Inflorescence Characters Research Articles

Population genetic structure and trait associations in forest savory using molecular, morphological and phytochemical markers.

In this investigation, morphological, phytochemical and ISSR markers were used to estimate the relationships among and within seven populations of white savory (Satureja mutica), belonging to four provinces in Iran. The individuals were phenotypically diverse, which stamen length, corolla length, corolla diameter, calyx length, bract length, inflorescence length, calyx length and bracteole width were characteristics with the highest variation. Leaf dimensions were in significant correlation with flower and inflorescence characteristics. Chemical compounds of essential oils were found variable in various individuals and all samples were principally composed of phenolic constituents (carvacrol and/or thymol). As a consequence, the plants were classified into two major chemotypes including carvacrol and thymol. A total of 197 band positions were produced by 14 ISSR primers, of which 176 were found polymorphic with 88.91% polymorphism. ISSR genetic similarity values among individuals ranged between 0.45 and 0.94 which was indicative of a high level of genetic variation. Multiple regression analysis (MRA) revealed that phytochemical compositions as dependent variable, showed statistically significant correlation and in association with leaf and flower traits as independent variable, indicating a main role of leaf and flower on production of these compounds. Also, several ISSR fragments were found associated with some morphological traits and phytochemical compositions. The high diversity within and among populations of S. mutica according to different data systems could provide useful information for conservation and selection of cross-parents in breeding programs.

Molecular and morphological variability of Satureja bachtiarica in Iran

Satureja bachtiarica is a valuable medicinal plant that belongs to family Lamiaceae. In this research, genotypic and phenotypic variations among 57 individuals of this species were assessed based on three marker systems, namely, ISSR, RAPD and morphological traits. Principal component analysis showed that 75.91 % of the morphological variability was explained by all components for the studied individuals. Variables such as stem number, plant diameter, total weight, leaf and flower weight, stem weight, sepal length, petal length, petal tube length, sepal diameter, bracket length and bracket width were predominant in the first three components and contributed to most of the total variation. Leaf dimensions were in significant positive correlation with flower and inflorescence characteristics. Also, plant height showed significant positive correlation with characteristics related to inflorescence and weight. Clustering from morphological data allocated individuals into two main clusters with high variations. Profile patterns of 15 ISSR and 11 RAPD primers revealed 135 (98.78 %) and 84 (97.94 %) polymorphic fragments, respectively. The range of similarity coefficient by ISSR and RAPD markers were 0.08–0.63 and 0.09–0.69, respectively, indicating high genetic variation among individuals that originated from different geographic sites. UPGMA dendrograms based on ISSRs, RAPDs and ISSRs+RAPDs revealed high genetic diversity between studied individuals and grouped them into two main groups. Some cases of similarity and dissimilarity were observed between clustering based on ISSR and RAPD data. Also, the results showed that grouping based on molecular markers and morphological traits were different so these two systems could not discriminate individuals as the same way. The genetic relatedness among the studied individuals could provide useful information for conservation and selection of cross-parents in breeding.

Is morphology supporting a monophyletic Proustia Lag., (Nassauvieae, Asteraceae)?

Proustia is an Andean genus traditionally considered to have three species and ten infraspecific taxa, which has often been placed in tribes other than Nassauvieae mainly because of its distinctive style features. Currently, each of the three species of Proustia is included in its own section denoting a consistent morphological variability within the genus. The heterogeneity among Proustia species mainly relies on habit, spiny structures arrangement, capitula arrangement, and pappus features. On the contrary, the forms or varieties within each species are apparently more homogeneous. The phylogenetic analysis performed here is based on morphological features and includes all the species, and all but two varieties and forms of Proustia. We test the boundaries of Proustia and the hypothesis that morphological discontinuities in the genus are phylogenetically uninformative. A total of 26 taxa and 29 morphological, anatomical, and palynological characters were studied. A maximum parsimony analysis yield six most parsimonious trees that showed almost identical topologies. Our results do not support the current generic concept of Proustia. Independently, each species of Proustia was monophyletic when taxa at sub-specific level were considered. Proustia pyrifolia was retrieved sister to the genus Berylsimpsonia although this clade did not obtain significant support. The spiny structures usually referred to as diagnostic for Proustia are not homologous for the genus. Characteristics of habit, spiny structures, secondary inflorescences and pappus support clades representing each species of Proustia, which may in turn, represent different genera.

