Identifier: ecologicalrelati00weav Title: The ecological relations of roots Year: 1919 (1910s) Authors: Weaver, John E. (John Ernest), 1884-1966 Subjects: Roots (Botany) Plant ecology Publisher: Washington, Carnegie institution of Washington Contributing Library: The Library of Congress Digitizing Sponsor: The Library of Congress View Book Page: Book Viewer About This Book: Catalog Entry View All Images: All Images From Book Click here to view book online to see this illustration in context in a browseable online version of this book. Text Appearing Before Image: haracter. Hence we will proceed at once to adiscussion of root distribution. THE ROOT SYSTEMS OF THE GRASSES. Over 60 individuals of the four dominant grasses were excavatedand examined. Three, Koeleria cristata, Poa sandhergii, and Festucaovina ingrata, are shallow-rooted, the bulk of the absorbing systemlying above the 18-inch level, while Agropyrum spicatum penetrates toa maximum depth of 4 feet 10 inches. Agropyrum spicatum.—This is the dominant bunchgrass in eastern Wash-ington. It has its best development westward of the high upland prairiesof extreme eastern Washington and along the rim-rock through the easternpart. The bunches are often 10 inches in diameter and reach a height of over3 feet. The plant blossoms in June and dries out in early July, only to takeon renewed growth after the autumn rains and to remain green all winter. This grass has coarser roots than any of the other three important nativegrasses. These coarse, fibrous roots have many short laterals. Some of the Text Appearing After Image: THE PRAIRIES OF THE PACIFIC NORTHWEST. 33 roots reach a depth of 4 feet 10 inches, although on an average 4 feet 2 incheswas the greatest depth attained. Festuca ovina ingrata.—The blue bunchgrass ranks in importance withAgropyrum on the well-developed high prairies west of the foothills of theBitterroot Mountains between Spokane, Washington, and Lewiston, Idaho.Because of its abundance the very appropriate name Palouse (Fr. pelouse, aland clothed with a short, thick growth of herbage) was early applied to thisregion. The whole plant dries out considerably by the middle of July, but theautumn rains revive it and it is green throughout the rest of the year. Festuca ovina has a great mass of jet-black roots which occupy the soilthoroughly from the surface to a depth of about 18 inches, below which depthrelatively few roots extend. None of the roots are over 1 mm. in diameter.They branch profusely to the third order mostly, and the laterals are usuallyless than an inch in length. This Note About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.