Dihydrostyryl-2-pyrone as a chemical marker of three non-xanthone-producing Polygala species (Polygalaceae)

The phytochemical investigation of the ethyl acetate fraction of Polygala longicaulis Kunth resulted in the isolation and identification of two dihydrostyryl-2-pyrones (1–2). This is the third species of the Polygala L. genus, along with Polygala altomontana Lüdtke, Boldrini & Miotto and Polygala sabulosa A.W. Benn., to present the accumulation of dihydrostyryl-2-pyrones. The data reported herein make an important contribution to the chemotaxonomy of this genus. This is the first report of dihydrostyryl-2-pyrone (1) and dihydrometisticin (2) in P. longicaulis and the first report of dihydrometisticin in the genus Polygala. Furthermore, this is the first grouping of non-xanthone-producing Polygala species.     

RAPD and microsatellite transferability studies in selected species of <Emphasis Type="Italic">Prosopis</Emphasis> (section Algarobia) with emphasis on <Emphasis Type="Italic">Prosopis juliflora</Emphasis> and <Emphasis Type="Italic">P. pallida</Emphasis>

The genus Prosopis (Leguminosae, Mimosoideae), comprises 44 species widely distributed in arid and semi-arid zones. Prosopis pallida (Humb. & Bonpl. ex Willd.) Kunth and P. juliflora (Sw.) DC. are the two species that are truly tropical apart from P. africana, which is native to tropical Africa (Pasiecznik et al. 2004), and they have been introduced widely beyond their native ranges. However, taxonomic confusion within the genus has hampered exploitation and better management of the species. The present study focusses primarily on evaluating the genetic relationship between Prosopis species from the section Algarobia, containing most species of economic importance, though P. tamarugo from section Strombocarpa is also included for comparison. In total, 12 Prosopis species and a putative P. pallida × P. chilensis hybrid were assessed for their genetic relationships based on RAPD markers and microsatellite transferability. The results show that P. pallida and P. juliflora are not closely related despite some morphological similarity. Evidence also agrees with previous studies which suggest that the grouping of series in section Algarobia is artificial.     

A new species of Polygala L. (Polygalaceae) from south‐west Anatolia

Polygala peshmenii Eren, Parolly, Raus & Kürschner is described and illustrated as a new species from Antalya province in south‐west Anatolia, Turkey. Within subgenus Polygala section Polygala, it seems to be taxonomically quite isolated. As far as the Flora of Turkey area is concerned, technical comparison can be made with the informal P. alpestris Rchb. and P. vulgaris L. groups. The habitat conditions of P. peshmenii and its conservation status are considered. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 82–86.     

A new species of <Emphasis Type="Italic">Polygala</Emphasis> subgenus <Emphasis Type="Italic">Hebeclada</Emphasis> (Polygalaceae) from central Brazil

Polygala pauciramosa, a new species from the Federal District and the state of Goiás is described, illustrated, and compared with related species of Polygala subgenus Hebeclada. The new species is an herb that grows in seasonally to permanently wet savannas. A key to the species of Polygala subgenus Hebeclada from Goiás state, Brazil is provided.     

Ecological and morphological seed traits of Polygala sardoa and P. sinisica: A comparative study on two endemic species of Sardinia

Polygala sardoa Chodat and P. sinisica Arrigoni (Polygalaceae) are two exclusive endemics to Sardinia and P. sinisica is affiliated under “Critically Endangered” in the IUCN Red Lists. In this work comparative studies on two populations of P. sardoa and in the only one of P. sinisica were carried out. In particular, seed output calculations and morphometric measurements on seed and elaiosome sizes were carried out. The effect of chipping, constant (15 °C) and alternating (25/10 °C) temperature regimes and light (8 h irradiance/day and dark) on germination were investigated. Seedling vigor assessments and a study on seed persistence in the soil were also carried out. P. sinisica had a higher seed output than P. sardoa and P. sinisica seeds were smaller than those of P. sardoa, with lower elaiosome area and elaiosome ratio values. Neither species had alternating temperature or light requirements for germination. P. sardoa achieved high germination percentages (> 80%) at all the tested conditions. P. sinisica had a lower maximum germination (<60%), suggesting the presence of physiological dormancy, and took more than twice as long to reach the maximum germination percentage. Seedlings of P. sardoa were larger than those of P. sinisica, and neither species formed a persistent soil seed bank. These new data may help implement effective conservation measures for these two species and, more generally, for threatened endemic species of this genus.     

