Justus Liebig and the Plant Physiologists

In his book Organic Chemistryin its Application to Agriculture andChemistry, Justus Liebig attacked ``the plantphysiologists' for their support of the humustheory and for their general ignorance ofchemistry. Two leading botanists, MatthiasSchleiden and Hugo von Mohl, responded bysharply criticizing Liebig for his lack ofknowledge of plants and his misrepresentationof the views of plant physiologists. The originand character of this debate can be understoodin part through the temperaments of Liebig andSchleiden, but can be viewed also as a contestfor control between the well-establisheddiscipline of chemistry and a potentialdiscipline of plant physiology that had as yetacquired no stable institutional foundations.     

Reginald Cory, Benefactor of Cambridge University Botanic Garden

Summary.  Reginald Cory (1871–1934) had a lifelong passion for plants and gardens and gave generously in support of many horticultural causes and establishments including Cambridge University Botanic Garden and the Royal Horticultural Society. On his death he left the residue of his estate to the Garden, its largest ever benefaction. Cory's relationship with the Garden is described, and the impact and subsequent use of the donation, which continues to be vital to the Garden's work today is considered.     

Alien species reflecting history: medieval castles in Germany

Ninety‐seven alien plant species were found in habitats provided by rocks and walls around 56 castles in Germany. Compared to Central European agriophytes (i.e. alien species naturalised in natural vegetation), the flora adjacent to castles had more species introduced before 1500. More alien species introduced earlier were found at castles built earlier compared to castles built later. Fifty percent of the species introduced before and during the Middle Ages were usable plants at that time, compared to 20% of usable plants among the native species in the same habitats. Species introduced earlier were mainly used for medication and nutrition, whereas later introductions were used for ornamental purposes. Compared to the total alien flora of Germany, there were more useable species at the castles, nearly the same percentage of ornamentals and fewer plants without use. These results imply that the species composition of alien species growing in the vicinity of medieval castles today may be traced back to the historical reasons for their introduction to these places.     

THE BIOLOGY OF THYSANOPTERA WITH REFERENCE TO THE COTTON PLANT

Investigations were made of the degree of infestation of plants grown in light soil and in clay soil sown at different dates. The plants sown late in the season in light soil were more affected by the thrips, the infestation being relatively high almost from the germination of the plant and causing death before the flowering stage was reached. On the blocks of plants in light soil sown earlier in the year the infestation was relatively low for a considerable period, and although, at the end of the season, the thrips became very numerous on these plants it was not until after the bolls had been formed, and in this case the practical damage was small.
The plants sown in clay soil at different dates did not show such a marked difference in the degree of infestation, and all were less infested by the insects than the corresponding blocks of plants in light soil. This corroborates the findings of previous experiments, namely, that plants grown in light soil are found to be more heavily infested by T. tabaci than plants grown under similar conditions in clay soil.
I should like to take this opportunity of thanking Prof. Dunkerly for his helpful criticism, Miss R. M. Smith and Mr I. Thomas for their assistance in making the counts, and Mr R. Stewart for his analysis of the soils used.     

Lorenz Hiltner, a pioneer in rhizosphere microbial ecology and soil bacteriology research

Lorenz Hiltner is recognized as the first scientist to coin the term “rhizosphere” in 1904. His scientific career and achievements are summarized in this essay. Most of his research he performed in the Bavarian Agriculture–Botanical Institute (later named the “Bavarian Institute of Plant Growth and Plant Protection”) in Munich, where he was the director from 1902 to 1923. Beginning with intensive and thorough investigations on the germination and growth of different crop plants (legumes and non-legumes) Hiltner became convinced, that root exudates of different plants support the development of different bacterial communities. His definition of the “rhizosphere” in the year 1904 centered on the idea, that plant nutrition is considerably influenced by the microbial composition of the rhizosphere. Hiltner observed bacterial cells even inside the rhizodermis of healthy roots. In analogy with fungal root symbionts, Hiltner named the bacterial community that is closely associated with roots “bacteriorhiza.” In his rhizosphere concept, Hiltner also envisioned, that beneficial bacteria are not only attracted by the root exudates but that there are also “uninvited guests,” that adjust to the specific root exudates. Based on his observations he hypothesized that “the resistance of plants towards pathogenesis is dependent on the composition of the rhizosphere microflora.” He even had the idea, that the quality of plant products may be dependent on the composition of the root microflora. In addition to his scientific achievements, Hiltner was very dedicated to applied work. Together with F. Nobbe he had the first patent on Rhizobium inoculants (Nitragin). He continuously improved formulations and the effectivity of the Rhizobium preparations and he also initiated seed dressing with sublimate for plant protection of seedlings. Thus, Hiltner tightly linked breakthroughs in basic research to improved rhizosphere management practices. In addition, he wrote a pioneering monograph on plant protection for everybody’s practical use. His emphasis on understanding microbes in the context of their micro-habitat, the rhizosphere, made him a pioneer in microbial ecology. Even now, in the era of genome and postgenome analysis with our better understanding of plant nutrition and soil bacteriology, his ideas and contributions are as fresh as they were more than 100 years ago.     

