Ericameria ×bolanderi (A. Gray) G. L. Nesom & G. I. Baird, based on Linosyris bolanderi A. Gray is the hybrid between E. discoidea and E. nauseosa (L. C. Anderson and J. L. Reveal 1966).
Ericameria ×uintahensis (L. C. Anderson) G. L. Nesom & G. I. Baird, "Uinta rubber rabbitbrush," based on Chrysothamnus nauseosus subsp. uintahensis L. C. Anderson, is the hybrid between E. nauseosa and E. parryi (L. C. Anderson 1984).
Ericameria ×viscosa (D. D. Keck) G. L. Nesom & G. I. Baird, based on Chrysothamnus nauseosus subsp. viscosus D. D. Keck, is the hybrid between E. cuneata and E. nauseosa (L. C. Anderson 1986b).
Rubber rabbitbrush is sensitive to competition. Sites with a dense stand of perennial grasses and forbs are less likely to be dominated by rabbitbrush after fire than those where the understory has been depleted. Burning can temporarily eliminate sagebrush and other plants that compete for water and space. Release from competition stimulates rubber rabbitbrush to produce large numbers of seed [82].
Rubber rabbitbrush biomass production remains low for 1 to 3 years after fire and then often increases rapidly [145]. Rubber rabbitbrush can be a major component of vegetation within 3 to 5 years after a burn [12]. Wright [145] reported that burning reduced rubber rabbitbrush by 59% the first year after fire near Dubois, Idaho. Three years after burning, production doubled; it tripled by the end of year 12. Rubber rabbitbrush reestablished from seed after fire in a Great Basin dry meadow. It peaked in abundance 12 years later [50].
Rubber rabbitbrush may dominate postfire shrub-grass communities in degraded condition if perennial grasses are poorly represented [149]. In many Intermountain shrub-steppe communities, seedlings of rubber rabbitbrush will occupy the sites for 10 to 15 years before big sagebrush again assumes dominance [147].
In pinyon-juniper communities of California, rubber rabbitbrush colonizes higher elevation burns (> 6,600 feet (2,000 m)). Along with other shrubs, it increases in cover and density for 30 to 50 years [135]. It serves as a "nurse shrub" and is rarely found on burns older than 47 years. Two general postfire patterns were noted in these communities: 1) understory fires followed by rapid postfire perennial grass succession, and 2) canopy fires followed by slow postfire shrub and tree succession [135]. General cover by year was as follows [135]:
Lyon's Research Paper
(Lyon 1971)
also provides information on prescribed fire use and postfire response of plant
species including rubber rabbitbrush.
210 Interior Douglas-fir
220 Rocky Mountain juniper
237 Interior ponderosa pine
238 Western juniper
239 Pinyon-juniper
247 Jeffrey pine
FRES15 Oak-hickory
FRES17 Elm-ash-cottonwood
FRES20 Douglas-fir
FRES21 Ponderosa pine
FRES29 Sagebrush
FRES30 Desert shrub
FRES34 Chaparral-mountain shrub
FRES35 Pinyon-juniper
FRES36 Mountain grasslands
FRES38 Plains grasslands
FRES40 Desert grasslands
K011 Western ponderosa forest
K012 Douglas-fir forest
K016 Eastern ponderosa forest
K017 Black Hills pine forest
K018 Pine-Douglas-fir forest
K019 Arizona pine forest
K023 Juniper-pinyon woodland
K037 Mountain mahogany-oak scrub
K038 Great Basin sagebrush
K040 Saltbush-greasewood
K051 Wheatgrass-bluegrass
K055 Sagebrush steppe
K057 Galleta-three-awn shrubsteppe
K060 Wheatgrass-needlegrass shrubsteppe
K063 Foothills prairie
K064 Grama-needlegrass-wheatgrass
K065 Grama-buffalograss
