Pollen morphology in <Emphasis Type="Italic">Lysipomia</Emphasis> (Campanulaceae: Lobelioideae) and interpretation of shape artifacts

The pollen of 32 species of Lysipomia was examined by light, scanning, and transmission electron microscopy. Two pollen types occur in the genus: 3-colporate and 6-colporate. The 3-colporate condition occurs in only two species, L. laciniata and L. pumila. The remaining 30 species are 6-colporate, a condition known from only one other genus in the Campanulaceae. Surface sculpturing among the species is uniformly striate. Pollen shape was highly variable within a single individual in comparisons of pollen gathered from herbarium specimens, FAA preserved material collected in the field, and fresh pollen from cultivated individuals grown from seed. Shape may change from oblate spheroidal to subprolate as a result of drying time and temperature, and should not be used as a morphological character in systematic studies if infraspecific variation is seen. When fresh or preserved pollen is not available, rehydrated pollen should be compared to reduce the possibility of inadvertent artifact production confounding the analysis of morphological data.     

Pleistocene origin and colonization history of Lobelia columnaris Hook. f. (Campanulaceae: Lobelioideae) across sky islands of West Central Africa

We aimed to infer ancestral area and historical colonization of Lobelia columnaris in the sky islands of Bioko and Cameroon through dated phylogeny using chloroplast genomes. Specifically, we aim to answer the following questions: (1) What are the phylogenetic relationships among Bioko Island and Cameroon populations? (2) Are the older populations found in the older sky islands? We assembled novel plastomes from 20 individuals of L. columnaris from 5 mountain systems. The plastome data were explored with phylogenetic analyses using Maximum Likelihood and Bayesian Inference. The populations of L. columnaris have a monophyletic origin, subdivided into three plastomes‐geographic clades. The plastid phylogenomic results and age of the sky islands indicate that L. columnaris colonized first along with the Cameroon Volcanic Line''s young sky islands of Bioko. The crown group (1.54 Ma) split the population in Bioko and mainland Cameroon. It is possible that Bioko was the ancestral area and likely isolated during cold and dry conditions in forest refugia. Presumably, the colonization history occurred during the middle‐late Pleistocene from South Bioko''s young sky island to North Bioko and the northern old sky islands in Cameroon. Furthermore, the central depression with lowland forest between North and South Bioko is a current geographic barrier that keeps separating the populations of Bioko from each other. Also, the shallow sea channel keeps isolated the populations of Bioko and the mainland populations. The Pleistocene climatic oscillations led to the divergence of the Cameroon and Bioko populations into three clades. L. columnaris colonized the older sky islands in mainland Cameroon after establishment in Bioko''s younger sky islands. Contrary to expectations, the biogeography history was an inverse progression with respect to the age of the Afromontane sky islands.     

Revision of the Endemic Hawaiian genus <Emphasis Type="Italic">Trematolobelia</Emphasis> (Campanulaceae: Lobelioideae)

Trematolobelia (Campanulaceae: Lobeliodeae) is a genus of semelparous pliestesial pachycaul rosette treelets endemic to the Hawaiian Islands. Eight species are re-cognized. The most widespread is T. macrostachys, found in the Ko‘olau Mountains of O‘ahu and on Moloka‘i and Maui. The remainder are single-island endemics: T. auriculata (Lna‘i); T. grandiflora (Hawai‘i); T. kaalae, comb. et stat. nov. (Wai‘anae Mountains of O‘ahu); T. kauaiensis (Kaua‘i); T. rockii (Moloka‘i); T. singularis (Ko‘olau Mountains of O‘ahu); and T. wimmeri (Hawai‘i).     

Review of the neotropical endemics Burmeistera, Centropogon, and Siphocampylus (Campanulaceae: Lobelioideae), with description of 18 new species and a new section

Burmeistera, Centropogon, and Siphocampylus together comprise more than 500 species endemic to the Neotropics, Current knowledge of these genera is unsatisfactory, with much diversity yet to be described. Over the past seven years, one out of every 28 specimens received for identification has represented a new species, many characterized by unique or unusual character states. Siphocampylus smilax (Bolivia) is unique in the genus in its parallelodromous leaf venation and extra-floral nectaries. Centropogon dianae (Peru) cannot be accommodated in any recognized infrageneric taxon, and a new section, Centropogon sect. Niveopsis, is proposed for it. The flowers of C. steinii (Ecuador) are the smallest known in the genus, while C. connatilobatus (Venezuela) is the first species to combine arbusculiform pubescence and connate calyx lobes. Burmeistera venezuelensis is only the second species of the genus known to occur in Venezuela and the first to be endemic; similarly, Centropogon wilburii is only the third species of Centropogon known from Mexico and the first to be endemic to that country. Additional novelties are also described.     

