Highly different flavonol content explains geographic variations in the UV reflecting properties of flowers of the corn poppy, Papaver rhoeas (Papaveraceae).

Papaver rhoeas, the corn poppy, is a very common weed in cereal fields all over the world. Its flowers generally display a bright red coloration, but their reflectance in the ultraviolet (UV) wavelength range varies geographically. Whereas the UV reflectance of East Mediterranean flowers is minor, that of Central European ones is substantial. By comparing the pigmentation of the differently reflecting flowers, we found that only East Mediterranean flower petals contain high amounts of UV absorbing flavonol glycosides. The most abundant compounds were isolated by solid phase extraction and preparative HPLC, and their structures were elucidated by NMR and HRESI-MS, yielding seven kaempferol and quercetin glycosides, mostly unknown in P. rhoeas petals. Additionally, reflectance and transmittance measurements revealed that wavelength-selective scattering effects do not contribute to the flower color differences observed within this species. Possible abiotic and biotic factors influencing the UV reflecting properties of East Mediterranean and Central European poppies are discussed.

The relationship between nectaries and floral architecture: a case study in Geraniaceae and Hypseocharitaceae.

Background and Aims: Flowers of Geraniaceae and Hypseocharitaceae are generally considered as morphologically simple. However, previous studies indicated complex diversity in floral architecture including tendencies towards synorganization. Most of the species have nectar-rewarding flowers which makes the nectaries a key component of floral organization and architecture. Here, the development of the floral nectaries is studied and placed into the context of floral architecture. Methods: Seven species from Geraniaceae and one from Hypseocharitaceae were investigated using scanning electron microscopy and light microscopy. Samples were prepared and processed using standard protocols. Key Results: The development of the nectary glands follows the same trajectory in all species studied. Minor differences occur in the onset of nectarostomata development. The most striking finding is the discovery that a short anthophore develops via intercalary growth at the level of the nectary glands. This anthophore lifts up the entire flower apart from the nectary gland itself and thus plays an important role in floral architecture, especially in the flowers of Pelargonium. Here, the zygomorphic flowers show a particularly extensive receptacular growth, resulting in the formation of a spur-like receptacular cavity ('inner spur'). The nectary gland is hidden at the base of the cavity. Various forms of compartmentalization, culminating in the 'revolver flower' of Geranium maderense, are described. Conclusions: Despite the superficial similarity of the flowers in Geraniaceae and Hypseocharitaceae, there is broad diversity in floral organization and floral architecture. While the receptacular origin of the spur-like cavity in Pelargonium had already been described, anthophore formation via intercalary growth of the receptacle in the other genera had not been previously documented. In the context of the most recent phylogenies of the families, an evolutionary series for the floral architecture is proposed, underscoring the importance of synorganization in these seemingly simple flowers.

Geraniales flowers revisited: evolutionary trends in floral nectaries.

BACKGROUND AND AIMS: The detailed relationships in Geraniales in their current circumscription have only recently been clarified. The disparate floral morphologies and especially the nectaries of the corresponding group have consequently not previously been studied in a phylogenetic context. METHODS: The present study investigates floral and especially nectary morphology and structure for representatives of 12 of the 13 currently accepted genera in the five families of the Geraniales. Flowers were studied using light microscopy and scanning electron microscopy. KEY RESULTS: The data demonstrate the derivation of even the most disparate floral morphologies from a basic pentamerous and pentacyclic organization, with an obdiplostemonous androecium and receptacular nectaries associated with the antesepalous stamens. Divergent morphologies are explained by modifications of merosity (tetramerous flowers), symmetry (several transitions to zygomorphic flowers) and elaboration of the nectaries into variously shaped outgrowths and appendages, especially in Francoaceae. The divergent development of nectar glands ultimately leads to either a reduction in their number (to one in some Geraniaceae and Melianthaceae) or their total loss (some Vivianiaceae). CONCLUSIONS: Floral morphology of the Geraniales shows a high degree of similarity, despite the variation in overall floral appearance and nectary morphology. A hypothesis on the transformation of the nectaries within the Geraniales is presented.