K066 Wheatgrass-needlegrass
K067 Wheatgrass-bluestem-needlegrass
K081 Oak savanna
K098 Northern floodplain forest
107 Western juniper/big sagebrush/bluebunch wheatgrass
314 Big sagebrush-bluebunch wheatgrass
315 Big sagebrush-Idaho fescue
316 Big sagebrush-rough fescue
317 Bitterbrush-bluebunch wheatgrass
318 Bitterbrush-Idaho fescue
319 Bitterbrush-rough fescue
401 Basin big sagebrush
402 Mountain big sagebrush
403 Wyoming big sagebrush
406 Low sagebrush
408 Other sagebrush types
Rubber rabbitbrush occurs as a dominant to minor component in many types of plant communities [96]. It grows in openings in sagebrush (Artemisia spp.), pinyon-juniper (Pinus-Juniperus spp.), and ponderosa pine (P. ponderosa) stands [142]. It also grows in mixed conifer forests of California with Jeffrey pine (P. jeffreyi), white fir (Abies concolor), and sugar pine (P. lambertiana) and in salt deserts with species such as greasewood (Sarcobatus spp.) and saltbush (Atriplex spp.). WIllowlie rabbitbrush grows on relatively mesic sites and occurs with mountain big sagebrush (A. tridentata) and quaking aspen (Populus tremuloides) [81,137].
Published classifications listing rubber rabbitbrush as an indicator or dominant species are presented below:
Natural production potential of some Rio Puerco soils in New Mexico [1]
Vegetation and soils of the Cow Creek Watershed [13]
Plant communities and habitat types in the Lava Beds National Monument, California [34]
Preliminary habitat types of a semiarid grassland [39]
A taxonomy for classification of seral vegetation of selected habitat types in western Montana [49]
Plant associations of the Crooked River National Grassland [58]
Forest vegetation of the Gunnison and parts of the Uncompahgre National Forests: a preliminary habitat type classification [68]
Classification of pinyon-juniper sites on National Forests in the Southwest [93]
Rubber rabbitbrush has been rated "good" in energy and protein content [30]. Dry matter digestibility has been reported as 44.4% and crude protein content at 7.8% [25,140]. Nutritional value varies seasonally, with highest crude fat values noted in fall [120]. Crude protein levels also fluctuate seasonally. Protein value varied seasonally in 1964 as follows [131]:
01/2 2/5 3/1 4/2 11/30
% crude protein 8.4% 8.0% 9.1% 8.2% 9%
Additional nutritional information is listed below [120]:
summer winter
crude fat 15-19% ----
carotene 7 µg/g ----
ash ---- 8.0%
P 0.09-0.11% 0.30%
K 0.80% 3.10%
Na 0.0169% 0.032%
AZ CA CO ID KS MT NE NV NM
ND OK OR SD TX UT WA WY
AB BC SK
MEXICO
Palatability of rubber rabbitbrush varies greatly according to varieties. In general, the white or gray varieties such as willowlike and gray rabbitbrush are more palatable to wildlife and livestock than are the green varieties [99]. Generalized palatability ratings by varieties are as follows [77,111]:
pungent rabbitbrush
- low to medium
white rabbitbrush
- medium to high
willowlike rabbitbrush
- medium to high
All varieties are considered to be slightly toxic to livestock [30]. Rubber rabbitbrush fruit and flowers tend more palatable than other parts of the plant, and palatability of all varieties is generally highest in fall and winter. New leaders may be preferred by some browsers [73]. Meyers and others [87] report that white rabbitbrush is most palatable]. The following tables summarize reported palatability ratings of rubber rabbitbrush varieties by state.