Flora was His Interest and Prime Course of Study: A Botanical Career for W.E. Ricker Disappears

Synopsis Bill Ricker’s career went through many twists in his academic years. He had taken botany in his senior matriculation year at high school and he had collected over 100 species of flora before commencement of university life. At the conclusion of his first university year, he set out over the summer to collect a much larger sample of species, primarily from the Great Lakes-St. Lawrence ecoregion, to fulfil a requirement for a second year botany course (spermatophytes). He identified about 390 species, and some 254 were collected and pooled with those from previous years to make a final submission of 354 spermatophyte species. Field plant identification continued in each academic year thereafter, in concert with collections and identifications of aquatic invertebrates in his summer projects while under the employment of the Ontario Fisheries Research Laboratory. At the conclusion of his undergraduate years, Bill had taken more courses in botany than in zoology, and it was the summer employment that had really prepared him for postgraduate work in fisheries biology, which was ecologically oriented. When Bill left Ontario in the autumn of 1931 he had identified over 600 species of plants, excluding lower cryptogams, but including many aquatic species of higher plants. In western North America Bill’s botanical career began at Cultus Lake in 1931. He again studied all aspects of the basin while employed with the federal government, and from the work he assembled a Ph.D. thesis. At the time of thesis completion he had identified over 300 species of flora, including alpine plants at timberline, 1500 – 1800 m above lake level, and planktonic algae in its water column. In 1939, after more field fisheries work in the Fraser River basin of British Columbia, Bill accepted a position with the biological staff at Indiana University. In this period which concluded in 1950 he identified another 50 – 110 species of flora, all in the Carolinian ecoregion, and hitherto not seen by him. Considering all floral classes, Bill’s eastern North American repertoire had by then added up to 791 species, representative of more than 112 families of plants. Returning west for the remainder of his life, new identifications elsewhere added to his Cultus Lake list which slowly added up to about 1000 species for the west coastal region of North America. Flora was also identified elsewhere in the mid-continental region of North America, in Eurasia where the Abisko region of Lappland was a highlight, and in South America and New Zealand. Records of his botanical prowess, were kept primarily in his diaries, which began in 1923 and were maintained consistently to the end of 1934, and thereafter intermittently to 1949. The diaries reveal that his career as a budding botanist was subtly hijacked by a wily Professor W.H.K. Harkness in the rival Biology Department who out-manoeuvred Drs. R.B. Thompson and R.A. Sifton in the Botany Department. The former always managed to employ Bill in summer and keep him occupied in the department’s labs during the autumn and winter and spring, tying up any free time when the botanist had approached him on lab work. Certainly, the botany courses taken and which he excelled at were more appropriate for his aquatic ecological pursuits. Salesmanship won the day for the zoologists, but Bill was a life-long botanist regardless of whatever else he studied or managed throughout his professional career. The last days of his life had a botanical conclusion.     

Mendel's experiments: A reinterpretation

Conclusion My conclusion is that Mendel deliberately, though without any real falsification, tried to suggest to his audience and readers an unlikely and substantially wrong reconstruction of the first and most important phase of his research. In my book I offer many reasons for this strange and surprising behavior,⁵³ but the main argument rests on the fact of linkage. Mendelian genetics cannot account for linkage because it was based on the idea of applying probability theory to the problem of species evolution. Central to the theory is the law of probability according to which the chance occurrence of a combination of independent events is the product of their separate probabilities. This is the common basis of Mendel's first and second laws, but this is why Mendel's second law on independent assortment is enunciated in too general a way. From Morgan's work we now know that characters may not always be independent if their genes are located very close one to the other on the same chromosome. And this was also the basis of Mendel's personal drama: he surely observed the effects of linkage, but he had no theoretical tools with which to explain it. So he presented his results in a logical structure consistent with the central idea of his theory. Had he described the real course of his experiments he would have had to admit that his law worked for only a few of the hundreds of Pisum characters — and it would thus have been considered more of an exception than a rule. This is why he insisted on the necessity of testing the law on other plants, and this is why in his second letter to Carl Nägeli he admits that the publication of his data was untimely and dangerous.⁵⁴.We can argue that already in 1866 Mendel was less confident that his so-called second law had the same general validity as the first — and that later he lost his confidence altogether. Contemporary testimony indicates that in the end he became as skeptical as all his contemporaries as to the scientific relevance of his theory.⁵⁵ But he was wrong. His research is in no way the fruit of methodological mistakes or forgery, and it remains a landmark in the history of science. He was only the victim of a strange destiny in which the use of probability theory was responsible, at the same time, for the strength and for the weakness of his theory. We must still consider him the father and founder of genetics.     

