Open Access. Powered by Scholars. Published by Universities.®

Ecology and Evolutionary Biology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Plant Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1711 - 1740 of 2464

Full-Text Articles in Ecology and Evolutionary Biology

A Taxonomic Study Of The Genus Acris And The Status Of Acris Crepitans Blanchardi (Harper), Blanchard's Cricket Frog, In Southern Ohio And Western West Virginia, Amy M. Hamilton Jan 2008

A Taxonomic Study Of The Genus Acris And The Status Of Acris Crepitans Blanchardi (Harper), Blanchard's Cricket Frog, In Southern Ohio And Western West Virginia, Amy M. Hamilton

Theses, Dissertations and Capstones

Distributions of Acris crepitans and Acris gryllus cover most of the eastern United States with some overlap, and the subspecies Acris crepitans blanchardi and Acris crepitans crepitans also occur sympathric in parts of their ranges. My study analyzed 15 morphological characteristics of A. c. blanchardi, A. c. crepitans, and A. g. gryllus using Canonical Discriminate Analysis. Results support current taxonomy, showing the most separation between A. crepitans and A. gryllus and some overlap between A. c. blanchardi and A. c. crepitans. Sexual dimorphism was seen only in A. c. blanchardi and A. c. crepitans with females being larger …


Seed Predators Of Canada Milk-Vetch And Their Parasitoids, Arvid Boe, Paul J. Johnson Jan 2008

Seed Predators Of Canada Milk-Vetch And Their Parasitoids, Arvid Boe, Paul J. Johnson

Native Plant Focused Publications

Canada milk-vetch (Astragalus canadensis L.), North America’s most widespread species of Astragalus, is important for herbivores and granivores in natural ecosystems but suffers heavy seed losses to bruchids and curculionids. Our objectives were: (1) compile a species inventory and describe life histories of insects associated with seed production in Canada milk-vetch, and (2) determine frequencies of pod predation and primary parasitism in Canada milk-vetch. The seed predators were Acanthoscelides perforatus (Horn) and Tychius liljebladi Blatchley. Frequency of pod predation varied between two plant populations (46 and 70%) and between A. perforatus (37 %) and T. liljebladi (21 %). The primary …


Competitive Abilities Of Native Grasses And Non-Native (Bothriochloa Spp.) Grasses, Cheryl D. Schmidt, Rob Channell Ph.D., Karen R. Hickman, Keith Harmoney, William J. Stark Ph.D. Jan 2008

Competitive Abilities Of Native Grasses And Non-Native (Bothriochloa Spp.) Grasses, Cheryl D. Schmidt, Rob Channell Ph.D., Karen R. Hickman, Keith Harmoney, William J. Stark Ph.D.

Biological Sciences Faculty Publications

Old World Bluestems (OWB), introduced from Europe and Asia in the 1920s, recently have begun to raise concerns in the Great Plains. Despite suggestion in the late 1950s that OWB were weedy and negatively impacted biological diversity, they were widely introduced throughout the Great Plains for agricultural purposes. Anecdotal evidence suggests that OWB exhibit invasive characteristics that promote competitive exclusion of native species. The objective of our study was to quantify the competitive abilities of two OWB species (Caucasian bluestem; Bothriochloa bladhii (Retz.) S. T. Blake (= Bothriochloa caucasica (Trin.) C. E. Hubb.) and yellow bluestem; Bothriochloa ischaemum (L.) Keng) …


Terrestrial Habitat Use Of Marbled Salamanders Ambystoma Opacum: A Site Specific Approach, Frank Piccininni Jan 2008

Terrestrial Habitat Use Of Marbled Salamanders Ambystoma Opacum: A Site Specific Approach, Frank Piccininni

Theses, Dissertations and Capstones

Habitat destruction, fragmentation and degradation have contributed heavily to the decline of amphibian populations such as Marbled Salamanders (Ambystoma opacum). Often, ambystomatid water resources are conserved without consideration for the equally important terrestrial habitat. This is partly due to a lack of information regarding the relationship between ecological succession, plant community composition, microhabitat and salamander abundance. Three sampling transects consisting of drift fence arrays, vegetation assessments and microhabitat surveys were extended 100 m into the terrestrial habitat surrounding a seasonal wetland at Beech Fork State Park in Wayne County, West Virginia. Principal components analysis was used to identify …


Seed Predation By Acanthoscelides Submuticus And A. Pallidipennis (Coleoptera: Bruchidae) In False Indigo In The Northern Great Plains, Arvid Boe, Paul J. Johnson Jan 2008