Pungent rabbitbrush: CO MT ND UT WY
---------------------------------------------------------------
Cattle ---- ---- poor poor ----
Sheep ---- ---- fair poor ----
Horses ---- ---- fair poor ----
Pronghorn ---- fair good fair good
Elk ---- fair ---- fair good
Mule deer ---- good good fair good
White-tailed deer good ---- ---- ---- ----
Small mammals ---- ---- ---- good good
Small nongame birds ---- ---- ---- fair fair
Upland game birds ---- ---- ---- fair fair
Waterfowl ---- ---- ---- poor poor
Typical variety:
CO MT ND UT WY
---------------------------------------------------------------
Cattle poor poor poor poor fair
Sheep fair fair fair good fair
Horses fair poor fair poor fair
Pronghorn ---- fair good good good
Elk ---- poor ---- good good
Mule deer ---- good fair good good
White-tailed deer good fair ---- ---- ----
Small mammals ---- ---- ---- good good
Small nongame birds ---- ---- ---- fair fair
Upland game birds ---- ---- ---- fair fair
Waterfowl ---- ---- ---- poor poor
FIRE REGIMES:
Find fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find FIRE REGIMES".
3 Southern Pacific Border
5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
8 Northern Rocky Mountains
9 Middle Rocky Mountains
10 Wyoming Basin
11 Southern Rocky Mountains
12 Colorado Plateau
13 Rocky Mountain Piedmont
15 Black Hills Uplift
16 Upper Missouri Basin and Broken Lands
The scientific name of rubber rabbitbrush is Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird (Asteraceae) [63,151]. This species is described as the most complex and widespread species within the genus [7]. Some morphological characteristics are difficult to observe and overlapping characteristics are sometimes noted [54]. The following varieties are recognized [151].
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. arenaria (L. C. Anderson) G. L. Nesom & G. I. Baird, sand rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. bernardina (H. M. Hall) G. L. Nesom & G. I. Baird, Bernardina rabbitbursh
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. bigelovii (A. Gray) G. L. Nesom & G. I. Baird, BigelowÃÂs rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. ceruminosa (Durand & Hilgard) G. L. Nesom & G. I. Baird, desert rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. graveolens (Nuttall) Reveal & Schuyler, pungent rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. hololeuca (A. Gray) G. L. Nesom & G. I. Baird, white rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. iridis (L. C. Anderson) G. L. Nesom & G. I. Baird, Rainbow Hills rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. juncea (Greene) G. L. Nesom & G. I. Baird, rush rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. latisquamea (A. Gray) G. L. Nesom & G. I. Baird, broadscale rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. leiosperma (A. Gray) G. L. Nesom & G. I. Baird, smooth-fruit rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. mohavensis (Greene) G. L. Nesom & G. I. Baird, Mohave rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. nana (Cronquist) G. L. Nesom & G. I. Baird, dwarf rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. nauseosa, rubber rabbitbrush (typical varitey)
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. nitida (L. C. Anderson) G. L. Nesom & G. I. Baird, shiny-bract rabbitbrush
Ericameria nauseosa(Pallas ex Pursh) G. L. Nesom & G. I. Baird var. oreophila (A. Nelson) G. L. Nesom & G. I. Baird, Great Basin rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. psilocarpa (S. F. Blake) G. L. Nesom & G. I. Baird, smooth-fruit rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. salicifolia (Rydberg) G. L. Nesom & G. I. Baird, willowlike rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. speciosa (Nuttall) G. L. Nesom & G. I. Baird, gray rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. texensis (L. C. Anderson) G. L. Nesom & G. I. Baird, Texas rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. turbinata (M. E. Jones) G. L. Nesom & G. I. Baird, turban rabbitbrush
Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. washoensis (L. C. Anderson) G. L. Nesom & G. I. Baird, Washoe rabbitbrush
Numerous races and ecotypes of rubber rabbitbrush have also been identified [95]. Certain varieties occur across a wide ecological amplitude whereas others, such as Ericameria nauseosa var. salicifolius, are narrowly restricted in either habitat or range [7,89]. Intermediate morphological forms occur at the edges of the varieties' geographic ranges [78]. However, Anderson [7] reports that all infrataxa "are relatively well-defined and often coexist with little or no genetic exchange."