Morphological and phytochemical variation of Satureja bachtiarica populations from Iran

Satureja bachtiarica Bunge is an endemic species plant widely distributed in Iran. Phenotypic and chemical characterization of this species from different natural regions of Iran was evaluated. Twenty-six morphological traits analyzed showed significant differences among and within populations. The samples were phenotypically diverse, which stem weight, total weight and leaf and flower weight were characteristics with the highest variation. Leaf dimensions were in significant correlation with flower and inflorescence characteristics and also plant height showed significant positive correlation with characteristics related to inflorescence and weight. Clustering from morphological data allocated samples into two main clusters with high variability. Thirty-four components were identified in the essential oils, so that carvacrol, thymol, γ-terpinene and p-cymene were the major components of all samples and showed the high eigenvalues variance according to principal component analysis. Among populations, Ilam population showed the highest essential oil content, p-cymene, γ-terpinene and thymol and Yazd population had the highest carvacrol. Carvacrol was negatively correlated with p-cymene, γ-terpinene, borneol and thymol. Multiple regression analysis (MRA) revealed that phytochemical compositions as dependent variable, showed statistically significant correlation and in association with leaf and flower traits as independent variable, especially variables sepal and petal trichomes, indicating a main role of leaf and flower on production of these compounds. The high morphological differences and high value of the essential oil composition within and among S. bachtiarica populations could provide useful information for conservation and selection of cross-parents in breeding programs.

HE GENERA BELOTIA Rich. AND TRICHOSPERMUM Bl. (Tiliaceae)

The genus Belotia was founded in 1845 by A. Richard (in R. de la liagra, Hist. Cuba, Bot. 1: 207), based on a single species: B. grewiifolia; liichard added Grewia mexicana DC. (1824) as a synonym.Sprague (in Kew Bull. 1921: 270-278) wrote a monograph on the knus. He characterized Belotia as follows: Presence of nectaries at the Itase of the petals and their absence on the androgynophore; the blue or Inlet, rarely white petals, the bilocular ovary with pluriovulate loculi; the a– culicidal capsule, strongly compressed transversally to the septum and a–ediscoid ciliate seeds. He than adds: In all these respects Belotia resem-Ihles the Old-World genus Trichospermum, which differs in having a pair of I nectaries at the base of the lamina, and a pseudo- umbellate inflorescence.The differences are consequently very small and since I found that le laminal nectaries occur only occasionally in one species of Tricho-tpermmn (javanicuvi), it becomes debatable, whether the inflorescence character is of such importance as to keep both genera apart.Burret (in Notizbl. bot. Garten Berlin 9: 603. 1927) keys out Belotia against Trichospermum in the following way: Trichospermum with 25-50 ovules,irregularly placed, as against Belotia with 12-16 ovules per locule in two regular rows; inflorescences in the former axillary and bi-or pluri-chasial,in Belotia axillary and terminal panicles.Furthermore he adds: fruit with 2, rarely 3 cells Trichospermum is to the 2-3 celled fruit in Belotia; this- of course -is a differential character of little or no value. Burret does not mention at all the laminal nectaries; according to him (p. 855) the number of ovules and their placentation should be the main differential character.I had at my disposal far more material of Trichospermum than Burret and could examine numerous young fruit,where the number of ovules and their placentation may be easily observed.

Morphological differentiation of Polygonum viviparum (Polygonaceae) in European populations

AbstractThe variation of Polygonum viviparum L. in Europe was studied in 584 plants sampled from 14 populations at different altitudes and from different substrates in the Carpathians, Alps, Dinaric Alps, Pyrenees and Scandinavian Mts. The samples were analyzed biometrically, using 12 measured stem and inflorescence characters and 10 characters calculated from those 12. The obtained ranges of values were only slightly wider than those given in the literature. All characters significantly differed between populations and six characters were statistically significant in identifying differences between regions. Altitude, substrate and the interactions between them significantly affected the differences in characters between samples. The values of most of the measured characters were lower in samples from higher locations and on poor substrate than in those from lower localities and on rich substrate. Substrate type affected the calculated characters less but it influenced the shift between vegetative and generative reproduction. Multidimensional analyses confirmed the proximity of samples from regions either geographically close or linked via routes of postglacial migrations, despite altitude and substrate differences between them.

