Nutlet Shape Research Articles

A new species of Onosma (Boraginaceae) from Bakhtiari Mountains in Iran

A new species, Onosma bakhtiarica (Boraginaceae), has been discovered in Iran’s Chaharmahal and Bakhtiari province. The plant is found in the Tang-e Beheshtabad and belongs to sect. Onosma subsect. Haplotricha. Morphologically, it is closely related to O. pachypoda and O. sericea. Still, it differs from the mentioned species by the rosette leaf shape, shape of rosette leaf apex, shorter cauline leaf, cauline leaf width and shape, arrangement of setae, corolla color and shape, shorter pedicel length in flowering and fruiting, shorter fruiting calyx, bract shape, nutlet shape and size, nutlet ornamentation, and a hairy annulus. In addition, O. bakhtiarica is distinguished from O. pachypoda by its light brown nutlet, rosette leaf with a long petiole, and cauline leaf with an acute apex. It can also be distinguished from O. sericea by the dense short hairs covering the corolla’s exterior. Diagnostic characters, a comprehensive description, photographs, and a distribution map are provided. An identification key for haplotrichous Onosma species of Iran is also provided.

Phylogeny of Trigonotis in China—with a special reference to its nutlet morphology and plastid genome

The genus Trigonotis comprises nearly 60 species mainly distributed in East and Southeast Asia. China has the largest number of Trigonotis species in the world, with a total of 44 species, of which 38 are endemic. Nutlet morphology is useful for the taxonomic delimitation of Trigonotis. However, there are still controversial circumscriptions of nutlet shape in some species. In previous studies, interspecies phylogenetic relationships were inferred using few DNA markers and very few taxa, which possibly led to erroneous or incomplete conclusions. In this study, the nutlet morphology of 39 Trigonotis taxa and the characteristics of 34 complete chloroplast genomes (29 taxa) were investigated and analyzed. Then, the phylogenetic relationships were discussed within this genus based on complete chloroplast genomes. To the best of our knowledge, this study is the first comprehensive analysis of nutlet morphology and complete chloroplast genome of Trigonotis. Based on nutlet morphology, Trigonotis can be divided into two groups: Group 1, hemispherical or oblique tetrahedron with carpopodiums, and Group 2, inverted tetrahedron without carpopodiums. The chloroplast genome of Trigonotis exhibited a typical quadripartite structure, including 84–86 protein-coding, 37 transfer RNA, and 8 ribosomal RNA genes, with a total length of 147,247–148,986 bp. Genes in the junctions were well conserved in Trigonotis, similar to those in other Boraginaceae s.str. species. Furthermore, Trigonotis chloroplast genomes showed relatively high diversity, with more conserved genic regions than intergenic regions; in addition, we detected 14 hot spots (Pi > 0.005) in non-coding regions. Phylogenetic analyses based on chloroplast genome data identified highly resolved relationships between Trigonotis species. Specifically, Trigonotis was divided into two clades with strong support: one clade included species with hemispherical or oblique tetrahedron nutlets with carpopodiums and bracts, whereas the other clade included species with inverted tetrahedron nutlets without carpopodiums or bracts. Our results may inform future taxonomic, phylogenetic, and evolutionary studies on Boraginaceae.

GEOGRAPHICAL VARIATION OF AJUGA ORIENTALIS L. TRICHOME, NUTLET AND POLLEN

In this study, the main features of the trichomes, nutlet, and pollen of A. orientalis, which growing in four different provinces of Turkey, were examined as detail and the results were illustrated. A. orientalis carries both peltate and capitate trichomes, as well as non-glandular ones. However, the subtypes of capitate glandular and non-glandular trichomes were recognized. The shape of nutlets is obovate, oblong-obovate and the nutlet surface sculpturing is alveolate. The shape of pollen grains is euprolate (P/E 1.59-1.7). The basic exine ornamentation in pollen grains is regulated, regulate-perforated.