Chrysothamnus nauseosus, col nome común de rubber rabbitbrush, gray rabbitbrush, o Chamisa, ye una especie de parrotal del xéneru Chrysothamnus que crez nes grebes rexones del oeste de Norteamérica. El gran númberu de subespecies identificaes (28 conocíes), ye la resultancia d'una significativa variación dientro de la especie.[1]
Trátase d'un parrotal qu'algama los 30-230 cm d'altor, perenne, con un golor caltriante, les flores son de color mariellu-doráu y prodúcense a finales del branu y principios de la seronda. Son numberoses y prodúcense en recímanos terminales con forma de paragües. El parrotal reproducir a partir de granes y biltos del raigañu. Les fueyes, dependiendo de la subespecie, son llargues y estreches en forma d'espátula. Los tarmos y les fueyes son de color verde-gris.
La especie ganó popularidá como un parrotal xerófito ornamental pa utilizar nes zones onde'l caltenimientu de l'agua ye importante. Espolleta nos suelos alcalinos que son comunes a los ambientes desérticos.[1]
Los especímenes crecen en Bayu Canyon, cerca de Los Álamos, Nuevu Méxicu, y presenten una concentración de estroncio radiactivu 90 a 300.000 vegaes cimera a una planta normal. Los sos raigaños fundir nuna área zarrada de tratamientu de borrafes nucleares, confundiendo'l estroncio col calciu por cuenta de les sos propiedaes químiques similares. Los parrotales radiactivos son "indistinguibles d'otros parrotales, ensin un contador Geiger".[2]
Ye usáu na Terapia floral californiana pa persones con dificultaes p'atender delles coses al empar o situaciones que riquen gran atención, facilita la conciencia activo y viviego, procura un estáu mas flexible y alerta de la mente..[3]
Chrysothamnus nauseosus describióse por (Pall. ex Pursh) Britton y espublizóse en An Illustrated Flora of the Northern United States 3: 326. 1898.[4]
Xeneral:
Chrysothamnus nauseosus, col nome común de rubber rabbitbrush, gray rabbitbrush, o Chamisa, ye una especie de parrotal del xéneru Chrysothamnus que crez nes grebes rexones del oeste de Norteamérica. El gran númberu de subespecies identificaes (28 conocíes), ye la resultancia d'una significativa variación dientro de la especie.
Ericameria nauseosa (formerly Chrysothamnus nauseosus), commonly known as chamisa, rubber rabbitbrush, and gray rabbitbrush, is a shrub in the sunflower family (Aster) found in the arid regions of western North America.
Two subspecies have been described, consimilis (the green form with 8 varieties) and nauseosa (the gray form with 14 varieties).[2]
Ericameria nauseosa is a perennial shrub growing to 2 to 8 metres (6+1⁄2 to 26 feet).[3] The leaves, depending on the subspecies, are 2–7.5 centimetres (3⁄4–3 inches) long[4] and narrow to spatula-shaped. Both the flexible (rubbery) stems and the leaves are greenish-gray with a soft felt-like covering.[5]
It blooms from August to October[6] and produces pungent-smelling, golden-yellow flowers. The flower heads are 6–13 millimetres (1⁄4–1⁄2 in) long[4] and made up of 5 small, yellow, tubular disk flowers, and occur in umbrella-shaped terminal clusters.[7][5] The shrub reproduces from seeds and root sprouts.[5]
Rubber rabbitbrush was moved from the genus Chrysothamnus to the genus Ericameria in a 1993 paper.[2] The findings of a 2003 phylogenetic investigation of Ericameria were consistent with the move of the species to Ericameria.[8] The second edition of the Jepson plant manual[9] and the United States Department of Agriculture's Germplasm Resources Information Network[10] have adopted the name Ericameria nauseosa.