Molecular evidence for the phylogenetic position ofHanabusaya asiatica Nakai (Campanulaceae), an endemic species in Korea

The phylogenetic relationship of the Korean endemic genus,Hanabusaya, to other campanulaceous genera has been controversial since it was described by Nakai in 1911. Three genera of Campanuloideae,Symphyandra, Adenophora, andCampanula, have been considered closely related by various taxonomists on the basis of anther shape, gross morphology, and pollen characters, respectively. We have tested these competing taxonomic hypotheses using the internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA from 12 taxa representing 7 genera of Campanulaceae. The molecular phylogeny indicates strongly thatHanabusaya is more closely allied toAdenophora than toCampanula orSymphyandra. The phylogenetic affinity ofHanabusaya andAdenophora is supported by a 100% bootstrap value and a high decay index (13). The average sequence divergence value (Kimura’s 2-parameter method) betweenHanabusaya and theAdenophora species is 2.58. The value is significantly (about ten times) lower than the ones observed betweenHanabusaya and the species ofCampanula (average of 23.52) and betweenHanabusaya andSymphyandra (24.95). The ITS sequence phylogeny suggests that some morphological characters, such as fused anthers and corolla shape, are homoplastic in the Campanulaceae genera.     

Nectar spur evolution in the Mexican lobelias (Campanulaceae: Lobelioideae)

Phylogenetic studies are often hampered by the independent evolution of characters that may potentially obscure relationships. The adaptive significance of the nectar spur and its evolution within the Mexican lobeliads (Campanulaceae) is considered here. The taxonomic delimitations of Heterotoma from the Mexican species within the genera Lobelia and Calcaratolobelia were tested. Independent molecular data were gathered to determine whether the Mexican spurred lobeliads should be treated as distinct genera. The internal transcribed spacer (ITS) region from 18-26S nuclear rDNA and chloroplast DNA from the 3' trnK intron were sequenced from 14 representative species. Our data suggest that Heterotoma, as originally conceived, is a good evolutionary unit within Lobelia and that the presence of a nectar spur is an important morphological character that can be used in defining phylogenetic position. This study also suggests that morphological changes associated with hummingbird pollination have evolved more than once in the Mexican lobeliads, from small blue-flowered, insect-pollinated relatives.     

A new species of Siphocampylus (Campanulaceae: Lobelioideae) from northern Peru

Siphocampylus platysiphon (Campanulaceae: Lobelioideae) is described as a new species from northern Peru. It is a member of subsect.Megastomi in sect.Brachysiphon and is most closely related toS. giganteus, a species common to the north in Ecuador and Colombia.     

Four species from western Mexico new to Lobelia (Campanulaceae: Lobelioideae)

Lobelia knoblochii, L. mcvaughii, andL. villaregalis are described and referred, withHeterotoma macrocentron Benth., toLobelia “grex Eriniformes” Wimmer. All are narrow endemics occurring on volcanic soils in the Sierra Madre Occidental of Mexico.Lobelia macrocentron, L. mcvaughii, andL. villaregalis are known only from the type localities.     

<Emphasis Type="Italic">Lobelia proctorii</Emphasis> sp. nov. (Lobelioideae,Campanulaceae/Lobeliaceae) from the Philippines

A new Lobelia species is described from Mount Guiting Guiting, an ultramafic mountain on Sibuyan Island in the Philippines.     

Karyotype evolution in the genus Boronia (Rutaceae)

New chromosome counts are reported for Boronia clavata 2 n  = 14, B. heterophylla 'Near White' 2 n  = 15, B.  'Carousel' 2 n  = 16, B. deanei 2 n  = 22, B. chartacea 2 n  = 32, B. keysii 2 n  = 32, B. pilosa 2 n  = 44, B. anethifolia 2 n  = 36 and B. citriodora 2 n  = 108. Studies in 20 genotypes of 18 species and one interspecific hybrid revealed that they are highly complex in terms of chromosome number, ploidy level, chromosomal length, karyotype constitution and asymmetry. Karyotype analysis indicated that Boronia taxa with high chromosome numbers are primitive and those with lower numbers are derived. The basic chromosome number for this genus is suggested to be x = 18. Analysis of chromosome number, variations of total chromosome length (TCL) and average chromosome length (ACL), Nombre Fondamental (NF) and karyotype asymmetry suggest that dysploid reduction is the major mechanism in Boronia karyotype evolution. Chromosomal rearrangements might also have been involved. Origin, chromosome number changes and spread of Boronia are discussed in relation to the species divergence and the geological and climatic changes of the Australian continent.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 142 , 309–320.     