Symbolic plant(s) of the Olympic Games

The victors of the Olympic Games in ancient Greece were awarded crowns made of olive branches. In Antiquity, the symbolism of plants was related to myths, properties, aesthetic values, and civilization. Theophrastus first classifies and identifies plants, and gathers information about them, in his classic books (4th century BC). Symbolic plants are native to the Mediterranean region and they exhibit some convergent behaviour with respect to their functional characteristics. These plants were collected (among other species) by Professor J. Sibthorp and his partners in two botanical journeys in the Levant during the 18th century, and they have been illustrated for Flora Graeca Sibthorpiana.     

Perspective: Evolution of flower color in the desert annual Linanthus parryae: Wright revisited

Linanthus parryae, a diminutive desert annual with white or blue flowers, has been the focus of a long-standing debate among evolutionary biologists. At issue is whether the flower color polymorphism in this species is the product of random genetic drift, as Sewall Wright argued, or of natural selection, as proposed by Carl Epling and his colleagues. Our long-term studies of three polymorphic populations in the Mojave Desert demonstrate that flower color is subject to selection that varies in both time and space in its direction and magnitude. For all sites taken together, blue-flowered plants produced more seeds than white-flowered plants in years of relatively low seed production, whereas white-flowered plants had higher fitness in years of high seed production. Evidence of selection on flower color was found in two of the three study sites. Differences in fitness between the color morphs were sometimes large, with selection coefficients as high as 0.60 in some years. Our longest period of observations was at Pearblossom site 1, where plants reached appreciable densities in seven of the 11 years of study. Here we found significant differences in the seed production of the color morphs in six years, with three years of blue advantage and three years of white advantage. For all sites taken together, total spring precipitation (March and April) was positively correlated with both absolute and relative seed production of the color morphs. At Pearblossom site 1, blue-flowered plants typically had a fitness advantage in years of low spring precipitation, whereas white-flowered plants had a fitness advantage in years of high spring precipitation. This temporal variation in selection may contribute to the maintenance of the flower-color polymorphism at Pearblossom site 1, whereas gene flow from neighboring populations is proposed as the principal factor maintaining the polymorphism at the other study sites. We found no significant differences between the color morphs in pollinator visitation rate or in their carbon isotope ratio, a measure of water-use efficiency. Although the mechanism of selection remains elusive, our results refute Wright's conclusion that the flower color polymorphism in L. parryae is an example of isolation by distance, a key component of his shifting balance theory of evolution.     

Tolerance to manganese toxicity among cultivars of lucerne (Medicago sativa L.)

Two sand culture experiments were carried out to identify commercial cultivars of lucerne or alfalfa (Medicago sativa L.) which contain elite, Mn-tolerant plants for use in a selection programme to increase the acid-soil tolerance of this perennial legume. Differences in Mn tolerance, both within and between cultivars, were observed when a range of cultivars were exposed to regular waterings with dilute nutrient solution containing 20 or 25 mg Mn L^–1. Under these moderately toxic regimes, the winter dormant cultivars Cimmaron and WL 318 were found to contain elite plants that had greater dry matter yields than their mean cultivar yield under non-toxic Mn conditions.Cultivars which contained elite, Mn-tolerant plants could not be identified by phenotypic characteristics such as their height or their toxicity symptom score, nor by their winter dormancy class. Possible reasons for the occurrence of elite plants in these cultivars are discussed. The elite, high yielding Mn-tolerant plants could not be identified from the other plants within their cultivar population by their Mn toxicity symptoms nor by their height.     

