope (SEM), and transmission electron microscope (TEM) were used to produce images. Micrographs of stereomicroscopy and SEM showed the presence of non-glandular trichomes. In addition, pearl glands were observed on the abaxial surface using a stereo microscope and SEM. These were characterized by a short stalk and a spherical- shaped head. The density of trichomes decreased on both surfaces of leaves as the leaf expanded. Idioblasts that contained raphide crystals were also detected in tissues. The results obtained from various microscopy techniques confirmed that non-glandular trichomes serve as the main external appendages of the leaves. Additionally, their functions may include serving as a mechanical barrier against environmental factors such as low humidity, intense light, elevated temperatures, as well as herbivory and insect oviposition. Our results may also be added to the existing body of knowledge with regard to microscopic research and taxonomic applications.

Primulina malingheensis (Gesneriaceae), a New Species from a Karst Area in Guizhou Province, China

Primulina malingheensis X.X. Bai, F. Wen & Y.L. Zhou, a new species of Gesneriaceae from a karst area in Guizhou Province, China, is described and illustrated. It morphologically resembles P. leei in the shape of leaves and flowers but differs especially in the densely pubescent and sparsely villous leaf indumentum and much larger, ovate bracts.

Artemisiacalcicola (Asteraceae, Anthemideae), a new species from karst region in Guizhou, southwestern China.

Artemisiacalcicola (Asteraceae, Anthemideae), a new species from karst region in Shibing county, Guizhou province, southwestern China, is described and illustrated. The species can be readily assigned to A.subg.Artemisia in having fertile disk florets and glabrous receptacles. Within this subgenus, A.calcicola is distinguished by having (2- or) 3-pinnatipartite leaves and narrowly ellipsoid involucres 0.9-1.3 mm in diameter. It resembles A.annua to some extent, but differs immediately by the plant duration, stem and leaf indumentum, and involucre shape and size. A detailed description and distribution map of this species are also provided herein.

Hibbertia subvillosa (Dilleniaceae), a new Western Australian species segregated from H. striata

The south-west Western Australian species Hibbertia striata (Steud.) K.R.Thiele was reinstated in 2017, segregated from the historically misunderstood H. huegelii (Endl.) F.Muell. Since that time, field work has shown that H. striata comprises two distinctly different morphotypes. Plants from the eastern (drier) edge of the range are consistently single-stemmed at the base and are obligate reseeders after fire and other disturbances, in contrast to a more widespread morphotype (which includes the type of H. striata), that is abundantly multi-stemmed from the base and is a resprouter after fire. The difference in habit is consistent, has been observed at multiple locations and is consistently associated with distinct (though subtle) differences in leaf indumentum and morphology. The two morphotypes have not been found growing in mixed populations, due to habitat differences. Field work has shown that they are narrowly sympatric and do not intergrade where they approach each other; for this reason, and the consistency of both morphotypes over a wide range, they are regarded here as distinct species. The reseeding taxon has a validly published name, H. huegelii (Endl.) F.Muell. var. subvillosa Domin, and this is raised here to species rank as Hibbertia subvillosa (Domin) K.R.Thiele & T.Hammer.

Clarification of some morphological characters in Artemisia anomala (Asteraceae, Anthemideae), with reduction of var. tomentella and var. acuminatissima to the synonymy of the species

Based on observations on herbarium specimens (including type material) and living plants in the wild, we demonstrate that Artemisia anomala (Asteraceae, Anthemideae), a distinctive Chinese species yet morphologically imperfectly understood since its description, is variable with respect to its leaf indumentum and shape within and between populations. The leaves are ovate, ovate-lanceolate, elliptic-lanceolate, or lanceolate, and adaxially sparsely pubescent or glabrous, abaxially tomentose to sparsely pubescent, or rarely glabrescent. Morphologically, the two currently recognized varieties of A. anomala, var. tomentella and var. acuminatissima, fall within the variation range of the species in leaf indumentum and shape, and thus are synonymized herein. Lectotypification is proposed for A. anomala.