Taxonomy of the Solidago virgaurea Group (Asteraceae) in Poland, with Special Reference to Variability along an Altitudinal Gradient

The morphological differentiation and taxonomic treatment of lowland and high-mountain morphotypes within the Solidago virgaurea group are controversial. To clarify the taxonomic status of these taxa, we conducted a morphometric analysis of 1,746 individuals from 80 localities along an altitudinal gradient from the lowlands of northern Poland to the Carpathians and Sudetes of southern Poland. Multivariate morphometric analyses, cluster analyses and principal component analyses, were used to examine the morphological differentiation within the S. virgaurea group in Poland. Canonical discriminant analysis was applied to determine the morphological characters that best discriminate among the taxa. The stability of the high-mountain Solidago minuta morphotype was tested in an experimental field established in lowland Poland; individuals transplanted from various mountain sites were cultivated at this site, and the morphotypes remained stable in terms of their floral and vegetative characters. Multivariate analyses revealed two morphologically distinct taxa in the S. virgaurea group, which correspond to lowland S. virgaurea s. str. and high-mountain S. minuta as recognised in some European floras. The most important morphological characters for distinguishing the taxa are the number of tubular florets per capitulum, inner involucral bract width and involucre height. Vegetative and inflorescence characters appear to have less taxonomic value because they changed continuously with altitude. A key for identifying S. virgaurea and S. minuta in Poland is presented.

Systematic studies in the Gloriosa superba complex (Colchicaceae): a re-assessment of species boundaries

Background and aims – Gloriosa superba L. is a highly variable species occurring in a wide range of ecological habitats in South Africa, tropical Africa and Asia. The morphological variation in G. superba was found to be complicated and therefore numerical methods were used to re-evaluate morphological variation and species delimitation in the G. superba complex. Methods – This study was based on 79 herbarium specimens from B, BM, BR, C, COI, F, K, L, SRGH, U, UPS and WAG (abbreviations follow Holmgren et al. 1990). Cluster and ordination analyses were used to explore morphological variation within the study group. The morphometric data set based on both qualitative and quantitative characters was entered directly into a computerized matrix and a cluster analysis was computed using NTSYS package. The variability of individual characters was evaluated by box-plots using SPSS. Key results & conclusions – The morphological study has revealed the existence of four phenetic species in the G. superba complex. Recognition of these species is based on habit, inflorescence characters and distribution patterns. It is here proposed that four species should be recognized in the G. superba complex: G. baudii (Terracc.) Chiov., G. carsonii Baker, G. superba L. and G. simplex L. Gloriosa superba is the most widespread taxon, occurring in South Africa, tropical Africa and Asia. Gloriosa simplex, G. carsonii and G. baudii are confined to the African continent, with G. simplex widespread in tropical Africa, G. carsonii common in south, central to east tropical Africa, and G. baudii having the most restricted range, confined to the arid regions of northern Kenya, Ethiopia and Somalia.

Transgressive character expression in hybrid zones between the native invasives Tithonia tubaeformis and Tithonia rotundifolia (Asteraceae) in Mexico

Natural hybridization frequently promotes gene introgression among closely related species in sympatric populations, producing complex patterns of morphological variation. Therefore, a detailed understanding of the dynamics of interspecific gene flow and its morphological patterns is of widespread interest. We tested if introgressive hybridization promotes an increase in transgressive characters in comparison with the parental species. A sunflower species complex occurring in Mexico formed by two native invasive species, Tithonia tubaeformis and Tithonia rotundifolia, was analyzed using 46 morphological characters (leaf, flower and fruit) in five hybrid zones (N = 150 individuals) and two pure sites for each parental species (N = 80 individuals). In general, T. tubaeformis differed significantly from T.rotundifolia in all the examined characters, except six foliar and one inflorescence character. Morphological characters support the hypothesis of hybridization in this complex, even though both species remain morphological distinct in mixed stands. Individual hybrids appear to be a mosaic of parent-like (24.8 % of traits), intermediate (26.1 %) and transgressive (37.8 %) phenotypes (the remaining 11.3 % of the traits did not differ significantly from both parental species). Our results suggest that individuals from the same parental species were more similar among themselves than to putative hybrids, indicating occasional hybridization with segregation in hybrid types or backcrossing to parents. Evidence indicates a unidirectional pattern of gene flow toward T. rotundifolia.