Polygala webbiana (Polygalaceae), the first record for Europe and a synopsis of Polygala subgen. Chamaebuxus

Polygala subgen. Chamaebuxus comprises five perennial species, distributed in Europe and northwestern Africa. Polygala webbiana was hitherto thought to be endemic to Morocco. In this paper, we report the first known population of this species in Europe, present in the province of Málaga (Spain). Detailed pictures of the flower, fruit, and seed are presented, as well as a map of the whole distribution. Moreover, a key to identify the species of Polygala subgen. Chamaebuxus is provided. The names P. chamaebuxus and P. vayredae are lectotypified.     

937. PASSIFLORA PUNICEA

Passiflora punicea Ruiz & Pavón ex DC., considered by Maxwell T. Masters (1872) and E. P. Killip (1938) to be a synonym of P. vitifolia Kunth is here reinstated at species rank. It is described and illustrated in colour and with black and white line drawings. Its history, distribution, similarities to related species and cultivation are discussed. A key to its closest related species is provided.     

POLYOL PATTERNS IN BIOFILM‐FORMING AEROTERRESTRIAL GREEN ALGAE (TREBOUXIOPHYCEAE,CHLOROPHYTA)1

The distribution of polyols was examined for the first time in 34 green algal strains from four different clades belonging to the class Trebouxiophyceae, which dominate aeroterrestrial biofilms of many regions. Sorbitol was detected in representatives of the Prasiola clade, while ribitol was present in the Elliptochloris and Watanabea clades. Apatococcus lobatus (Chodat) J. B. Petersen contained erythritol in addition to ribitol. Polyols are considered as effective stress metabolites exerting multiple protective functions in metabolism and hence mainly occur in organisms colonizing extreme environments. In contrast, members of the Chlorella clade, which mainly occur in aquatic habitats, did not contain polyols. Thus, the constitutive presence of specific polyols facilitates a differentiation between species of the Prasiola clade from the Elliptochloris and Watanabea clades, respectively, and further allows differentiation of morphologically converging taxa.     

Re-establishment of <Emphasis Type="Italic">Stylosanthes gracilis</Emphasis> (Leguminosae) at species level

In most taxonomic revisions of Stylosanthes Sw., Stylosanthes gracilis Kunth has been regarded as a variety or even a synonym of S. guianensis (Aubl.) Sw. This has created considerable confusion among scientists working with the latter species which is an agriculturally important tropical forage and cover legume. This study collected taxonomically relevant evidence, for evaluating S. gracilis as a valid species. Since the type specimen is lost, a collection from the same location as the original type is proposed here as a neotype.     

On the types of <Emphasis Type="Italic">Maxillaria grandiflora</Emphasis> and <Emphasis Type="Italic">Heterotaxis valenzuelana</Emphasis> (Orchidaceae: Maxillariinae)

The type specimen of Maxillaria grandiflora (Kunth) Lindl. was collected by Alexander von Humboldt and Aimé Bonpland during their scientific expedition to Tropical America. Its type locality, which has been the subject of confusion, is identified as a place on the eastern part of La Cruz municipality in the province of Nari?o, Colombia. The type of M. grandiflora is shown to be a mixed collection and a lectotype is designated; the protologue illustration represents an amalgamation of both species. The type of Heterotaxis valenzuelana (A. Rich.) Ojeda & Carnevali was collected by José María Valenzuela but has been erroneously cited as Wright 3314 in the recent literature.     

