New species of grasses in Arberella,Cryptochloa, and Raddia (Poaceae: Bambusoideae: Olyreae)

Two new species are described inArberella, one from Panama (Arberella lancifolia) and one from Bahia, Brazil (a. bahiensis), the latter representing a considerable extension of the known range of the genus.Cryptochloa decumbens, described from Panama, brings to ten the species recognized in this genus andRaddia angustifolia, from Bahia, increases to five the number of species in that genus. Each new species is fully illustrated and keyed.     

New species of cryptochloa and piresia (Poaceae: Bambusoideae)

Two new species are added toCryptochloa,C. unispiculata from Peru andC. capillata from Brazil, the latter transferred from the genusOlyra. The genusPiresia is also augmented by two new species,P. macrophylla from Peru andP. leptophylla from Bahia, Brazil. These species represent, respectively, the westernmost and easternmost limits of distribution of the genus.     

Phylogenetic relationships among Southeast Asian climbing bamboos (Poaceae: Bambusoideae) and the Bambusa complex

A phylogenetic analysis of Bambusa and allies based on the plastid DNA non-coding regions rps16-trnQ, trnC-rpoB, trnH-psbA and trnD-T, and a partial nuclear GBSSI gene, was carried out. This included representatives from all four Bambusa subgenera (including type species), a group of segregate Southeast Asian genera distinctive by their climbing–scrambling culms (Dinochloa, Holttumochloa, Kinabaluchloa, Maclurochloa, Soejatmia, Sphaerobambos), and two other Bambusinae genera (Dendrocalamus, Gigantochloa). The results do not support the present subgeneric classification of Bambusa. The climbing Southeast Asian genera, all of which include species previously placed in Bambusa, are distinct from the “core Bambusa group” (type species and alliance) and the Bambusa complex generally.     

Chusquea sect. Swallenochloa (Poaceae: Bambusoideae) and allies in Brazil

The 13 high altitude/latitude, dwarf species ofChusquea in Brazil are described, illustrated, and mapped, and their morphology, habitats, distributions, and taxonomic affinities are discussed. Two keys to species are provided, one based solely on vegetative characters, and the other on vegetative and flowering characters.Chusquea erecta, C. nutans, C. riosaltensis,C. windischii, C. caparaoensis, andC. nudiramea are described as new, andC. microphylla is elevated to specific status. Two subspecies are recognized within the variableC. mimosa: C. mimosa subsp.australis and subsp.mimosa. Seven species are formally classified withinChusquea sect.Swallenochloa; the remaining six species are classified into two informal categories, theNudiramea andHeterophylla groups. A list of all the species currently included withinChusquea sect.Swallenochloa is provided.     

Chusquea and Swallenochloa (Poaceae: Bambusoideae): Generic relationships and new species

One new species of Chusquea and three of Swallenochloa are described. Morphological characters, especially of the culm leaves and branching, are pointed out as useful in distinguishing the two genera. A key to the 7 recognized species of Swallenochloa is given, and a discussion of its habitat, the páramo. Comment is made upon the recent evolution of the páramo habitat and therefore of the bamboo adapted to it, and reasons offered for the apparent active speciation which characterizes this bamboo genus.     

Arberella (Poaceae: Bambusoideae): A new genus from tropical America

Arberella, a new genus of bambusoid grasses, is established, based on the newly described species,A. dressiert. Also belonging to this new genus are the taxa originally namedOlyra flaccida andRaddia costa-ricensis and several new species from Panama and Brazil which will be described later. The new genus is presented in a key to the genera of the tribe Olyreae, of which it is a member, and a key is given to the three species treated in this paper.     

Four new species of Chusquea (Poaceae: Bambusoideae) from Brazil and Ecuador

Four new species ofChusquea—C. bahiana, C. bradei, C. leonardiorum, andC. loxensis—are described and illustrated.Chusquea bahiana andC. bradei, classified within subg.Rettbergia withinChusquea based on their infravaginal, geniculate branching and spatheate, often contracted inflorescences, are endemic to the Atlantic forests of Bahia and Espírito Santo, Brazil, where they are relatively uncommon.Chusquea leonardiorum andC. loxensis are native to the páramos of southern Ecuador;C. leonardiorum is moderately widespread, butC. loxensis is known from only two populations in the Parque Nacional Podocarpus in the province of Loja. These two species are allied withChusquea sect.Chusquea based on their erect to arching or scandent habit, extravaginal branching, and relatively numerous subsidiary branches per node.     