Nutlet micromorphology of Mardin in Turkey Salvia L. (Lamiaceae) and its systematic implacations

The nutlet (mericarp) morphology of nine species of Salvia sect. Salvia (Salvia bracteata Banks & Sol., Salvia macrochlamys Boiss. & Kotschy, Salvia suffruticosa Montbret & Aucher ex Benth., Salvia trichoclada Benth.), Hymenosphace (Salvia multicaulis Vahl), Aethiopis (Salvia montbretii Benth., Salvia palaestina Benth., Salvia syriaca L.) and Hemisphace (Salvia russellii Benth.) (Lamiaceae) has been studied by scanning electron microscopy (SEM), and a detailed description of the nutlet morphological features of all examined taxa is provided. The basic shape of nutlets in most species is subprolate or prolate and the size ranged between 3.02 and 6.47 mm in length and between 1.78 and 5.10 mm in width. Three basic types of sculpturing can be distinguished: colliculate, reticulate and verrucate. The colliculate type is the most common among the studied species. The colliculate type is characteristic for sect. Salvia. Subsection Salvia with colliculate/slightly furrowed sculpturing is easily distinguished from the other subsections. The systematic and biological implications of the nutlet characteristics are shortly discussed.

Nutlet micromorphology and its taxonomic and phylogenetic significance in Salvia (Lamiaceae)

Salvia (sage) is a species rich and medicinally important genus. Species-level identification is usually very difficult, particularly in closely related species. Here, we investigated nutlet micromorphological characteristics of 51 taxa belonging to S. subg. Salvia, S. subg. Sclarea and Salvia verticillata clade (S. subg. Heterosphace) by stereo binocular microscopy and scanning electron microscopy to show their taxonomic and phylogenetic value. The present study is the most comprehensive nutlet micromorphological study based on the number of taxa studied in the genus so far. The size of nutlets varies from 1.61 mm (S. verticillata subsp. verticillata) to 8.44 mm (S. albimaculata) in length, 1.02 mm (S. verticillata subsp. verticillata) to 4.20 mm (S. macrochlamys) in width. Nutlet length/width ratio ranges from 1.02 (S. bracteata and S. indica) to 3.06 (S. albimaculata). The basic shape of nutlets is elliptic, widely elliptic, circular, ovate or obovate. Five nutlet sculpturing patterns are present namely colliculate, reticulate, verrucate, rugose and foveate. The variation of surface sculpturing, nutlet shape, size, and exocarp cell shape provide useful diagnostic properties at species and subgenus level. However, nutlet micromorphological characters are of low phylogenetic value in studied Salvia species.

Nutlet morphology in the tribe Elsholtzieae (Lamiaceae)

A comprehensive study on nutlet morphology on 46 taxa from the tribe Elsholtzieae was conducted using stereomicroscopy, light microscopy and scanning electron microscopy. The objectives were to evaluate the nutlet characteristics in a systematics context and to provide additional evidence for taxon delimitation. The nutlet shape varied from elliptical, widely elliptical, spheroidal and ovate to pyriform. The size ranged from 0.50 to 2.70 mm in length and 0.34 to 2.65 mm in width. The three types of trichomes included simple non‐glandular trichomes (Collinsonia punctata), clavate non‐glandular trichomes (Elsholtzia cephalantha) and peltate glandular trichomes (Mosla grosseserrata and M. chinensis). We also report the presence of a mucilaginous reaction in nine species of the genus Elsholtzia in Elsholtzieae for the first time. Four types (undulate, papillae‐like projection, thorn‐like pattern and reticulate) and three subtypes (reticulate, reticulate‐cellular and supra‐reticulate) of nutlet surface patterns in the mid‐ventral region were recognized in Elsholtzieae based on the differences in cell outline, outer periclinal walls and dentations of the anticlinal walls. These nutlet micromorphological results may serve as a reference for future hypotheses on the classification of the tribe Elsholtzieae.

'Teucrium elymaiticum' (Lamiaceae): a new species for Flora of Iran

A new endemic species from western Iran, Teucrium elymaiticum Attar, Sotoodeh & Mirtadzadini, spec. nova is described. It belongs to section Scordium. Considering the combination of some characteristics like indumentum, bracts, pedicel, calyx, corolla size, and nutlet shape and size, the new species is related to T. scordium subsp. scordioides (Schreb.) Arcang.. The differences between these two species are highlighted. Images, distribution map and an updated identification key for the genus are presented.

Nutlet structures of subsection Fragiles of the genus Stachys (Lamiaceae) from Turkey and their systematic applications

This paper includes the morphological and anatomical characters of the nutlets of 7 endemic species of the subsection Fragiles of the genus Stachys (Lamiaceae) from Turkey and the systematic significance of these characteristics, using one-way analysis of variance and cluster and principal component analyses. Morphological characters such as the dimensions, shapes, colors, and surfaces of the nutlets were studied using light and scanning electron microscopes. The structures and thicknesses of the pericarp and endosperm layers, as well as the sizes of the cotyledon in the nutlets, were anatomically studied. The outcomes revealed that the taxa varyfrom each other in terms of nutlet shape and color. The nutlet dimensions range from 1.31 mm to 3.49 mm in length and from 0.84 mm to 1.95 mm in width. While Stachys longiflora and S. pseudopinardii have the largest nutlets, S. chasmosericea has the smallest. The nutlet surface ornamentation was recorded as 5 types: reticulate, scalariform, reticulate-foveate, ruminate, and rugose. The most common type is reticulate; however, the other ornamentation types are specific for the studied taxa. Anatomically, the structure and thickness of the pericarp parts and the endosperm and the size of the cotyledon are very important characteristics that disclose interspecific relations within the studied taxa. A key is presented for the identification of the examined taxa based on the nutlet properties.