Taxa and names in Cynoglossum sensu lato (Boraginaceae, Cynoglosseae): an annotated, synonymic inventory, with links to the protologues and mention of original material.

BACKGROUND: An inventory is presented of all names so far validly published in Cynoglossum sensu lato and its segregate genera: Adelocaryum, Afrotysonia, Kuschakewiczia, Lindelofia, Mattiastrum, Paracaryum, Rindera, Solenanthus, Trachelanthus, and their synonyms. Names and designations that were not validly published in the cited place, and later isonyms, are accounted for when they have been included in the International Plant Name Index (IPNI). Problems with IPNI entries, including errors and omissions, are discussed, and the hope is expressed that the present inventory may be of use for fixing them. NEW INFORMATION: The inventory, generated from a list of structured data, is presented in two Supplements, as a searchable HTML document comprising a sequence of entries with internal cross-links and links to external sources, in particular to protologues accessible online or, copyright restrictions permitting, made available as scanned documents via DOIs, and as machine-readible file. With minor exceptions, all names have been verified in their original place of publication, and all were nomenclaturally assessed. Colour coding is used to distinguish between names (in green) pertaining to Cynoglossum sensu lato, for which complete synonymies are provided; and names (in orange) pertaining to other genera but published under Cynoglossum or its segregates. They are listed together with their basionym and the corresponding correct name (if it exists), but without complete synonymy. Acceptable, potentially correct names appear in bold-face type, both under a broadly defined Cynoglossum (for which purpose validation of 81 new combinations and the name of 1 new species was necessary) and under one or more of its segregates. When a name was published for a new taxon, original material is indicated, usually by direct quotation from the protologue. New type designations are exceptional (two cases), whereas former type designations are cited whenever known. Furthermore, types and original specimens, especially when their digital images are available online, are mentioned with their locations and accession numbers. Comments are added whenever appropriate, especially to explain nomenclatural assessments that are not self-evident.

J.G.C. Lehmann's 'Botanical Observations' of 1818 on Coldenia, Colsmannia, Cynoglossum, and Omphalodes (commented translation).

An annotated English translation of a German early 19th century text including Latin diagnoses is presented with a high-quality scan of the original publication and direct links to the cited pages with taxon and literature citations (including TL-2 entries).

Evidence for nonallopatric speciation among closely related sympatric Heliotropium species in the Atacama Desert.

The genetic structure of populations of closely related, sympatric species may hold the signature of the geographical mode of the speciation process. In fully allopatric speciation, it is expected that genetic differentiation between species is homogeneously distributed across the genome. In nonallopatric speciation, the genomes may remain undifferentiated to a large extent. In this article, we analyzed the genetic structure of five sympatric species from the plant genus Heliotropium in the Atacama Desert. We used amplified fragment length polymorphisms (AFLPs) to characterize the genetic structure of these species and evaluate their genetic differentiation as well as the number of loci subject to positive selection using divergence outlier analysis (DOA). The five species form distinguishable groups in the genetic space, with zones of overlap, indicating that they are possibly not completely isolated. Among-species differentiation accounts for 35% of the total genetic differentiation (F ST = 0.35), and F ST between species pairs is positively correlated with phylogenetic distance. DOA suggests that few loci are subject to positive selection, which is in line with a scenario of nonallopatric speciation. These results support the idea that sympatric species of Heliotropium sect. Cochranea are under an ongoing speciation process, characterized by a fluctuation of population ranges in response to pulses of arid and humid periods during Quaternary times.

Molecular delimitations in the Ehretiaceae (Boraginales).