Calliscirpus, a new genus for two narrow endemics of the California Floristic Province, C. criniger and C. brachythrix sp. nov. (Cyperaceae)

Although the polyphyletic genus Scirpus L. s.l. (formerly > 200 species) has been divided into more than 50 separate genera and now consists of only 64 species, its circumscription remains problematical. Three new genera have been segregated from Scirpus s.s. in the past decade, and the delimitation of Scirpus from its possible sister genus Eriophorum L. (c. 18 species) is still unresolved. The primary character used to delimit Eriophorum from Scirpus is ≥ 10 smooth, elongate perianth bristles vs ≤ 6 short, serrulate bristles or a lack of bristles, but some species display character combinations that make it difficult to place them in either genus. Eriophorum crinigerum (A. Gray) Beetle (= Scirpus criniger A. Gray), endemic to the California Floristic Province, USA, is one such species, possessing a unique combination of bristle and inflorescence features that suggest affinities with both Scirpus and Eriophorum. In this study we use molecular (matK, ndhF), morphological, and embryological data to demonstrate that E. crinigerum is not closely related to either Scirpus or Eriophorum, but represents a new generic lineage, here named Calliscirpus C. N. Gilmour, J. R. Starr & Naczi (tribe Scirpeae). Within the genus, molecular (matK, ETS 1f) and morphological data strongly support the recognition of two species, each of which is restricted to a distinct region of high endemism. Calliscirpus criniger (A. Gray) C. N. Gilmour, J. R. Starr & Naczi comb. nov. is common to the Klamath-Siskiyou and North Coast mountain ranges of Oregon and California, whereas a new species, Calliscirpus brachythrix C. N. Gilmour, J. R. Starr & Naczi, is unique to the Sierra Nevada mountain range of California. Scirpus maximowiczii C. B. Clarke, another transitional species that has blurred the limits of Scirpus and Eriophorum, and has been cited as morphologically similar to Calliscirpus species in the past, is strongly placed within a Scirpus s.s. + Eriophorum s.s. clade (100% bootstrap) on the basis of molecular and embryological data. Tree support and taxonomic sampling are not sufficient to resolve the delimitation of Eriophorum s.s. from Scirpus s.s.

A distinctive new species of wild banana (<i>Musa</i>, Musaceae) from northern Vietnam

A new banana species, Musa haekkinenii, is described from northern Vietnam. It differs notably from a well-known ornamental species, M. coccinea, by inflorescence features and leaf blade shape and especially the habit, shape, size and color of the male bracts of the inflorescences and male bud shape. A mixed watercolor and ink plate is provided for the new taxon and an identification key to species of Musa sect. Callimusa is included, along with a note comparing the morphology of the seven Indo-Chinese species.

Genetic diversity and species delimitation in the cultivated and wild Guinea yams (Dioscorea spp.) from Southwest Ethiopia as determined by AFLP (amplified fragment length polymorphism) markers

