Ephemerals


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Ephemerals

 

(in Russian, ingredienty), species of plants that temporarily become part of plant communities in arid regions (dry steppes, semideserts). Ephemerals develop episodically: they may be represented in large numbers in wet years. Some ephemerals use excess moisture in early spring, others in late autumn, when components or species that constitute the permanent base of the plant cover (prevailers) are just beginning to grow or finishing growing. In dry years ephemerals may not develop altogether, surviving through unfavorable times in the form of seeds that retain their germinating power for a long time. Biennials develop leaf rosettes in late autumn and blossom and bear fruit in early spring. Typical ephemerals include bristly brome, hop clover, common whitlow grass, and perfoliate pepperwort. The term ingredienty was proposed by J. K. Paczoski in 1910 for the southern Russian steppes.


Ephemerals

 

a group of annual herbs that complete a full cycle of development in a very short period of time. Ephemerals have fall-winter-spring vegetative cycles that last from six weeks (Gamanthus gamocarpus, orache) to eight months (desert bos-tryx, desert madwort, Ceratocephala falcata). They constitute a large part of the vegetative cover of deserts, semideserts (57–63 percent of the species composition), and some steppe regions. Ephemerals are noted for their exceptional adaptability to changes in the environment.

Early ephemerals retain a mesomorphic leaf structure; later ones have a xeromorphic structure that is expressed in various degrees. The seeds of vernal ephemerals germinate in the spring; those of winter forms, in the fall. The dormant period of the seeds and fruits coincides approximately with the summer season. The seeds of grasses and legumes remain viable for as many as seven years; those of other ephemerals, for no more than three years.

References in periodicals archive ?
The best time to see the ephemerals at Garden in the Woods begins in April, when the site reopens to the public for the spring and summer.
Tom Smarr, director of horticulture, enjoys the "welcoming of spring" that ephemerals bring to the gardens.
Strick says she appreciates ephemerals so much because they are "very polite - they come out every year but die right back very politely - they don't turn all brown and ugly.
A nice way to start the spring off early (besides prepping your green thumb by reading gardening books) is to plant some of your own ephemerals to enjoy.
Study sites were subject to severe ephemeral erosion and were representative of regional soil and cropping patterns (corn and soybeans).
During the summer of the 1988 drought, rainstorms were not sufficiently intense or persistent to produce ephemeral erosion.
Finally, we included a parameter that described the shortest horizontal distance from the location of interest to a known ephemeral channel position.
For example, if I ask the computer to search for each instance where the Times mentions ephemeral within five words of baseball, I get a story that discusses the general managership of the Yankees, ".
The Anchorage Dails News and the Soviet news agency TASS each could muster only a single ephemeral.
Which leads to the conclusion that the only thing that's truly ephemeral in the information retrieval world is money.