Major taxa of Ehretiaceae (including parasitic Lennoaceae) have not all been included in previous molecular phylogenetic analyses. As a result, the generic limits and their circumscriptions have not been satisfactorily resolved, despite its importance for floristic studies. To clarify which monophyletic groups can be recognized within the Ehretiaceae, sequences from one nuclear (ITS) and three plastid loci (rps16, trnL-trnF, trnS-trnG) were obtained from 67 accessions tentatively assigned to the Ehretiaceae (including 91 new GenBank entries) and covering the known diversity of the group. In phylogenetic analyses, Ehretiaceae were monophyletic when Lennoaceae were included and segregated into nine monophyletic lineages that correspond to accepted, morphologically distinct taxonomic units, namely Bourreria (s.l., paraphyletic in its current circumscription if not including Hilsenbergia), monotypic Cortesia, Ehretia (s.l., paraphyletic in its current circumscription if not including Carmona and Rotula), Halgania, monotypic Lennoa, Lepidocordia, Pholisma, Rochefortia, and Tiquilia. Bourreria and Ehretia have representatives in both the Old World and the New World, but all other taxa are restricted to the tropical and subtropical Americas (Cortesia, Lennoa, Lepidocordia, Pholisma, Rochefortia, Tiquilia) or Australia (Halgania). The historical biogeography of Ehretiaceae can be explained by few colonization events. The molecular trees are also discussed with respect to fruit evolution, where the fusion of endocarp parts may have taken place several times independently.

From capsules to nutlets-phylogenetic relationships in the Boraginales.

Multiple family-level subdivisions of Boraginales have been proposed in the past. The relationships of several constituent genera have been enigmatic, including Codon (Codonaceae), Hoplestigma (Hoplestigmataceae), Pholisma (Lennoaceae), Vahlia (Vahliaceae), and Wellstedia (Wellstediaceae), all of which are included in the present study. We present a molecular analysis with four chloroplast loci, including 89 ingroup taxa and a broad outgroup sampling in the asterids. The genus Vahlia is excluded from Boraginales and appears to represent an early branching lineage of Lamiales. The study provides a well supported topology for the relationships within Boraginales, including all of the genera with previously unclear relationships. Within Boraginales, two major clades are recognized, with "herbaceaous" Boraginales I resolved as [Codonaceae,[Wellstediaceae,[Boraginaceae]]] and "woody" Boraginales II resolved as [Hydrophyllaceae I,[Hydrophyllaceae II,[Heliotropiaceae,[Cordiaceae,[Ehretiaceae,Lennoaceae]]]]. A close relationship between Ehretiaceae and Lennoaceae is well supported, but the exact placement of Lennoaceae remains unresolved. The Cordiaceae lineage includes the monotypic genus Coldenia and the aberrant western and central African genus Hoplestigma. Woody Boraginales II are retrieved in two highly supported clades. Hydrophyllaceae are retrieved in two separate clades, but with poor support. There appear to be clear morphological progressions in vegetative, floral, and fruit morphology in both major Boraginales lineages. Thus capsular fruits are found in the first branching lineages of both clades, whereas reduced seed numbers in indehiscent fruits predominate in the more derived phylogenetic positions. Based on these results, we advocate the recognition of eight morphologically well defined clades in the order, namely Boraginaceae s.str., Codonaceae, Cordiaceae (incl. Coldenia and Hoplestigmataceae), Ehretiaceae (incl. Lennoaceae), Heliotropiaceae, Hydrophyllaceae I and Hydrophyllaceae II, and Wellstediaceae.

Multiple origins for Hound's tongues (Cynoglossum L.) and Navel seeds (Omphalodes Mill.)--the phylogeny of the borage family (Boraginaceae s.str.).

