Gymnocladus Dioicus Research Articles

Environmental quality assessment of soil as a component of green spaces in parks of the megalopolis

Intensive land degradation occurs under conditions of accelerated urbanization; it is strongly associated with the loss of soil natural capital, primarily animals, plant cover, and biological diversity in general. The creation and functioning of parks, in particular green spaces, in the urbanized areas is an effective mechanism for optimizing the ecological situation within the cities and preventing desertification. The soils of parks are an integral component of green infrastructure; they determine the conditions for the growth and development of both individual plants and green spaces as a whole. The soil buffering capacity actively participates in the mechanisms of implementation of the development and stabilization of soil fertility potentials. The buffering capacity determines the proportion of the soil potential that controls the processes of immobilization (deposition) and mobilization (release, loss) of a particular element of fertility: first of all, mineral nutrients for plant growth, productive moisture, thermal energy in soil, gas composition of soil air, and acidity. We collected soil samples beneath the crowns of trees growing in the territory of the Taras Shevchenko Central Culture and Leisure Park, as one of the largest parks in the city of Dnipro (Ukraine). The soil samples were collected in order to assess the soil acid-base (pH) buffering capacity (pHBC) and determine the direction of microbiological processes in urban soils of the park area afforested with stands from such introduced tree species as green ash (Fraxinus pennsylvanica), black locust (Robinia pseudoacacia), northern red oak (Quercus rubra), tree of heaven (Ailanthus altissima), Kentucky coffee tree (Gymnocladus dioica), and box elder (Acer negundo). The acid-base buffering capacity of the urban soil was determined using the Arrhenius method and estimated according to the buffering area within the acid-base range, calculated using the Simpson formula. Direction of microbial processes in the soil was determined according to the indexes of mineralization-immobilization, pedotrophicity, and oligotrophicity. The output was processed using statistical methods (arithmetic mean and standard deviation were calculated; the difference in the means was found according to the Tukey’s comparison test; interdependencies were determined by linear correlation). We have found significant, strong positive correlations between the pH level of urban soils in the rhizosphere area of the introduced species of park dendroflora and the buffering area within the acid and acid-base (total) range of external influence, as well as a strong negative correlation between pH and buffering area in the alkaline range of external influence. We identified weak mineralization signs according to the ratio of functional groups of microbiota in the studied sites forested with Fraxinus pennsylvanica and Acer negundo.

Suitability of a single imager multispectral sensor for tree health analysis

The objective of this project was to validate the efficacy of a miniature multispectral, single-sensor camera for detecting stress in deciduous juvenile tree foliage in a controlled environment. To that end, deciduous liners (one year old, nursery-grown transplants) representing five tree species (Celtis occidentalis L., Gleditsia triacanthos forma inermis Schneid, Gymnocladus dioicus (L.) K. Koch, Quercus rubra L., and Ulmus americana L.) were containerized and subsequently subjected to two treatments representing common landscape site stresses: drought and elevated soil pH. To minimize any atmospheric effects on reflectance values, the trees were placed in enclosed, artificially lit chambers during the detection process. The normalized difference vegetation index (NDVI) was utilized as the metric for analysis. Results showed the single imager sensor derived NDVI values were reliable indicators of tree stress within the species groups. Results also revealed that the derived values were not reliable indicators of tree stress across the species groups.

Identification of gluten-like proteins in selected pod bearing leguminous tree seeds.

The protein composition, molecular weight distribution, and rheological properties of honey locust, mesquite, Kentucky coffee tree, and carob seed germs were compared against wheat gluten. Polymeric and Osborne fractionation protocols were used to assess biochemical properties. Dynamic oscillatory shear tests were performed to evaluate protein functionality. All samples had similar ratios of protein fractions as well as high molecular weight disulfide linked proteins except for the Kentucky coffee tree germ proteins, which were found to have lower molecular weight proteins with little disulfide polymerization. Samples were rich in acidic and polar amino acids (glutamic acid and arginine,). Rheological analyses showed that vital wheat gluten had the most stable network, while Kentucky coffee seed proteins had the weakest. High molecular weight disulfide linked glutenous proteins are a common, but not universal feature of pod bearing leguminous trees.