Herbivore-induced plant volatiles mediate host selection by a root herbivore

In response to herbivore attack, plants mobilize chemical defenses and release distinct bouquets of volatiles. Aboveground herbivores are known to use changes in leaf volatile patterns to make foraging decisions, but it remains unclear whether belowground herbivores also use volatiles to select suitable host plants. We therefore investigated how above- and belowground infestation affects the performance of the root feeder Diabrotica virgifera virgifera, and whether the larvae of this specialized beetle are able to use volatile cues to assess from a distance whether a potential host plant is already under herbivore attack. Diabrotica virgifera larvae showed stronger growth on roots previously attacked by conspecific larvae, but performed more poorly on roots of plants whose leaves had been attacked by larvae of the moth Spodoptera littoralis. Fittingly, D. virgifera larvae were attracted to plants that were infested with conspecifics, whereas they avoided plants that were attacked by S. littoralis. We identified (E)-β-caryophyllene, which is induced by D. virgifera, and ethylene, which is suppressed by S. littoralis, as two signals used by D. virgifera larvae to locate plants that are most suitable for their development. Our study demonstrates that soil-dwelling insects can use herbivore-induced changes in root volatile emissions to identify suitable host plants.     

Rank and sequence in Caspar Bauhin's Pinax

CAIN, A. J., 1994. Rank and sequence in Caspar Bauhin's Pinax. Bauhin's consistent use of genera, species and binominals, applauded by historians as anticipating Linnaeus's theory and practice, does not appear on closer examination to be intended as anything of the sort. His use of the terms genus and species is as in Aristotelian logic, with a shifting reference, at all taxonomic levels. His typographical layout, emphasizing (but far from invariably employing) single-word names for effectively generic entities, often qualified by ‘and its species’, gives the impression of Linnaean practice, and coincides with it not infrequently, but not with Linnaean theory. The main entities for which it can be said that Bauhin uses fairly consistently a biverbal binominal name-phrase, like Linnaeus' trivial names, were in fact in Linnaeus's eyes two levels of supraspecific groupings. The main entities in Bauhin which Linnaeus recognized as species, as is shown by his quotations in the Species plantarum, are subdivisions of his biverbally or nearly biverbally named groupings, but themselves have multiverbal names. These correspond closely to Linnaeus's diagnostic specific names, not at all to his biverbal trivial names. Bauhin probably had no conception of the species and genus as ranks in the modern sense, first adumbrated by Tournefort and utilized by Linnaeus. Bauhin certainly tried to group forms by natural affinity, as did Theophrastus before him and Linnaeus afterwards. Not being alerted to the importance of the details of the flower and fruit, he used what characters he could find, notably, but not by any means exclusively, leaf shape. He composed the Pinax as a nomenclatural concordance to earlier authors, notably Dioscorides, Theophrastus and Pliny. He retained the sequence of major groups of Theophrastus (as the greatest authority on plants) but reversed it to start with the best-known plants, grasses. Where Theophrastus gave no help, in the cryptogams, Bauhin inserted as a pendant his own series from ferns down to fungi, using the Aristotelian principles of the gradation of forms. His overall arrangement, therefore, is not a simple progression but a chain with pendants. Bauhin is far closer to earlier authors than to Linnaeus, but his typography, along with other authors, may well have helped to incite Linnaeus to a more rigorous and consistent use of ranked groups and biverbal names.     

Huron Smith's ethnobotany of the Hocąk (Winnebago)

The Hocak, commonly known as the Winnebago, are one of the original tribes in the present state of Wisconsin. The field notes of Huron Smith, compiled in the late 1920s and early 1930s, document the extensive use of plant materials by Hocak people. Smith's notes contain references to 199 vascular plant species in 74 families, with recorded uses for 153 of these species. Medicinal plants (with 117 species) comprise the largest category, followed by food (37 species), and fiber and material uses (22 species). Smith's work is unique for its time because he thoroughly explored the tribal uses of the plants in addition to collecting voucher specimens and photographic plates, and because it remains the most extensive Hocąk ethnobotanical study. Added to Smith's other works of tribes in Wisconsin (Menominee, Meskwaki, Ojibwe, and Potawatomi), the Hocak ethnobotany broadens the cultural base of his regional compilation of Native North American plant uses. In addition, this is an important body of information for the Hocąk people and those interested in their use of plants.     

The meaning of Darwin's 'abominable mystery'