Recent studies all indicated that both the affinities and subdivision of Boraginaceae s.str. are unsatisfactorily resolved. Major open issues are the placement and affinities of Boraginaceae s.str. in Boraginales and the major clades of the family, with especially the large tribes Cynoglosseae and Eritrichieae repeatedly retrieved as non-monophyletic groups, and the doubtful monophyly of several larger genera, especially Cynoglossum and Omphalodes. The present study addresses and solves these questions using two plastid markers (trnL-trnF, rps16) on the basis of a sampling including 16 outgroup taxa and 172 ingroup species from 65 genera. The phylogeny shows high statistical support for most nodes on the backbone and on the individual clades. Boraginaceae s.str. are sister to African Wellstediaceae, Wellstediaceae-Boraginaceae s.str. is sister to African Codonaceae. Echiochileae are retrieved as sister to the remainder of Boraginaceae s.str., which, in turn, fall into two major clades, the Boragineae-Lithospermeae (in a well-supported sister relationship) and the Cynoglosseae s.l. (including Eritrichieae). Cynoglosseae s.l. is highly resolved, with Trichodesmeae (incl. Microcaryum, Lasiocaryum) as sister to the remainder of the group. Eritrichieae s.str. (Eritrichium, Hackelia, Lappula) are resolved on a poorly supported polytomy together with the Omphalodes-clade (incl. Myosotidium, Cynoglossum p.p.), and the Mertensia-clade (incl. O. scorpioides, Asperugo). The Myosotideae (Myosotis, Trigonotis, Pseudomertensia) are retrieved in a well-supported sister-relationship to the core-Cynoglosseae, the latter comprising all other genera sampled. Cynoglossum is retrieved as highly para- and polyphyletic, with a large range of generic segregates embedded in Cynoglossum, but other species of Cynoglossum are sister to Microula or to the American "Eritrichieae" (Cryptantha and allied genera). Representatives of the genus Cynoglossum in its current definition are segregated onto six independent lineages, members of Omphalodes onto three independent lineages. At least 11 of the genera here sampled are deeply nested in other genera. The data show that individual details of nutlet morphology (e.g., winged margins, glochidia) are highly homoplasious. Conversely, a complex of nutlet characters (e.g., characters of the gynobase and cicatrix together with nutlet orientation and sculpturing) tends to circumscribe natural units. Geographical distribution of major clades suggests that the family originated in Africa and western Asia and radiated to eastern Eurasia, with several independent dispersal events into Australia and the New World.

Function of calcium-dependent protein kinase CPK28 of Arabidopsis thaliana in plant stem elongation and vascular development.

After a period of vegetative growth, plants undergo a developmental switch to the reproductive phase, inducing the transition to bolting, elongation of the inflorescence and flowering. We have identified calcium-dependent protein kinase CPK28 from Arabidopsis thaliana as a regulatory component that controls stem elongation and vascular development. In two independent mutant alleles of cpk28, a reduction of stem elongation, accompanied by shorter leaf petioles and enhanced anthocyanin levels, is observed upon the transition to the generative phase. Anatomical analysis revealed an altered vascular pattern characterised by fewer xylem tracheary elements but at the same time increased lignification and secondary growth. Coincident with these morphological changes, cpk28 mutants showed altered expression of NAC transcriptional regulators NST1 and NST3 as well as of GA3ox1, a key regulator of gibberellic acid homeostasis. In vitro protein kinase activity of CPK28 is strictly calcium-dependent. Furthermore, CPK28 is phosphorylated in vivo at several sites. Site-specific amino acid substitutions at these phosphorylation sites resulted in reduced in vitro activity. However, when introduced into a cpk28 mutant background, wild-type and phosphorylation site variants, but not kinase-inactive variants of CPK28 complemented the morphological and developmental defects. Our data identify CPK28 as a developmentally controlled regulator for coordinated stem elongation and secondary growth.

Diversification in the Andes: age and origins of South American Heliotropium lineages (Heliotropiaceae, Boraginales).