Development of Root Architecture in Thirty-seven Tree Species of Field Grown Nursery Stock1

AbstractThe number and size of lateral roots of a tree seedling can be evaluated visually, and could potentially be used to select plants with better root systems early in nursery production. To evaluate how root architecture develops in young trees, root architecture of 37 species of trees was compared at two stages of development: as harvested seedlings, and then one year after replanting. The total number of lateral roots and the number of roots >2mm (0.08 in) diameter that were present on the portion of the taproot remaining on seedlings after standard root pruning were recorded. Neither could consistently predict the number of lateral roots on the root system one year after replanting. Development of roots (sum of diameters) regenerated from the cut end of the seedling taproot was equal or greater than lateral root development in 84 percent of evaluated species. Even when regenerated root development was significantly less than lateral root development, the regenerated roots still comprised up to 44 percent of the root system. Regenerated roots from the cut end of the taproot can become a major component of the architecture of the structural root system in nursery stock.Index words: structural roots, nursery production, root regeneration.Species used in this study: European black alder (Alnus glutinosa Gaertn.), green ash (Fraxinus pennsylvanica Marshall), quaking aspen (Populus tremuloides Michx.), European white birch. (Betula pendula Roth), river birch (Betula nigra L.), black locust (Robinia pseudoacacia L.), northern catalpa (Catalpa speciosa (Warder) Warder ex Engelm.), Mazzard cherry [Prunus avium [L.) L.], chokecherry (Prunus virginiana L.), American elm (Ulmus americana L.), Siberian elm (Ulmus pumilia L.), goldenchain tree (Laburnum anagyroides Medik.), northern hackberry (Celtis occidentalis L.), Cockspur hawthorn (Crateagus crus-galli L.), single seed hawthorn (Crateagus monogyna Jacq.), honeylocust (Gleditsia tricanthos L.), Japanese pagodatree [Sophora japonica (L.) Schott], Katsura tree (Cercidiphyllum japonicum Siebold & Zucc.), Kentucky coffee tree [Gymnocladus dioicus (L.) K. Koch], littleleaf linden (Tilia cordata Mill.), boxelder (Acer negundo L.), hedge maple (Acer campestre L.), Norway maple (Acer platanoides L.), red maple (Acer rubrum L.), silver maple (Acer saccharinum L.), sugar maple (Acer saccharum Marshall), sycamore maple (Acer pseudoplatanus L.), English Oak (Quercus robur L.), northern red oak (Quercus rubra L.), Siberian peashrub (Caragana arborescens Lam.), American plum (Prunus Americana Marshall ), Myrobalan plum (Prunus cerasifera Ehrh.), redbud (Cercis Canadensis L.), Russian olive (Elaeagnus angustifoliaI L.), tuliptree (Liriodendron tulipifera L.), black walnut (Juglans nigra L.), Japanese zelkova (Zelkova serrata (Thunb.) Makino).