[竹思]簩竹属及其近缘属叶表皮微形态特征

用扫描电镜和光学显微镜对[竹思]簩竹属（Schizostachyum Nees）7个种,及其近缘的梨竹属（Melocanna Trin．）、泡竹属（Pseudostachyum Munro）、薄竹属（Lepzocanna Chia et H．L．Fung）各1个种以及空竹属（Cephalostachyum Munro）6个种的叶表皮微形态特征进行了观察。结果表明竹叶下表皮乳突的形状和在气孔器上及周围的排列式样在这5个属中各有不同,具有重要的分类学和系统学价值。同时我们的结果不支持广义的笃竹属;而梨竹属、空竹属和泡竹属则被支持独立成属。另外,薄竹（Leptocanna chinensis）和红毛[竹思]簩竹（Schizostachyum sanguineum）的叶表皮微形态特征非常接近空竹属;香糯竹（Cephalostachyum pergracile）和金毛空竹（C．virgatum）的叶表皮微形态特征则十分接近[竹思]簩竹属。     

(竹思)篣竹属及其近缘属叶表皮微形态特征

用扫描电镜和光学显微镜对(竹思)篣竹属(Schizostachyum Nees)7个种,及其近缘的梨竹属(Melocanna Trin.)、泡竹属(Pseudostachyum Munro)、薄竹属(Leptocanna Chia et H.L. Fung)各1个种以及空竹属(Cephalostachyum Munro)6个种的叶表皮微形态特征进行了观察.结果表明竹叶下表皮乳突的形状和在气孔器上及周围的排列式样在这5个属中各有不同,具有重要的分类学和系统学价值.同时我们的结果不支持广义的以属;而梨竹属、空竹属和泡竹属则被支持独立成属.另外,薄竹(Leptocanna chinensis)和红毛葸(竹思)篣竹(Schizostachyum sanguineum)的叶表皮微形态特征非常接近空竹属;香糯竹(Cephalostachyum pergracile)和金毛空竹(C.virgatum)的叶表皮微形态特征则十分接近(竹思)篣竹属.     

Sucrea (Poaceae: Bambusoideae), a new genus from Brazil

Sucrea, a new genus of herbaceous bambusoid grasses is based on the newly described species,S. monophylla. Also belonging to this genus is another new species,S. maculata, and the taxon originally namedOlyra sampaiana. The new genus is contrasted in a key with others of its tribe Olyreae, and a key is given to its three species.     

Genetic and morphological divergence in theAndrocymbium gramineum complex (Colchicaceae)

Narrow endemism is a poor predictor of genetic potential in the six taxa that conform theAndrocymbium gramineum complex, as shown by the unexpectedly high values of variability associated with ten allozymic loci and 13 biometrical variables. Although both levels are shown not to be correlated, variability is always concentrated within populations. This result, together with environmental, reproductive and historical data strongly suggests differentiation in local isolates, where changes can be quickly assimilated by stochastic processes. A key implication for conservation is that sampling within the largest population will save effort while neglecting only very low frequency alleles.     

Population genetic structure of Yushania niitakayamensis (Bambusoideae, Poaceae) in Taiwan

Yushania niitakayamensis is distributed in Taiwan, south-west China and northern Philippines. In Taiwan, the species occurs in the central mountain ranges from 1500 to 3500 m in altitude. Morphological variation, especially in terms of plant height, is large, with plants ranging from 10 cm to 5 m in height. The species appears to spread mainly by rhizomes and flowers rarely, leading to the prediction that most populations are comprised of a single or a few clonal genotypes and that the observed morphological variation is primarily due to phenotypic plasticity. The purpose of the present study was to investigate the genetic structure of this species on Mt Hohuan in central Taiwan. Ten plants from a single clone and ten plants of unknown genetic background were surveyed at one site in order to select RAPD primers useful for clone identification. Plants at a second site were collected at 1-m intervals across a 50-m transect through the population. Plants at one extreme (exposed portion) of the transect were approximately 15–30 cm in height, whereas plants up to 410 cm in height were found at the other shaded end of the transect. Comparison of amplification profiles for 12 primers revealed that in contrast to our predictions of genetic uniformity, many samples had reproducibly different RAPD amplification profiles, with the 51 samples representing 31 clones. These data imply that the clone size is relatively small, and the population is actually highly diverse genetically. The genetic variation in this population may be due to a higher frequency of sexual reproduction during the evolutionary history of the species and/or a high somatic mutation rate for RAPD loci in clones of Yushania.     

