Stephen E Williams

Lebanon Valley College · Department of Biology

Traps of Dionaea which have captured prey by a rapid closure mechanism continue to close with the lobes of the trap assuming a tightly appressed condition called the narrowed phase. Traps fed ants, which make up about one-third of the prey captured in the field, assumed the narrowed condition within about 7 h of feeding. Ants were alive and capable...

Voltage fluctuations identified as receptor potentials can be detected with electrodes applied to the mucilage surrounding the head of a tentacle of Drosera intermedia if the head is stimulated by contact with a live insect, by the touch of a clean, inert object, or by application of salt solutions. Associated with a low receptor potential are acti...

Molecular support for the monophyly of Droseraceae and its phylogenetic relationships to other dicot families was investigated using parsimony analysis of nucleotide sequences of the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL). Analysis of 100 species of plants including families of subclasses Rosidae, Hamamelidae, Dilleniidae, an...

Many descriptions of prey capture by Dionaea muscipula (Venus flytrap) in popular publications and educational literature are inaccurate. Here we review well documented literature on prey capture in this plant’s natural habitat and add observations on prey capture and attraction mechanisms we have observed in plants cultivated in a greenhouse and g...

The rapid closure of leaves in the Venus flytrap (Dionaea muscipula) involves irreversible cell enlargement, which can be initiated by acidifying the cell walls to pH 4.50 and below. Leaves infiltrated with neutral buffers that keep the pH above 4.50 to 4.75 will not close in response to stimulation of their trigger hairs even though the action pot...

Measurements in the field on dry days indicate that when the traps of Dionaea muscipula (Venus' flytraps) close, they capture prey about 40% of the time at one site and 44% at another. The 60% and 56% of traps that close but do not catch prey reach their maximum closure on average in about 10 minutes, begin reopening in about 7 hours and completely...

Dionaea muscipula traps, in a natural setting, are sometimes triggered to close without capturing prey. In the Florida panhandle, in dry weather, time-lapse photographs show the frequency of closure without capture to be 2.1 closures/% of active-traps/day. A sudden burst of intense rain can increase this by two to three orders of magnitude for a br...

Trail cameras can be used for the study of the interaction between plants and insects if they have a close-up lens and the capability of doing time-lapse photographs or videos. Typical trail cameras are mounted vertically, often on unstable camera stands. We have used the Bushnell NatureView HD Cam Model# 119740 and RC Williams Co. TopView Quick-Mo...

Dionaea flowers are pollinated by insects, primarily bees, in both their native habitat in the Carolinas and in the population growing from seed scattered many years ago in the Florida panhandle, the location of this study. The green sweat bee (Augochlorella sp. is a major pollinator in both habitats, while various flower visiting beetles play a pr...

Dionaea muscipula selectively allows small animals to escape using a system of interlocking features that complement each other very efficiently. Ants of the species Lasius neglectus (length 3.5 mm) ran through open traps, pausing on the alluring glands along the rim of the trap moving their mouthparts over them. Analysis of videos revealed the ant...

http://www.carnivorousplants.org/cpn/articles/ICPS2002confp77_81.pdf

Phylogenetic studies, using molecular characters indicate that Plumbago (Plumbaginaceae) is related to Drosera (Droseraceae) and Drosophyllum (Drosophyllaceae). Sepals of Plumbago auriculata Lamb. and Plumbago indicia L. bear large mucilage secreting trichomes, which resemble those of Drosophyllum. These trichomes are capable of capturing insects....

GC/MS analysis of methylene chloride extracts from leaf samples was used to analyze the distribution of napthoquinones in the Juglandaceae (Juglandales) and related orders of plants. The orders Fagales and Mericales were selected as related because traditional classification systems and a cladistic study of the gene rbcL from chloroplast DNA indica...

Molecular support for the monophyly of Droseraceae and its phylogenetic relationships to other dicot families was investigated using parsimony analysis of nucleotide sequences of the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL). Analysis of 100 species of plants including families of subclasses Rosidae, Hamamelidae, Dilleniidae, an...

L-Canavanine, a nonprotein amino acid found in many leguminous plants is related structurally to L-arginine. We cultured rat liver hepatocyte cells, introduced canavanine and found the amino acid to exhibit marked inhibition of cell propagation. At a concentration as low as 0.1mM, canavanine limited propagation, while at 50.0mM, cell growth was non...

http://www.carnivorousplants.org/cpn/articles/CPNv22n1_2p31_33.pdf

We present the results of two exploratory parsimony analyses of DNA sequences from 475 and 499 species of seed plants, respectively, representing all major taxonomic groups. The data are exclusively from the chloroplast gene rbcL, which codes for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO or RuBPCase). We used two...

