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Roselle (Hibiscus sabdariffa L.) is recognized as a valuable food crop due to its nutraceutical potential, rich pigment content, and medicinal properties. However, there is limited information on planting dates and suitable genotypes for roselle cultivation in arid and semi-arid regions. The objective of this field study was to investigate the influence of five planting dates (March, April, May, June, and July) on morphological and phytochemical characteristics of different roselle genotypes. Among genotypes, eight (Jiroft, Dalgan, Bampoor, Iranshahr, Nikshahr, Roodbar, Saravan, and Qaleganj) were Iranian landraces, and HA and HS-24 were originated from Ghana and Bangladesh, respectively. Planting date significantly influenced the number of branches, bolls and seeds per plant, sepal fresh weight, calyx and biomass yields, and harvest index in tested roselle landraces. The greatest morphological growth, fresh sepal weight (50.6 g plant−1) and calyx yield (1519 kg ha−1) were observed with the roselle planted in early May. Moreover, amounts of chlorophyll, flavonoids and antioxidant remained higher in roselle when planted between April–May. The number of branches/plant was found to be an important determinant of calyx yield (r = 0.707) in roselle. Dalgan resulted in the greatest growth and yields within a comparatively shorter period of time compared to other tested landraces. Both principal component analysis (PCA) and cluster analysis also indicated that Dalgan landrace possessed most suitable morphological and phytochemical traits among tested landraces, and therefore, it could be planted adopted for extensive cultivation settings in the arid and semi-arid regions.

Se describe e ilustra Deiregyne tenorioi Soto Arenas & Salazar, especie nueva de los estados de Hidalgo, Estado de México, Oaxaca, Puebla y Tlaxcala en México. Es similar a D. eriophora (B.L. Rob. & Greenm.) Garay y a D. chartacea (L.O. Williams) Garay; de la primera se distingue por el ovario y la inflorescencia con el raquis esparcidamente glandular-pubescente (vs. lanuginoso), las flores inodoras y el labelo proporcionalmente más largo y angosto, con garganta de color verde brillante a amarillo limón, angosta, con los lados rectos (vs. garganta amarilla dorada, amplia, con los lados redondeados); de la segunda difiere en las flores mucho más grandes, los sépalos y pétalos no teñidos de color café verdoso abajo de la mitad, los sépalos laterales extendidos (vs. fuertemente recurvados) y el lóbulo distal del labelo proporcionalmente más largo y angosto.

Fruit yield is the most important horticultural trait of tomato. SlMBP21, a SEPALLATA subclass MADS-box gene has been reported to have functions in regulating pedicel abscission zone identity and development and controlling sepal size in tomato. However, we generated transgenic tomato plants which overexpress SlMBP21 and found the transformants displayed curly leaves, abnormally shaped flowers with twisted and opened stamens, reduced yield parameters, and small and light seeds. Our studies on the gain-of-function phenotype and gene expression level showed that its novel aspects played important roles in determining leaf morphology, flower and inflorescence architecture, and seed size, as well as the fruit yield. Overexpression of SlMBP21 in tomato resulted in curly leaves with fewer leaflets due to the regulation of the critical leaf polarity genes that cause an imbalance between the midvein adaxial–abaxial cell growth. Defects in the architecture of flowers and inflorescences resulted in reduced fruit set. Furthermore, we demonstrated that SlMBP21 plays its role through inhibiting the expression of the genes involved in the determination of seed development in tomato and SlMBP21 protein can interact with other MADS-box protein (SlAGL11, TAGL1 and SlMBP3) to control seed size. Thus, these results suggest that overexpression of SlMBP21 causes multiple types of damage to plant growth and development, especially fruit yield, in tomato.