<p><strong>Sorting out the muddle: taxonomy and nomenclature of <em>Thymus </em>×<em>porcii </em>(Lamiaceae) and related nothotaxa, with comments on parent species delimitation</strong></p>

Thymus ×porcii is a natural hybrid between T. pannonicus and T. pulegioides, occurring within the co-occurrence range of its parental species in the forest and forest-steppe zones of Europe. Taxonomy and nomenclature of this hybrid present a longstanding puzzle due to the lack of critical evaluations of the original material as well as conflicting taxonomic interpretations of the parent taxa both at specific and intraspecific levels. The present paper attempts to clarify these issues, arguing against the synonymic treatment and/or consolidation of T. pannonicus and T. pulegioides, which is accepted in modern taxonomies apparently as a result of nomenclatural confusion related to T. pannonicus typification. Based on morphology and reported molecular data, it is proposed to treat T. pannonicus and T. pulegioides as separate species, each containing two varieties being well-distinguished by the presence or absence of leaf indumentum: T. pannonicus var. latifolius (glabrous leaves) and T. pannonicus var. pannonicus (pubescent leaves), and T. pulegioides var. pulegioides (glabrous leaves) and T. pulegioides var. vestitus (pubescent leaves). In view of such treatment, T. ×porcii is divided into three nothovarieties, representing natural crosses between different varieties of the parent species. Namely, in addition to the typical T. ×porcii nothovar. porcii [T. pannonicus var. latifolius × T. pulegioides var. pulegioides] (with T. ×pilisiensis and T. ×goginae as the taxonomic synonyms), we describe a new nothovariety T. ×porcii nothovar. calvariensis [T. pannonicus var. pannonicus × T. pulegioides var. pulegioides], and propose a new nomenclatural combination T. ×porcii nothovar. opizii [T. pannonicus × T. pulegioides var. vestitus] based on the previously published name T. ×opizii. On the basis of original material examination, two collections from BP are designated here as the lectotypes of T. ×porcii (≡ T. ×porcii nothovar. porcii) and T. ×pilisiensis respectively, and one specimen from PR is designated as the lectotype of T. ×opizii (≡ T. ×porcii nothovar. opizii). Main diagnostic traits of T. ×porcii nothovarieties and their parental taxa are compared and discussed.

Novelties in Lepidaploinae (Asteraceae, Vernonieae) from the easternmost campos rupestres of Minas Gerais, Brazil: two new species and a range expansion

Background – Recent collection efforts in Serra do Padre Ângelo, Pico da Aliança, and Sete Salões State Park, all located in the state of Minas Gerais, have uncovered many botanical and zoological novelties. The region is an outlying campos rupestres area inserted in the Atlantic Forest phytogeographic domain, with its flora mostly related to that of the core campos rupestres area in the Espinhaço Range. Three species of Asteraceae, one of the most representative families in the campos rupestres, have been recently described for the area. Here we report two new species from the genera Lepidaploa and Lessingianthus and one range extension in Lessingianthus, both from subtribe Lepidaploinae.Methods – This study was based on specimens from the herbaria HUFU, MBML, SPF, UFP, and on field observations. Morphological observations and measures were taken following standard practices. Preliminary conservation assessments are based on field observations and spatial analyses (i.e. extent of occurrence, area of occupancy), following IUCN guidelines and criteria.Results – Two new species are described: Lepidaploa campirupestris, related to Lepidaploa aurea, differing from the latter by leaf indumentum, pedunculate heads, and number of florets; and Lessingianthus petraeus, related to Lessingianthus adenophyllus, but differing by leaf position and leaf blade morphology. We also report a range extension for Lessingianthus squamosus, previously known only for the state of Espírito Santo, ca 200 km away. Our results shed light on the interesting biogeography of the region, which mostly contains components of other campos rupestres areas intermixed with typical inselberg vegetation. It also highlights the importance of compiling floristic inventories in poorly collected localities and the need for conservation strategies for this biodiverse region.

