Ernest Small

Evolution and Classification of Cannabis sativa (Marijuana, Hemp) in Relation to Human Utilization

Cannabis sativa has been employed for thousands of years, primarily as a source of a stem fiber (both the plant and the fiber termed “hemp”) and a resinous intoxicant (the plant and its drug preparations commonly termed “marijuana”). Studies of relationships among various groups of domesticated forms of the species and wild-growing plants have led to conflicting evolutionary interpretations and different classifications, including splitting C. sativa into several alleged species. This review examines the evolving ways Cannabis has been used from ancient times to the present, and how human selection has altered the morphology, chemistry, distribution and ecology of domesticated forms by comparison with related wild plants. Special attention is given to classification, since this has been extremely contentious, and is a key to understanding, exploiting and controlling the plant. Differences that have been used to recognize cultivated groups within Cannabis are the results of disruptive selection for characteristics selected by humans. Wild-growing plants, insofar as has been determined, are either escapes from domesticated forms or the results of thousands of years of widespread genetic exchange with domesticated plants, making it impossible to determine if unaltered primeval or ancestral populations still exist. The conflicting approaches to classifying and naming plants with such interacting domesticated and wild forms are examined. It is recommended that Cannabis sativa be recognized as a single species, within which there is a narcotic subspecies with both domesticated and ruderal varieties, and similarly a non-narcotic subspecies with both domesticated and ruderal varieties. An alternative approach consistent with the international code of nomenclature for cultivated plants is proposed, recognizing six groups: two composed of essentially non-narcotic fiber and oilseed cultivars as well as an additional group composed of their hybrids; and two composed of narcotic strains as well as an additional group composed of their hybrids.

Pollen-ovule patterns in tribeTrifolieae (Leguminosae)

Relative pollen and ovule production in the genera of the legume tribeTrifolieae is explored particularly as to howMedicago with its explosive pollination mechanism compares with its allies.Medicago produces much larger, although much fewer pollen per ovule than the other five genera in the tribe; this is interpreted as a consequence of its highly specialized, irreversible pollination mechanism, which allows only one effective exchange of pollen with pollinators.Melilotus andTrifolium produce a comparatively large quantity of pollen; this can be related to their floral characteristics requiring abundant pollen to achieve fertilization. InMedicago andTrigonella, annuals convert a higher proportion of pollen grains and ovules into seeds than perennials.

Tetrahydrocannabinol Levels in Hemp (CANNABIS SATIVA) Germplasm Resources

In most of the western world where industrial hemp, Cannabis sativa, is licensed for cultivation, the plants must not exceed a level of 0.3% tetrahydrocannabinol (THC), the principal intoxicating constituent of the species. Because there are no publicly available germplasm hemp collections in North America and only a very few, recent North American cultivars have been bred, the future breeding of cultivars suitable for North America is heavily dependent on European cultivars and European germplasm collections. Based mostly on material from Europe, this study surveyed THC levels of 167 accessions grown in southern Ontario, making this the largest survey to date of germplasm intended for breeding in North America. Forty-three percent of these had THC levels ≥0.3% and, therefore, are unsuitable for hemp development in North America. Discrepancies were found between THC levels reported for some germplasm holdings in Europe when they were grown in Canada and, accordingly, verification of THC levels developed in North America is necessary.

The evolution of cannabinoid phenotypes inCannabis

The medical and public concern over the use of marihuana in our society strongly reflects the fact that Cannabis sativa is indeed an exceptionally important plant. Apart from its drug and fibre products, it is economically important from yet another aspect: that of being a serious weed in some countries, necessitating costly eradication. Botanists are participating in the accelerated research on Cannabis which began roughly five years ago, and several botanical programs are in progress around the world. The research described here may duplicate to some extent the findings of other researchers. We believe, however, that verification of research findings is necessary for a plant as important as Cannabis, particularly as some of our findings either contradict earlier generalizations or have not yet been recorded in the literature. In Canada, one research project on Cannabis is being conducted jointly between the Plant Research Institute of the Canada Department of Agriculture, and the Health Protection Branch of the Canada Department of National Health and Welfare. The senior author is directly responsible for the botanical aspects, and the second author for chemical analysis. Although several aspects are being investigated, the research reported focuses mainly on the question of natural variation in Cannabis sativa, with particular emphasis on the cannabinoids the class of compounds responsible for the psychoactive properties of cannabis drugs. A

The new Noah's Ark: beautiful and useful species only. Part 2. The chosen species

