Seed germination characteristics of Chrysothamnus nauseosus ssp. viridulus (Astereae, Asteraceae)

Rubber rabbitbrush ( Chrysothamnus nauseosus [Pallas] Britt. ssp. viridulus ) may prove to be a source of high-quality cis-isoprene rubber, but its establishment is limited by a lack of information on seed germination. Consequently, seeds were germinated at alternating temperatures (5–15, 5–25, 15–25, and 20–30 C) in light and dark as well as constant temperatures (15–40 C with 5-C increments) to determine temperature response. Seeds were also germinated in solutions of polyethylene glycol 6000 (0 to –5 bar), salinity regimes (1, 17, 51, and 86 mM) at all the above-mentioned temperatures to determine salinity and temperature interaction. The hormones GA 3 (0, 2.9, 29.0, and 58.0 um) and kinetin (0, 4.7, 23.5, and 47.0 um) were used to study their effect on overcoming salt- and temperature-induced germination inhibition. Seeds of C. nauseosus ssp. viridulus were very sensitive to low temperature. Best germination was achieved at 25 and 30 C, but these seeds also germinated at a higher temperature (35 C). The seeds of rabbitbrush germinated at both constant and alternating temperatures. Light appears to play little or no role in controlling germination of the seeds of rubber rabbitbrush. However, seeds of rabbitbrush were sensitive to salinity, and seed germination was progressively inhibited by increase in salt concentration, although a few seeds still germinated at the highest saline level. Progressively higher concentrations of polyethylene glycol also progressively inhibited germination. Suppression of seed germination induced by high salt concentrations and high temperatures can be partially alleviated by the application of either GA 3 or kinetin.     

Effect of salinity on seed germination of Triglochin maritima under various temperature regimes

Triglochin maritima L. (arrow grass), an herbaceous perennial in the family Juncaginacea, is widely distributed in inland and coastal salt marshes of North America. Triglochin maritima seeds from a population growing in a salt marsh at Faust, Utah, were germinated at 4 temperature regimes (12-h night/12-h day, 5-15° C, 10-20° C, and 15-25° C) and 5 salinities (0, 100, 200, 300, 400, and 500 mol m -3 NaCl) to determine optimal conditions for germination and level of salt tolerance. Ungerminated seeds were returned to distilled water after 20 d to determine whether seeds could recover from salinity treatments. Maximum germination occurred in distilled water, and increases in NaCl concentration progressively inhibited seed germination. No seeds germinated at concentrations higher than 400 mol m -3 NaCl. A temperature regime of low night (5° C) and high day (25° C) temperature yielded maximum germination; all other temperature regimes significantly inhibited seed germination relative to this optimum. Recovery of germination was highest at 5-25° C and lowest at 5-15° C. Recovery of seed germination when seeds were transferred to distilled water from salt solutions was highest at 5-25° C (72%) for seeds exposed to the 500 mol m -3 NaCl pretreatment and significantly reduced at other temperature regimes. The recovery germination response indicates a synergistic inhibitory interaction effect on germination when seeds were exposed to high salinities at suboptimal thermoperiods.     

Temperature and high salinity effects in germinating dimorphic seeds of Atriplex rosea

Atriplex rosea L. (Chenopodiaceae; tumbling orach), an annual herb, is a widely established weedy species of disturbed sites in all counties of Utah. Seeds of Atriplex rosea were collected from a salt marsh in Faust, Utah, and are dimorphic, light brown, and 2-2.5 mm wide, or black and 1-2 mm wide. Seed germination responses of the black and brown seeds were studied over a range of salinity and temperature. Both brown and black seeds germinated at 1000 mM NaCl, and the optimal temperature for germination of both types was 20°-30°C. Variation in temperature, however, affected germination of black seeds more than brown seeds. At lower thermoperiod only 40%-50% black seeds germinated in nonsaline control, and germination was almost completely inhibited with the inclusion of salinity. However, all brown seeds germinated in control at temperatures above 5°-15°C, and inhibition caused by salinity was comparatively lower. Brown seeds had a higher germination rate than black seeds at all temperature and salinity treatments. The highest rate of germination of both seeds occurred at the temperature regime of 5°-15°C. Recovery of germination for black seeds when transferred to distilled water after being in various salinity treatments for 20 days was quite variable. Recovery decreased with increase in salinity at lower temperature regimes, increased with salinity at optimal thermoperiod, and had no effect at 20°-30°C. Brown seeds recovered poorly from salinity at all thermoperiods except 5°-15°C, where recovery decreased with an increase in salinity. Brown seeds are adapted to germination in the early part of the growing season, whereas black seeds are capable of surviving harsher conditions and can germinate in later time periods. Characteristics of the dimorphic seeds increase chances for survival in the harsh saline desert environment.     

