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This study was conducted to evaluate the abundance and distribution pattern of three keystone Vachellia taxa in wadi Khoda and wadi Rahaba, Gebel Elba National Park, a protected area in south-eastern Egypt. These taxa included Vachellia tortilis subsp. tortilis, Vachellia tortilis subsp. raddiana, and Vachellia ehrenbergiana. In wadi Khoda, only two of these taxa were detected (V. tortilis subsp. raddiana and V. tortilis subsp. tortilis), while all three taxa were encountered in wadi Rahaba. The density of trees in wadi Khoda was 34.3 plant ha−1 compared to 26.3 plant ha−1 in wadi Rahaba. Vachellia tortilis subsp. raddiana was the most frequently observed tree, with an average of 47.93% and 68.25% in wadi Rahaba and wadi Khoda, respectively. Crown depth and tree height were mainly associated with elevation, indicating that elevation plays a key role in the growth of these Vachellia taxa. Our results suggest that human activities have had limited effect on the distribution of these three keystone taxa. Thus, management in Gebel Elba National Park should continue to limit the impact of human activities on these three keystone species. [ABSTRACT FROM AUTHOR]

This study examined the detailed pollen morphological structures of sixteen Hypericum taxa (four endemic, twelve non endemic) including eight sections showing the natural distribution in Turkey: H. sect. Ascyreia ( H. calycinum L.), H. sect. Heterophyllum ( H. heterophyllum Vent.), H. Sect. Taeniocarpium ( Hypericum confertum Choisy subsp. confertum, H. venustum Fenzl , H. linaroides Bosse), H. sect. Drosocarpium ( H. montbretii Spach, H. bithynicum Boiss.), H. sect. Crossophyllum ( H. adenotrichum Spach, H. orientale L.), H. sect. Olympia ( H. olympicum L. subsp. olympicum), H. sect. Origanifolia ( H. origanifolium Willd., H. avicularifolium Jaub and Spach subsp. depilatum (Freyn and Bornm.) Robson var. depilatum, H. avicularifolium Jaub. and Spach subsp. byzantinum) and H. sect. Hypericum ( H. tetrapterum Fries, H. perforatum L., H. triquetrifolium Tura). These taxa were studied under light microscope and scanning electron microscope for the first time. Of the taxa studied, H. tetrapterum has the smallest pollen grains (on average 15.85-17.20 × 15.45-16.05 μm); and H. olympicum subsp. olympicum the largest grains (on average 22.90-23.10 × 21.40-22.10 μm). The pollen grains of 15 taxa are subprolate and one taxon is prolate-spheroidal. The regular pollen grains of all 16 taxa are 3-zonocolporate. Ornamentation is microreticulate; lumina regularly spaced in eight taxa, tectum perforatum; tectal perforations regularly spaced in seven taxa and tectum perforatum; and tectal perforations grouped together in one taxon. Endoaperture is cruciform porus, with short lateral and meridional extensions in ten taxa, cruciform porus, transversally elongated, with very small lateral extensions in one taxon and lalongate colpus in five taxa. Basic pollen types are ten taxa in type X, five taxa in type IV and one taxon in type II. [ABSTRACT FROM AUTHOR]

Molecular characterization of Tulipa L. species can elucidate the relationships among the species and provide more information about the taxonomy of this valuable genus. In this study, the genetic relationship among 39 Tulipa accessions from Khorassan and Yazd Provinces, located in east and northeast Iran, were analyzed using inter-simple sequence repeat (ISSR) primers. Ten selected ISSR primers from 20 screened primers generated a total of 97 polymorphic DNA bands. Unweighted pair-group method of cluster analysis based on Dice similarity values separated the accessions into nine groups. Seven species were recognized within these groups, and T. micheliana Hoog was the most frequently encountered species. The subgroups formed within both T. micheliana and T. lehmanniana Merckl. revealed a low level of diversity within these species. T. biebersteiniana Schultes & Schultes fil. and T. biflora Pallas accessions made a separate clusters. The grouping of accessions was generally consistent with principal coordinate analysis (PCA) and clearly showed the position of species in the subgenera and sections of Tulipa. These results clearly showed the usefulness of DNA fingerprinting for identification of Tulipa accessions, and it is imperative to collect and characterize more genetic variability from the other distribution areas of this genus. [ABSTRACT FROM AUTHOR]