In the present study, the surface and external structure of petals, sepals, hypanthium and pedicel of eight Rosa species were examined. Micromorphological investigation of distribution and dimension of different trichome types, which were found in analysed plant parts was done using scanning electron microscopy (SEM). Our results showed that the adaxial epidermal cells of all analysed petals formed papillae, whereas the abaxial epidermis was with flat walls and had cuticle striation. Two types of trichomes, the capitate glandular and nonglandular trichomes (ribbon and acicles) were observed. Ribbon trichomes were presented on the adaxial side of all analysed sepals with the exception of R. spinosissima samples. Multicellular glandular trichomes were distributed on the surface of the hypanthium and the sepals of R. gallica, R. micrantha, R. pendulina, R. tomentosa and R. villosa samples. In addition, they were presented on the pedicel of most analysed species, except in R. dumetorum samples. Micromorphological analysis had shown that capitate glandular trichomes, based on their size, can be classified into two typeslong and short trichomes. Their presence, type and length were specific for each analysed species. Additionally, acicles were found only on the pedicel and hypanthium of R. spinosissima and R. gallica samples. This study provided useful information of different trichomes of genus Rosa which could be helpful in more accurate plant determination.

Three new species of Ronnbergia (Bromeliaceae: Bromelioideae) and two new records of the same genus for Colombia are described. The three new species correspond to (1) Ronnbergia igneosepala from the slopes of the Western Cordillera in Narino (Colombia), which is unique by its orange floral bracts and sepals; (2) R. robusta from the Pacific Littoral of Colombia, which can be easily recognized by its involucrate peduncle bracts that only cover 1/3 of the inflorescence, green to dull-purple sepals and long sepal mucros; and (3) R. veitchioides, a species from the isolated mountain peak of Cerro del Torra (Choco) that can be identified by its serrulate, purple, reflexed floral bracts, and long sepals. We report the occurrence of R. campanulata in the department of Cauca, almost 800 km apart from the already known populations in the Cordillera del Condor of southern Ecuador. Moreover, we register R. aciculosa in Colombia and provide a short discussion on the differentiation of this species from R. tonduzii.

Novel strategies for improvement of plants’ ornamental and other properties relay on miRNA control of differential plant gene expression modulation. Still, in response to the same abiotic stresses, some conserved miRNA families show different expression patterns in different plant species. In parallel, the use of deep sequencing technologies reveals new levels of complexity of regulatory networks in plants through identification of new miRNAs. These are two major reasons why more studies are needed before envisioned new strategies may take their course in practical application domain. This research revealed 21 conserved miRNAs, matching 15 miRNA families, in Fritilaria imperialis. Among identified conserved miRNA families in crown imperial, miR166, miR169 and miR396 families were the most abundant ones. The expression of seven conserved miRNAs (Fim-miR156b, Fim-miR159, Fim-miR166a-5p, Fim-miR169d-5p, Fim-miR171c, Fim-miR393 and Fim-miR396e-3p) was further investigated in different tissues and three developmental stages, suggesting different roles these miRNAs have in growth and development of crown imperial. Gained knowledge from this research can open the door to find efficient ways to secure crown imperial survival, preservation and utilization and if proven useful may be applied in other plant species as well.

A species new to science, Dendrobium ormerodii Handoyo, Naive & J.Champ. from Kalimantan, Borneo is herein described and illustrated. The species is superficially similar to D. fulminicaule but differs in having shorter stem, narrower leaf, dorsal sepal with acute apex, labellum without sidelobes or without the broadening at the base, labellum apex obtuse-truncate, and shorter column. Detailed description, a colour plate, line drawing, notes on phenology, distribution, and a conservation assessment are provided below.

Calolisianthus speciosus, an endemic species of cerrado and campos rupestres in Brazil, bears colleters in both the leaf base and sepal. These colleters (leaf and sepal) were anatomically compared to identify differences in their structure and secretion mechanism. Samples of sepals and leaves in different development stages were collected and processed according to standard methodologies for anatomical and ultrastructural studies. Sepal and leaf colleters were anatomically similar, being non-vascularized, sessile or short-stalked and composed of a multicellular secretory head with large intercellular spaces where secretion, with a predominance of protein and polysaccharides, is accumulated. The secretory cells have thin walls, dense cytoplasm with granular endoplasmic reticulum, numerous dictyosomes and mitochondria. The ultrastructural characters are in agreement with the production of mucilaginous/protein secretion. The large secretion-filled vacuole merges with the plasma membrane releasing its contents to the periplasmic space where it remains until release outside of the cell wall, where it is accumulated in intercellular spaces formed by schizogeny. This accumulation generates pressure that promotes the passage of secretion through the external wall and the cuticle of superficial secretory cells of the head of the colleter.