Nutlet micromorphology of Iranian Nepeta (Lamiaceae) species

To evaluate nutlets characteristics for systematic relationships, a comprehensive morphological and micro‐morphological study of the nutlets of 16 Iranian taxa of Nepeta (Lamiaceae) was conducted using scanning electron microscopy (SEM). Differences in surface ornamentation, size, shape and color were observed between the species. The studied taxa were categorized in two basic types based on surface ornamentation: non‐sculptured (smooth‐type) and sculptured nutlets. The non‐sculptured nutlets type could be further divided into four sub‐types, including smooth, granulate, undulate‐cellular and reticulate. In the sculptured nutlets, three subtypes of tuberculate, tuberculate‐cellular and verrucate were recognized. The shape of nutlets were described as oblong, ovoid‐oblong, oblong‐linear, to elliptic‐oblong and their size range are 1.2–2.0 mm in length and 0.5–2.0 mm in width. Based on micrographs, the areole form and location were defined as bi‐lobed, straight, basal, sub‐basal or lateral. Nutlet micromorphological characteristics such as surface ornamentation can be useful for classification and identification of e.g. medicinal species of Nepeta in Iran.

A taxonomic revision of Schoenus cuspidatus and allies (Cyperaceae, tribe Schoeneae)—Part 1

The first of a two-part taxonomic revision of the morphologically complex Schoenus cuspidatus and allies group is presented. This revision builds on two recent taxonomic works of which the first transferred 24 southern African species from Tetraria and Epischoenus into Schoenus, and the second revised the taxonomy of the Schoenus compar – Schoenus pictus and allies group, as well as described three new species from South Africa. Here, we use data from recent field collections and a review of specimens from 12 herbaria to revise the delimitations and distributions of three species (Schoenus bolusii, Schoenus exilis and Schoenus graminifolius). In addition, we describe seven new species: six of which are endemic to the Cape Floristic Region (Schoenus calceolus, Schoenus crassiculmis, Schoenus submarginalis, Schoenus prophyllus, Schoenus purpurascens and Schoenus quartziticus), while the seventh is endemic to the Eastern Cape and KwaZulu Natal Provinces of South Africa (Schoenus limosus). We also resolve nomenclatural and species delimitation issues in Schoenus auritus and Schoenus ligulatus, with Schoenus autumnalis and Schoenus variabilis being subsumed in an enlarged circumscription of Schoenus ligulatus. Species in the Schoenus cuspidatus group are caespitose, perennial graminoids, with scapose and terete culms. However, there are differences in sheath and ligule type, which can be either firm or membranaceous, as well as leaf type, which vary from channelled and terete to non-channelled and flat. Importantly, differences in spikelet and nutlet shape distinguish many of the species in this group. A taxonomic key is presented, the nomenclature is updated, and detailed descriptions and distribution maps are provided for these 12 Schoenus species.

Cryptantha nevadensis var. rigida elevated to species with a new name, C. juniperensis

A replacement name, Cryptantha juniperensis, nomen et status novum, is proposed for Cryptantha nevadensis A.Nelson & P.B.Kennedy var. rigida I.M.Johnston. A new name was necessary because the name C. rigida was unavailable, due to its previous use for the South American Cryptantha rigida (Phil.) Reiche. Cryptantha juniperensis is similar to what has been treated as Cryptantha nevadensis var. nevadensis, with which it shares appressed upper stem trichomes and a relatively long fruiting calyx, often with erect to reflexed apices. However, Cryptantha juniperensis differs significantly from Cryptantha nevadensis var. nevadensis by the nutlet shape, which is narrowly ovate to widely lance-ovate, narrowly acute, and tuberculate in the former but lance-ovate, strongly acuminate, and elongate-tuberculate to muricate in the latter. In addition, Cryptantha juniperensis is erect (vs. lax and sprawling in Cryptantha nevadensis var. nevadensis), has fruiting calyces between 4.5–7.5 mm (vs. 6–11 mm long), and has a corolla limb that ranges between 2–5 mm in diameter (vs. 1–2 mm in diameter). Cryptantha juniperensis, which has also been classified as Cryptantha intermedia (A.Gray) Greene var. rigida Brand, is similar to recognized varieties of C. intermedia in nutlet morphology and in growth habit but differs in having upper stems with trichomes mostly appressed (vs. mostly spreading), a smaller corolla size (ca. 2–5 mm vs. 3–11 mm), and cymules that are mostly paired (vs. cymules that are arranged in threes). Preliminary molecular studies also support the recognition of C. juniperensis as a taxon separate from both C. nevadensis and C. intermedia.