Sporogenesis and Gametogenesis of Endangered Adenophora lobophylla Hong (Campanulaceae)

Reported in this paper are the microsporogenesis, megasporogenesis and the development of male and female gametophytes of the endangered species Adenophora lobophylla. The anther is four-sporangiate with its wall composed of four layers: epidermis, fibrous endothelium, middle layer and glandular tapetum of binucleate cells. The cytokinesis of microspore mother cell in meiosis is simultaneous, and tetrads are tetrahedral. Pollen grains are 2-celled at the dispersal stage. Ovule is anatropous, unitegmic and tenuinucellate with a hypodermal archesporial cell developing directly as the megaspore mother cell which undergoes meiotic division and then forms a linear tetrad. The embryo sac is of Polygonum type. The polar nuclei fuse before fertilization. An endothelium differentiates when the uninucleate embryo sac forms. Comparative studies were made with the closely related and widely distributed species A. potaninii. No differences between them were found. No obstacle to sexual reproduction in this endangered species was observed. As a conclusion, no endangering factors were found to influence the sporogenesis and gametogenesis of A. lobophylla. According to our observision and the references on embryological studies of the Campanulaceae(s. l. ), there is no evident differentiation in sporogenesis and gametogenesis in this family.     

Conservation genetics of the endangered endemic Hawaiian genus Brighamia (Campanulaceae)

The endemic Hawaiian genus Brighamia (Campanulaceae) comprises two federally endangered, morphologically similar species, B. insignis from Kaua`i and Ni`ihau and B. rockii from Moloka`i. To assist the design of conservation management programs for these taxa, isozyme analyses were performed to assess the levels of genetic diversity at the population and species levels, including comparisons within and among seven natural populations and one ex situ collection each of B. insignis and B. rockii. Our sampling (N = 80) represents ~41% of all known individuals in the wild. Isozyme analyses revealed levels of genetic variation comparable to those reported for other Hawaiian flowering plant taxa but low levels of genetic variation at the population and species levels when compared to flowering plants in general. Ex situ individuals (N = 61) were genetically representative of natural populations and hence may appropriately serve as stock for population augmentations. The two morphologically similar Brighamia species were highly distinct genetically. The combination of morphological and ecological similarity with allozymic dissimilarity observed in Brighamia is unique among the Hawaiian taxa studied to date.     

Historical biogeography of the endemic Campanulaceae of Crete

Aim The clade Campanulaceae in the Cretan area is rich in endemics, with c. 50% of its species having restricted distributions. These species are analysed in the context of a larger phylogeny of the Campanulaceae. Divergence times are calculated and hypotheses of vicariance and dispersal are tested with the aim of understanding whether Cretan lineages represent remnants of an older continental flora. Location The Cretan area: Crete and the Karpathos Islands (Greece). Methods We obtained chloroplast DNA sequence data from rbcL, atpB and matK genes for 102 ingroup taxa, of which 18 are from the Cretan area, 11 are endemics, and two have disjunct, bi‐regional distributions. We analysed the data using beast , a Bayesian approach that simultaneously infers the phylogeny and divergence times. We calibrated the tree by placing a seed fossil in the phylogeny, and used published age estimates as a prior for the root. Results The phylogenetic reconstruction shows that all Campanula species fall within a well‐supported campanuloid clade; however, Campanula is highly polyphyletic. The Cretan endemics do not form a monophyletic group, and species are scattered throughout the campanuloid clade. Therefore, the Cretan taxa did not evolve following a single vicariance or dispersal event. Most Cretan lineages represent remnants of an older continental flora, with the exception of one clade that radiated in situ after island isolation, and one lineage that appears to have arrived by dispersal. Main conclusions Most Cretan species were present in the islands at the time of their isolation, and very little long‐distance dispersal to Crete and diversification within Crete has occurred since then. Endemism is probably driven by loss of species on the mainland after island isolation. Species on the islands may have been more widespread in the past, but they are now restricted to often inaccessible areas, probably as a result of human pressure.     