Effets de la température sur la croissance de deux algues vertes du fleuve St-Laurent,secteur de Gentilly,Québec

Two abundant phytoplankters from the St-Lawrence river: Scenedesmus spinosus Chodat 1913 and Pediastrum boryanum (Turp.) Menegh (Chlorophyta, Chlorococca) were sampled, isolated and cultured in monospecific culture. Growth responses were measured after acclimation to different temperatures and after thermal shock treatments.Post-acclimation specific growth rates followed similar patterns with optimal temperatures at about 24°C (S. spinosus) and 26°C (P. boryanum). Final densities were much less influenced by temperature in S. spinosus than in P. boryanum. Post-treatment responses depended on the temperature level maintained after treatment rather than on treatment conditions. No treatment seemed to delay the exponential growth phase. The time needed to reach final densities corresponding to stationary growth phase was not influenced by any thermal treatment. In situ thermal effects at Gentilly nuclear site could be more severe, due to differences in time-temperature history experienced by the algae.

     

On the nature of bristles in Scenedesmus

Summary The existence of bristles, the hair-like appendages in several species of the genus Scenedesmus has been confirmed.The ultrastructure of bristles in Scenedesmus helveticus Arlet, Sc. acutus Meyen and Sc. acuminatus/Lagerh./Chodat has been studied by negative staining. While bristles of Sc. helveticus are composed of several microstrands with a regular pattern of cross-striation, the bristles of spineless species Sc. aculus and Sc. acuminatus seem to be composed only of individual microstrands.These investigations of bristles suggest their protein composition.     

Are <Emphasis Type="Italic">Deschampsia antarctica</Emphasis> Desv. and <Emphasis Type="Italic">Colobanthus quitensis</Emphasis> (Kunth) Bartl. Migratory relicts?

It remains unclear why there are only two vascular plant species in Antarctica, Deschampsia antarctica Desv. (Poaceae) and Colobanthus quitensis (Kunth) Bartl. (Caryophyllaceae). Despite progressing climate warming, there is also just one alien plant species found in the region, introduced by humans and spreading mainly in disturbed habitats. In the present article, we try to interpret the data concerning the history of the biota and glaciations of the continent, proceeding from the assumption that both plants migrated to Antarctica during the Oligocene-Pliocene, when it was less isolated and the climate was more favorable for their naturalization. Genetic evidence was also taken into consideration. Our data allow the suggestion of secondary dispersal in the region, due to transference by birds with regard to climate changes. With this in mind, we believe that D. antarctica and C. quitensis are migratory relicts. The text was submitted by the authors in English.     

Absence of Learning and Local Specialization on Host Plant Selection by <Emphasis Type="BoldItalic">Heliconius erato</Emphasis>

There is considerable interspecific variation in larval host plants (Passifloraceae) used among Heliconius erato (Lepidoptera: Nymphalidae) populations. This study evaluates the role of learning and the influence of interspecific variation in host plant attributes on such local specialization in H. erato host plant choices. Experiments were conducted under laboratory, insectary, and field conditions, with the two most widely used host plants in southern Brazil (Passiflora suberosa Linnaeus and Passiflora misera Humbold, Bonpland et Kunth). Larval feeding preference and induction were evaluated through choice tests for all instars. Oviposition was evaluated in relation to host plant preference, Hopkins host-selection principle, and conditioning time (for 3, 7, 11, or 15 days). Also, oviposition choice was tested regarding density, intemode length, and presence of intact terminal bud on P. suberosa and P. misera shoots. Both larvae and adults of H. erato phyllis showed preference for P. misera compared to P. suberosa, under all conditions. Larval feeding preference could not be induced for most instars. The Hopkins effect was not detected and oviposition choice could not be conditioned. Females alternated use of host plant species as a function of variation in either density or presence of terminal buds on shoots. Thus, our data indicate host plant preference in H. erato phyllis is not learned but innate. Therefore, we concluded that variation in local use of host plant by this butterfly in southern Brazil results from qualitative and quantitative variation of the passion vine species.     