Improving seed germination of Salicornia rubra (Chenopodiaceae) under saline conditions using germination-regulating chemicals

Salicornia rubra Nels. (Chenopodiaceae) is a salt-tolerant annual species occurring in salt playas of the Great Basin desert in western United States. It forms pioneer communities on the most saline location of an inland salt playa at Goshen, Utah. Seeds of Salicornia rubra are capable of germinating at 1000 mM NaCl at 25-35° C alternating temperature regime. Dormancy-regulating chemicals were evaluated for their ability to alleviate the innate and salinityenforced dormancy in seeds of Salicornia rubra . Betaine, GA3, kinetin, fusicoccin, ethephon, thiourea, proline, and nitrate had no effect in alleviating primary dormancy. Increases in NaCl concentration progressively inhibited germination of Salicornia rubra seeds. Ethephon, fusicoccin, GA3, kinetin, thiourea, and nitrate promoted germination under low saline conditions. At high salinity fusicoccin had no effect, whereas GA3, kinetin, and ethephon substantially alleviated salinity effects. Application of these dormancy-regulating compounds could be of practical value in seeding a saline area for restoration purposes, particularly under high saline conditions.     

Seed production and seedling establishment of a Southwest riparian tree, Arizona walnut ( Juglans major )

A four-year study of five populations has revealed influences on seed production and seedling establishment of the Southwest riparian tree Juglans major . Germination is abundant after production of large seed crops (masts), but masts are produced infrequently. Within years, germination is stimulated by summer rains, enabling seedlings to establish on riparian terraces as well as streambanks. Traits such as capacity for dormancy during summer drought allow some seedlings to survive on terraces, but abundant rainfall is essential for high rates of seedling success. Ranges of moisture tolerance vary among seeds collected from different populations, suggesting that ecotypes may exist between riparian sites with dissimilar moisture regimes. Population-based differences are associated, in part, with differences in seed size.     

Variation in germination response to temperature and water availability in blackbrush ( Coleogyne ramosissima ) and its ecological significance

Blackbursh ( Coleogyne ramosissima Torr.) is a dominant desert shrub in a distinct mid-elevations vegetation belt between creosote bush-bursage ( Larrea tridentata-Ambrosia dumosa ) shrubland below and big sagebrush-pinyon pine- Utah juniper ( Artemisia tridentata-Pinus monophylla-Juniperus osteosperma ) woodland above in the Mojave Desert. Seed germination patterns of blackbrush seeds collected from 2 elevations (1200 and 1550 m) in 5 mountain ranges within the blackbrush shrublands were investigated. Morphological features of blackbrush seeds, including weight, length, and width, were not significantly different ( P > 0.05) among elevations and mountain ranges in the Mojave Desert. Germination of blackbrush seeds was optimal when preceded by a prechill period of 4-6 wk. Seeds incubated at room temperature germinated poorly. Seeds collected at warm, low-elevation sites appeared to be less dormant (required less prechill time), germinated faster, and showed a higher overall germination response; watering at 2-wk intervals revealed the greatest germination. Some ecotypic variation among populations establishing at different elevations was evident with regard to dormancy duration and germination response at certain constant temperatures.     