Yams (Dioscorea spp.) rank as the fourth most important root and tuber crop after potatoes, cassava and sweet potatoes. They are an economic crop in most of the tropics especially in West Africa, which produces over 95 % of the world output. Despite their cultural and economic importance there is taxonomic confusion regarding Guinea yams. The currently used classification scheme, which relies on vegetative and inflorescence characters, does not consistently delimit species boundaries between members of Guinea yams (D. cayenensis Lam.–D. rotundata Poir. complex), their wild relatives (D. abyssinica Kunth and D. praehensilis Benth.,) and D. sagittifolia Pax. Establishing the taxonomic identity of the germplasm and understanding the systematic relationships among crops is vital to the management of genetic resources and the utilization of accessions. In this study, amplified fragment length polymorphism (AFLP) genetic fingerprinting was used to evaluate and characterize 43 individual plants, belonging to different populations of wild and cultivated Guinea yams. The three primer combinations used in the AFLP analyses generated 158 scorable bands, with an overall polymorphism of 78 %. Ordination and cluster analyses of AFLP data failed to produce any clear species boundary between either the Guinea yam accessions or between them and their wild relatives. The average genetic similarity between the study individuals of Guinea yams and their wild relatives ranged from 60 to 100 %. The first, second and third principal coordinates axes cumulatively account for 77.45 % of the total variation. AFLP analyses also revealed a higher genetic divergence among cultivated Guinea yam accessions of the Sheko cultivars. Ordination and cluster analysis using UPGMA revealed no clear species boundaries between members of the complex. Thus, the taxonomy of these “species” needs to be revisited using other markers.

Insights into panicoid inflorescence evolution

Inflorescence forms can be described by different combinatorial patterns of meristem fates (indeterminate versus determinate). In theory, the model predicts that any combination is possible. Whether this is true for grasses is unknown. In this paper, the subfamily Panicoideae s.s. (panicoid grasses) was chosen as the model group to investigate this aspect of grass inflorescence evolution. We have studied the inflorescence morphology of 201 species to complement information available in the literature. We have identified the most recurrent inflorescence types and character states among panicoids. Using multivariate approaches, we have indentified correlations among different inflorescence character states. By phylogenetic reconstruction methods we have inferred the patterns of panicoid inflorescence evolution. Our results demonstrate that not all theoretical combinatorial patterns of variation are found in panicoids. The fact that each panicoid lineage has a unique pattern of inflorescence evolution adds an evolutionary component to combinatorial model.

Piper relictum sp. nov. (Piperaceae) from northern Western Ghats, India

A new species of Piper, P. relictum Lekhak, S. S. Kambale & S. R. Yadav sp. nov. is described and illustrated. It grows as a climber on the edges of high altitude lateritic plateaus in evergreen forests of the northern Western Ghats in India. The new species is similar to P. galeatum, but differs in the characters of the male inflorescence.

애기초롱꽃(Campanula punctata Lam.)과 자주초롱꽃(C. punctata Lam. var. rubriflora Mak.)의 교잡을 통한 자주색 꽃을 가진 왜성 초롱꽃 '직녀' 육성

한국에 자생하는 초롱꽃식물은 분화 및 조경용으로써의 이용가치가 높은 식물이다. 본 연구는 애기초롱꽃(C. punctata Lam.)을 모본으로, 자주초롱꽃(C. punctata Lam. var. rubriflora Mak.)을 부본으로 하여 표현형이 왜화된 <TEX>$F_1$</TEX> 식물 '직녀'를 육 성하였다. 2001년 6월에 교배 시작하여 10월에 채종하였다. 이후 <TEX>$5^{\circ}C$</TEX> 저온저장 후 2002년 3월에 파종하였다. <TEX>$F_1$</TEX> 품종 특성으로는 화색은 자주색이며 초장, 엽장, 엽폭, 화경 등에서 각각의 모본에 비해 중간형질을 보였다. 개화특성은 각 소화경의 개화기간은 평균 14일이며, 식물체 전체 개화기간은 4개월이었고, 재배 시 추대를 위한 저온감응을 꼭 필요로 하는 식물로써 관수 시 과습은 피하는 것이 좋다. Campanula, native to Korea, is potentially an attractive potted or bedding plant. Experiments were conducted to produce a <TEX>$F_1$</TEX> hybrid plant for a reduced plant height, 'Jiknyeo', by a conventional cross breeding between C. punctata Lam. and C. punctata Lam. var. rubriflora Mak. The crossing was carried out in July 2001 and the seeds were harvested in October 2001. Seeds were stored for two months at <TEX>$5^{\circ}C$</TEX> for vernalization, and then were sown in March 2002. The <TEX>$F_1$</TEX> hybrid have a purple flower color, and decreased plant height, leaf length, leaf width, and peduncle length. Each flower maintained freshness for a period of 20 days on the average. The whole flowering period of a plant was four months. The plant has flowering characteristics of an indeterminate inflorescence, prefers low humidity during the whole cultivation period, and requires low temperature in winter for flower bud differentiation.

