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Full-Text Articles in Life Sciences

Pollinator Visitation Frequency Associated With Native And Non-Native Plants In A Mid-Atlantic Piedmont (Usa) Urban Garden, Nicholas J. Ruppel, Saunders M. Riley, Ellis D. Mumford, Barbara L. Swedo Jul 2019

Pollinator Visitation Frequency Associated With Native And Non-Native Plants In A Mid-Atlantic Piedmont (Usa) Urban Garden, Nicholas J. Ruppel, Saunders M. Riley, Ellis D. Mumford, Barbara L. Swedo

Virginia Journal of Science

The recent focus on the importance of native plants and their pollinators has highlighted the critical role of local species in their natural environment. As urban encroachment, climate change, and invasive species continues to threaten native habitats, it is increasingly important to promote the use of local green spaces as refugia for native plants and their pollinators. The aim of this project, therefore, was to identify and assess the visitation frequency of insect pollinators associated with an urban setting within the Piedmont region of Virginia, and compare their association with native versus closely-related but non-native summer-flowering plants. Several modes of ...


There's Much Left To Learn: Clethra's Chromosomes, W. John Hayden Oct 2015

There's Much Left To Learn: Clethra's Chromosomes, W. John Hayden

Biology Faculty Publications

Many would argue that chromosomes, genes, and DNA form the ineluctable essence of modern biology. Not only do these fundamental components of living cells provide moment-to-moment instructions by which cells carry out basic life processes, they also control inheritance of characteristics from one generation to the next. These essential functions of DNA stem from its repetitive structure. Hugely long DNA molecules are built from just four components, referenced by their singleletter abbreviations, A, C, G, and T. It is the specific sequence of these As, Cs, Gs, and Ts that constitutes the coded information of DNA. Moreover, molecular biologists have ...


When It Comes To Clethra: Roots Matter, W. John Hayden Jul 2015

When It Comes To Clethra: Roots Matter, W. John Hayden

Biology Faculty Publications

Roots, too often, are out of sight and out of mind, but they are critical for vigorous, healthy plant growth. All plant enthusiasts—including gardeners, farmers, foresters, and naturalists—should think about and appreciate roots if they wish to acquire a holistic understanding of plant biology. This article introduces readers to the mycorrhizal roots of the 2015 VNPS Wildflower of the Year, Clethra alnifolia (Sweet Pepperbush), and explores the diversity of mycorrhizae in a closely related family, Ericaceae.


Upside-Down Anthers Of Clethra Stand Out, W. John Hayden Apr 2015

Upside-Down Anthers Of Clethra Stand Out, W. John Hayden

Biology Faculty Publications

For the most part, the flowers of the 2015 VNPS Wildflower of the Year, Clethra alnifolia (Sweet Pepperbush), are unremarkable. Five separate sepals, 5 sepa rate petals, 10 stamens in 2 whorls, and a 3-carpellate superior ovary—an organization that can only be considered prosaic among the dicots. One floral feature, however, stands out: the anthers in the open flowers are upside-down! (See Figure 1A.) Further, these upside-down anthers open by pores (Figures 1B, 1C) rather than longitudinal slits, as in most flowering plants. These pores initially form on what would normally be the lowermost extremity of the anther, the ...


Native Orchids In Winter?, W. John Hayden Jan 2015

Native Orchids In Winter?, W. John Hayden

Biology Faculty Publications

A very special place in Southwest Virginia will soon expand its borders, thanks in part to the annual fundraising appeal by the Virginia Native Plant Society. The Cedars Natural Area Preserve supports ex ceptional natural communities including rocky, dry limestone glades and woodlands located across nearly 20 square miles in Lee County near the Powell River. The karst landscape, where thin soils develop over easily dissolved limestone bedrock, creates terrain that tends to be rolling, rocky, rugged, and full of sinkholes, caves, and sinking streams. The preserve is a haven for rare plants that have adapted to the mostly thin ...


2015 Virginia Wildflower Of The Year: Sweet Pepperbush, Clethra Alnifolia, W. John Hayden Jan 2015

2015 Virginia Wildflower Of The Year: Sweet Pepperbush, Clethra Alnifolia, W. John Hayden

Biology Faculty Publications

Clethra alnifolia is a rhizomatous shrub with aerial stems from 1 to 3 m tall. Leaves are simple, alternate, and bear stellate hairs; petioles are short, 5–10 mm long; leaf blades are obovate to oblong, 5–10 cm long, with relatively blunt apices, cuneate (wedgelike) bases, and margins that are entire toward the base but finely serrate above the middle; venation is pinnate with secondary veins that extend to leaf margins. Stipules are lacking. Flowers are borne on erect terminal racemes that may be solitary or accompanied by additional racemes terminating few-leaved branches arising from upper nodes. Raceme axes ...