Production, losses, and germination of Ceanothus fendleri seeds in an Arizona ponderosa pine forest

I quantified seed production and ovule losses for Ceanothus fendleri Gray (Fendler ceanothus) plants protected from large ungulate herbivores in a ponderosa pine ( Pinus ponderosa [Laws]) forest of northern Arizona. I also tested seed germination responses to cold stratification and heat treatments in the laboratory. Fruit production on fecund stems ranged from 7.4 to 38.2 fruits per stem, which equated to 22.2-118.2 potential seeds based on 3 ovules per fruit. Stems that produced fruit were significantly large relative to their expected sizes. Predispersal ovule losses ranged from 70.7% to 91.4% across the 2 years studied. A chalcidoid seed parasite ( Eurytoma squamosa Bugbee) consumed 11%-28% of the total number of seeds produced. Postdispersal seed predation varied from 0% to 24% and was significantly affected by forest floor substrate in 1 study year. Cumulative ovule losses were estimated to be 71%-92%. Cold stratification did not significantly affect seed germination, and exposure to 90°C resulted in the highest germination percentage. Both dormant and nondormant seeds suggested a bet-hedging life history strategy. This study provides basic ecological information important for management of ponderosa pine forest and nursery production of C. fendleri .     

Three naturally occurring Penstemon hybrids

Three wild Penstemon hybrids are documented herein: Penstemon clevelandii × spectabilis, P. centranthifolius × spectabilis , and P. centranthifolius × eatonii . Each putative hybrid was compared to its respective parental species using manifold floral and vegetative characters for which the parents differed. For each hybrid hypothesis, characters were counted as being intermediate or not intermediate. There were significantly more intermediate characters in all 3 cases (one-sided sign tests, P Penstemon species evidently do hybridize naturally, and for nearly all characters the hybrids are consistent with the view that the parents differ largely by additive genetic effects.     

A new status for Penstemon cyananthus Hook. ssp. subglaber Pennell (Scrophulariaceae)

Penstemon cyanathus Hook. ssp. subglaber Pennell, a plant found frequently in northwestern Utah, southeastern Idaho, and southeastern Wyoming, is elevated to species status. A new name, Penstemon holmgrenii Clark is proposed because P. subglaber is preoccupied.     

Survival, reproductive output, and transplant potential of Penstemon tubiflorus (tube penstemon)

Survival, reproductive output, and transplant success were studied for an Iowa population of Penstemon tubiflorus (tube penstemon), a species that is rare to uncommon through much of its range. The population was discovered in 2003 and is one of only 6 populations that have been documented in Iowa. I began monitoring the new population when 2 cohorts were permanently marked, the first in 2005 and the second in 2007. I estimated survival, flowering, and reproductive output. Then, I introduced greenhouse-grown transplants to 2 new sites and the original site. Survival data showed that P. tubiflorus is a short-lived perennial (approximately 50% survival after 3 years) with substantial variation in the percentage of individuals that flower in a given year. Recruitment over the 5 years of monitoring varied from zero to 26 individuals per year. Transplant survival was site-specific. However, high survival and robust reproduction output of transplants at one site indicated that there are additional suitable sites near the parent population and suggested that these sites remain unoccupied due to limited seed dispersal. While it is unlikely that pollinator limitation is the cause of low reproduction, further study is needed on the pollination syndrome of the Iowa populations of this and other Penstemon species. Future studies should investigate the possibility that the species is limited by site-specific factors that inhibit germination and the survival of small seedlings. Estudiamos la supervivencia, el rendimiento reproductor y el éxito de transplante en una población de Penstemon tubiflorus (tube penstemon) en Iowa, una especie rara o poco común en gran parte de su rango. Esta población fue descubierta en 2003 y es una de sólo seis poblaciones documentadas en el estado. El monitoreo de la nueva población comenzó cuando se marcaron permanentemente dos cohortes, una en 2005 y la segunda en 2007. Se estimó la supervivencia en la floración y el rendimiento reproductor. Transplantes crecidos en invernadero se introdujeron en dos nuevos sitios y en el sitio original. Los datos de supervivencia indicaron que esta especie es una planta perenne efímera (con una supervivencia de aproximadamente 50% después de tres años), con variación considerable en el porcentaje de individuos que florecen en un año determinado. El reclutamiento de la población nativa durante los cinco años fue monitoreado y varió de cero a 26 individuos entre años. La supervivencia de los transplantes fue específica de cada sitio. No obstante, una alta supervivencia y vigorosa rendimiento reproductor de los transplantes en un sitio indicaron que existen sitios adecuados adicionales cerca de la población parental, y sugiere que estos sitios permanecen desocupados debido a la limitada dispersión de semillas. Aunque es improbable que la causa de la baja reproducción se deba a una escasez de polinizadores, se requiere más investigación sobre el síndrome de polinización de las poblaciones de Iowa de esta y otras especies de Penstemon. Se debe investigar la posibilidad de que la especie se vea limitada por factores específicos al sitio que inhiben la germinación y la supervivencia de las plántulas. Normal.dotm 0 0 1 231 1322 Iowa State University 11 2 1623 12.0 0 false 18 pt 18 pt 0 0 false false false /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";}     