As the supplement of the flora of Zhejiang, East China, two new species were described with illustrations. Cerastium huadingense Y.F.Lu, W.Y.Xie & X.F.Jin (Caryophyllaceae) differs from C. qingliangfengicum in having sterile stems absent, leaves sessile, petals slightly longer than sepals, and stamens slightly shorter than sepals. Ixeridium dimorphifolium Y.L.Xu, Y.F.Lu & X.Cai (Asteraceae) differs from I. beauverdianum in having plant stoloniferous, basal leaves dimorphic, involucre 8‒10 mm long, inner phyllaries 8, and florets 7‒10. Paraphlomis setulosa C.Y.Wu & H.W.Li (Lamiaceae) was reviewed and morphological characters of the corolla and stamens of its type and the specimens collected in the field survey were critically examined. With barbate anthers and strongly divergent anther cells, Paraphlomis setulosa was transferred to Sinopogonanthera, and S. setulosa (C.Y.Wu & H.W.Li) H.W.Zhang & X.F.Jin was consequently combined.

— Three new species of Microlicia endemic to Serra do Cipó, Minas Gerais state, Brazil, are described here. Microlicia joaosemiriana and M. longiglandulosa are characterized by their sessile leaves, congested flowers at the apex of the branches, dimorphic stamens with tetrasporangiate and bicolorous anthers. However, M. joaosemiriana differs in having hypanthium and sepal covered only with spherical glands and sepal shorter than the hypanthium length. Microlicia longiglandulosa has hypanthium and sepal with glandular trichomes mixed with spherical glands and sepal longer than the hypanthium length. Microlicia jolyana has a petiolate and thickened leaf, lanceolate to oblong leaf blade, rounded to slightly acuminate at the apex, smooth and not striate hypanthium surface, triangular-oblong and thickened sepal, dimorphic stamens, and purple to purple-blackish anther on both whorls. Also, Microlicia linifolia var. naudiniana is elevated to species rank with a new name (Microlicia acerosa), and M. nortecipoana and M. petiolulata are synonymized under M. hirtoferruginea. Additionally, we provide an updated checklist of Microlicia species in the Serra do Cipó.

A new species, Corybas papillatus, is described and illustrated from peninsular Thailand. The new species is easily recognized through a combination of the following characters: the purplish flower, the rounded apex of the dorsal sepal, the outer surface of dorsal sepal covered with irregular papillae in the upper half, the lateral sepals adnate laterally at the base to the connate petals, the V-shaped throat, the labellum bearing short hairs, dentate to erose labellum margins, and well-developed conical spurs. A key to the species of Corybas in Thailand is presented.

Eight new species from China, Cheirostylis chuxiongensis, C. yei, Myrmechis lingulata, M. longii, Bulbophyllum ximaense, B. xizangense, B. retusum and B. pulcherissimum, are described and illustrated. Cheirostylis chuxiongensis differs from C. thailandica by having 5–9 irregular and papillae-like calli on each side in the sac of the lip, epichile with entire lobes, petals narrowly obliquely obovate and an apex that is not recurved. Cheirostylis yei is easily distinguished from its relatives similar by having a long stem, pubescent ovary and sepals, epichile lobes with irregular and undulate margins, a subquadrate callus without teeth in the saccate hypochile. Myrmechis lingulata differs from M. chinensis by having a simple and lanceolate to ligulate lip, glabrous bracts and ovary, oblique and narrowly ovate petals. Myrmechis longii differs from M. pumila by having white-veined leaves, oblong-lanceolate epichile lobes, and viscidium attached to the middle of the caudicle. Bulbophyllum ximaense is easily distinguished from its relatives similar by having distant pseudobulbs, shorter scape, an inflorescence with 9–16 orange-red flowers, shorter lateral sepals with a long acuminate apex, incurved and tubular apical margins, a papillate lip disk and triangular-subulate stelidia. Bulbophyllum xizangense is easily distinguished from its relatives similar by having narrow lanceolate leaves, shorter inflorescence with 1–3 greenish-yellow flowers, falcate-ovoid lateral sepals, a lip with small lateral lobes and 3 keels at the base. Bulbophyllum retusum differs from B. spathulatum by having shorter inflorescence, peduncles with 2 tubular sheaths, dorsal sepals with a retuse apex, lateral sepals with lower edges that are connate to each other and free and divergent toward the apex, obovate petals with an acute or slightly retuse apex. Bulbophyllum pulcherissimum differs from B. lopalanthum by its 5-veined dorsal sepal, ovate-lanceolate lateral sepals, obliquely ovate-oblong petal, erose-toothed margins and obovate lip with a large, oblong basal callus, and an obtuse base. In addition, three species (Bulbophyllum frostii, B. raskotii and B. nematocaulon) are reported for the first time in China.