Seed Predation By Acanthoscelides Submuticus And A. Pallidipennis (Coleoptera: Bruchidae) In False Indigo In The Northern Great Plains, Arvid Boe, Paul J. Johnson

Native Plant Focused Publications

False indigo (Amorpha fruticosa L.) is a native North American leguminous shrub frequently found on shores of lakes and banks of rivers and streams in eastern and central United States and is present in 46 of the 48 contiguous states. It is planted for wildlife habitat, streambank erosion control, and ornamental purposes. Over several years, 16 collections of mature pods of false indigo were obtained from shorelines of four lakes and one cultivated planting in the northern Great Plains to determine frequency of pod predation by bruchid beetles. Frequency of pod predation by Acanthoscelides submuticus (Sharp) varied significantly among locations, …


Capturing Genetic Variation During Ecological Restorations: An Example From Kankakee Sands In Indiana, Rebecca W. Dolan, Deborah L. Marr, Andrew Schnabel Jan 2008

Capturing Genetic Variation During Ecological Restorations: An Example From Kankakee Sands In Indiana, Rebecca W. Dolan, Deborah L. Marr, Andrew Schnabel

Scholarship and Professional Work - LAS

Genetic variation in populations, both natural and restored, is usually considered crucial for response to short term environmental stresses and for long term evolutionary change. To have the best chance of successful long-term survival, restored populations should reflect the extant variation found in remnants, but restored sites may suffer from genetic bottlenecks as a result of founder effects. Kankakee Sands is a large-scale restoration being conducted by The Nature Conservancy (TNC) in northwestern Indiana. Our goal was to test for loss of genetic variation in restored plant populations by comparing them with TNC’s seed source nursery and with local remnant …


Use Of Passive Integrated Transponders In Hatchling Texas Horned Lizards, Scott E. Henke Jan 2008

Use Of Passive Integrated Transponders In Hatchling Texas Horned Lizards, Scott E. Henke

The Prairie Naturalist

The Texas horned lizard (Phrynosoma cornutum) is a Texas state-threatened species and acquisition of data related to the species' ecology is essential. To accomplish this task individual animals need to be marked. Many marking techniques are available for lizards, however the majority of techniques have been tested on adults only. Studies involving hatchling and juvenile horned lizards are scarce due to problems associated with marking and relocating individuals in these age classes. I demonstrated that injection of passive integrated transponders (PIT's) can safely be used as a marking method in young Texas horned lizards. Thirty-two captive bred hatchling lizards were …


Mortality Of An American Marten From An Off-Highway Vehicle, Joshua B. Smith, Jonathan A. Jenks Jan 2008

Mortality Of An American Marten From An Off-Highway Vehicle, Joshua B. Smith, Jonathan A. Jenks

The Prairie Naturalist

While there are several reviews of the effects of OHVs and recreational activity on wildlife populations (Knight and Gutzwiller 1995, Joslin and Youmans 1999), most studies have focused on physiological (Creel et al. 2002) or behavioral (Van Dyke et al. 1986, Riley et al. 2003) responses to disturbance; none have addressed the potential for direct mortality. In 2005, we documented the death from an OHV of a juvenile, female American marten (F299) that had been radiocollared during a study documenting the distribution and abundance of American marten in the Black Hills, South Dakota (Smith 2007); the Institutional Animal Care and …


The Pollination Biology And Mating System Of A Peripheral Population Of Witheringia Solanacea (Solanaceae), Timothy Miller Jan 2008

The Pollination Biology And Mating System Of A Peripheral Population Of Witheringia Solanacea (Solanaceae), Timothy Miller

Honors Theses

Pollinator visitation rates over the life of a flower are determined by pollinator abundance and floral longevity. If flowers are not visited frequently enough, pollen limitation may occur, favoring the evolution of self-compatibility (SC). In plant species with varying SC levels, central populations often are self-incompatible (SI) and peripheral populations are SC. Witheringia solanacea (Solanaceae) is a species that follows this trend with the exception of one population in the Monteverde Cloud Forest Reserve, which is peripheral yet SI. I investigated this population using multiple techniques including floral bagging, pollinator observations, microsatellite analysis, and floral longevity manipulations. My results confirmed …


Seeding Effectiveness And Natural Regeneration Of Mojave Desert Plant Communities After 2005-2006 Wildland Fires, E. Cayenne Engel, Scott R. Abella, Christina L. Lund Jan 2008

Seeding Effectiveness And Natural Regeneration Of Mojave Desert Plant Communities After 2005-2006 Wildland Fires, E. Cayenne Engel, Scott R. Abella, Christina L. Lund

Fire Science Presentations

1) Assessment of BLM seeding effectiveness in mid-elevation burn where pre-burn plant communities were dominated by blackbrush, Joshua trees, and creosote.