Seed dispersal, seed entrapment, and seedling recruitment in a temporally variable desert playa

Natural establishment of seedlings in desert playas with temporally variable precipitation hinges on many factors, including seed production, seed dispersal, seed entrapment, seed germination, and seedling survival. We investigated natural seed dispersal patterns and the effects of surface texture, wind barriers, resource availability (water and nutrients), and protection from herbivory on seedling establishment in a desert playa. We hypothesized that the seed rain would be consistent throughout the year and that seedling establishment would improve in resource-amended plots with barriers to wind dispersal. Contrary to our hypotheses, seed flux peaked seasonally during the winter, and fertilization had no consistent effect on seedling establishment. Seed availability for dispersal correlated with precipitation in the previous water year, whereas seedling recruitment was greatest when current-year precipitation during the spring germination and summer seedling growth periods was high. Gravel and barrier surface treatments contained more surviving seedlings than other surface treatments. Comparison with plots located outside of herbivore exclosures, however, showed that greater seedling presence in gravel plots may be due somewhat to protection from herbivory provided by the gravel, rather than simply to the greater seed-trapping quality of the gravel. With abundant seed availability, application of surface treatments, like coarse gravel, combined with increased seasonal water availability could lead to improved shrub establishment from seed in desert playas.     

A mixed pollination system in Penstemon pseudospectabilis M. E. Jones (Scrophulariaceae)

A population of Penstemon pseudospectabilis M. E. Jones (Scrophulariaceae) on Cave Creek in Cochise County, Arizona, was used in an experimental test of reproductive fitness with three caging treatments: all flying pollinators excluded, hummingbirds excluded, and no exclusion. Twenty plants were chosen and three shoots on each used in the experiment. The flowers were 25.6 (s.d. = 1.5) mm long, the end diameter was 8.5 (s.d. = 1.0) mm, the tube opening was 6.5 (s.d. = 1.0) mm, and the greatest diameter, 75% distal from the receptacle, was 10.1 (s.d. = 0.8) mm (N= 59). Floral nectar contained 11.7% (s.d. = 2.9%) fructose, 13.8% (s.d. = 2.7%) glucose, and 74.5% (s.d. = 5.4%) sucrose (N = 74). There was some evidence, significant only for fructose, that nectar-sugar composition varies between morning and evening. Larger floral dimensions were correlated with lower sucrose and higher hexoses. Casual observation showed Xylocopa sp., small bees, flies, and hummingbirds to be visitors. There was no sign of nectar robbing. Five percent of flowers set seed with all pollen vectors excluded, 44% with hummingbirds excluded, and 63%with no exclusion. Seed set per fruit was 2 with all excluded, 23 with hummingbirds excluded, and 46 with no exclusion. Mean seed set on pollinated flowers was 60, with a range of 2 to 192. Multiple linear regression showed the fraction of fruit setting seed when hummingbirds were excluded to be related to larger flower diameters and shorter flowers. With no pollinator exclusion, fruits setting seed were related to larger diameters and nectar fructose. For seeds per fruit, multiple regression gave similar, but less clear, results. We conclude that P. pseudospectabilis is pollinated by both bees and hummingbirds, with other pollinators not to be excluded as possible contributors. We found no hard evidence of selective forces currently at work.     