Little Things Reveal The Big Picture, W. John Hayden Jan 2015

Little Things Reveal The Big Picture, W. John Hayden

Biology Faculty Publications

As enthusiasts who enjoy native plants in natural habitats, we tend to focus on gross morphology— aspects of plant form that can be readily observed with the naked eye or with a hand lens. And there is plenty to see at the gross level. The Flora of Virginia contains 1,269 pages of keys and descriptions devoted to gross morphology of the commonwealth’s botanical treasures. Morphological diversity, however, does not stop at the magnifi cation limit of a hand lens. Light and electron microscopes open up whole new worlds of intricate structure for appreciation and study. And tiny structural ...


Two Honeysuckles: A Tale Of Dr. Jekyll And Mr. Hyde, W. John Hayden Feb 2014

Two Honeysuckles: A Tale Of Dr. Jekyll And Mr. Hyde, W. John Hayden

Biology Faculty Publications

There are about 180 species of Lonicera (honeysuckles) widely distributed in the north temperate zone. These are mostly shrubby plants, but in Virginia, we have two species that are woody vines (lianas). These two lianous honeysuckles should be familiar to all Virginia Native Plant Society members. One is this year’s VNPS Wildflower of the Year, Lonicera sempervirens (coral honeysuckle), and the other is Lonicera japonica (Japanese honeysuckle), widely and deservedly reviled as one of our most aggressive invasive exotic species. Together, these two plants make an odd pair, a sort of botanical Dr. Jekyll and Mr. Hyde. What is ...


Redbud Seedpods Hold Surprises, W. John Hayden Oct 2013

Redbud Seedpods Hold Surprises, W. John Hayden

Biology Faculty Publications

As fall advances across the Old Dominion, canopies of redbud, the 2013 VNPS Wildflower of the Year, transform themselves from green to gold, revealing seed pods also changing color from pale green to dark chocolaty brown. These seedpods, which may be retained on the tree into winter, are typical legume fruits, the product of the flower’s simple pistil, each containing several seeds. Unlike most legumes, however, redbud seed pods seem disinclined to open and release individual seeds for dispersal. Redbud fruits tend to disperse intact. Once on the ground, the inevitable action of weather and microbes gradually degrades the ...


Redbud Cauliflory: The Inside Story, W. John Hayden Jan 2013

Redbud Cauliflory: The Inside Story, W. John Hayden

Biology Faculty Publications

One of the most distinctive features of redbuds, Cercis canadensis, the 2013 VNPS Wildflower of the Year, is its production of flowers on mature trunks and major branches, a habit termed cauliflory. Redbud flowers also form on young, one-year old twigs; as explained below, twig- and trunk-borne flowers are parts of a single developmental continuum; twigs bearing flowers eventually becoming trunks and large branches that continue to bear flowers.


2013 Virginia Wildflower Of The Year: Redbud, Cercis Canadensis, W. John Hayden Jan 2013

2013 Virginia Wildflower Of The Year: Redbud, Cercis Canadensis, W. John Hayden

Biology Faculty Publications

Redbuds are small trees or shrubs that may attain heights of 10 m or so. Leaves are alternate and two-ranked, simple, entire, deciduous, broadly cordate, with an acute apex, 611 cm long, 712 cm wide, and palmately veined. Petioles have two swollen pulvini, one at its connection with the stem, the other at its junction with the leaf blade.


Partridge Berry: Simple Beauty Belies Complexity, W. John Hayden Mar 2012

Partridge Berry: Simple Beauty Belies Complexity, W. John Hayden

Biology Faculty Publications

Superficially, plants seem so simple. Rooted in place, they do not move around. And while plant growth is a dynamic process, without time-lapse photography, growth events are so imperceptibly slow that, to us impatient humans, plants seem both immobile and static. Nevertheless, there is a lot going on inside the plant body, and this is especially true for the events of reproduction that play out inside flowers and fruits. As one of my students recently commented, “I used to think it was just a matter of pollen plus stigma and, presto-change-o, seeds happen.” That student, I hope, learned otherwise, as ...