Morphological diversity in breadfruit (Artocarpus, Moraceae): insights into domestication, conservation, and cultivar identification

Over millennia of breadfruit cultivation, hundreds of named cultivars have been developed that display a high degree of morphological diversity. The current study was undertaken to evaluate morphological diversity within the National Tropical Botanical Garden’s breadfruit germplasm collection, the largest and most diverse breadfruit collection in the world. A set of 57 standardized morphological descriptors including 29 leaf, 22 fruit, four seed, and two male inflorescence characteristics were used to describe and contrast 221 accessions of breadfruit including accessions of Artocarpus camansi Blanco, A. altilis (Parkinson) Fosberg, A. mariannensis Trecul, early generation A. altilis × A. mariannensis hybrids, and domesticated A. altilis × A. mariannensis hybrids. A morphological transition from heavily seeded fruit covered with flexible spines to fewer seeded, smoother skinned fruit of similar size was observed in the domestication of A. altilis from A. camansi. Further selection of true seedless, smooth-skinned cultivars of A. altilis appears to have occurred with human migrations from Melanesia into Polynesia. Cultivars from Micronesia exhibit morphological characteristics indicative of hybridization with the endemic species A. mariannensis. These data were used to generate a multi-access cultivar identification key on the Lucid platform that can be used to identify trees of known cultivars or to predict nearest cultivar relationships for previously undescribed cultivars. Overall, this study provides new insights into the morphological changes that occurred during domestication, helps visualize the diversity that exists across geographical regions, and provides a framework for cultivar identification and germplasm conservation.

Floral traits mediate the vulnerability of aloes to pollen theft and inefficient pollination by bees.

Pollen-collecting bees are among the most important pollinators globally, but are also the most common pollen thieves and can significantly reduce plant reproduction. The pollination efficiency of pollen collectors depends on the frequency of their visits to female(-phase) flowers, contact with stigmas and deposition of pollen of sufficient quantity and quality to fertilize ovules. Here we investigate the relative importance of these components, and the hypothesis that floral and inflorescence characteristics mediate the pollination role of pollen collection by bees. For ten Aloe species that differ extensively in floral and inflorescence traits, we experimentally excluded potential bird pollinators to quantify the contributions of insect visitors to pollen removal, pollen deposition and seed production. We measured corolla width and depth to determine nectar accessibility, and the phenology of anther dehiscence and stigma receptivity to quantify herkogamy and dichogamy. Further, we compiled all published bird-exclusion studies of aloes, and compared insect pollination success with floral morphology. Species varied from exclusively insect pollinated, to exclusively bird pollinated but subject to extensive pollen theft by insects. Nectar inaccessibility and strong dichogamy inhibited pollination by pollen-collecting bees by discouraging visits to female-phase (i.e. pollenless) flowers. For species with large inflorescences of pollen-rich flowers, pollen collectors successfully deposited pollen, but of such low quality (probably self-pollen) that they made almost no contribution to seed set. Indeed, considering all published bird-exclusion studies (17 species in total), insect pollination efficiency varied significantly with floral shape. Species-specific floral and inflorescence characteristics, especially nectar accessibility and dichogamy, control the efficiency of pollen-collecting bees as pollinators of aloes.

Assessing genetic divergence in interspecific hybrids of Aechmea gomosepala and A. recurvata var. recurvata using inflorescence characteristics and sequence-related amplified polymorphism markers

Conventional hybridization and selection techniques have aided the development of new ornamental crop cultivars. However, little information is available on the genetic divergence of bromeliad hybrids. In the present study, we investigated the genetic variability in interspecific hybrids of Aechmea gomosepala and A. recurvata var. recurvata using inflorescence characteristics and sequence-related amplified polymorphism (SRAP) markers. The morphological analysis showed that the putative hybrids were intermediate between both parental species with respect to inflorescence characteristics. The 16 SRAP primer combinations yield 265 bands, among which 154 (57.72%) were polymorphic. The genetic similarity was an average of 0.59 and ranged from 0.21 to 0.87, indicating moderate genetic divergence among the hybrids. The unweighted pair group method with arithmetic average (UPGMA)-based cluster analysis distinguished the hybrids from their parents with a genetic distance coefficient of 0.54. The cophenetic correlation was 0.93, indicating a good fit between the dendrogram and the original distance matrix. The two-dimensional plot from the principal coordinate analysis showed that the hybrids were intermediately dispersed between both parents, corresponding to the results of the UPGMA cluster and the morphological analysis. These results suggest that SRAP markers could help to identify breeders, characterize F(1) hybrids of bromeliads at an early stage, and expedite genetic improvement of bromeliad cultivars.