2) Patterns driving fire recovery at the landscape scale:

  • Link initial vegetation, environment, and soils
  • Are there patterns that can be gleaned that can then be applied to management prescriptions?


Management Techniques For The Control Of Sahara Mustard (Brassica Tournefortii) In The Mojave Desert, Dianne N. Bangle, Scott R. Abella, Public Lands Institute, Jan 2008

Management Techniques For The Control Of Sahara Mustard (Brassica Tournefortii) In The Mojave Desert, Dianne N. Bangle, Scott R. Abella, Public Lands Institute,

Vegetation Monitoring Presentations

In the southwestern United States, Brassica tournefortii(Sahara mustard) is a highly invasive plant that colonizes roadsides, beaches, sand dunes, and open desert threatening native annuals. Sahara mustard is believed to contribute to fuel loads in the Mojave Desert in areas where Schismussp. and Bromussp. occur. Sahara mustard may act as ladder fuel, thereby facilitating the spread of fire throughout the landscape. Manpower limitations and insufficient funding limits the abilities of managers to effectively control Sahara mustard. We tested seed germinability in Sahara mustard after fruiting plants were treated with either 2%, 5%, or 12% triclopyr. Sahara mustard seed pods were …


Exotic Annual Plant Invasions And Their Relationships To Roads And Native Perennial Species In The Mojave Desert, Southwestern Usa, Donovan J. Craig, Jill Pacovsky Craig, Scott R. Abella Jan 2008

Exotic Annual Plant Invasions And Their Relationships To Roads And Native Perennial Species In The Mojave Desert, Southwestern Usa, Donovan J. Craig, Jill Pacovsky Craig, Scott R. Abella

Vegetation Monitoring Presentations

For the last five years, roadside monitoring for exotic invasive species has been a common practice for documenting distributions in Clark County, Nevada (Abella et al., in press). Yet, studies have shown that weed relationships to road corridors differ depending upon the natural system (Hansen and Clevenger, 2005). In the Mojave Desert, it is unknown whether exotic species are limited to or even predominant along roadsides.

Compounding this uncertainty, fertile islands under shrubs are known to enhance conditions for many annuals (Thompson et al., 2005). Thus, a site’s shrub composition could influence exotic invasive plant distributions.


Implications For Management Prioritization Of Exotic Annual Weed Monitoring Near Roadsides In The Eastern Mojave Desert, Usa, Donovan J. Craig, Jill E. Craig, Scott R. Abella, Public Lands Institute, Jan 2008

Implications For Management Prioritization Of Exotic Annual Weed Monitoring Near Roadsides In The Eastern Mojave Desert, Usa, Donovan J. Craig, Jill E. Craig, Scott R. Abella, Public Lands Institute,

Vegetation Monitoring Presentations

Invasive exotic plants provide an unnatural conduit for fires in the Mojave Desert. For the last five years, roadside monitoring for exotic invasive species has been a common practice for documenting distributions in Clark County, Nevada (Abella et al., in press). Yet, studies have shown that weed relationships to road corridors differ depending upon the natural system (Hansen and Clevenger, 2005). In the Mojave Desert, it is unknown whether exotic species are limited to or even predominant along roadsides.

Compounding this uncertainty, fertile islands under shrubs are known to enhance conditions for many annuals (Thompson et al., 2005). Thus, a …


Response Of Sahara Mustard (Brassica Tournefortii) To Water Addition And Soil Disturbance, Alexis Suazo, Jessica E. Spencer, Scott R. Abella Jan 2008

Response Of Sahara Mustard (Brassica Tournefortii) To Water Addition And Soil Disturbance, Alexis Suazo, Jessica E. Spencer, Scott R. Abella

Vegetation Monitoring Presentations

Invasive exotic species can have a significant impact on the structure, function, and diversity of ecological communities. Sahara mustard (Brassica tournefortii) is one of the top exotic invasive species spreading through the southwestern deserts of North America. In arid environments, it is well documented that species abundance is sensitive to rainfall (Beatly 1974, Ernest et al. 2000). In the Mojave Desert, winter precipitation can trigger massive germination events (Beatly 1974). As a winter annual, Sahara mustard may have a positive response to winter precipitation by germinating, growing, and reproducing before native annuals, monopolizing soil moisture and nutrients, and potentially changing …