Breeding biology and flower visitors of the rare White River penstemon, Penstemon scariosus var. albifluvis (Scrophulariaceae)

We studied the breeding system and flower visitors of White River penstemon, a rare endemic from the Uintah Basin of eastern Utah and western Colorado. Bagging treatments and hand-pollination treatments showed that Penstemon scariosus var. albifluvis has a mixed mating system: while some seeds and fruits are produced through selfpollination (both autogamy and geitonogamy), significantly more are produced when flowers are cross-pollinated. The primary flower visitors, and likely pollinators, were several species of native twig- and ground-nesting bees in the families Apidae, Halictidae, and Megachilidae. We found no differences in fruit or seed production between open-pollinated controls and hand-outcrossed flowers, suggesting that pollinator visits were sufficient to maximize female reproductive success. Management plans to conserve White River penstemon must recognize that full reproductive success of this rare plant taxon relies on a suite of pollinating bees, and that the species richness and abundances of bee visitors should be maintained.     

Polymorphic Indian ricegrass populations result from overlapping waves of migration

Indian ricegrass ( Achnatherum hymenoides [Roem. & Schult.] Barkworth) is a rangeland species native to western North America with populations that may exhibit distinct seed-size morphs borne on separate plants. These morphs are often associated with very different levels of seed dormancy. We compared RAPD profiles of the relatively infrequent and highly dormant jumbo seed morph to its more germinable small or large (non-jumbo) companion seed morphs collected from 9 sites where they were sympatric. Jumbo seed accessions from 9 additional sites that did not exhibit seed polymorphism were included to better sample this seed morph across the species' range. Sympatric seed morphs were consistently distinguishable by their RAPD profiles, and sympatric seed morphs were no more likely to cluster together than nonsympatric seed morphs. The ability of sympatric seed morphs to maintain their genetic identity is compatible with the hypothesis of a predominately autogamous breeding system. Furthermore, these data support the hypothesis that local polymorphic populations result from overlapping waves of migration with distinct geographical origins. The jumbo seed morphs exhibited moderate correlation between genetic distance and geographic distance, but the non-jumbo seed morphs exhibited no such correlation. Jumbo seed morphs that were collected at or east of the Continental Divide in New Mexico and Colorado are more genetically homogeneous than those west of the Continental Divide, and non-jumbo seed morphs from the east are more genetically variable than jumbo seed morphs from the same locations. This suggests that gene flow eastward across the Rocky Mountains has been more frequent for the non-jumbo seed morphs than for the jumbo seed morphs.     

Tamarix aphylla : a newly invasive tree in southern Nevada

In the southwestern United States, the nonnative athel pine ( Tamarix aphylla ) was presumed to be sterile and therefore not as likely to spread as its widely distributed, nonnative congener, T. ramosissima . However, at Lake Mead National Recreation Area (LMNRA) in southern Nevada, populations of T. aphylla have recently spread beyond their limited pre-1990 distribution and now form extensive monospecific stands. Over a 3-year period, we quantified seed production and germination from 60 T. aphylla trees at LMNRA. The annual mean seed production period was 50.6 days, and the mean potential germination (under laboratory conditions) was 22%, indicating that T. aphylla trees at LMNRA are capable of sexual reproduction in southern Nevada. No seeds germinated in field experiments, apparently because of high soil salt levels. However, seedling regeneration is becoming increasingly common at LMNRA. Tamarix aphylla trees occupied a distinct zone along the shoreline of Lake Mead, above T. ramosissima in elevation and below native Larrea tridentata communities, suggesting either competitive exclusion or differential resource utilization. The T. aphylla zone tended to have the highest mean values for total vegetation cover, leaf litter depth, soil salinity, soil moisture, pH, total Kjeldahl nitrogen, and soil organic matter. The capacity for sexual reproduction of this alien plant, combined with a suite of characteristics shared with the invasive T. ramosissima (e.g., drought tolerance and copious saline leaf litter), makes T. aphylla a potentially invasive species along the shores of LMNRA and other mesic areas in the desert Southwest.     