Фітосанітарний стан зелених насаджень міста Херсон

Проаналізовано фітосанітарний стан зелених насаджень міста Херсон, багатий видовий склад дерев і кущів якого зумовили широкий спектр патогенних організмів та шкідників, що їх уражають. З'ясовано, що підвищення техногенного навантаження в урбанізованих екосистемах призвели до зниження життєздатності деревних рослин-едифікаторів Херсона. Встановлено, що патогенними організмами уражаються 45 видів досліджених деревних рослин міста. Виявлено, що найбільш вразливими до патогенних організмів є Acer negundo L., A. platanoides L., A. saccharinum L., Quercus robur L., Tilia cordata Mill., Aesculus hippocastanum L., Juglans regia L., Fraxinus excelsior L. За інтенсивністю пошкодження, яке впливає на життєвий стан рослин та їх декоративність, найбільш вразливими до дії фітопатогенів та ентомошкідників виявились Aesculus hippocastanum L., Buxus sempervirens L., Buxus sempervirens (Du Roi) Moench, Prunus divaricata Ledeb., Rosa canina L., Pinus pallasiana D. Don, Picea pungens Engelm., Juniperus virginiana L. З'ясовано, що низка дерев і кущів (Quercus rubra L., Betula pendula Roth, Betula pubescens Ehrh., Cotinus coggyria Scop., Sophora japonica L., Gymnocladus dioicus (L.) Koch, Mahonia aquifolium (Purh.) Nutt., Maclura acuminata L., Populus simonii Carr., Eucomia ulmoides Oliv., Albizia julibrissin Durazz, Symphoricarpos albus (L.) Blake, Ginkgo biloba L., Taxus baccata L.) є стійкими до дії шкідників та хвороб. Дослідження показали, що різні типи насаджень відрізняються за видовим складом патогенних організмів, а також за інтенсивністю пошкодження рослин-господарів. У паркових насадженнях частіше трапляються хвороби та шкідники листя або хвої деревних рослин. У вуличних насадженнях деревні рослини частіше пошкоджуються збудниками стовбурових і кореневих гнилей, листя рослин пошкоджуються американським білим метеликом та комахами-мінерами. Появі уражень та захворювань сприяють перестиглий вік насаджень, велике рекреаційне навантаження на зелені зони, а також відсутність регулярного кваліфікованого догляду за насадженнями. Тому на території дослідження рекомендовано проведення рубок формування та вибіркових санітарних рубок, а також регулярне та своєчасне здійснення агротехнічних заходів.

PECULIARITIES OF INTRODUCTION OF SMALL-WIDENED DECORATIVE TYPES IN THE CONDITIONS OF THE LADYZHYN DENDROPARK

The floristic analysis of the low-frequency ornamental species of the arboretum «Ladyzhyn Dendropark» was carried out, according to which the taxonomic composition and the description of the investigated species of the arboretum were determined. Based on the results of the integrated numerical assessment of the viability of trees and shrubs based on visual observations, the prospects for the introduction of woody plants in the study region were evaluated. The species composition of the introduced ornamental plants of the arboretum is systematized, which today is more than 25 species, arranged in accordance with the formed dendroplan. The peculiarities of the introduction of low-abundant ornamental plants were investigated, and the inventories of native and introduced arboreal and shrub vegetation of the areas of the arboretum were conducted. Based on these studies, a dendroplan was developed for a dendrological park of the local importance. The age and quantitative structure of the plantations has been determined, according to which 21 composite areas have been created in the studied area of more than 10 ha. In the course of research it is determined that 9 species of plants are quite promising (Catalpa speciosa Warder., Nyssa sylvatica Marsh, Gymnocladus dioicus (L.) K.Koch, Liriodendron tulipifera L., Magnolia kobus DC., Liquidambar styraciflua L., Malus sieboldii, Pseudotsuga menziesii (Mirb.) Franco, Ginkgo biloba L. Betula nigra L); promising – 10 species (Zelkova serrata (Thunb.) Makino, Stephanandra incisa (Thunb.) Zabel, Koelreuteria bipinnata Franch., Magnolia soulangeana Soul, Rhus typhina L., Catalpa bignonioides, Chamaecyparis pisifera (Siebold & Zucc.) Endl., Malus «Evereste», Malus domestica «Rajka», Diospyros virginiana L.), less promising – 5 species (Paulownia tomentosa (Thunb.) Steud., Cercis siliquastrum L., Magnolia George Henry Kern, Coffea liberica (W. Bull ex Hiern), Magnolia acuminata L.) The low adaptive index of the last 5 species is related to the inconsistency of the temperature regime in the study conditions. Inventory of the assortment of 20 shrubs and arboretum plants was made and a design decision was made to increase the species and form content of arboretum of section No. 21. The current state of compositions and flower beds of the arboretum was analyzed and recommendations for their improvement on the principle of selection and placement of species were presented. Keywords: dendropark, introduction, compositions, flower beds, integral evaluation, taxonomic composition, decorative properties, systematic principle, exotics.