Mojave Applied Ecology Notes Winter 2008, Scott R. Abella, E. Cayenne Engel, Jill E. Craig Jan 2008

Mojave Applied Ecology Notes Winter 2008, Scott R. Abella, E. Cayenne Engel, Jill E. Craig

Mojave Applied Ecology Notes

Mojave Desert collaborative projects, fire history in Spring Mountains, Northshore Road rehabilitation, wildfires and invasive plants in American deserts conference, weed sentry surveys


Reestablishing The Juneberry On The Fort Berthold Indian Reservation: Cultural, Horticultural, And Educational Connections, Kerry E. Hartman Jan 2008

Reestablishing The Juneberry On The Fort Berthold Indian Reservation: Cultural, Horticultural, And Educational Connections, Kerry E. Hartman

Electronic Theses and Dissertations

Tribal people of the Northern Great Plains have utilized plants for centuries. Amelanchier anifolia (Juneberries/Serviceberries) historically played an important part in the diet and culture of the Mandan, Hidatsa, and Arikara (MHA) Tribal Nations. Research conducted as part of this study into historical and contemporary uses of the Juneberry by MHA Tribal Members indicated extensive historical use and a high interest in Juneberry reestablishment for cultural, nutritional, and economic reasons. Previous research on Juneberries has investigated factors including state of dormancy, propagation method, transplant type, and mulch type. Another purpose of this study was to elucidate the impact of presence …


Validation Case Study : Treatment Effectiveness In Aspen Vegetation Type : A Comparison Of Two Types Of Treatments On The Manti-La Sal National Forest, Diane M. Cote Jan 2008

Validation Case Study : Treatment Effectiveness In Aspen Vegetation Type : A Comparison Of Two Types Of Treatments On The Manti-La Sal National Forest, Diane M. Cote

Aspen Bibliography

No abstract provided.


Tillage Effects On Soil Quality Indicators And Nematode Abundance In Loessial Soil Under Long- Term No-Till Production, R. B. Mendoza, T. G. Franti, John W. Doran, Thomas O. Powers, C. W. Zanner Jan 2008

Tillage Effects On Soil Quality Indicators And Nematode Abundance In Loessial Soil Under Long- Term No-Till Production, R. B. Mendoza, T. G. Franti, John W. Doran, Thomas O. Powers, C. W. Zanner

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Soil quality indicators and nematode abundance were characterized in a loessial soil under long-term conservation tillage to evaluate the effects of no-till, double-disk, chisel, and moldboard plow treatments. Indicators included soil electrical conductivity (EC), soil texture, soil organic matter (SOM), and total particulate organic matter (tPOM). Nematode abundance was positively correlated with EC, silt content, and total POM and negatively correlated with clay content. Clay content was the main source of variation among soil quality indicators and was negatively correlated with nematode abundance and most indicators. The gain in SOM in the no-till system amounted to 10887 kg over the …


Floristic Records In The Platte And Loup River Bottomlands Of Platte County, Nebraska, Michael P. Gutzmer, Robert B. Kaul Jan 2008

Floristic Records In The Platte And Loup River Bottomlands Of Platte County, Nebraska, Michael P. Gutzmer, Robert B. Kaul

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

A recent inventory of vascular plants in the Loup and Platte riverbottoms in Platte County has greatly increased knowledge of the area's flora. Of the 542 species of vascular plants now known to grow in the county, 289 were discovered after 1977, with more than 100 of those after 1990. 425 native and 117 naturalized species are known so far. Nearly 700 native and naturalized alien species are expected to occur in the county, based upon totals from nearby counties. Thus, almost 150 years after European settlement, more than 20% of the species remain unverified; of those, many are undoubtedly …


Sex-Specific Feeding Rates And Provisioning Of Fruit To Nestling Bell's Vireo, Greg H. Farley Jan 2008

Sex-Specific Feeding Rates And Provisioning Of Fruit To Nestling Bell's Vireo, Greg H. Farley

The Prairie Naturalist

Provisioning of fruit to nestlings and possible sex-specific differences in feeding rate have not been reported for Bell's vireo (Vireo bellii; Brown 1993). While studying nesting ecology of Bell's vireo on Konza Prairie Biological Station, Geary and Riley counties, Kansas, I quantified feeding rate by sex and food type delivered to nestlings. Sex was determined by capturing adults with mist-nets and inspecting for a cloacal protuberance, as well as conducting behavioral observations of uniquely-marked individuals. Males sing regularly while moving around territories, as well as during incubation (Nolan 1960). I assigned "female" to the individual in these socially …