Charles Darwin's "abominable mystery" has come to symbolize just about all aspects of the origin and early evolution of flowering plants. Yet, there has never been an analysis of precisely what Darwin thought was so abominably mysterious. Here I explicate Darwin's thoughts and frustrations with the fossil record of flowering plants as revealed in correspondence with Joseph Hooker, Gaston de Saporta, and Oswald Heer between 1875 and 1881. I also examine the essay by John Ball that prompted Darwin to write his "abominable mystery" letter to Hooker in July of 1879. Contrary to what is generally believed, Darwin's abominable mystery has little if anything to do with the fossil prehistory of angiosperms, identification of the closest relatives of flowering plants, questions of the homologies (and character transformations) of defining features of flowering plants, or the phylogeny of flowering plants themselves. Darwin's abominable mystery and his abiding interest in the radiation of angiosperms were never driven primarily by a need to understand the literal text of the evolutionary history of flowering plants. Rather, Darwin was deeply bothered by what he perceived to be an abrupt origin and highly accelerated rate of diversification of flowering plants in the mid-Cretaceous. This led Darwin to create speculative arguments for a long, gradual, and undiscovered pre-Cretaceous history of flowering plants on a lost island or continent. Darwin also took refuge in the possibility that a rapid diversification of flowering plants in the mid-Cretaceous might, if real, have a biological explanation involving coevolutionary interactions between pollinating insects and angiosperms. Nevertheless, although generations of plant biologists have seized upon Darwin's abominable mystery as a metaphor for their struggle to understand angiosperm history, the evidence strongly suggests that the abominable mystery is not about angiosperms per se. On the contrary, Darwin's abominable mystery is about his abhorrence that evolution could be both rapid and potentially even saltational. Throughout the last years of his life, it just so happens that flowering plants, among all groups of organisms, presented Darwin with the most extreme exception to his strongly held notion natura non facit saltum, nature does not make a leap.     

Aromatic plants in nests of the blue tit <Emphasis Type="Italic">Cyanistes caeruleus</Emphasis> protect chicks from bacteria

Several bird species add fresh fragments of plants which are rich in volatile secondary compounds to their nests. It has been suggested, although never tested, that birds use fresh plants to limit the growth of nest microorganisms. On Corsica, blue tits (Cyanistes caeruleus) incorporate fresh fragments of aromatic plants into their nests. These plants do not reduce infestation by nest ectoparasites, but have been shown to improve growth and condition of chicks at fledging. To understand the mechanisms underlying such benefits, we experimentally tested the effects of these plants on the bacteria living on blue tits. Aromatic plants significantly affected the structure of bacterial communities, in particular reducing bacterial richness on nestlings. In addition, in this population where there is a strong association between bacterial density and infestation by blood-sucking Protocalliphora blow fly larvae, these plants reduced bacterial density on the most infested chicks. Aromatic plants had no significant effect on the bacteria living on adult blue tits. This study provides the first evidence that fresh plants brought to the nests by adult birds limit bacterial richness and density on their chicks.     

Re-reading Ronald Berndt: Exploring the Depths of his Yolngu Ethnography

The title of this essay sets its dialogic structure. Ronald Berndt's writing at times obscured the core insights that he had about Yolngu society, and partly as a consequence Australian anthropology has not yet made the best use of the immense richness of his ethnographic legacy. In retrospect, in many areas of their research the Berndts were pioneers addressing themes and topics that had been for too long ignored. They opened up new fields of study and redressed some of the imbalances associated with functionalism, the dominant paradigm of their early years as anthropologists. In this essay I examine two areas of Ronald Berndt's writings in which he had insights that were not fully appreciated at the time: the analysis of Yolngu social organisation and the analysis of Yolngu sexual symbolism. In both cases, his absorption in Yolngu ethnography made him aware that his predecessors had overlooked important themes of Yolngu society, yet in both cases his analysis was less convincing than it might have been.     

Plant invaders outperform congeneric natives on amino acids

As a key nitrogen (N) source, soil amino acids play an important role in plant N nutrition. However, how amino acids differentially influence the N use strategies of native and invasive plants remains unclear. We performed a potted experiment using five pairs of native and invasive plant congeners, which were subject to 23 N treatments (i.e., 20 protein primary amino acids, nitrate, ammonium, and control), each with 10 replicates. We determined their growth, biomass allocation, N use efficiency, and the growth advantage of plant invaders over their natives. Native and invasive plants used the same 18 amino acid N sources (i.e., a similar amino acid economics spectrum). The growth of plant invaders was invariably better than the growth of native plants, and this superior growth of invaders was linked to their higher root biomass allocation and greater N use efficiency. Additionally, invasive plants had a greater growth advantage on amino acid N than on inorganic N, so was this advantage greater on neutral amino acids than on acidic amino acids. These findings suggest that the differences in amino acid use strategies between invasive and native congeners could help to explain plant invasiveness, as indicated by a growth advantage.     

The Henry Parker Sartwell herbarium of Hamilton College

H. P. Sartwell's private herbarium was donated to the New York Botanical Garden in 1983 by Hamilton College of Clinton, New York. This herbarium was assembled by Dr. Sartwell (1792–1867) throughout his carcer and was eventually sold to Hamilton College. The collection is particularly rich in type material, western New York plants, and carices. Dr. Sartwell had an active exchange program with his contemporaries and, therefore, his herbarium also has collections from many parts of the world. An index to collectors is presented, as well as a list of verified and probable types.