Effect of the kind of habitat on flowering of Hierochloë repens (Host) Simonkai

Studies on flowering of &lt;i&gt;Hierochloë repens&lt;/i&gt; were performed over the years 2005-2007 in five habitats located in Bydgoszcz. The first habitat is a degenerated fresh ryegrass meadow (&lt;i&gt;Arrhenatheretum elatioris&lt;/i&gt;). Another one is a degenerated form of initial xerothermic swards (&lt;i&gt;Tunico&lt;/i&gt;-&lt;i&gt;Poetum compressae&lt;/i&gt;). The third habitat in which the occurrence of &lt;i&gt;Hierochloë repens&lt;/i&gt; was found and flowering was analyzed is sandy sward (&lt;i&gt;Koelerio&lt;/i&gt;-&lt;i&gt;Corynephoretea&lt;/i&gt;). Yet another habitat is ruderal in character and it was located on the side of the road (&lt;i&gt;Convolvulo&lt;/i&gt;-&lt;i&gt;Brometum inermis&lt;/i&gt;). The last one is a fertile and moist habitat of elm-ash marshy meadow being gramineous herb fringe communities in character. The evaluation was based on the following analyses: morphological characters of inflorescences (length of inflorescence, stem length, number of inflorescence branches and number of spikelets), stem and inflorescence weight and reproduction effort as well as the share of generative individuals in the population and the number of generative individuals per m&lt;sup&gt;2&lt;/sup&gt;. Differences were found in the structure of &lt;i&gt;Hierochloë repens&lt;/i&gt; inflorescence in the habitats analyzed. The biggest inflorescence, in terms of all the characters analyzed, was found in fertile elm-ash marshy meadow, and the smallest in poor xerothermic sward. The highest generative reproduction potential of &lt;i&gt;Hierochloë repens&lt;/i&gt; was found in the ruderal habitats. They are the basic potential source of generative diaspora production, which can affect the spreading of this species in Poland.

Evolutionary origin of the Asteraceae capitulum: Insights from Calyceraceae

Phylogenies based on molecular data are revealing that generalizations about complex morphological structures often obscure variation and developmental patterns important for understanding the evolution of forms, as is the case for inflorescence morphology within the well-supported MGCA clade (Menyanthaceae + Goodeniaceae + Calyceraceae + Asteraceae). While the basal families share a basic thyrsic/thyrsoid structure of their inflorescences, Asteraceae possesses a capitulum that is widely interpreted as a racemose, condensed inflorescence. Elucidating the poorly known inflorescence structure of Calyceraceae, sister to Asteraceae, should help clarify how the Asteraceae capitulum evolved from thyrsic/thyrsoid inflorescences. The early development and structure of the inflorescence of eight species (five genera) of Calyceraceae were studied by SEM, and patterns of evolutionary change were interpreted via phylogenetic character mapping. The basic inflorescence structure of Calyceraceae is a cephalioid (a very condensed botryoid/thyrsoid). Optimization of inflorescence characters on a DNA sequence-derived tree suggests that the Asteraceae capitulum derives from a simple cephalioid through two morphological changes: loss of the terminal flower and suppression of the cymose branching pattern in the peripheral branches. Widely understood as a condensed raceme, the Asteraceae capitulum is the evolutionary result of a very reduced, condensed thyrsoid. Starting from that point, evolution worked separately only on the racemose developmental control/pattern within Asteraceae and mainly on the cymose developmental control/pattern within Calyceraceae, producing head-like inflorescences in both groups but with very different diversification potential. We also discuss possible remnants of the ancestral cephalioid structure in some Asteraceae.