Genetic and morphological variability in South American rodent Oecomys (Sigmodontinae, Rodentia): evidence for a complex of species

The rodent genus Oecomys (Sigmodontinae) comprises ~16 species that inhabit tropical and subtropical forests in Central America and South America. In this study specimens of Oecomys paricola Thomas, 1904 from Belém and Marajó island, northern Brazil, were investigated using cytogenetic, molecular and morphological analyses. Three karyotypes were found, two from Belém (2n = 68, fundamental number (FN) = 72 and 2n = 70, FN = 76) and a third from Marajó island (2n = 70, FN = 72). No molecular or morphological differences were found between the individuals with differing cytotypes from Belém, but differences were evident between the individuals from Belém and Marajó island. Specimens from Belém city region may represent two cryptic species because two different karyotypes are present in the absence of significant differences in morphology and molecular characteristics. The Marajó island and Belém populations may represent distinct species that have been separated for some time, and are in the process of morphological and molecular differentiation as a consequence of reproductive isolation at the geographic and chromosomal levels. Thus, the results suggest that O. paricola may be a complex of species.     

Phylogenetic relationships and natural hybridization among the North American woody bamboos (Poaceae: Bambusoideae: Arundinaria)

In spite of the ecological and economic importance of temperate bamboos, relatively little is known about their population biology or evolutionary history. Recently, hybridization has emerged as a potential source of diversity in this group, as well as an underlying cause of taxonomic problems. As part of a broader phylogenetic study of the temperate bamboos, we report the results of an analysis of the North American Arundinaria gigantea species complex, including estimates of genetic variation and molecular evidence of natural hybridization among A. gigantea, A. tecta, and A. appalachiana. The study involved a comparative analysis of amplified fragment length polymorphisms (AFLPs) and chloroplast DNA sequences representing diversity within and among all three species plus individuals with intermediate or unusual morphological characteristics (putative hybrids). Molecular results support the recognition of three species previously defined on the basis of morphology, anatomy, and ecology, with most of the molecular variance accounted for by among-species variation. Molecular evidence also demonstrates that A. tecta and A. appalachiana are sister species, forming a clade that is significantly divergent from A. gigantea. The role of hybridization in the phylogenetic history of Arundinaria is discussed along with implications for the evolution and taxonomy of the temperate woody bamboos.     

Aulonemia yanachagensis (Poaceae: Bambusoideae: Bambuseae): A new species from central Peru

Aulonemia yanachagensis is described from cloud forests at 2600–3000 m elevation in the Parque Nacional Yanachaga-Chemillén Prov. Oxapampa, Dept. Pasco, Peru. It differs from all other congeners in its combination of prominent sheath auricles, with abundant radiate fimbriae, small foliage leaf blades, and awnless spikelets.     

Molecular phylogeny of the arthrostylidioid bamboos (Poaceae: Bambusoideae: Bambuseae: Arthrostylidiinae) and new genus Didymogonyx

We present the first multi-locus chloroplast phylogeny of Arthrostylidiinae, a subtribe of neotropical woody bamboos. The morphological diversity of Arthrostylidiinae makes its taxonomy difficult and prior molecular analyses of bamboos have lacked breadth of sampling within the subtribe, leaving internal relationships uncertain. We sampled 51 taxa, chosen to span the range of taxonomic diversity and morphology, and analyzed a combined chloroplast DNA dataset with six chloroplast regions: ndhF, trnD-trnT, trnC-rpoB, rps16-trnQ, trnT-trnL, and rpl16. A consensus of maximum parsimony and Bayesian inference analyses reveals monophyly of the Arthrostylidiinae and four moderately supported lineages within it. Six previously recognized genera were monophyletic, three polyphyletic, and two monotypic; Rhipidocladum sect. Didymogonyx is here raised to generic status. When mapped onto our topology, many of the morphological characters show homoplasy.     

Characterization of 10 KDA prolamin genes in Phyllostachys aurea (Bambusoideae, Poaceae)

Prolamin is the dominant class of seed storage protein in grasses (Poaceae). Information on the 10 kDa multigene family coding for prolamins characteristic of the bambusoid-oryzoid grasses is limited. Two genes encoding 10 kDa prolamin were cloned and sequenced in the bambusoid species Phyllostachys aurea to assess the sequence diversity of this gene family in the oryzoid-bambusoid grasses. The genes, ~417 bp in length, were 96% similar at the DNA sequence level, differing in 12 base substitutions dispersed throughout the sequence. Eight of these mutations were nonsynonymous, leading to amino acid substitutions in the coding region, and one was nonsense, producing an amber stop codon. One gene had an open reading frame (ORF) of 139 amino acids, while the other gene had a shorter ORF (106 amino acids) due to the presence of a stop codon in the coding region and, thus, represents a pseudogene. Deduced proteins showed amino acid composition similar to that of rice. The study underscores the overall conserved nature of this multigene family and reflects considerable sequence divergence at the DNA and amino acid levels between the Oryza and the Phyllostachys genes. The systematic implication of the data is discussed in light of the inconsistent placement of Oryza in the Bambusoideae or Oryzoideae.