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This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Excerpt from Guayule (Parthenium Argentatum Gray): Rubber-Plant of the of Desert the Desert Dr. Theo. Holm has afforded me the benefit of his criticism of the portion of this work treating of the anatomy, and has been good enough to examine inaccessible literature for me. Dr. W. E. Safford did a like service regarding a few pages in the first chapter. T 0 Prof. W. L. Bray I am indebted for information about the Texas guayule fields, later verified by me personally and to my colleagues, Prof. C. L. Hare and Prof. J. P. C. Southall, for assistance in making chemical analyses and for mathematical formulae, respectively. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

This report examines the state of knowledge and the future promise of guayule Parthenium argentatum Gray, a little known shrub native to the desert of southwest Texas and northern Mexico that was a commercial source of natural rubber during the first half of this century.This perennial shrub thrives in arid conditions and can survive heavy frosts. Guayule, after thorough drying, has been found to contain as much as 26% rubber. This rubber can be used to make vehicle tires or any other item currently made with natural rubber. It is a promising plant for use in reforestation of desert fringe lands and is easy to grow. Extraction of the rubber is not technically difficult; in fact, small-scale household extraction is possible. The plant can be cut down to the ground and will grow again from the roots.The book covers: background and history, botanical information, rubber extraction, agricultural production, rubber quality, economics, research needs, selected readings and recommendations.When guayule grows actively, it produces little or no rubber. If the plant is stressed, growth slows and the products from photosynthesis are diverted into rubber production. Thus when growth slows during cold weather or because of reduced moisture supply, the rubber content begins to increase.