A New Understanding of the Early Evolution of Flowering Plants

Category(-ies): Plant Discoveries , Plant Relationships

Text courtesy of Dr. Sean Graham:

A research team led by scientists at the UBC Botanical Garden & Centre for Plant Research announce a startling discovery in the March 15, 2007 issue of Nature concerning Hydatellaceae, an obscure family of dwarf, aquatic flowering plants. The researchers, led by garden researchers Associate Professor Sean Graham and his graduate students Jeffery Saarela (now at the Canadian Museum of Nature) and Hardeep Rai, discovered that these plants, once thought to be diminutive relatives of grasses and rushes, instead belong near the very root of the evolutionary tree of flowering plants. They have the water lilies as their closest living relatives. The flowering plants began to diversify at least 135 million years ago, in the age of the dinosaurs.

Graham and his students collaborated on this project with colleagues at the University of California, Davis, the Royal Botanical Gardens in Sydney, Australia, the University of Zurich, and Harvard University. The researcher team examined numerous genes from the two genera of Hydatellaceae, Hydatella and Trithuria. Their results are supported with a detailed consideration of Hydatellaceae plant anatomy and morphology.

The family Hydatellaceae has about ten species in two genera, Hydatella and Trithuria. The plants stand a few centimetres tall (or less) at maturity, and have multiple, minute, unisexual flowers (each lacking petals and sepals) that are collected into a compact flowering head. They grow and flower under water (up to a depth of a metre), or at the edges of drying pools. Hydatellaceae were previously thought to be monocots (a large and diverse group of the flowering plants that includes grasses, sedges, gingers, palms and onions) – largely on the basis of their narrow, pointed leaves. They are native to Australia, India and New Zealand.

The family is rather poorly known, and many details of its biology remain to be discovered. Today’s announcement overturns some previous ideas on the early evolution of flowering plants such as the water lilies – and is the first time that a family has been ejected from the monocots.

Posted by Daniel Mosquin at 11:00 AM

Ant Uses Herbicide to Create Habitat

Category(-ies): Plant Relationships

Curious tracts of Amazonian rainforest containing only a single species of tree, Duroia hirsuta, have puzzled people who have encountered them. Locals called them devil's gardens, referring to the belief that evil spirits created them. Botanists had suspected allelopathy, a process where one plant suppresses the growth of others by secreting toxins. Studies by Stanford University researchers indicate that the devil's gardens are actually created by an ant species that builds its nests in D. hirsuta trees. The ant, Myrmelachista schumanni, poisons other plants around the host trees with formic acid, a toxin commonly produced by ants.

Link: Ants, not evil spirits, create poisonous devil’s gardens in the Amazon rainforest a Stanford University news report

Posted by Eric La Fountaine at 3:08 PM

Weeds Harbour Grape Disease

Category(-ies): Plant Diseases and Pests , Plant Relationships

New research indicates that one of the most destructive diseases of grapes, Pierce's disease, is present in many of the common weeds found in California vineyards. Insect pests spread the bacterial infection to grapes. The level of infection varied greatly among host species in different environmental conditions. Scientists are evaluating the individual responses of weeds to the disease. The findings suggest that better weed control in fields and adjacent areas will aid in suppression of the disease.

Link: Vineyard Weeds Found to Host Pierce’s Disease of Grapes from Newswise

Posted by Eric La Fountaine at 10:00 AM

Burning to Regenerate Aspen Woodlands

Category(-ies): Plant Conservation , Plant Relationships

Aspen woodlands are declining in western Canada and the US. The hardwood groves provide a wildlife habitat that is much more diverse than the coniferous forests that are replacing them in many areas. Populus tremuloides reproduce primarily by vegetative means, sprouting suckers from existing root systems after fires or other disturbances. Without periodic wildfires aspen groves become dominated by conifers that tower over them, blocking needed sunlight.