SCENEDESMUS WALL ORNAMENTATION. I. SCENEDESMUS PARISIENSIS CULTURES1

Four strains of Scenedesmus parisiensis Chodat were studied in xenic and axenic culture in 3 media as well as in cultures incubated in sterile vessels in nature. Organized coenobia are usually produced but these may have merely short spines, spines and serrate edges, or lack wall ornamentation. Because the serrate edge is either not formed or cannot be readily detected in most cases, it is not a satisfactory morphological feature for delimiting this species. In laboratory studies it is noted that S. parisiensis might be confused with S. denticulatus rather than S. brasilien-sis. Inasmuch as both xenic and axenic cultures of the -f strains produced similar results, S. parisiensis can be readily characterized.     

STUDIES IN THE FLORAL ANATOMY OF POLYGALA (POLYGALACEAE)

Flowers of Polygala are irregular, each having three small and two long winglike sepals, three petals, eight stamens, and a bilocular ovary. These flowers have been considered pentamerous, and placentation has been subject to various interpretations. Development and anatomy of flowers of Polygala alba, P. lanceolata, and P. lutea were studied to see if evidence of pentamery and change in placentation could be found. These studies reveal no evidence of vestigial petals or stamens nor of vascular traces to organs that are missing in the three species studied. Neither are there abortive sporangia in the bisporangiate anthers. Observations on development of carpel primordia and on the vascular plan of mature carpels indicate that placentation is fundamentally parietal rather than axile. Speculation is offered as to the derivation of this type of placentation.     

Some new and uncommon British volvocales

British material of the following algae is described: Pyramimonas tetrarhynchus Schmarda; Spermatozopsis exsultans Korshikov; Myochloris collorhynchus nov. gen. et sp.; Pedinomonas minor Korshikov; Monomastix opisthostigma Scherffel; Lobomonas ampla Pascher var. okensis Korshikov; L. rostrata Hazen; Diplostauron pentagonium (Hazen) Pascher; Phacotus lendneri Chodat; Chlorobrachis sp.     

Genetic diversity of fragmented populations of<Emphasis Type="Italic"> Polygala reinii</Emphasis> (Polygalaceae), a perennial herb endemic to Japan

Genetic variation at 10 allozyme loci was analyzed in 14 populations of Polygala reinii (Polygalaceae), a perennial herb endemic to central Honshu, Japan, with a fragmented geographical distribution. The levels of genetic variation within species (P=80.0, A=3.10, H_E=0.303) and within populations (P=42.1, A=1.61, H_E=0.163) were considerably higher than the mean for other endemic plants or short-lived perennial herbs. Genetic differentiation among populations was also high (G_ST=0.404). The genetic distance phenogram tended to show a clustering of the populations reflecting the fragmentation of the species range. A principal component analysis revealed the same tendency, as well as three groupings of populations in the Tokai district, on the Kii Peninsula and in the northern Kinki district. A negative correlation was obtained between the levels of gene flow and geographical distance among the populations (r=–0.745, P<0.0001). These results indicated limited gene flow among populations in P. reinii, presumably due to the geographical isolation accompanying the fragmented distribution. On the other hand, the geographical differentiation between the Japan Sea and Pacific Ocean sides was found in P. reinii, suggesting the influence of postglacial migration on the establishment of the genetic structure of this species.     

Myrmecochory in Polygala vulgaris L., Luzula campestris (L.) DC. and Viola curtisii Forster in a Dutch dune area

Summary Seed dispersal by ants in Polygala vulgaris, Luzula campestris and Viola curtisii was studied in a primary dune valley on the island of Terschelling, The Netherlands. Normally developed seeds of all three species are taken by the ants into their nests. The ants show a distinct preference for the seeds of the specialized myrmecochore Polygala vulgaris, as compared with the two diplochorous species. It could be demonstrated that the elaiosome is the attractive part of the seed. Mapping studies demonstrate that the dispersal of the seeds by ants has a marked effect on the distribution pattern of the standing population of Polygala and Viola. Adult plants are often found on or close to the active nest mounds of all ant species present, while the growing sites of juvenile individuals and seedlings are practically restricted to the nest environment. The nests of two of the seed-dispersing ant species, viz., those of Lasius niger and Tetramorium caespitum, show differences in soil chemistry with the surroundings. The ant nests are significantly richer in some essential plant macronutrients, such as phosphate, potassium and nitrate. The advantage of myrmecochory in the dune area of Terschelling is discussed.