More than symbioses : orchid ecology ; with examples from the Sydney Region

The Orchidaceae are one of the largest and most diverse families of flowering plants. Orchids grow as terrestrial, lithophytic, epiphytic or climbing herbs but most orchids native to the Sydney Region can be placed in one of two categories. The first consists of terrestrial, deciduous plants that live in fire-prone environments, die back seasonally to dormant underground root tubers, possess exclusively subterranean roots, which die off as the plants become dormant, and belong to the subfamily Orchidoideae. The second consists of epiphytic or lithophytic, evergreen plants that live in fire-free environments, either lack specialised storage structures or possess succulent stems or leaves that are unprotected from fire, possess aerial roots that grow over the surface of, or free of, the substrate, and which do not die off seasonally, and belong to the subfamily Epidendroideae. Orchid seeds are numerous and tiny, lacking cotyledons and endosperm and containing minimal nutrient reserves. Although the seeds of some species can commence germination on their own, all rely on infection by mycorrhizal fungi, which may be species-specific, to grow beyond the earliest stages of development. Many epidendroid orchids are viable from an early stage without their mycorrhizal fungi but most orchidoid orchids rely, at least to some extent, on their mycorrhizal fungi throughout their lives. Some are completely parasitic on their fungi and have lost the ability to photosynthesize. Some orchids parasitize highly pathogenic mycorrhizal fungi and are thus indirectly parasitic on other plants. Most orchids have specialised relationships with pollinating animals, with many species each pollinated by only one species of insect. Deceptive pollination systems, in which the plants provide no tangible reward to their pollinators, are common in the Orchidaceae. The most common form of deceit is food mimicry, while at least a few taxa mimic insect brood sites. At least six lineages of Australian orchids have independently evolved sexual deception. In this syndrome, a flower mimics the female of the pollinating insect species. Male insects are attracted to the flower and attempt to mate with it, and pollinate it in the process. Little is known of most aspects of the population ecology of orchids native to the Sydney Region, especially their responses to fire. Such knowledge would be very useful in informing decisions in wildlife management

Greek love, orientalism and race : intersections in Classical reception

Classics has been characterised as both a radical and a conservative discipline. Classical reception studies has enjoyed exploring this paradox: antiquity has provided an erotic example for modern homosexual counter-culture as well as a model for running exploitative empires. This article brings these aspects of reception studies together, to examine how the Victorian homosexual reception of the ancient Greeks was framed and worked out in a particular imperial context at the end of the nineteenth century

Rhodora

Index v.1-50 (1953

John Lubbock, science, and the liberal intellectual

John Lubbock's longest-standing scientific research interest was entomology. Some of his earliest systematic investigations of insect and marine life began under the tutelage of Darwin. Darwin shaped the trajectory of, and the programme for, Lubbock's natural history work. However, to understand John Lubbock's identity as a scientist, he must be located within the context of the Victorian ‘intellectual’. This paper traces Lubbock's entomological work from its early development under Darwin to his later work on insect sensory physiology and comparative psychology. Far from being the death of his scientific career, Lubbock's entry into Parliament marked the pinnacle of his career as a scientific intellectual. He built on his early work on invertebrate anatomy, physiology and taxonomy, and on his archaeological and anthropological research to expound his vision of mental evolution. His research on ‘savages’, on ants, bees and wasps, and on his dog, ‘Van’, permitted him to expatiate upon the psychic unity of all sentient beings, which, in turn, underpinned his overarching educational programme.PostprintPeer reviewe

Reproductive and life history characteristics of a North American prairie orchid Spiranthescernua cernua (Linnaeus) L.C. Richard.

Introduction: Reproductive systems have a profound effect on the genetic structure of plant populations. How genes are passed from one generation to the next influences the amount and structure of genetic variation in succeeding generations (Clegg, 1980; Bell, 1982). Sexual reproduction increases the genetic variation within a population through recombination while asexual reproduction duplicates the maternal genome (Williams, 1975). A variety of systems have evolved in plants which combine both sexual and asexual reproduction (Lloyd, 1984 )

Washington University Record, September 8, 2000

https://digitalcommons.wustl.edu/record/1870/thumbnail.jp