Continue reading "Burning to Regenerate Aspen Woodlands"

Posted by Eric La Fountaine at 11:39 AM

Making the Garden Attractive to People and Wildlife

Category(-ies): Plant Relationships , Plants in the Landscape

Gardeners in the northern hemisphere will soon be busy with fall cleanup - trimming back all the dried plants and raking everything into the compost pile to make everything neat and tidy. It might be a good idea to allow a little mess in the garden this fall. As space for wildlife diminishes, animals and plants can be given a little space in home gardens.

Leaving dried seed heads on plants provides food for birds and other creatures during the winter. Leaving some leaves and twigs can provide habitat for creatures. The hardest part of doing this can be developing a new sense of aesthetics that allows for the beauty of nature's natural process of decay. It is not necessary to let the garden go wild, just allow a little space for nature.

Richard Burkmar comments on this.

Link: Gardening for Yourself from Space For Nature

Posted by Eric La Fountaine at 7:57 AM

Treehoppers?

Category(-ies): Plant Relationships

Most grasshoppers live in the grass as one would expect from the name. But at least one grasshopper prefers trees to grass. A rare grizzly spur-throat grasshopper, Melanoplus punctualatus was recently found by a Kansas middle-school student, participating in a schoolyard prairie project. The insect is native to eastern and southern forests in the USA. It is rarely seen in other areas. A local entomologist confirmed the identification and is studying the feeding habits of the group of insects found in the area.

Links:

• Grasshopper Takes to the Trees on Prairie Research Site from Kansas City infoZine


• This Grasshopper Prefers Trees from Live Science

Posted by Eric La Fountaine at 2:02 PM

Plant Insect Interactions of Ancient Times

Category(-ies): Plant Diseases and Pests , Plant Relationships

Researchers are examining fossils from Patagonia and three sites in North America to gain insight into the historic biodiversity of the regions. Insect fossils are rarely found. By studying the damage caused by insects on the more abundant plant fossils, researchers are able to evaluate the type and level of insect feeding in prehistoric times. Life in Patagonia is among the most varied on the planet. The research shows that the region's biodiversity exceeded that of the other research sites as long as 52 million years ago.

Link: Fossil Patagonian plants show high insect feeding diversity 52 million years ago from EurekAlert

Posted by Eric La Fountaine at 5:56 PM

The Science of Gardening

Category(-ies): Botanical Resources , Plant Relationships , Plants, Food and Medicine

In a recent issue of the Christian Science Monitor, writer Jim Regan reviews the latest addition in the Accidental Scientist series from the Exploratorium, the website of the Museum of Science in San Francisco. Even if, like Mr. Regan, you are not a gardener, you will enjoy the friendly perspective in which the photos, videos and interactive displays are presented.

Continue reading "The Science of Gardening"

Posted by Eric La Fountaine at 4:07 PM

The Darwinian Interlude

Category(-ies): Plant Relationships

Microbiologist Carl Woese makes an argument for a new biological model based on communities and eco-systems rather than on genes and molecules. He theorizes that in the earliest days of life’s existence on the planet genetic information was shared on a lateral basis between life forms. At some point a bacterium developed that kept its genetic innovation to itself and began to out compete other forms of life. Thus the era of Darwinian evolution began.

Continue reading "The Darwinian Interlude"

Posted by Eric La Fountaine at 2:41 PM

India's Mizoram State Prepares for Bamboo Bloom

Category(-ies): Plant Relationships

Every 48 years in India's Mizoram state wild bamboo blooms in unison and after fruiting the plants die. In 1959, as in previous blooms, rats gorged on the abundant fruits and their population soared. After the supply of bamboo fruit was exhausted, the rats turned to the farmer�s crops. Famine followed. Authorities hope to be better prepared when the bloom comes again in 2007.

Continue reading "India's Mizoram State Prepares for Bamboo Bloom"

Posted by Eric La Fountaine at 4:43 PM