A New, Large-Flowered Variety ofEremocarya micrantha(Boraginaceae)

Abstract Eremocarya (Boraginaceae), a resurrected segregate of the genus Cryptantha, has recently been recognized as containing two species: E. lepida and E. micrantha. These two species differ in nutlet shape, nutlet size, and features of the corolla, including limb width, presence or absence of a prominent yellow coloration at the fornices of the corolla center, and, perhaps most importantly, presence or absence of distinctive “fornix bodies” at the corolla mouth. Here we present evidence for a large-flowered form of E. micrantha that we argue should be treated as a new taxonomic variety, which we call E. micrantha var. pseudolepida. In nutlet morphology, E. micrantha var. pseudolepida is very similar to E. micrantha var. micrantha and different from E. lepida. Eremocarya micrantha var. pseudolepida differs from E. micrantha var. micrantha and is similar to E. lepida in corolla limb diameter and in having a tendency to possess a prominent yellow coloration in the corolla throat. However, E. micrantha va...

Deviacer pidemarmanii sp. nov. (Polygalaceae) from the Late Eocene–Early Oligocene Badger’s Nose Paleoflora, Modoc County, California

Premise of research. Fossils of asymmetrically winged samaras, informally referred to as Acer negundoides MacGinitie (Sapindaceae), from the late Eocene–early Oligocene Badger’s Nose flora (∼34 Ma) of northern California, are described as Deviacer pidemarmanii Myers and Erwin sp. nov. The genus Deviacer Manchester is emended and attributed to the family Polygalaceae. Methodology. The morphological features of more than 40 samaras exquisitely preserved as compressions in lacustrine siltstone of the Badger’s Nose member of the Steamboat Formation were compared to similar extant and fossil-winged fruits. Pivotal results. Deviacer includes compressions of nonschizocarpic asymmetrical samaras with a small dorsal projection. Similar projections characterize the fruits of extant Securidaca (Polygalaceae) and the extinct genus Paleosecuridaca Pigg, Devore, and Wojciechowski, but Acer L. (Sapindaceae) fruits lack these structures. Morphologically, Deviacer is indistinguishable from the anatomically preserved fruits of Paleosecuridaca. Deviacer pidemarmanii sp. nov. is described based on overall fruit size; nutlet shape, size, and orientation to the wing; and wing size, form, and venation. Anatomical features such as locule and seed number in D. pidemarmanii are not preserved, but one specimen appears to be two-seeded, as in Paleosecuridaca. Conclusions. Deviacer is emended and assigned to the Polygalaceae. Paleosecuridaca may be congeneric with Deviacer, but Deviacer fruits are compressions and lack the nutlet anatomy described by Pigg, Devore, and Wojciechowski. Deviacer pidemarmanii records Securidaca-like plants in warm temperate regions of the Pacific Northwest (North America) at least until the latest Eocene–early Oligocene climatic and biotic transition, whereas today extant Securidaca and most other members of the Polygaleae are pantropical. Deviacer pidemarmanii closely resembles the liana Securidaca paniculata Rich. var. lasiocarpa Oort., today a native of northern South America. Recognizing asymmetrically winged samaras from well-dated Cenozoic sediments as related to Securidaca will advance our understanding of the evolutionary relationships and biogeographic history of Polygalaceae and the ecology of Securidaca-like plants in Paleogene vegetation at north temperate latitudes.