The carnivorous habit in flowering plants represents a grade of structural organization. Different morphological features associated with the attraction, trapping, and digestion of prey characterize a diversity of specialized forms, including the familiar pitcher and flypaper traps. Phylogenetic analysis of nucleotide sequence data from the plastic...

On Mar 14, 2000 this sequence version replaced gi:454338.

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On Mar 14, 2000 this sequence version replaced gi:455012.

On Mar 14, 2000 this sequence version replaced gi:424048.

http://www.carnivorousplants.org/cpn/articles/CPNv21n3p46_51.pdf

http://www.carnivorousplants.org/cpn/articles/CPNv21n1_2p14_17.pdf

Cacao seeds killed by drying stress showed decreased amounts of phospholipid and declining levels of unsaturation in the polar lipid fraction compared with fresh seeds or seeds stored in polyethylene bags. The neutral lipid fraction was not affected by drying.

http://www.carnivorousplants.org/cpn/articles/CPNv09n3p65_75_78.pdf http://www.carnivorousplants.org/cpn/articles/CPNv09n4p91_100.pdf

The first demonstration of action potentials in plants was of those that control the rapid movements of the trap of the carnivorous plant Dionaea. The experiments in which physician John Burdon-Sanderson made this discovery were stimulated by conversations with Charles Darwin (1). As a result of these discussions, Darwin sent Burdon-Sanderson on Se...

Traps of Dionaea which have captured prey by a rapid closure mechanism continue to close with the lobes of the trap assuming a tightly appressed condition called the narrowed phase. Traps fed ants, which make up about one-third of the prey captured in the field, assumed the narrowed condition within about 7 h of feeding. Ants were alive and capable...

"Comparative Sensory Physiology of the Droseraceae" was read before the American Philosophical Society November 14, 1975 and published in the Proceedings June, 1976. It is a review paper with several original experiments. Despite its length it has no abstract. This belated summary of the paper by its author is intended to make up for that deficienc...

The neuroid action potentials ofDrosera rotundifolia recorded from single cells resemble those recorded from the surface of tentacle stalks. They have similar amplitudes and durations and they show the same variation of duration with interval that characterizes the extracellularly recorded action potentials. All living cells of the stalk appear to...

http://www.carnivorousplants.org/cpn/articles/CPNv04n4p64_65.pdf

http://www.carnivorousplants.org/cpn/articles/CPNv03n2p23_24.pdf

The extracellular space of tentacles of Drosera capensis L. is divided into two compartments by cuticular material between cells of an endodermoid layer and by the nonporous cuticle of the stalk and neck. The distal compartment includes the mucilaginous secretion as well as the free space of the secretory cap, since the cuticle covering the cap is...

http://www.carnivorousplants.org/cpn/articles/CPNv02n3p41_43.pdf

http://www.carnivorousplants.org/cpn/articles/CPNv02n2p23_25.pdf

Action potentials of Drosera tentacles resemble those of vertebrate peripheral nerves in that they appear to be comprised of relatively uniform spikes, variable shoulders or negative after-potentials, and variable positive after-potentials. The peaking of the spike corresponds to a period of great refractoriness, while action potentials of low ampl...

Dissertation (Ph. D.)--Washington Univ., 1971. Dept. of Biology. Includes bibliographies. 105 pp. Major: Professor Brbara G. Pickard Committee: Walter H. Lewis, J. Emil Morhardt

Canavanine is an arginine analogue found in the seeds of many common legumes and is known to inhibit protein synthesis and growth in a number of organisms. Yet canavanine may comprise as much as 4% of the seed dry weight of the jackbean (Canavalia ensiformis).Canavanine is accumulated during earlier development in the pod, but disappears upon ripen...

Studies on Canavanine Metabolism in Canavalia ensiformis L. DC. (Jackbean), 1966 A Thesis Presented to the Graduate Council of the University of Tennessee By Stephen E. Williams Major Professor: Gordon E. Hunt Committee members: JD Caponetti and RW Holton Summary This 1966, 62 page, MS Thesis includes information later published in SE Williams and...