The uplift of the Andes was a major factor for plant diversification in South America and had significant effects on the climatic patterns at the continental scale. It was crucial for the formation of the arid environments in south-eastern and western South America. However, both the timing of the major stages of the Andean uplift and the onset of aridity in western South America remain controversial. In this paper we examine the hypothesis that the Andean South American groups of Heliotropium originated and diversified in response to Andean orogeny during the late Miocene and a the subsequent development of aridity. To this end, we estimate divergence times and likely biogeographical origins of the major clades in the phylogeny of Heliotropium, using both Bayesian and likelihood methods. Divergence times of all Andean clades in Heliotropium are estimated to be of late Miocene or Pliocene ages. At least three independent Andean diversification events can be recognized within Heliotropium. Timing of the diversification in the Andean lineages Heliotropium sects.Heliothamnus, Cochranea, Heliotrophytum, Hypsogenia, Plagiomeris, Platygyne clearly correspond to a rapid, late Miocene uplift of the Andes and a Pliocene development of arid environments in South America.

Marbleseeds are gromwells--systematics and evolution of Lithospermum and allies (Boraginaceae tribe Lithospermeae) based on molecular and morphological data.

Phylogenetic relationships are complex within the Lithospermeae, a large subgroup of the Boraginaceae s.str. The relationships of New World Lasiarrhenum, Macromeria, Nomosa, Onosmodium, Perittostoma, and Psilolaemus to subcosmopolitan and much larger Lithospermum have not been critically investigated in the recent past. No molecular data on the phylogeny of these genera and Lithospermum have so far been published. We investigated the relationships within Lithospermeae using three loci (nuclear ITS plus 5.8S rRNA, chloroplast trnL-F-spacer, and trnS-G-spacer) and micromorphological character traits (pollen, nutlets). Lithospermums.l. constitutes the sistergroup of Asian Ulugbekia and is monophyletic only when its American segregates "Macromeria", monotypic Nomosa, and Onosmodium are included. Both the African and the South American species groups of Lithospermum are monophyletic, but North American representatives are not resolved in a single clade. Morphological characters that have been considered as important for generic delimitation in the past (such as large, yellow corollas without faucal scales, particular pollen types, coarsely veined leaves, shrubby habit) have evolved in at least two only distantly related lineages within Lithospermums.l. The reduction of American "Macromeria", Nomosa, and Onosmodium as well as Asian Ulugbekia under Lithospermum is proposed to render the latter monophyletic. This redefined Lithospermum s.l. appears to have undergone a type of recent "island radiation" in the Americas, reflected in a morphological diversity far exceeding that found in the Old World.

First fossil record of transfer cells in angiosperms.

Transfer cells are specialized plant cells that optimize short-distance transport by an extension of the interior surface of the cell walls. Using scanning electron microscopy (SEM), we found transfer cells in the fossil seed coat of Ehretia clausentia (Ehretiaceae, Boraginales) from the London Clay flora (Lower Eocene). This is the first fossil record of transfer cells in angiosperms.

A systematic analysis of Heliotropium, Tournefortia, and allied taxa of the Heliotropiaceae (Boraginales) based on ITS1 sequences and morphological data.

The relationships of Heliotropium, Tournefortia, Schleidenia, Ixorhea, and Ceballosia of the Heliotropiaceae (Boraginaceae in the traditional sense, Boraginales) are investigated using molecular data (ITS1). These genera form a monophyletic group. Five clades can be distinguished on the basis of molecular data, morphological traits, and distribution. In their current circumscription, Tournefortia is polyphyletic and Heliotropium is paraphyletic. Tournefortia section Cyphocyema is the sister group to all other ingroup taxa. Heliotropium section Orthostachys including Schleidenia sensu lato is the well supported sister group of a clade comprising the other species of Heliotropium sensu stricto (s.s.), Tournefortia section Tournefortia, and Ceballosia. Heliotropium s.s. forms two clades: one clade includes all species of the Old World and represents the only monophylum of Heliotropium s.s. The other clade consists of all Heliotropium s.s. species of the New World but also includes Tournefortia section Tournefortia and Ceballosia. The results suggest that taxonomic changes are inevitable.