Changes in Tree Root Architecture Resulting from Field Nursery Production Practices1

AbstractNursery production practices subject tree root systems to mechanical and environmental factors that are not imposed on plants regenerated naturally from seed. Architecture of undisturbed root systems of nine trees species commonly planted in urban landscapes was compared to root architecture of these tree species produced using common field nursery production practices. When young nursery production seedlings are root-pruned prior to replanting, the loss of the lower portion of the main root and lateral roots emerging from it, and initiation of adventitious roots from the cut end, alter the root system architecture. Nursery production plants have 7 to 48 percent fewer natural lateral roots that could develop into flare roots than undisturbed plants. New roots initiated from the cut end of the main root on nursery production plants can substitute for the loss of lateral roots, if accepted practices are followed. Root architecture of trees is established early. With minor exceptions attributed to the loss of small roots less than 1 mm diameter, there were no significant changes in the number of lateral roots over the 4 year period in both nursery production and undisturbed plants. This consistent number of roots also suggests that pruning the main root did not stimulate additional lateral roots above the pruning cut. Root architecture of liner stock produced in nurseries can be equivalent to undisturbed root systems.Index words: Structural roots, root pruning, bare root, root depth, taproot, root flare.Species used in this study: Norway maple (Acer platanoides L.); green ash (Fraxinus pennsylvanica Marsh.); littleleaf linden (Tilia cordata L.); red maple (Acer rubrum L.); European white birch (Betula pendula Roth.); Kentucky coffee tree (Gymnocladus dioicus L.); domestic apple (Malus spp.); red oak (Quercus rubra L.); Siberian elm (Ulmus pumila Jacq.).

Host‐plant range expansion to Gymnocladus dioica by an introduced seed predatory beetle Megabruchidius dorsalis

AbstractA seed predatory beetle, Megabruchidius dorsalis (Coleoptera: Chrysomelidae: Bruchinae) native to the Oriental region was first found to utilize a North American Gymnocladus dioica (Fabaceae: Caesalpinioideae) in its introduced area in Central Europe. A maximum of three adult exit holes were found on a single seed. Host‐plants of the bruchine beetle have been reviewed from its native and introduced regions, including a host record of Gleditsia fera from Taiwan. Our review indicated the beetle's strict oligophagy on caesalpinioid Gleditsia species. On the contrary, our finding suggests that the beetle's host‐range extends to the caesalpinioid Umtiza clade. On the plant side, this study provides a counterexample to the enemy release hypothesis that predicts fewer predators/parasites in an organism's range of introduction than in their native range; Gy. dioica is attacked by the seed predator in its introduced region, whereas in its native range it is free from seed predators.

Tree Seedling Root Architecture Alteration by Tap Root Pruning1

Abstract Nursery production of strong taprooted woody plants typically includes pruning to interrupt taproot development. To discern the impact this practice could have on seedling root architecture, we quantified changes to root architecture after taproot pruning and restriction separately in Catalpa (Catalpa speciosa) and Kentucky coffee tree (Gymnocladus dioicus). Taproot pruning resulted in a large and significant increase in the number of new, vertically oriented roots from the cut end of the primary root (regenerated taproots) in both species. Catalpa seedlings, which produced many strong laterals on unpruned taproots, showed greater reduction in lateral root number and size after taproot pruning than Kentucky coffee tree (with fewer and smaller natural lateral roots). The two species responded differently to restriction of the single, unpruned taproot by container depth (15, 30, 60 cm). For catalpa, with more shallow laterals naturally, the number of laterals was not significantly changed by restriction of the taproot by air pruning at any container depth, but lateral diameter was reduced by the 15 cm-deep container and biomass was reduced by the 30 cm-deep container, compared to the 60 cm-deep container. For Kentucky coffee tree with fewer natural laterals, restricting the taproot at 15 cm significantly increased the number and diameter of lateral roots compared to the 30 and 60 cm-deep containers, suggesting that restricting the taproot could increase the number of laterals in species that naturally produce fewer. Restricting multiple taproots on root-pruned plants generally did not affect lateral root development for either species, but this may have been due to the low number of lateral roots on those root systems. Index words: root architecture, nursery production, urban soils Species used in this study: Catalpa [Catalpa speciosa (Warder) Warder ex Engelm. ]; Kentucky coffee tree [Gymnocladus dioicus (L.) K. Koch]