The specific epithet means 'heavy scented'.[11]
Recognized infraspecific taxa from The Plant List[1] with distribution information from Flora of North America[5] and Tropicos:[12]
It grows in the arid regions of western Canada, western United States (from the western Great Plains to the Pacific) and northern Mexico.[14]
Along with associated species, like big sage and western wheat grass, rubber rabbitbrush is only lightly or occasionally used by herbivores during the summer. However, it can be heavily used during the winter when other food sources are scarce and on depleted rangelands.[15][16] Some of the species that consume it include mule deer, elk, pronghorns, and black-tailed jackrabbits. It is considered poor forage for almost all domestic animals, though sheep are reported to consume significant amounts of it in Utah.[15] It is also frequently used as shelter by jackrabbits.[17] Dense stands of this species often grow on poorly managed rangelands, in disturbed areas along roadways and on abandoned agricultural property.[16]
The species often occurs with Chrysothamnus viscidiflorus.[11]
Rabbitbrush, Ericameria nauseosa, has gained popularity as an ornamental xeriscaping shrub in areas where water conservation is important. It thrives in a wide range of coarse, alkaline soils that are common to desert environments. Pruning the shrub back to several inches in early spring, before new growth begins, may help improve the shrub's ornamental value.[18] The varieties Ericameria nauseosa var. nauseosa and Ericameria nauseosa var. speciosa are especially valued as they rarely exceed 24 inches and will often only reach a foot in height. Gardeners appreciate the enthusiastic late season blooms as well as the foliage.[17]
Specimens growing in Bayo Canyon, near Los Alamos, New Mexico, exhibit a concentration of radioactive strontium-90 300,000 times higher than a normal plant. Their roots reach into a closed nuclear waste treatment area, mistaking strontium for calcium due to its similar chemical properties. According to Joseph Masco, the radioactive shrubs are "indistinguishable from other shrubs without a Geiger counter."[19]
The Zuni people use the blossoms bigelovii variety of the nauseosa subspecies to make a yellow dye.[20] They use the stems to make baskets.[21] The Navajo also made a yellow dye from some of the flower heads.[4]
Rubber rabbitbrush was considered as a source of rubber as early as 1904.[22] Several studies have been conducted on the possible use of rubber rabbitbrush as a source of rubber including ones during World Wars I and II, and in 1987.[23] Between 2005 and 2008, the University of Nevada researched possible material applications of rubber rabbitbrush.[24] One possible commercial use of the species would be as a source for hypoallergenic rubber for use in products designed for people with latex allergies.[25]
Rabbitbrush native to the area near the post office in Crestone, Colorado
Ericameria nauseosa (formerly Chrysothamnus nauseosus), commonly known as chamisa, rubber rabbitbrush, and gray rabbitbrush, is a shrub in the sunflower family (Aster) found in the arid regions of western North America.
Two subspecies have been described, consimilis (the green form with 8 varieties) and nauseosa (the gray form with 14 varieties).
Chrysothamnus nauseosus, con el nombre común de "rubber rabbitbrush", "gray rabbitbrush" o "chamisa", es una especie de arbusto del género Chrysothamnus que crece en las áridas regiones del oeste de Norteamérica. El gran número de subespecies identificadas (28 conocidas), es el resultado de una significativa variación dentro de la especie.[1]
Se trata de un arbusto que alcanza los 30-230 cm de altura, perenne, con un olor penetrante, las flores son de color amarillo-dorado y se producen a finales del verano y principios del otoño. Son numerosas y se producen en racimos terminales con forma de paraguas. El arbusto se reproduce a partir de semillas y brotes de la raíz. Las hojas, dependiendo de la subespecie, son largas y estrechas en forma de espátula. Los tallos y las hojas son de color verde-gris.