Five new species (Gastrochilus yei, Gastrochilus minimus, Luisia simaoensis, Taeniophyllum xizangense, Tuberolabium subulatum) and two newly recorded species (Cleisostoma tricornutum, Luisia inconspicua) of Vandeae (Orchidaceae) from China are described and illustrated. Gastrochilus yei is similar to G. affinis and G. nepalensis, but differs from them by having an epichile not lobed, the apex of the hypochile not bilobed, and a tine on the apex of the leaf. Gastrochilus minimus is similar to G. acinacifolius, but can be distinguished from the latter by having a flabellate epichile that is densely hirsute on the adaxial surface and an inconspicuous central cushion; in addition, the hypochile of G. minimus has a keel that extends to the apex of the epichile. Taeniophyllum xizangense is similar to T. stella and T. radiatum, but it is distinguished from them by having much bigger flowers, inflorescences densely covered with short-bristly hairs, papillae on the external surface of sepals, and bigger triangular-ovate viscidium. Luisia simaoensis is similar to L. magniflora and L. ramosii, but can be easily distinguished from them by having lateral sepals longer than dorsal sepals and petals, lip with irregular and waved margins, and lip with bilobed apex. Luisia inconspicua is moved from Gastrochilus to Luisia based on phylogenetic analyses of plastid matK sequence data. Tuberolabium subulatum is similar to T. carnosum, but it can be easily distinguished from the latter by having an inflorescence much shorter than the leaves, yellow sepals and petals, and many small papillae outside the lip lobes., Highlights • Five new orchid species belonging to Vandeae were described based on morphological characters. • Two new recorded orchids of China were reported. • Phylogenetic position of Luisia inconspicua is confirmed based on molecular systematics.

Double flower is an invaluable trait in ornamental peach, but the mechanism underlying its development remains largely unknown. Here, we report the roles of ABCE model genes in double flower development in peach. A total of nine ABCE regulatory genes, including eight MADS-box genes and one AP2/EREBP gene, were identified in the peach genome. Subcellular localization assay showed that all the ABCE proteins were localized in the nucleus. Four genes, PpAP1, PpAP3, PpSEP3 and PpPI, showed a difference in expression levels between single and double flowers. Ectopic overexpression of PpPI increased petal number in Arabidopsis, while transgenic lines overexpressing PpAP3 or PpSEP3 were morphologically similar to wild-type. Ectopic overexpression of PpAP1 resulted in a significant decrease in the number of basal leaves and caused early flowering. These results suggest that PpPI is likely crucial for double flower development in peach. Additionally, double flowers have petaloid sepals and stamens, and single flower could occasionally change to be double flower by converting stamens to petals in peach, suggesting that the double-flower trait is likely to have evolved from an ancestral single-flower structure. Our results provide new insights into mechanisms underlying the double-flower trait in peach. This article is protected by copyright. All rights reserved.

The HAWAIIAN SKIRT (HWS) gene was originally described in Arabidopsis for the characteristic fusion of sepals in the mutant. A tomato line mutated in the putative ortholog gene was isolated in a previous study. The tomato hws-1 mutant showed facultative parthenocarpy and produced fruits with elevated Brix, revealing the gene as a hopeful resource for crop improvement. To confirm the orthology relationship between the Arabidopsis and tomato HWS genes, the hws-1 mutant was complemented with either the tomato wild-type genomic fragment or the Arabidopsis sequence of the gene. In both complementation experiments, defective phenotypes of hws-1 are rescued, albeit to different extents. Recovery of these phenotypes, which include parthenocarpic fruit production, increased Brix, loss of leaflet serration, alteration of bud and petal shape, firmly establishes SlHWS as an ortholog of the originally described HWS in Arabidopsis. This work indicates that the function of HWS is likely to be conserved in a wide range of plant species.