A new species ofAdenophora (Campanulaceae) from Korea

Adenophora erecta S. Lee, J. Lee et S. Kim, is described as a new species from an open north-facing mountain slope on the coast of Sukpo-Dong, Ullungdo Is., Kyungsangbukdo, Korea. This species resemblesA. remotiflora Miq., but is well separated by having the leaves compactly arranged along the upper part of the stem, condensed raceme, distinct veins on the corolla and especially shallow dome-shaped epigynous nectar disc.     

Conservation Genetics of an Endangered Herb, Hanabusaya asiatica (Campanulaceae)

Abstract: Hanabusaya asiatica (Nakai) Nakai (Campanulaceae), a bee- pollinated, perennial herb, is restricted to the mountainous regions of the eastern-central Korean peninsula. Allozyme analyses for 348 individuals assessed the levels of genetic diversity for five populations. Spatial autocorrelation statistics were also used to examine the spatial distribution of allozyme polymorphisms. The species maintains high levels of allozyme diversity ( H _eS = 0.217) and it exhibits low allozyme differentiation among populations ( G _ST = 0.132) compared with other endemics (mean H _e = 0.096, G _ST = 0.248). There is an apparent pattern of isolation by distance among populations. These results suggest that H. asiatica is at a genetic equilibrium. A considerable deficit in numbers of heterozygotes suggests mating among relatives in populations. At least three populations of H. asiatica should be sampled or conserved to capture or maintain > 99 % of the genetic diversity in the species as a whole. Within local populations, individuals are distributed in a structured, isolation by distance, manner. Approximate genetic patch width in the populations of H. asiatica examined is 5 - 8 m. For conservation purposes, it is suggested that, in general, the sampling of H. asiatica should be conducted at intervals in order to efficiently sample the genetic diversity across an entire population.     

The Restoration of the Genus Cyclocodon ( Campanulaceae) and Its Evidence from Pollen and Seed-coat

The genus Cyclocodon Griff. was reduced by C. B. Clarke in 1881 into a section of the genus Campanumoea. Our LM and SEM observations on pollen morphology show that the pollen of all the three species in the former is 3-colporate with the exine sparsely high-spinulose, whereas that of the two species in the latter is 5～8-colpate with the exine relatively densely short-spinulose. SEM observations on seed-coat indicate that the primary ornamentation of the seed-coat of the two species in Campanumoea (s. str. ) is characterized by regular and polygonal areoles which are much larger than the radial walls in diameter and by the bead-like secondary ornamentation on the radial walls, while that of the three species in Cyclocodon is characterized by irregular-shaped areoles which are nearly equal to the radial walls in diameter and by the rope-like secondary ornamentation on the radial walls. Thus, the pollen morphology is closely correlated with the seed-coat morphology. Taking the characteristics of pollen, seed-coat and gross morphology into consideration, the genus Cyclocodon is restored, separate from Campanumoea (s. str. ). One new combination, Cyclocodon celebicus (B1.)Hong, is made in the present paper. The genus Cyclocodon is con-sidered closely related to Platycodon rather than to Campanumoa.     

Evolution and biogeography of the endemic Roucela complex (Campanulaceae: Campanula) in the Eastern Mediterranean

At the intersection of geological activity, climatic fluctuations, and human pressure, the Mediterranean Basin – a hotspot of biodiversity – provides an ideal setting for studying endemism, evolution, and biogeography. Here, we focus on the Roucela complex (Campanula subgenus Roucela), a group of 13 bellflower species found primarily in the eastern Mediterranean Basin. Plastid and low‐copy nuclear markers were employed to reconstruct evolutionary relationships and estimate divergence times within the Roucela complex using both concatenation and species tree analyses. Niche modeling, ancestral range estimation, and diversification analyses were conducted to provide further insights into patterns of endemism and diversification through time. Diversification of the Roucela clade appears to have been primarily the result of vicariance driven by the breakup of an ancient landmass. We found geologic events such as the formation of the mid‐Aegean trench and the Messinian Salinity Crisis to be historically important in the evolutionary history of this group. Contrary to numerous past studies, the onset of the Mediterranean climate has not promoted diversification in the Roucela complex and, in fact, may be negatively affecting these species. This study highlights the diversity and complexity of historical processes driving plant evolution in the Mediterranean Basin.