Вікові дерева парків-пам’яток садово-паркового мистецтва Тернопільщини

Наведено дані щодо сучасного стану збереження вікових дерев та їх кількісної структури в парках-пам’ятках садово-паркового мистецтва Тернопільщини. Вікові дерева на об’єктах культурної спадщини представлені 30 видами та двома культиварами (Fagus sylvatica L.‘Atropunicea’ West. і Stypholobium japonicum Schott. ‘Pendula’), більшість з яких (24 види) відносяться до відділу покритонасінних. Вікові особини деревних інтродуцентів виявлено на території восьми парків (Більче-Золотецького, Заліщицького, Раївського, Скала-Подільського, Плотицького, Коропецького, Гримайлівського парків та в залишках парку в с. Млиниська).
 Впродовж інвентаризаційних досліджень здійснено комплексне оцінювання п’яти вікових дерев, які мають статус ботанічних пам’яток природи (вікові дерева, що мають вагоме культурне, історичне значення та повний заповідний режим) і ростуть у Раївському і Заліщицькому парках, охарактеризовано санітарний стан та визначено їхні таксаційно-біометричні показники. На зазначених об’єктах виявлено вікові дерева-інтродуценти Gymnocladus dioicus (L.) C. Koch віком 130 років та Sophora japonica L. віком 150 років, які можуть бути рекомендовані до заповідання як ботанічні пам’ятки природи місцевого значення.
 За результатами оцінки санітарного та естетичного стану визначних дерев запропоновано низку організаційних і технологічних заходів щодо їх лікування, збереження та раціонального використання (створення карти геопросторового розташування вікових дерев, здійснення організаційних заходів з метою зменшення рекреаційного навантаження в межах площі проекції крони, встановлення інформаційних іменних табличок, проведення лікувальних заходів щодо уражених хворобами вікових дерев за сучасними екологічно обґрунтованими технологіями, у т. ч. і методами арбористики).

Coordinated responses of plant hydraulic architecture with the reduction of stomatal conductance under elevated CO2 concentration.

Stomatal conductance (gs) generally decreases under elevated CO2 concentration (eCO2) and its sensitivity varies widely among species, yet the underlying mechanisms for these observed patterns are not totally clear. Understanding these underlying mechanisms, however, is critical for addressing problems regarding plant-environment interactions in a changing climate. We examined gs, water transport efficiency of different components along the whole-plant hydraulic system and allometric scaling in seedlings of six tree species grown under ambient and eCO2 treatments (400 and 600 ppm, respectively). Growth under eCO2 caused gs to decrease in all species but to highly variable extents, ranging from 13% (Populus tremuloides Michx.) to 46% (Gymnocladus dioicus (L.)). Accompanying this significant decrease in gs, substantial changes in plant hydraulic architecture occurred, with root hydraulic conductance expressed both on leaf area and root mass bases overall exhibiting significant decreases, while stem and leaf hydraulic efficiency either increased or showed no consistent pattern of change. Moreover, significant changes in allometry in response to eCO2 affected the whole-plant water supply and demand relations. The interspecific variation in gs response among species was not correlated with relative changes in stem and leaf hydraulic conductance but was most strongly correlated with the relative change in the allometric scaling between roots and leaves, and to a lesser extent with the intrinsic root hydraulic conductance of the species. The results underscore that allometric adjustments between root and leaf play a key role in determining the interspecific sensitivity of gs responses to eCO2. Plant hydraulics and their associated allometric scaling are important changes accompanying gs responses to eCO2 and may play important roles in mediating the interspecific variations of leaf gas exchange responses, which suggests that mechanistic investigations regarding plant responses to eCO2 need to integrate characteristics of hydraulics and allometric scaling in the future.