Most Neotropical Malpighiaceae species are characterized by having zygomorphic flowers and oil glands in the sepals called elaiophores; these floral characteristics are associated with a particular pollination syndrome through oil-collecting bees. This work proposes a study about the structural characteristics of elaiophores in 18 species of Malpighiaceae present in Argentina. The main objectives are to describe the morphology and anatomy of the elaiophores, to detect variation in the number of glands, to compare similarities or differences in elaiophores of species belonging to different lineages, and to know about the potential pollinators and their association with the structural traits of the elaiophores. The morphology and the anatomy were studied using traditional methods of scanning electron and bright-field microscopes. Field trips were carried out to capture oil-collecting bee species on flowers, in different natural populations. Different measurements were taken in the flowers, elaiophores, and oil-collecting bees and were statistically analyzed. Although elaiophores showed a common pattern, some particularities in number, morphology, and anatomy were detected; few of these seem to be restricted to some groups of species phylogenetically related. As regards pollinators, a positive tendency was observed between the size of the flowers, elaiophores, and oil-collecting bees. However, the thickness of the cuticle presented a negative association with the size of the elaiophore and consequently with the floral diameter, which could be presumably related to the foraging behavior and/or the structure of oil-collecting apparatus of the bee species.

Organ sizes and shapes are highly reproducible, or robust, within a species and individuals. Arabidopsis thaliana sepals, which are the leaf-like organs that enclose flower buds, have consistent size and shape, which indicates robust development. Counterintuitively, variability in cell growth rate over time and between cells facilitates robust development because cumulative cell growth averages to a uniform rate. Here we investigate how sepal morphogenesis is robust to changes in cell division but not robust to changes in cell growth variability. We live image and quantitatively compare the development of sepals with increased or decreased cell division rate ( lgo mutant and LGO overexpression, respectively), a mutant with altered cell growth variability ( ftsh4 ), and double mutants combining these. We find that robustness is preserved when cell division rate changes because there is no change in the spatial pattern of growth. Meanwhile when robustness is lost in ftsh4 mutants, cell growth accumulates unevenly, and cells have disorganized growth directions. Thus, we demonstrate in vivo that both cell growth rate and direction average in robust development, preserving robustness despite changes in cell division., Competing Interests: Competing interests The authors declare they have no competing interests.

Growth of living organisms originates from molecular events. These events add up, and generate cellular behaviors that together produce morphogenesis. In my PhD, I studied how such microscopic events contribute to plant morphogenesis. More specifically, in a first set of projects, we investigated the dynamics of the microtubule cytoskeleton in Arabidopsis pavement cells by quantifying distribution of microtubule orientation and tip dynamics at subcellular scale. Disruption of microtubule patterning was predicted to lead to mechanical failure of cells, but we highlighted compensation mechanisms that prevented it. In my main project, we investigated the role of cellulose synthase guidance along microtubules via a protein called CELLULOSE-SYNTHASE INTERACTIVE 1 (CSI1). In the absence of CSI1, cellulose synthases follow previously deposited cellulose microfibrils, which should lead to increased alignment. Contrary to the current growth model where cellulose alignment is associated with growth anisotropy, we found that this did not lead to an increase in cell elongation and even led to a decrease of organ elongation in Arabidopsis sepal. Sepals also presented less anisotropic mechanical properties and displayed cells with a snake-like shape. At a multicellular scale, we found that spatial consistency of growth direction was impaired in csi1, which explains the reduced length of its organs, the reduced mechanical anisotropy of organs, and the defects in cell shape. Our results contribute to bridging knowledge between scales, from the cytoskeleton, to the cell wall and to plant morphogenesis.; La croissance des organismes vivants est le résultat d'événements moléculaires. Ces événements s'additionnent et génèrent des comportements cellulaires qui, ensemble, produisent la morphogenèse. J'ai étudié comment ces événements microscopiques contribuent à la morphogenèse des plantes. D’une part, nous avons étudié la dynamique des microtubules dans les cellules de pavage d'Arabidopsis, en quantifiant la distribution d’orientation des microtubules et la dynamique de leurs extrémités à échelle subcellulaire. La perturbation de l'orientation des microtubules est censée entraîner une défaillance mécanique des cellules, mais nous avons mis en évidence des mécanismes de compensation qui l'empêchent. Dans mon projet principal, nous avons étudié le rôle du guidage des complexes synthétisant la cellulose le long des microtubules par une protéine appelée CELLULOSE-SYNTHASE INTERACTIVE 1 (CSI1). En l'absence de CSI1, les complexes synthétisant la cellulose suivent les fibres de cellulose précédemment déposées, ce qui devrait conduire à un alignement accru. Contrairement au modèle selon lequel l’alignement de la cellulose augmente l’anisotropie de croissance, nous avons constaté que cela n’augmente pas l'élongation cellulaire et entraîne même une diminution de l’élongation du sépale d'Arabidopsis. Ces sépales présentent également des propriétés mécaniques moins anisotropes et des cellules ondulant en forme de serpent. À l'échelle multicellulaire, nous avons constaté que la cohérence spatiale de la direction de la croissance est altérée chez csi1, ce qui explique la longueur réduite de ses organes, l'anisotropie mécanique réduite des organes et les défauts de forme des cellules. Nos résultats contribuent à éclairer le lien entre échelles spatiales lors de la morphogenèse végétale.