2012 Wildflower Of The Year: Partridge Berry, Mitchella Repens, W. John Hayden Jan 2012

2012 Wildflower Of The Year: Partridge Berry, Mitchella Repens, W. John Hayden

Biology Faculty Publications

Although partridge berry is a small and creeping herb, its jewel-like beauty rewards attentive naturalists year-round.


Diversifying Monoculture Crops By Incorporating Prairie Buffer Strips, Sarah Marie Hirsh Jan 2012

Diversifying Monoculture Crops By Incorporating Prairie Buffer Strips, Sarah Marie Hirsh

Graduate Theses and Dissertations

Monoculture crop production and prevailing farming practices have greatly reduced perennial plants on the landscape and nearly eliminated native Iowa prairie vegetation. The STRIPs (Science-based Trials of Row crops Integrated with Prairies) project is a watershed-scale experiment at the Neal Smith National Wildlife Refuge, in Jasper County, Iowa, US, in which strips of prairie vegetation were planted within watersheds of corn (Zea mays) and soybean (Glycine max) production to aid in soil and water conservation. The project includes 12 0.5- to 3.2-ha watersheds. Nine watersheds included buffer strips in one of three design treatments that varied the number ...


Exploring The Hydration Levels Of Malosma Laurina At Different Elevations On A Man-Made Trail, Eric S. Taylor, Brad J. Anderson, Brandon E. Stites Jan 2012

Exploring The Hydration Levels Of Malosma Laurina At Different Elevations On A Man-Made Trail, Eric S. Taylor, Brad J. Anderson, Brandon E. Stites

Featured Research

The purpose of this study is to examine the water potential of Malosma laurina at different elevations of a man made trail in the chapparal of the Santa Monica Mountains. Chaparral in the Santa Monica Mountains have been depleted because of human involvement effecting the chaparral ecosystem. Fire breaks and man made trails are a few of the major causes of the rapidly changing ecosystem and continues to cause stress among the plants. We are testing the effect that man made trails have on the water potential of Malosma laurina. This was measured by taking samples of Malosma laurina at ...


Stem Mechanical Strength In Thinned Versus Non-Thinned Ceanothus Spinosus, Ksp, David J. Kang, Hannah Y. Choe, Melinda L. Marchiano Jan 2012

Stem Mechanical Strength In Thinned Versus Non-Thinned Ceanothus Spinosus, Ksp, David J. Kang, Hannah Y. Choe, Melinda L. Marchiano

Featured Research

What effect does the thinning of chaparral around building structures have on plant health? More specifically, does the thinning of Ceanothus spinosus influence mechanical strength? The ability of our native chaparral to withstand environmental factors, such as the Santa Ana winds, and overall health is directly related to plant strength. Seeking to answer these questions, we hypothesized that a difference in water potential between thinned and non-thinned chaparral affects the stem mechanical strength of the plants.We believed that thinned C. spinosus due to greater hydration will be mechanically stronger than non-thinned chaparral.The knowledge of what helps chaparral to ...


The Differences In Vegetation Type On North And South-Facing Slopes, Andrew Villablanca, Katherine Mccabe, Daniel Galuhn Jan 2012

The Differences In Vegetation Type On North And South-Facing Slopes, Andrew Villablanca, Katherine Mccabe, Daniel Galuhn

Featured Research

Our project investigated the relationship between climate change and vegetation type conversion in the Santa Monica Mountains on north and south facing slopes. Our hypothesis is that with a shift in climate towards dryer, hotter, and longer summers, and shorter and dryer winters, we will see a shift in the density of native chaparral in the Santa Monica mountains, and possibly an influx of non-native species. We tested this hypothesis by choosing three study sites that were on north/south ridgelines to simulate a dryer, harsher climate (south) and a more temperate climate (north). Using the point-quarter method to measure ...


A Comparison Of Water Potential And Mechanical Strength Of Tip And Base Leaves In Heteromeles Arbutifolia, Aaron Tsai, James Maynard Jan 2012

A Comparison Of Water Potential And Mechanical Strength Of Tip And Base Leaves In Heteromeles Arbutifolia, Aaron Tsai, James Maynard

Featured Research

Heteromeles arbutifolia, commonly known as, Hollywood, is a plant that is extremely common in the California Chaparral ecosystem. It was observed that with Hollywood, the leaves grow on the tips of the branches predominantly. However, there are leaves that grow on the base of the branches that appear to be equally as healthy. The purpose of this investigation was to determine whether the leaves that grow at the tips of the branches or at the base of the branches were better suited to benefit the rest of the plant. Our hypothesis was that the leaves at the tips of the ...