Exploring the Native Range of Kentucky Coffeetree

Exploring the Native Range of Kentucky Coffeetree

Characteristics of subspontaneous dispersal of Kentucky coffetree (Gymnocladus dioicus (L). K. Koch)in Topcider

The paper presents the occurrence of subspontaneous dispersal of Kentucky coffeetree in the park-forest which is a part of a protected natural area "Topciderski park" in Belgrade. In 1949, three trees of Kentucky coffeetree not older than 85 years were recorded. In 2016, one sexually reproductive tree was recorded in Topcider which is assumed to be one of the three "mother" trees recorded in 1949. The diameter at breast height is 94.6 cm and the height of the tree is 24.1 m. During the past seven decades, the Kentucky coffeetree regenerated successfully from seed and root suckers in the area that was under anthropogenic influence and was left to succession, but the Kentucky coffeetree has not shown invasiveness. In the area of subspontaneous dispersal of Kentucky coffeetree (0.25 ha), all the trees that had diameter at breast height 1.0 cm and more were measured. Fourteen tree and shrub species were identified with a total of 624 trees and Kentucky coffeetree was the most represented species with 326 trees (52.2%). In the subspontaneous regenerated group of Kentucky coffeetree, the diameter at breast height of the thickest tree is 48.2 cm and the highest tree is 25.5 m tall. The diameter structure of Kentucky coffeetree trees shows the declining distribution. Compared to the habitus of "mother" tree, that has a slenderness of 25, the habitus of the dominant and codominant trees in the subspontaneous regenereted group of Kentucky coffeetree is characterized by slenderness of 75-110 that is characteristic of the trees grown in the stand closure.

Dendroflora parku zamkowego w Uniejowie – stan obecny i zmiany

The castle park in Uniejów was founded between 1860 and 1870. Today it has an area of 32 ha and 151 taxa of trees and shrubs, which consist of 101 native and non-native species of trees andbushes and 50 cultivated varieties. Owing to the natural character of trees found in most of the park area its dendroflora mainly consists of native species, of which Quercus robur, Fraxinus excelsior, Ulmus laevis and Fagus sylvatica stand out because of their size. The most valuable taxa include Gymnocladus dioicus, Juglans nigra, Quercus macranthera, Taxodium distichum ans Platanus x hispanica. In the past there were some tree species which are not found in the park today, such as Corylus colurna, Malus prunifolia, Populus nigra ‘Italica’, or Tilia platyphyllos ‘Laciniata’. In the years 2013−2014, 62 taxa were added to the park dendroflora. They mainly consist of cultivated species of shrubs, mostly colourful varieties of Rhododendron. The revitalisation of the castle park that is now under way is aimed at preservation of its natural landscape, especially in its northern part that is covered by forest.

Sequences of epicuticular wax structures along stems in four selected tree species

Abstract Wax layer formation accompanies the processes of epidermis and cuticle formation. To examine these changes, observationsalong current-year long shoots of four woody species (Acer negundo, A. rufinerve, Gymnocladus dioica, and Gingko biloba) were made. Long shoots are suitable objects for such observations, because from the same stem, several samples can be obtained that represent a well-defined sequence of fragments of different ages. The data that were obtained from different and sometimes distant stem regions suggest that epicuticular wax crystals appear on the stems very early and quickly, since they are found near the stem apex during intensive plant growth. This was confirmed for the four examined species. Some differences, however, were noted. Very rapid production of prominent wax crystals was observed in stems. In an experiment involving mechanical wax removal from the A. negundo stem surface and subsequent analysis of the surface after several days via scanning electron microscopy (SEM), it was shown that wax regenerates very quickly. After only several hours, new emerging crystals were observed and their morphologies were essentially the same. Nearly full regeneration was observed several days after removal.