Trichome micromorphology of the genus Stachys sect. Fragilicaulis subsect. Fragilis and its taxonomic implications

The leaf, stem, calyx, and corolla indumentum of seven endemic taxa belonging to Stachys subsect. Fragiles, growing in Turkey, were micromorphologically and anatomically analyzed under scanning electron and light microscopes with the use of cluster analysis and Principal Component Analysis. We detected 10 trichome types on the leaf, seven trichome types on the stem and calyx, and eight trichome types on the corolla. Especially, the type and distribution of the trichomes on the calyx and corolla surfaces were quite different. The calyx and corolla had seven and eight trichome types, including glandular or non-glandular, in the examined taxa, respectively. The most common type observed was a short clavate glandular trichome; however, conical thin-walled unicellular hairs were specific for the studied taxa. No branched trichomes were observed. In the examined taxa, the indumentum indicated variations and some important similarities. The indumentum types have a high taxonomical value for the species of the genus. A key has been offered for the identification of the studied taxa based on the trichome characters, by comparing the key of classic taxonomic characters.

Oreocharis wumengensis, a new species of Gesneriaceae from northeastern Yunnan, China

A new species of Gesneriaceae, Oreocharis wumengensis Lei Cai & Z.L.Dao from Wumeng Mountain area, Yanjin County, Yunnan Province, China, is described. The new species is morphologically similar to O. panzhouensis Lei Cai, Y.Guo & F.Wen in the shape of corolla, number of stigma and stamens, but it can be easily distinguished from this species by the leaf shape and indumentum characters of leaf blade, calyx and stamens. Detailed descriptions with photographs of the plant and holotype, and comparisons with morphologically similar species, are also provided.

Notes on Strobilanthes cuspidata with reinstatement of Endopogon versicolor (Acanthaceae)

Endopogon versicolor Wight, previously treated as a synonym of Strobilanthes cuspidata (Benth.) T. Anderson, is reinstated as a distinct species and a new name S. benthamii B. Mani, Sinj. Thomas, Britto, A.K. Pradeep, Y.F. Deng & E.S.S. Kumar is necessarily proposed here. It differs from S. cuspidata by the stem and leaf indumentum, bract/calyx length ratio, corolla shape, pollen morphology, etc. Detailed descriptions, illustrations, pollen morphology and comparison with similar species are provided.

Recircumscription of Bredia and resurrection of Tashiroea (Sonerileae, Melastomataceae) with description of a new species T. villosa

Bredia (Melastomataceae) is an Asian genus that extends from central and southern mainland China to Taiwan and the Ryukyu islands. Molecular phylogenetic analyses reveal that the type of Bredia is nested in a clade of 20 species, while Tashiroea, a genus previously synonymized in Bredia, falls in another distantly related clade of 10 species. Our morphological survey shows that the two clades can be distinguished by several diagnostic features including leaf indumentum, texture, leaf surface sculpture under SEM, presence/absence of yellowish uniseriate trichomes, and capsule morphology. Based on molecular and morphological evidence, Bredia is recircumscribed and Tashiroea is resurrected. Description and a list of species are provided for the two genera with the description of a new species, T.villosa.

Cytological and morphological variation of Fallopia sect. Reynoutria taxa (Polygonaceae) in the Krivánska Malá Fatra Mountains (Slovakia)

Representatives of Fallopia sect. Reynoutria (knotweeds) belong to the most aggressive invasive plants in Europe. Despite their significant role in biological invasions and the major interest devoted to them by botanists and environmentalists, the identification of the members of this group is still very difficult and often mistaken. We studied the distribution of this group in the northwestern part of the Krivanska Mala Fatra Mountains (northwestern Slovakia). Forty-three Fallopia sect. Reynoutria stands (53 stems, 106 leaves) were used in flow cytometry and multivariate morphometrics to evaluate their genome size and morphological variation. Our research revealed that the group in the study area includes three knotweed taxa and that each of them is represented by only one cytotype: hexaploid (2n = 6x ~ 66) in F. ×bohemica (23 stands), octoploid (2n = 8x ~ 88) in F. japonica var. japonica (18 stands) and tetraploid (2n = 4x ~ 44) in F. sachalinensis (2 stands). Morphometrics of 23 leaf characters revealed that the most reliable distinguishing character of Fallopia sect. Reynoutria taxa is leaf indumentum. Analyses showed that F. ×bohemica is much more similar in leaf morphology to F. japonica var. japonica than to F. sachalinensis, thus explaining the fact that F. ×bohemica is, in both Slovakia and Europe, very often confused with F. japonica var. japonica, whose presence outside cultivation is overestimated. Compared to the other two knotweed taxa, occurrences of F. japonica var. japonica in the study area were situated mainly along watercourses, due to its exclusively vegetative propagation.