Mechanical Strength And Hydration Level Of Heteromeles Arbutifola And Eriogonium Cinerium, Erin Hayes, Allison Naasz, Ariel Mangum Jan 2012

Mechanical Strength And Hydration Level Of Heteromeles Arbutifola And Eriogonium Cinerium, Erin Hayes, Allison Naasz, Ariel Mangum

Featured Research

The purpose of this study was to explore the hydration levels and mechanical strength of two species native to the same area: the dry Mediterranean region of the Santa Monica Mountains. The plants in this area must make adaptations to dry and arid climates, and We will compare how they stack up against each other in terms of drought resistance. Using Hollywood (heteromeles arbutifola) and Buckwheat (Eriogonium cinerium) we studied the different hydration levels and mechanical strengths and compared them. Both H. Arbutifola and the E. Cinerium are expected to mechanically stronger when hydrated.. We also expect the H. Arbutifola ...


The Effects Of Water Stress On Datura Wrightii, Tony Festa, Kristin Lapointe, Sara Tandon Jan 2012

The Effects Of Water Stress On Datura Wrightii, Tony Festa, Kristin Lapointe, Sara Tandon

Featured Research

The Santa Monica Mountains are home to a unique Mediterranean type ecosystem. Due to the effects of global warming and human disruption, the native species are beginning to decrease in population. It is imperative to observe and study the native species in order to preserve the local plant and animal life. This project focuses on the native flower Datura wrightii, specifically the causes of the opening and closing of its flowers. For Datura wrightii to be pollinated, it must be open. The results of this project will help to educate the public on how to sustain an environment in which ...


Oak Galls: A Strange Biology Indeed!, W. John Hayden Jul 2011

Oak Galls: A Strange Biology Indeed!, W. John Hayden

Biology Faculty Publications

Anyone who takes the time to look closely at several branches of oak will soon find one or another peculiar anomaly among the leaves and twigs. One can easily find structures resembling Ping-Pong balls, hard knots, fluffy tufts, horns—either single or clustered, or irregular thickenings, to mention just a few possibilities. These abnormal growths are galls, structures caused by the presence of small insect larvae living inside the tissue of the plant. Galls can be found on a wide variety of plants. They are common, for example, on the stems of goldenrods, and the leaves of maples, but oaks ...


Hybrid Oaks: Full Of Vexation And Wonder, W. John Hayden Mar 2011

Hybrid Oaks: Full Of Vexation And Wonder, W. John Hayden

Biology Faculty Publications

Distinguishing different species of oak in the forests of eastern North America can be challenging. For one thing, there are simply a lot of different species to sort out. A recent reference (Stein et al. 2003), describes 50 species in the genus Quercusoccurring naturally east of the 100th meridian, and 90 species are distinguished for all of North America north of Mexico (Nixon 1997). With so many species to parse, confident identification requires careful study of leaves, stem and leaf hairiness, and fully mature acorns with their caps. But care is not always enough, because in addition to the ...


2011 Wildflower Of The Year: White Oak, Quercus Alba, W. John Hayden Jan 2011

2011 Wildflower Of The Year: White Oak, Quercus Alba, W. John Hayden

Biology Faculty Publications

Emblematic of strength and longevity, white oaks grace the deciduous forests of eastern North America.


2010 Wildflower Of The Year: Wild Ginger, Asarum Canadense, W. John Hayden Jan 2010

2010 Wildflower Of The Year: Wild Ginger, Asarum Canadense, W. John Hayden

Biology Faculty Publications

Wild ginger is a low herbaceous plant. The stem consists of a branched creeping rhizome at or just below the soil surface. Soft-hairy leaves arise in pairs annually from rhizome branches. Petioles can be up to 20 cm long, elevating the 7—25 mm wide kidney-shaped leaf blades above the forest floor. Small flowers appear in the spring shortly after the leaves have expanded. Typically, one must push the leaves aside in order to glimpse the jug-like flowers. A single flower stalk appears between the paired leaf bases, but it is short and barely lifts the flower above the soil ...