Nutlet morphology and its taxonomic implication in some taxa of Lamiaceae in Egypt

Nutlet morphology of 28 taxa belonging to 15 genera of Lamiaceae were examined using light and scanning electron microscopy. The taxa included representatives of the three subfamilies Ajugoideae, Lamioideae and Nepetoideae which all collected especially from Sinai, Egypt. Morphological characters, including nutlet shape, color, size; hilum (shape, length x width and position); epidermal cell shape; anticlinal walls (level, undulation, thickness and secondary sculpture); outer periclinal cell walls (level and secondary sculpture) are presented. The reticulate type was the most common among the studied taxa. Four types of basic anticlinal cell wall boundaries were recognized and many different shapes of the outer periclinal cell wall were described. Nutlet ornamentation, shape, size, colour and particularly hilum characters proved to be good taxonomic characters for the Egyptian Lamiaceae taxa. A key for the identification of the investigated taxa based on nutlet characters is provided.

A comparative taxonomic study of nutlets of Stachys L. in Iraq

Nutlets of 22 taxa of Stachys (13 species and seven subspecies and two varieties), representing seven of the currently recognized sections distributed in northern Iraq were examined by light microscope. The basic shape of nutlets in most taxa studied is Obovoid, but Oblong also found in S.megalodanta Hausskn.& Bornm. ex P.H.Davis, S.setirefa C.A.Mey. subsp daenensis (Gandog.) Rech.f.and S. kurdica Boiss.& Hohen. var.kurdica, while the Subgloboid shape found in S. iberica M.Bieb. and S. inflata Benth., more over the Broad triangular shape was found in S. nephrophylla Rech.f. and S.lanigera (Bornm.) Rech.f.., the biggest size of nutlets was found in S.inflata L. and the smallest was in S.melampyroides Hand.-Mzt. Regarding sculpturing pattern of nutlet surface six basic types can be distinguishe and the reticulate type was the most common among the studied taxa, while the Foveate type appeared only in S. lavandulifolia Vahl.Symb. The type of sculpturing and the shape of nutlets are more useful than the size values, because there were convergence in the size values of the nutlets between species, it is seems that the type of the shape is useful in separating sections, rather than separating species within the same section, and the type of sculpturing is almost useful in separating between species within the same section.

A comparative taxonomic study of nutlets of Stachys L. in Iraq

Nutlets of 22 taxa of Stachys (13 species and seven subspecies and two varieties), representing seven of the currently recognized sections distributed in northern Iraq were examined by light microscope. The basic shape of nutlets in most taxa studied is Obovoid, but Oblong also found in S.megalodanta Hausskn.& Bornm. ex P.H.Davis, S.setirefa C.A.Mey. subsp daenensis (Gandog.) Rech.f.and S. kurdica Boiss.& Hohen. var.kurdica, while the Subgloboid shape found in S. iberica M.Bieb. and S. inflata Benth., more over the Broad triangular shape was found in S. nephrophylla Rech.f. and S.lanigera (Bornm.) Rech.f.., the biggest size of nutlets was found in S.inflata L. and the smallest was in S.melampyroides Hand.-Mzt. Regarding sculpturing pattern of nutlet surface six basic types can be distinguishe and the reticulate type was the most common among the studied taxa, while the Foveate type appeared only in S. lavandulifolia Vahl.Symb. The type of sculpturing and the shape of nutlets are more useful than the size values, because there were convergence in the size values of the nutlets between species, it is seems that the type of the shape is useful in separating sections, rather than separating species within the same section, and the type of sculpturing is almost useful in separating between species within the same section.

Nutlet micro‐morphology of the genus Microula (Boraginaceae) from the Qinghai–Tibetan Plateau, and its systematic implications

The micro‐morphology of nutlets in 30 taxa (28 species and 2 varieties) of Microula Benth. (Boraginaceae) was surveyed by light and scanning electron microscopy. A principal coordinate‐based ordination analysis (PCO) (8 morphological and 14 micro‐morphological characters) was applied to explore whether taxa clustered according to the current sectional taxonomy. The nutlet epidermis showed three major features: trichomes, papillae and lamellae. Two basic trichome types could be identified: branched and unbranched. Stellate trichomes (STT) and stipitate stellate trichomes (SST) can be considered as two subtypes of branched trichomes based on shape and branching location. Three kinds of unbranched trichomes were recognized by their shapes: slender trichomes (SLT), spear‐like trichomes (SPT) and conical trichomes (CT). Four types of papillae were revealed in this genus: central apiculate papillae (CAP), debris‐covered convex papillae (DCP), rugous papillae (RP) and tabular papillae (TP). The lamellae was classified in five types: glossy lamellae (GL), thread‐like lamellae (TL), rugous lamellae (RL), interrupted lamellae (IL) and debris‐covered lamellae (DCL). The variation in the nature of surface sculpturing, nutlet shape and size, dorsal aperture shape, and attachment scar positions proved useful diagnostic characters. Taxa belonging to the same section generally clustered together in the PCO analysis. A key based on the morphology and micro‐morphology of nutlets is provided to distinguish the sections of Microula. The presence of SLT, STT, DCP and DCL is consistent with the macro‐morphological classification and provides additional evidence for the subgeneric delimitations. The SST, SLT, CAP, DCP, RP, DCL, GL and RL are useful in discriminating species in Microula. Additionally, the distribution of some trichomes, papillae and lamellae types is correlated with the altitudinal distribution of the species.