La especie ha ganado popularidad como un arbusto xerófito ornamental para utilizar en las zonas donde la conservación del agua es importante. Prospera en los suelos alcalinos que son comunes a los ambientes desérticos.[1]
Los especímenes crecen en Bayo Canyon, cerca de Los Álamos, Nuevo México, y presentan una concentración de estroncio radiactivo 90 a 300.000 veces superior a una planta normal. Sus raíces se hunden en un área cerrada de tratamiento de residuos nucleares, confundiendo el estroncio con el calcio debido a sus propiedades químicas similares. Los arbustos radiactivos son "indistinguibles de otros arbustos, sin un contador Geiger".[2]
Es usado en la terapia floral californiana para personas con dificultades para atender varias cosas a la vez o situaciones que requieren gran atención, facilita la conciencia activa y vivaz, procura un estado más flexible y alerta de la mente.[3]
Chrysothamnus nauseosus fue descrito por (Pall. ex Pursh) Britton y publicado en An Illustrated Flora of the Northern United States 3: 326. 1898.[4]
Chrysothamnus nauseosus, con el nombre común de "rubber rabbitbrush", "gray rabbitbrush" o "chamisa", es una especie de arbusto del género Chrysothamnus que crece en las áridas regiones del oeste de Norteamérica. El gran número de subespecies identificadas (28 conocidas), es el resultado de una significativa variación dentro de la especie.
La Bigelovie puante (Ericameria nauseosa ou Chrysothamnus nauseosus) est un buisson de la famille des Asteraceae originaire des régions arides d'Amérique du Nord. On a identifié 28 sous-espèces de cette plante[1].
La plante est présente dans les états américains de l'Utah, de l'Arizona et du Nouveau-Mexique[2]. L'arbuste est présent dans les zones sauvages non entretenues, sur des propriétés abandonnées ou le long des routes[3]. Il peut supporter des conditions arides.
L'arbuste atteint une taille entre 30 cm et 2,3 mètres. Son nom lui vient de l'odeur désagréable qu'il dégage lors de la floraison de ses fleurs jaunes de la fin de l'été jusqu'au début de l'automne. L'arbuste se reproduit par les graines mais aussi par rejet de ses racines. Les feuilles sont longues et fines mais dépendent de la sous-espèce. Les branches sont flexibles, de couleur vert-gris[1].
Durant l'hiver, l'arbuste sert à l'alimentation de nombreux animaux.
L'Homme s'en sert comme plante d'ornement dans les régions où l'eau est rare ou encore comme petit bois pour faire du feu.
Les spécimens qui poussent dans le Bayo Canyon près de Los Alamos au Nouveau-Mexique ont une concentration en strontium-90 plus de 300 000 fois plus élevée qu'une plante normale. Cela est dû à la présence d'une proche usine des traitements des déchets et au fait que la plante confond cet élément radioactif avec le calcium. Ils sont identiques aux spécimens non touchés, et la seule façon de les détecter est d'utiliser un compteur geiger[4].
La Bigelovie puante (Ericameria nauseosa ou Chrysothamnus nauseosus) est un buisson de la famille des Asteraceae originaire des régions arides d'Amérique du Nord. On a identifié 28 sous-espèces de cette plante.
Ericameria nauseosa là một loài thực vật có hoa trong họ Cúc. Loài này được (Pall. ex Pursh) G.L.Nesom & G.I.Baird mô tả khoa học đầu tiên năm 1993.[1]
Ericameria nauseosa là một loài thực vật có hoa trong họ Cúc. Loài này được (Pall. ex Pursh) G.L.Nesom & G.I.Baird mô tả khoa học đầu tiên năm 1993.
一枝黃(學名:Ericameria nauseosa)為矮小的圓形灌木,葉柔軟呈羽毛狀管狀黃色小花成簇開放,花萼上有軟毛,結乾燥蒴果。生長於多碎石的乾燥地區,如北美西部。
美洲土著曾用其治病,吸入該植物燜燒的煙可治感冒,花與幼枝的浸製液可治療咳嗽、感冒和肺結核。花可提取黃色和桔黃色的染料。一戰期間土著部落從其莖節處割取口香糖膠,使當時美國政府考慮作為橡膠來源。