Don't Judge A Book By Its Cover: The Curious Case Of Wild Ginger Pollination, W. John Hayden Jan 2010

Don't Judge A Book By Its Cover: The Curious Case Of Wild Ginger Pollination, W. John Hayden

Biology Faculty Publications

What pollinates wild ginger? This seems like an easy question. The inconspicuous little flowers are held close to the forest floor, often completely hidden by a dense canopy of ginger leaves above. Flower color is rather drab, dominated by brown and maroon hues. Wind pollination seems completely unlikely and flowers pollinated by bees, butterflies, moths, or hummingbirds are always much more showy and accessible to these flying creatures. Flies, however, given their natural inclination to seek carrion as a food source for their babies (i.e. maggots), are often attracted to brown and maroon flowers. And because their actual quarry ...


2009 Wildflower Of The Year: Skunk Cabbage, Symplocarpus Foetidus, W. John Hayden Jan 2009

2009 Wildflower Of The Year: Skunk Cabbage, Symplocarpus Foetidus, W. John Hayden

Biology Faculty Publications

Skunk cabbage is a coarse herbaceous plant. The stem consists of a stout rhizome oriented vertically in the soil. Leaves and flowers arise from the tip of the rhizome which is often not visible, resulting in the appearance of leaves and flowers arising directly from the swampy mires where these plants grow. Flowers appear during the winter, long before the leaves. The flowers are minute, clustered into a ball-like group (spadix) almost entirely enclosed by a fleshy, hood-like, spathe. The spathe ranges from 8 to 15 cm in height, is more or less pear-shaped, widest near the bottom, and tapers ...


2008 Wildflower Of The Year: Virginia Spiderwort, Tradescantia Virginiana, W. John Hayden Jan 2008

2008 Wildflower Of The Year: Virginia Spiderwort, Tradescantia Virginiana, W. John Hayden

Biology Faculty Publications

Spiderwort is an herbaceous perennial that arises from a cluster of rather stout overwintering roots. Stems may be solitary or more commonly clumped, and usually grow unbranched, reaching heights up to 40 cm tall. Stems are smooth or bear scattered short hairs. Leaves are 2—5 per stem, attached by means of a leaf sheath that is 13 cm long. Leaf blades are dull green, elongate, ending in a gradually tapered tip, flat or keeled, smooth (without hairs), and 1—3.5 dm long by 0.5—2.5 cm wide. Flowers occur in tight clusters located at the stem ...


2007 Wildflower Of The Year: Atamasco Lily, Zephyranthes Atamasca, W. John Hayden Jan 2007

2007 Wildflower Of The Year: Atamasco Lily, Zephyranthes Atamasca, W. John Hayden

Biology Faculty Publications

Atamasco lily is a perennial herb that grows from a subterranean bulb. The bulb is dark, with a short neck and papery tunic formed by remnants of old leaf bases. Leaves are glossy green, linear, flat to somewhat concave, up to one half inch wide, approximately one foot in length and, overall, rather grasslike. When not in flower the plants can be easily overlooked. Flowering stems are leafless scapes that are about as long as the leaves. In crosssection the scapes are hollow. Each scape terminates in a single flower. A few papery bracts subtend the flower stalk where it ...


2006 Wildflower Of The Year: Spicebush, Lindera Benzoin, W. John Hayden Jan 2006

2006 Wildflower Of The Year: Spicebush, Lindera Benzoin, W. John Hayden

Biology Faculty Publications

Spicebush is a multistemmed deciduous shrub that grows to a height of one to three meters. Young stems are delicate and may be smooth or finely hairy. Leaves are alternate and simple, with an elliptic to obovate blade that tapers at both the base and apex and is bounded by a smooth margin. Examined closely, the margin will reveal a series of fine hairs that project directly out from the leaf edge. In size, leaves are neither remarkably large nor small; they range from one to six inches in length and up to about two and a half inches wide ...


2005 Virginia Wildflower Of The Year: Bloodroot, Sanguinaria Canadensis, W. John Hayden Jan 2005

2005 Virginia Wildflower Of The Year: Bloodroot, Sanguinaria Canadensis, W. John Hayden

Biology Faculty Publications

Bloodroot is an herbaceous perennial that grows from a persistent, branched underground stem or rhizome. Early each spring, while the forest canopy is still bare, each well-developed rhizome tip produces one leaf and one flower stalk. The leaf is kidney-shaped in its overall outline, but it is also divided into a pattern of rounded lobes and sinuses, rendering a complex overall shape. At flowering time, bloodroot leaves form a loose vertically-oriented collar around the flower stalk with the bluish-green lower leaf surface forming the outside of the collar; as the season progresses, the leaves open flat and expand to their ...