Agricultural Systems: Agroecology And Rural Innovations For Development [Book Review], Charles A. Francis Jan 2008

Agricultural Systems: Agroecology And Rural Innovations For Development [Book Review], Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

To welcome yet another book on sustainable development, a reviewer must look for what is unique and what adds value to the volumes already published. In Agricultural Systems, editors Sieglinde Snapp and Barry Pound have assembled a collection of chapters that goes beyond the usual praise and criticism of the green revolution and the focus on economic development. Their book provides a first-hand story by people with lengthy experiences in the field, especially in Africa, who have developed and tested grassroots, participatory development approaches. The result is a valuable set of principles, strategies and case studies that paint a new …


Microspore Wall Morphogenesis And Orbicule Ultrastructure Of Isoetes, Khalid Alarid Jan 2008

Microspore Wall Morphogenesis And Orbicule Ultrastructure Of Isoetes, Khalid Alarid

Biological Sciences Theses & Dissertations

The microspore wall morphogenesis and orbicule ultrastructure of Isoetes were studied using electron microscopy. Microspore wall morphogenesis in five species of Isoetes (I. appalachiana, I. engelmannii, I. hyemalis, I. piedmontana, and an undescribed species from York Co., VA, USA) was studied using scanning and transmission electron microscopy. Results show that they generally have the same developmental stages in terms of microspore wall morphogenesis. The mature microspore wall consisted of four layers: perispore, paraexospore, exospore and endospore. Paraexospore formation began during the tetrad stage. The exospore was then formed between the paraexospore and the plasma membrane. During the free spore …


Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis, Quarterly Progress Report, October 1, 2007 To December 31, 2007, Margaret N. Rees Dec 2007

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis, Quarterly Progress Report, October 1, 2007 To December 31, 2007, Margaret N. Rees

Fire Science

The task agreement was awarded to UNLV on October 1, 2007. This report covers the period October 1, 2007 to December 31, 2007. The following activities have been conducted toward meeting or exceeding deliverables in the statement of work: hiring and project start and experimental set-up


Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, October 1, 2007 To December 31, 2007, Margaret N. Rees Dec 2007

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, October 1, 2007 To December 31, 2007, Margaret N. Rees

Vegetation Monitoring

Executive Summary

  • The Weed Sentry program surveyed more than 750 miles of federal lands in Clark County for invasive, exotic plant species.
  • Weed Sentry also removed more than 600,000 individual invasive plants from federal
    lands. These removals represent pro-active efforts that may have forestalled large
    infestations difficult and costly to eradicate.
  • In response to a request by the manager of the Fish and Wildlife Service Desert National
    Wildlife Refuge, a major effort of surveying springs for plant community composition
    and invasive plants provided unique knowledge services by the Weed Sentry program.
    No such baseline information existed for the Sheep Range. …


Impact Of Small Scale Gold Mining On Soils Of The Wetland Forests In East Usambara, Tanzania, C. Kweyunga, R. B. M. Rbm Senzota Dec 2007

Impact Of Small Scale Gold Mining On Soils Of The Wetland Forests In East Usambara, Tanzania, C. Kweyunga, R. B. M. Rbm Senzota

Tanzania Journal of Science

Soil pits in disturbed and natural wetland forests of East Usambara were excavated and soil profile samples collected and analysed for physical and chemical properties. Their physical and chemical characteristics were found to be sharply different from those of the surrounding hills. Differences included lack of A Horizon, water saturation, presence of very high organic matter, very low pH and hence very poor in basic cations, and low microbial activity. Nutrient recycling, especially nitrogen and phosphorus, tended to shift from mineralization to immobilization. Effects of soil disturbance on both physical and chemical characteristics of the soils were also very vivid. …


Phylogenetic Relationships In Tribe Cariceae (Cyperaceae) Based On Nested Analyses Of Four Molecular Data Sets, Marcia J. Waterway, Julian R. Starr Dec 2007

Phylogenetic Relationships In Tribe Cariceae (Cyperaceae) Based On Nested Analyses Of Four Molecular Data Sets, Marcia J. Waterway, Julian R. Starr