For most species, conservation efforts are being determined by qualities that humans admire or dislike, including economic importance. The most universally admired physical characteristic is size: huge creatures elicit great respect, whereas the majority of species, which are small, tend to be ignored. Glamorous appearance is critical for sympathetic attention, and there are numerous features such as colour and impressive architecture that contribute to what makes a species attractive. However, bizarre or ferocious appearance, if entertaining, can also be a key to conservation. We are hard-wired to admire many of the larger mammals, provided that they have features reminiscent of health and intelligence in humans, or are ‘cute and cuddly’ like human babies. Most bird species also possess many admirable traits. However, most animals distantly related to humans, particularly invertebrates, usually have few characteristics considered attractive. The majority of the worlds threatened species are insects, but except for butterflies and bees, most are usually perceived very negatively. Unfortunately, numerous animal groups in dire need of conservation, such as frogs and snakes, are decidedly handicapped by both their appearance and behaviour. The majority of species are undiscovered, and so are hardly in a position to compete for conservation attention. While there are advantages to conservation focussed on particular species, preservation of diverse habitats is preferable in order to benefit the planets life-sustaining ecosystems and their constituent biodiversity, including humans.

The new Noah's Ark: beautiful and useful species only. Part 1. Biodiversity conservation issues and priorities

Most of the worlds species at risk of extinction are neither particularly attractive nor obviously useful, and consequently lack conservation support. In contrast, the public, politicians, scientists, the media and conservation organisations are extremely sympathetic to a select number of well-known and admired species, variously called flagship, charismatic, iconic, emblematic, marquee and poster species. These are extremely attractive, large, entertaining or useful, and they receive the lions share of public and private financial support, publicity, research, conservation and protective legislation. Such species have proven to be the best available means of increasing public awareness of the biodiversity crisis, and of mobilising financial support for conservation. They are widely touted as critical to the cause of conservation, not just symbolically, but also because preservation of their habitats, it has been claimed, can simultaneously preserve other species at risk. However, there is only limited evidence of ‘trickle-down’ benefits to rare, endemic and endangered species. Indeed, management strategies based on various ecologically-defined representative species (surrogate species, focal species, indicator species, keystone species, umbrella species) are only partially useful for aiding non-targeted species at risk. Aesthetic and commercial standards have become the primary determinants of which species in the natural world deserve conservation. Accordingly, the worlds biodiversity is being beautified by selective conservation of attractive species, while the plight of the overwhelming majority of species is receiving limited attention.

BLOSSOMING TREASURES OF BIODIVERSITY

Everyone detests at least some foods. Would you accept an invitation to a party to sample foods that normally taste awful? But imagine that the star attraction of the party is an exotic fruit that makes the sourest and the most bitter of substances taste wonderfully sweet. Your first reaction might be, “it must be dangerous, and is probably illegal”. To find out, read on.

42. Quinoa – is the United Nations’ featured crop of 2013 bad for biodiversity?

Quinoa (Chenopodium quinoa), an ancient staple grain crop of subsistence farmers in the highlands of South America, has recently become a premium-priced gourmet specialty of the world’s affluent. B...

37. Spirulina – food for the universe

Several crises are endangering the ecosystems, atmosphere and biodiversity of the world. The problems are caused substantially by the current needs to expand food production and to harvest fossil fuels for energy. For several decades, Spirulina species, which include some of the tiniest and most primitive organisms on Earth, have been slowly gaining significance as possible players in mankind’s quest to live more sustainably in relation to the planet’s finite resources. These species have the potential to produce both food and biofuel far more rapidly and efficiently, and with a much smaller environmental footprint, than conventional crops. The phrase ‘food of the future’ has become associated with these extraordinary microscopic organisms, and very recently they have been considered as key resources for human colonisation of the universe. As our environmental and associated societal problems continue to deteriorate, it is important that society becomes more familiar with the use of Spirulina to alleviate some of our most pressing issues.

A Preliminary Study of Pollen Dispersal in Cannabis sativa in Relation to Wind Direction

Abstract Pollen of Cannabis sativa is disseminated by wind in large amounts and for long distances, and regulations concerning the production of pedigreed seed of industrial hemp, therefore, often call for extremely large isolation distances to prevent unwanted pollination. In Europe and Canada, a standard distance of 5 km is required for the highest classes of hemp seed. This study examines the relative distribution of pollen from an isolated field over the 3-week maximum flowering period, with particular reference to wind direction. The amount of pollen distributed downwind was about six times the amount distributed upwind. In effect, this means that an isolation distance of 5 km on the downwind side is about equivalent to an isolation distance of 0.9 km on the upwind side. In theory, at the experimental site examined, the required isolation area could be reduced by about 58% while still achieving the equivalent of 5 km isolation in all directions. Given that weedy and illegally cultivated plants are widespread, making it difficult to ensure their absence over a distance of 5 km, it seems advisable, when possible, to take advantage of the considerably reduced isolation distance that is necessary on the upwind side. Pollen distribution appeared to follow the expected leptokurtic curve, reducing rapidly with initial distance from the source, but much more slowly with increasing distance. This makes it impossible to guarantee complete absence of potentially contaminating pollen in the field and, for practical purposes, a very low amount of undesired gene flow needs to be tolerated.