Gibberellin (GA) is a crucial hormone that drives parthenocarpy and fruit set progression. However, it remains unknown whether GA participates in the parthenocarpy and fruit set in jujube (Ziziphus jujuba Mill.). In this study, we observed the morphology and effect of parthenocarpy in jujube flowers with GA3 treatment. Liquid chromatography tandem-mass spectrometry analysis was performed to detect the levels of endogenous hormones in sepal spread (H), filament wilting (S), and ovary inflation (G) stages of jujube flowers, and the GA3-induced differentially expressed genes (DEGs) were identified by RNA sequencing. We found that GA3 improved jujube parthenocarpic fruit set and that the morphology and size of flowers after GA3 treatment were superior to those in control flowers. GA3 treatment increased the levels of gibberellin, ABA, auxins, and cytokinins in jujube flowers. RNA sequencing revealed that GA3-induced DEGs expressed in the H, S, and G stages. Functional and pathway analyses demonstrated that these DEGs belong to plant development, including glucan metabolic processes and plant hormone signal transduction. Moreover, quantitative reverse transcription polymerase chain reaction validated the reliability of the sequencing data. Fruit set–related genes were significantly induced in the H, S, and G stages of jujube flowers. Our study confirmed that GA3 induced phytohormone production and fruit set by regulating the expression of endogenous hormones and related genes.

Premise Floral spurs are key innovations associated with elaborate pollination mechanisms that have evolved independently several times across angiosperms. Spur formation can shift the floral symmetry from radial to bilateral, as it is the case in Tropaeolum, the only member of the Brassicales with floral nectar spurs. The genetic mechanisms underlying both spur and bilateral symmetry in the family have not yet been investigated. Methods We studied flower development and morphoanatomy of Tropaeolum longifolium. We also generated a reference transcriptome and isolated all candidate genes involved in adaxial-abaxial differential growth during spur formation. Finally, we evaluated the evolution of the targeted genes across Brassicales and examined their expression in dissected floral parts. Results Five sepals initiate spirally, followed by five petals alternate to the sepals, five antesepalous stamens, three antepetalous stamens, and three carpels. Intercalary growth at the common base of sepals and petals forms a floral tube. The spur is an outgrowth from the adaxial region of the tube, lined up with the medial sepal. We identified Tropaeolum specific duplications in the TCP3/4L and STM gene lineages, which are critical for spur formation in other taxa. In addition, we found that TM6 (MADS-box), RL2 (RAD-like7), and KN2/6L2 and OSH6L (KNOX1 genes), have been lost in core Brassicales but retained in Tropaeolum. Conclusions Three genes are pivotal during the extreme adaxial-abaxial asymmetry of the floral tube, namely, TlTCP4L2 restricted to the adaxial side where the spur is formed, and TlTCP12 and TlSTM1 to the abaxial side, lacking a spur.