Anatomical and micromorphological studies on Teucrium sect. Isotriodon (Lamiaceae) in Turkey with a taxonomic note

In this study, the anatomical features of the leaf and stem, besides the nutlet characteristics of some Teucrium sect. Isotriodon (Lamiaceae) taxa in Turkey, T. montbretii Betham subsp. montbretii, T. montbretii subsp. pamphylicum P. H. Davis, T. odontites Boiss. & Bal., T. cavernarum P. H. Davis, T. antitauricum T. Ekim, along with an isolated population of T. montbretii (T. montbretii subsp.) were investigated. The anatomical studies revealed that the taxa share generally similar anatomical characters, such as thicker upper leaf cuticles and larger upper leaf epidermal cells compared to lower ones and diacytic to anomocytic stomata on the leaves. However, the portion of the mesophyll occupied by palisade parenchyma and the occurrence of mucilage cells in leaf epidermis shows difference among the taxa. Furthermore, the studied taxa have general stem characteristics of the Lamiaceae family, except for having poorly developed collenchyma at the corners. With the amphistomatic leaves and developed sclerenchymatic tissue in the leaf median vein, T. cavernarum is seperated from the other taxa. Trichome types on the vegetative organs and nutlet shape and sculpturing are generally the same or similar in the studied taxa, but trichomes on the nutlets are different among them. Based on nutlet characteristics and some morphological ones, it was revealed that the isolated population of T. montbretii represent a new subspecies, T. monbretii subsp. yildirimlii M.DinA§ & S.DoAŸu subsp. nov.

Nutlet micromorphology of Turkish Stachys sect. Eriostomum (Lamiaceae) and its systematic implications

The nutlet morphology of 32 taxa of Stachys sect. Eriostomum (Lamiaceae) has been studied by scanning electron microscopy (SEM), and a detailed description of the nutlet morphological features of all examined taxa is provided. We found some groups within Stachys sect. Eriostomum that present nutlet micromorphological characters that appear to be useful in the species‐level taxonomy. The basic shape of nutlets in most taxa is obovoid or ± rounded and the size ranged between 1.5 and 3.0 mm in length and between 1.0 and 2.5 mm in width. Five basic types of sculpturing can be distinguished: reticulate–tuberculate, reticulate–smooth, reticulate–slightly furrowed, colliculate–tuberculate, colliculate–smooth. The reticulate type is the most common among the studied species. The colliculate type is characteristic for S. minor and S. cretica subsp. vacillans. Subsection Spectabiles with reticulate‐smooth/slightly furrowed sculpturing is easily distinguished from the other subsections. In addition, nutlet micromorphology is useful for separating the subspecies of S. cretica. The systematic and biological implications of the nutlet characteristics are briefly discussed.

Phylogeny of tribe Mentheae (Lamiaceae): The story of molecules and micromorphological characters

AbstractMentheae are the largest tribe in the family Lamiaceae and economically important, including herbs like mint, sage and thyme. The evolutionary history of this tribe was reconstructed based on ITS and trnL‐trnF spacer sequence data of 71 species, representing 47 out of 65 genera. The resulting phylogeny was used to analyse the distribution of selected morphological characteristics such as sexine ornamentation of pollen, nutlet shape with existence of abscission scar and its form, and trichome types. Two monophyletic groups are recognized, which largely correspond to the current subtribal circumscription. Subtribe Salviinae is monophyletic, including the genus Melissa which was a genus of uncertain affinity in Mentheae. Subtribe Menthinae is not monophyletic since Cleonia, Horminum, Hyssopus, Lycopus and Prunella are more closely related with subtribe Nepetinae. Although we could not detect any morphological synapomorphies for each clade, morphological variation seems to be correlated with the molecular phylogeny. A circular abscission scar without distinct lateral areole occurred mainly in Salviinae, while the majority of the species of Mentheae and Nepetinae had a clear areole at the abscission scar. In addition, a reticulate sexine ornamentation is rather common in the Menthinae clade.