Aliso: A Journal of Systematic and Floristic Botany

Phylogenetic reconstruction for Carex and relatives in tribe Cariceae is complicated by species richness and nearly cosmopolitan distribution. In this investigation, our main objective was to estimate evolutionary relationships in tribe Cariceae using DNA sequence data from two spacer regions in nuclear ribosomal genes (ITS and ETS-1f) combined with noncoding chloroplast DNA (trnL intron, trnL–trnF intergenic spacer, and trnE–trnD intergenic spacers). Parsimony analyses of separate and combined data and Bayesian analysis of the combined data matrix revealed strong support for monophyly of tribe Cariceae and for monophyly of two major lineages, one …


An Electronic World Grass Flora, Steve Renvoize, Derek Clayton, Tom Cope, Helen Williamson Dec 2007

An Electronic World Grass Flora, Steve Renvoize, Derek Clayton, Tom Cope, Helen Williamson

Aliso: A Journal of Systematic and Floristic Botany

The development of an electronic world grass flora database is described in which data for 1090 morphological characters gathered for 11,000 species in 700 genera organized according to accepted names. This descriptive information is linked to a synonym database of 60,000 names. Authors, literature references, and the status of each name are also recorded in the database along with geographical distribution and type information. The list of accepted species is linked to a global herbarium of 350,000 specimens at Kew arranged in a phylogenetic sequence at the generic and species levels and according to broad phytogeographic divisions. From the database, …


Classification And Biogeography Of New World Grasses: Anomochlooideae, Pharoideae, Ehrhartoideae, And Bambusoideae, Emmet J. Judziewicz, Lynn G. Clark Dec 2007

Classification And Biogeography Of New World Grasses: Anomochlooideae, Pharoideae, Ehrhartoideae, And Bambusoideae, Emmet J. Judziewicz, Lynn G. Clark

Aliso: A Journal of Systematic and Floristic Botany

Molecular data support Anomochlooideae and Pharoideae as the two most basal extant clades within Poaceae. Anomochlooideae are endemic to the New World and have two tribes and two genera including the widespread Streptochaeteae (3–4 spp.) and the critically endangered Anomochloeae (1 sp.) of coastal Bahia, Brazil. Pharoideae are pantropical with one tribe, three genera, and 14 species; all eight species of Pharus occur only in the New World. Bambusoideae and Ehrhartoideae are sister groups and together form a clade sister to Pooideae, although support for this set of relationships is low. Ehrhartoideae are a worldwide subfamily represented in the New …


Phylogenetic Relationships Of The Decumbentes Group Of Paspalum, Thrasya, And Thrasyopsis (Poaceae: Panicoideae: Paniceae), Silvia S. Denham, Fernando O. Zuloaga Dec 2007

Phylogenetic Relationships Of The Decumbentes Group Of Paspalum, Thrasya, And Thrasyopsis (Poaceae: Panicoideae: Paniceae), Silvia S. Denham, Fernando O. Zuloaga

Aliso: A Journal of Systematic and Floristic Botany

Paspalum (Poaceae: Panicoideae: Paniceae) includes 330 species distributed mainly in tropical and subtropical regions of America. Due to the large number of species and convergence in many characters, an adequate infrageneric classification is still needed. Studies on Paniceae based on molecular and morphological data have suggested that Paspalum is paraphyletic, including the genus Thrasya, but none of these analyses have included a representative sample of these two genera. In this study, phylogenetic relationships among the informal group Decumbentes of Paspalum, plus subgenera and other informal groups, and the genera Thrasya and Thrasyopsis were estimated. A cladistic analysis under …


The Jeweled Armor Of Tillandsia—Multifaceted Or Elongated Trichomes Provide Photoprotection, Simon Pierce Dec 2007

The Jeweled Armor Of Tillandsia—Multifaceted Or Elongated Trichomes Provide Photoprotection, Simon Pierce

Aliso: A Journal of Systematic and Floristic Botany

Foliar trichomes of gray-leaved Tillandsioideae (Bromeliaceae) are highly reflective, suggesting a role in protecting the leaf against direct sunlight in exposed niches. The performance of photosystem II, as denoted by the chlorophyll fluorescence characteristic Fv /Fm , was determined for seven Tillandsia species and Vriesea barclayana that were exposed to excessive light, with trichomes either present or removed. Additionally, trichome structure and interaction with light was recorded using extended depth-of-field photomicrography, and reflectance quantified using a novel photographic technique. Trichomes of mesomorphic Type IV life forms (T. cryptantha, T. cyanea) and of the intermediate life …