Pink, blue, and red hydrangea [(Hydrangea macrophylla subsp. Macrophylla var. macrophylla (Thunb.)] cultivars contain the anthocyanin pigment delphinidin-3-glucoside that color the sepal. Without a...

Floral secretory structures have been reported for Gentianaceae; however, morphoanatomical studies of these glands are rare. We described the development and secretory activity of the colleters and nectaries throughout the floral development of Chelonanthus viridiflorus. We collected flower buds, flowers at anthesis, and fruits to be investigated using light and scanning electron microscopy. We performed histochemical tests on the secretion of colleters and used glycophyte to confirm the presence of glucose in nectar. Colleters are located on the ventral surface of sepals and nectaries occur in four regions: (i) the dorsal and (ii) ventral surfaces of sepals; (iii) apex of petals; and (iv) base of ovary. The colleters have a short peduncle and a secretory portion with homogeneous cells. They are active in flower buds and secrete polysaccharides and proteins. In flowers at anthesis, they begin to senescence presenting protoplast retraction, cell collapse, and lignification; these characteristics are intensified in fruit. The nectaries of sepals and petals have two to five cells surrounding a central cell through which the secretion is released. Nectaries are numerous, forming a nectariferous area on the dorsal surface of sepals, like that observed on petals, and can form isolated units on the ventral surface of sepals. They are active from flower buds to fruits. A region with secretory activity was identified at the base of the ovary. The secretion of colleters acts in the protection of developing organs, while nectaries are related to defenses against herbivores and the supply of nectar to potential robbers or pollinators.

Ardisia pyrotechnica Julius, Tagane & Utteridge (Primulaceae-Myrsinoideae) is described and illustrated as a new species from Sarawak, Borneo. The new species is assigned into Ardisia subgenus Pyrgus based on its inflorescence terminal on specialized lateral branches below the indeterminate primary axis, which is arising directly from the stem. Remarkable for the massive inflorescences subtended by two large elliptic foliose bracts and the large pinkish-white sepals; a preliminary conservation status, photographs and a line illustration are also provided.

Primula atrodentata W. W. Sm. (Primulaceae) is recorded for the first time from the Trans-Himalayan region of Ladakh in India. The present study provides a taxonomic description, photographs of diagnostic features and distribution map of the species. Comparison of delimiting characters between P. atrodentata and closely related P. denticulata are provided to validate the new distribution record for the region. The species' differs from P. denticulata in lacking basal bud scales, black-colored sepals and mauve or pale blue-violet corolla with a prominent white or creamy eye. In addition, IUCN threat status of P. atrodentata was empirically assessed for the first time which revealed the species as Near Threatened (NT). In an era of rapid land-use and climate changes, the results from present study have wide relevance in devising successful conservation strategies for this endemic species in high-altitude habitats of the Himalaya.

Leaf shape is highly variable within and among plant species, ranging from slender to oval shaped. This is largely determined by the proximodistal axis of growth. However, little is known about how proximal-distal growth is controlled to determine leaf shape. Here, we show that Arabidopsis leaf and sepal proximodistal growth is tuned by two phytohormones. Two class A AUXIN RESPONSE FACTORs (ARFs), ARF6 and ARF8, activate the transcription of DWARF4, which encodes a key brassinosteroid (BR) biosynthetic enzyme. At the cellular level, the phytohormones promote more directional cell expansion along the proximodistal axis, as well as final cell sizes. BRs promote the demethyl-esterification of cell wall pectins, leading to isotropic in-plane cell wall loosening. Notably, numerical simulation showed that isotropic cell wall loosening could lead to directional cell and organ growth along the proximodistal axis. Taken together, we show that auxin acts through biosynthesis of BRs to determine cell wall mechanics and directional cell growth to generate leaves of variable roundness.

The new species discovered in Thanh Hoa Province of northern Vietnam described here as a new species for science. It is similar to B. muscicola but differs in smaller habit, inflorescence shorter than leaves, shorter lateral sepals with unequally lobed blunt apex, and slender stelidia. The newly described species also can be compared with B. japonicum but it differs in the size and shape of leaves, tepals, and lip. Detailed morphological description, illustration, data on distribution, and phenology of the new species are presented.