It is expected that plant species with multiple regenerative strategies have a wider ecological amplitude and geographical distribution. However there is still an anxious question why species with multiple regenerative strategies are not more frequent. In the presented work we asked whether short-lived plants with a potential bud bank i) have a wider geographical distribution, ii) occur more frequently in human-made habitats and iii) more frequently possess invasive status in comparison with the short-lived species without this additional regenerative strategy. Results show that short-lived plants with a potential bud bank are i) more widely geographically distributed, ii) under-represented in natural habitats and weakly over-represented in habitats disturbed by human activities and iii) contrary to expectation, less numerous among neophytes than species without a potential bud bank. This suggests that short-lived root-sprouters are more habitat-specialized when compared with such plants without adventitious bud-bank formation, but are more widely geographically distributed. A higher frequency of multiple regeneration strategies seems to be restricted by costs of having this ability in habitats or situations without a disturbance regime. [ABSTRACT FROM AUTHOR]

Helichrysum nicolai from the Cape Verdean island of São Nicolau is described as a species new to science and illustrated. The systematic position in Helichrysum of this acaulescent dwarf rosette shrub with heterogamous capitula, in which the female flowers outnumber the hermaphrodite ones, is established using an ITS phylogeny based on maximum parsimony and Bayesian inference analyses. The new species is most closely related to the Canary Island endemics H. alucense and H. monogynum. The closest relative to these three species are not the other members of the genus on the mid-Atlantic archipelagos but H. somalense from the Horn of Africa region and the southern Arabian Peninsula and the widespread tropical African-S Arabian-SE Iranian H. glumaceum, to which the SE Iranian H. makranicum is found to be conspecific. The phytogeographical significance of these relationships is discussed and at least three independent colonization events of the mid-Atlantic archipelagos by Helichrysum are concluded from the molecular data available. [ABSTRACT FROM AUTHOR]

This study focuses on a phytosociological system of the extensive Larix gmelinii and Larix cajanderi dominated forests and woodlands that span the nemoral, boreal and subarctic zones in northeast Asia in the Russian Far East, Eastern Siberia and northern China, an area that covers more than 5 million km2. A total of 299 relevés representing different parts of the larch forest range were used to classify communities in this area into the boreal Rhytidio rugosi-Laricetea sibiricae and Vaccinio-Piceetea and to the nemoral Querco mongolicae-Betuletea davuricae. The hierarchical system of lower syntaxa of larch forests and woodlands of northeast Asia includes 24 associations and nine subassociations. Nineteen associations and two alliances – Rhododendro aurei-Laricion cajanderi and Rhododendro daurici-Laricion gmelinii – are described for the first time. Two associations were classified into Dictamno dasycarpi-Quercion mongolicae of Lespedezo bicoloris-Quercetalia mongolicae representing the nemoral class Querco mongolicae-Betuletea davuricae. All larch communities in the nemoral zone represent different post-fire-event stages. Eleven associations occurring in humid conditions of the boreal zone and in the areas influenced by the Pacific Ocean are classified into Abieti nephrolepidis-Piceion jezoensis, Piceion jezoensis and Pino pumilae-Piceion jezoensis representing boreal forests of humid maritime regions belonging to the order Abieti veitchii-Piceetalia jezoensis. In this area seral larch communities occupy zonal sites, and primeval larch forests may occur only in edaphic conditions restricting the distribution of zonal dominants, Picea jezoensis and the species of Abies. The area of continuous permafrost within the boreal zone having continental and ultracontinental climate conditions is occupied by primeval larch forests united in Ledo palustris-Laricion cajanderi and Rhododendro aurei-Laricion cajanderi of Ledo palustris-Laricetalia cajanderi, and on sites with dry soils with a deeper frozen horizon in Lathyro humilis-Laricion cajanderi of Lathyro humilis-Laricetalia cajanderi. [ABSTRACT FROM AUTHOR]