Tree Growth and Resilience to Extreme Drought Across an Urban Land-use Gradient

Understanding the response of urban forests to extreme climatic events, such as drought, will be essential to predicting impacts of climate change on the urban tree canopy and related ecosystem services. This study evaluated variation in tree growth and drought resistance (growth during drought) and resilience (growth in period following drought) across four land-use categories (built, transportation, park, and semi-natural forest) and four species (Acer saccharum, Gymnocladus dioicus, Liriodendron tulipifera, and Pinus strobus) at The Morton Arboretum in suburban Lisle, Illinois, U.S. Tree growth and resistance to drought both varied as an interaction between landuse and species (F15, 100 = 5.25, p < 0.001; F15, 100 = 2.42, p = 0.005). Resilience of tree growth to extreme drought was generally high and did not vary across species and land-uses. In this study, individual tree species responses to drought varied across land-uses, illustrating the difficulty of predicting the reaction of urban forests to projected increases in the frequency of extreme climatic events. Tree growth response to drought varied even across the relatively narrow range of growing conditions studied here. Investigation of a broader range of sites, encompassing the full urban forest continuum, would likely demonstrate even greater variation in tree response to extreme climatic events.

ChemInform Abstract: Dioicine: A Novel Prenylated Purine Alkaloid from Gymnocladus dioicus

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The anomalous Kentucky coffeetree: megafaunal fruit sinking to extinction?

The Kentucky coffeetree (Gymnocladus dioicus, Fabaceae) is an ecological paradox. A rare tree in nature in eastern and central North America, G. dioicus produces legumes that are only known to be dispersed by water, but appear similar to fruits consumed and dispersed by elephants and rhinoceros. One would expect the pods to be consumed by livestock, but the pulp and seeds are toxic to cattle and sheep. We examine the puzzle of G. dioicus dispersal in light of its other reproductive and life history characteristics and find that it probably is a botanical anachronism, in terms of both a set of dispersal agents long extinct and habitats, including what we term megafaunal disclimaxes, which have disappeared. Large seeds, the megafaunal gestault of the fruit, a dioecious mating system, and shade-intolerance combined with vigorous cloning suggest a widely dispersed pioneer of Miocene through Pleistocene habitats profoundly altered by large-mammal herbivory. As to what ate it, we can only say there were once many candidates. We hypothesize that the plant is an ecological anachronism, sinking to extinction in the wild.

Dioicine: A Novel Prenylated Purine Alkaloid from Gymnocladus dioicus

- The Kentucky coffeetree, Gymnocladus dioicus (L., K. Koch) is a leguminous tree reputed to be toxic to livestock and to contain the toxic nicotinic acetylcholine receptor agonist cytisine. Analysis of extracts of various tree parts by gas chromatography-mass spectrometry failed to reveal the presence of cytisine. Neither [ 3 H]-epibatidine binding in rat cerebral cortex nor functional fluorescence assays in cultured cells expressing nicotinic receptor subunits indicated significant activity. However, a novel purine alkaloid, 3-((E)-3-methylbuta-1,3-dienyl)-1,7-dimethylisoguanine, which we have named dioicine, was identified as the major lipophilic alkaloid in the methanolic extract from leaves and seeds. Dioicine and its hydrolysis products are likely to be responsible for the historical use of the tree's seeds as a coffee substitute. Herein we describe the isolation, structure elucidation and preliminary biological characterization of dioicine.

Amending a Gravel Based Growing Medium with Calcined Clay Improves Physical Properties and Seedling Growth

Abstract The Missouri Gravel Bed (MGB) is a system that uses pea gravel with 10% sand (v/v) as a root growth medium, allowing plants to be removed from the gravel and planted, bare root, during the growing season. However, the low water holding capacity of the medium necessitates frequent irrigation. This study was conducted to determine the effects of amending pea gravel with calcined clay (Terra-Green®) on the physical properties of the medium and on growth of Gymnocladus dioicus (L.) K. Koch seedlings. Adding 10% sand (v/v) increased water holding capacity of the medium slightly at water tensions above 1 kPa. Gravel amended with 40% calcined clay had 16% air-filled porosity and had 3.5 times more plant available water than gravel with sand only. Dry weights of seedlings grown in gravel amended with 40% calcined clay and no sand were over twice as great as those of seedlings grown in the standard MGB medium.