Hydrocarbon-and rubber-producing crops

Agricultural production of rubber and other hydrocarbons in the United States may be compatible with increased food and fiber production if entire plants are harvested and processed for fiber, protein, and carbohydrate as well. Thus, procedures and criteria have been established for the preliminary evaluation of plant species as potential multi-use hydrocarbon-producing crops. Previously, 106 species representing 44 families and 81 genera were evaluated. Now an additional 100 species representing 13 additional families and 60 additional genera have been evaluated, and some of these species also offer promise as future crops. Several Labiatae are high in natural rubber (NR) content;Pycnanthemum incanum (Mountain Mint) andTeucrium canadense (American Germander) were evaluated as promising species. Three Compositae,Cacalia atriplicifolia (Pale Indian-Plant),Solidago graminifolia (Grass-leafed Golden-rod), andSolidago rigida (Stiff Goldenrod) were also evaluated as promising species for NR.Campanula americana (Tall Bellflower, Campanulaceae) has potential as a source of both oil and NR.Euphorbia dentata (Euphorbiaceae ) does not produce NR but is very high in protein and oil contents.Sassafras albidum (Sassafras, Lauraceae ) is of interest for its rapid growth rate in combination with a high oil content. A few other species offer some promise.