A new species of Melanoseris (Lactucinae, Cichorieae, Asteraceae) from SW Xizang, China, based on morphological and molecular data

Melanoseris jilongensis from SW Xizang, China, is described as a species new to science and illustrated, and its threat status is also assessed. It morphologically resembles M. macrorhiza, but differs in particular in leaf morphology, indumentum and achene characters. Molecular phylogenetic analysis based on nrITS and plastid DNA sequences revealed discordance between both DNA datasets as well as between morphological similarity and phylogenetic position. As in other cases of Sino-Himalayan taxa of the Melanoseris lineage, an event of reticulation in the speciation of M. jilongensis seems to have been taken place.

Analysis of trichome morphology and density in Salvia nemorosa L. (Lamiaceae) of Iran

AbstractSalvia nemorosa L. is an aromatic herb distributed widely in various regions of Iran, and is used in traditional and modern medicine. In the present study, leaf trichome densities and also type were investigated in six populations of the species, because the effective substances of this species exist in essential oil of glandular trichomes. For this, the mature intact leaves of each population were fixed in FAA solution, and then transverse hand sections were double-stained and studied using light microscopy. Leaf indumentum in all of the populations was dense pilose, with the exception of Tehran population that had loose pilose. Thirteen kinds of trichomes were identified, the main of which were peltate and capitate. PCA-biplot showed that each of these populations had prominent trichome trait(s). Furthermore, significant positive/negative correlations were found between some trichome types with main ecological factors of habitat. The studied populations clustered separately in the UPGMA tree, moreover, PCA and also PCO plots produced similar results. Our findings confirmed that ecological parameters of a habitat have strong effects on trichome morphology and density.

Molecular cytogenetic characterization, leaf anatomy and ultrastructure of the medicinal plant Potentilla alba L.

Potentilla alba L. is a valuable medicinal plant widely used in folk and traditional medicine and particularly promising in complex treatment of thyroid pathology. Natural resources of this species are insufficient due to ever-growing use in contemporary medicine. Comprehensive investigations of different P. alba populations are essential for the successful extension of P. alba plantings. Aiming for a better understanding of karyotype structure, chromosome behaviour in meiosis and developing new diagnostic characters, we performed molecular cytogenetic characterization and leaf structure and ultrastructure analyses of two introduced P. alba samples originating from different habitats. Based on chromosome morphology, distribution of 45S/5S rDNA and DAPI-banding patterns, all chromosomes in the karyotypes were identified and the P. alba chromosomal idiogram was constructed. Our findings confirmed P. alba karyotype stability and also revealed several diagnostic characters of this species: the features of cells of upper and lower leaf epidermis, the presence of calcium oxalate druses and three types of leaf indumentum, essential for evaluation of genetic diversity in different populations, validation of raw materials and further selection progress. The meiotic abnormalities were detected probably related to low pollen activity and indicated the advantages of vegetative propagation in the development of a P. alba plantation system.

Paepalanthus thomasianus, a new species of Paepalanthus subg. Platycaulon (Eriocaulaceae) from São Paulo State, Brazil

We describe and illustrate the new species Paepalanthus thomasianus (P. subg. Platycaulon, Eriocaulaceae) from São Paulo, Brazil, and compare it with other morphologically similar species. P. thomasianus is characterized mainly by its leaf indumentum, composed by long multicellular trichomes. Undulations formed by the vascular bundles in the leaf surface and the wide ratio between the leaf base and the middle region of the leaf are also useful to recognize the species. The morphological variation, habitat, geographic distribution, and conservation status of this new species are discussed.