The taxonomic status of Central European taxa Festuca pallens s.l., F. psammophila, F. polesica, and F. vaginata was revised using the multivariate morphological analysis of well karyologically documented plants, and AFLP analysis. Six species were recognised: F. pallens Host (relict rocky habitats; diploid); F. csikhegyensis Simonk. (base-rich rocks; tetraploid); F. psammophila (Čelak.) Fritsch (acidic sands) with two subspecies, F. p. subsp. psammophila (E Germany, Poland, Bohemia) and F. p. subsp. dominii (Krajina) P. Šmarda (SW Moravia, NE Austria, SW Slovakia, C and E Poland); F. vaginata Willd. (base-rich sands mainly in the Pannonian Lowland); F. polesica Zapał. (seaside and inland sand dunes); and F. pseudovaginata Penksza (base-rich sands in the Pannonian Lowland). Identification key and distribution maps as well as informations about type specimens, exsiccata collections, synonyms, and hybrids are provided. Evolutionary relationships with the assumed putative ancestor F. pallens and the rather isolated position of F. polesica are discussed. [ABSTRACT FROM AUTHOR]

Biebersteiniaceae comprise a single genus with four species of perennial herbs occurring from central Asia to Greece. A previous molecular phylogenetic study placed one of the species in an isolated position in Sapindales, while morphological studies had placed Biebersteinia in or near Geraniaceae, albeit doubtfully. We tested the monophyly and placement of the family with data from the chloroplast genes rbcL and atpB obtained for all four species, other major clades of Sapindales and outgroups for a total of up to 114 taxa. Parsimony, Bayesian, and likelihood analyses place Biebersteinia in Sapindales, possibly as sister to the other eight families. Strict and relaxed molecular clocks constrained with fossils of Biebersteinia and up to eight other Sapindales suggest that the Biebersteinia crown group diversified in the Oligocene and Miocene, while the stem lineage dates back to the Late Paleocene. Ages for other sapindalean families are earlier than those obtained in more sparsely sampled analyses, although estimates for Burseraceae agree surprisingly well. Ancestral area analyses suggest that Biebersteinia expanded from the eastern part of its range (i.e. Tibet and Inner Mongolia) to the west, although analyses are hampered by the unclear sister group relationships. [ABSTRACT FROM AUTHOR]

The use of genetic resources could be more effective and efficient if we were able to predict the presence or absence of useful traits in different populations or accessions. We analyzed the extent to which taxonomic, geographic and ecological factors can predict the presence of frost tolerance in wild potatoes. We used screening data for 1646 samples from 87 species that had been collected in 12 countries in the Americas. There was a strong association of frost tolerance with species and to a lesser extent with taxonomic series. There was significant geographic clustering of areas with wild potatoes with similar levels of frost tolerance. Areas with a high level of frost tolerance are the central and southern Peruvian Andes, the lowlands of Argentina and adjacent areas, and a small area in the central Chilean Andes. There is a greater chance of finding wild potatoes with high levels of frost tolerance in areas with a yearly mean minimum temperature below 3 °C than there is in warmer areas. However, temperature is only a weak predictor of frost tolerance. Temperature data alone did not predict observed frost tolerance in eastern Argentina/Uruguay and falsely predicted it in the southwestern United States. Because many wild potato species occur over small areas, taxonomic, ecological, and geographical factors are difficult to disentangle. [ABSTRACT FROM AUTHOR]