Desiccation sensitivity and heat tolerance of Prunus ilicifolia seeds dispersed by American black bears ( Ursus americanus )

Carnivore consumption of fruit is a principle means by which many fleshy-fruited plant species achieve long-distance seed dispersal. We examined carnivore dispersal of hollyleaf cherry ( Prunus ilicifolia ) seeds, specifically assessing the survival, desiccation sensitivity, and germination of seeds found in bear scats. Studies were conducted both in the laboratory and in 2 burn areas in Los Padres National Forest, California. Bear scats containing P. ilicifolia seeds were collected in burned and unburned chaparral. We counted seeds in each scat and noted whether endocarps had tooth punctures or rattled audibly when shaken. For comparative germination trials, we also collected fruits and seeds directly from mature shrubs. In the laboratory, following a cold-moist stratification period, seeds were assessed for germinability. In the field, we compared desiccation rates and germinability of seeds from bear scats and freshly collected seeds. We compared rates of moisture loss and germination for seeds subjected to several different conditions, including 25 °C (room temperature), 30 °C and 65 °C (in the lab), and placement on exposed soil in a burn area (in the field), where midday temperatures were approximately 45 °C but likely much higher by late afternoon. Prunus ilicifolia seeds collected from bear scats were largely undamaged; the vast majority of these seeds germinated. In some cases, germination rate was higher for seeds from scats than for seeds from intact fruits. Several results indicate that desiccation is an important cause of reduced germinability. First, seeds that rattled audibly germinated poorly; and the louder the rattle, the lower the germination percentage. Second, seeds (both fresh and those from bear scats) placed in the field under protective screens had greatly reduced levels of germination (an 84% decline) after only 7 days. Third, seeds dried in the lab, even at relatively moderate temperatures, showed a decline in germination with seed moisture loss. The addition of high temperatures accelerated this decline in germination. We discuss the relevance of heat and desiccation sensitivity of seeds dispersed by bears to successful seed germination in burned and late-seral mesic and xeric chaparral. El consumo de fruta por carnívoros es uno de los principales medios por los que muchas especies de plantas de frutos carnosos logran dispersar sus semillas a través largas distancias. Examinamos la dispersión por carnívoros de las semillas del islay ( Prunus ilicifolia ), un arbusto del chaparral, evaluando concretamente la supervivencia, la sensibilidad a la desecación y la germinación de semillas encontradas en las heces de oso. Estos estudios se llevaron a cabo tanto en el laboratorio como en dos áreas quemadas en Los Padres National Forest, California. Se colectaron heces de oso que contenían semillas de P. ilicifolia en el chaparral quemado y en el no quemado. Contamos las semillas en cada bola fecal y notamos si los endocarpios tenían marcas de dientes y si vibraban audiblemente al agitarse. Para llevar a cabo pruebas comparativas de germinación, también colectamos frutos y semillas directamente de los arbustos maduros. En el laboratorio, después de un período de estratificación fría-húmeda, evaluamos la capacidad de germinación de las semillas. En el campo, comparamos las tasas de desecación y de germinación de semillas de las heces de oso con aquellas de semillas colectadas directamente de los arbustos. Se compararon las tasas de pérdida de humedad y germinación de las semillas sujetas a diversas condiciones, entre ellas 25 °C (temperatura ambiente), 30 °C y 65 °C en el laboratorio, y en el campo sobre suelo expuesto en un área quemada, donde la temperatura al mediodía era ~45 °C pero probablemente mucho más alta por la tarde. En general, las semillas de P. ilicifolia colectadas en las heces de oso no estaban dañadas; la gran mayoría de estas semillas germinaron; en algunos casos la tasa de germinación fue más alta que la de frutos intactos. Varios resultados indicaron que la desecación es una causa importante de la reducción en la capacidad de germinación. Primero, las semillas que vibraban audiblemente germinaron poco, y cuanto más fuerte el sonido, menor la germinación. Segundo, las semillas (tanto las frescas como las colectadas de heces de oso) colocadas en el campo bajo una malla protectora exhibieron niveles de germinación muy reducidos (una disminución del 84%) después de sólo siete días. Tercero, la germinación de las semillas desecadas en el laboratorio, incluso a temperaturas relativamente moderadas, disminuyó con la pérdida de humedad de las semillas. Temperaturas más altas aceleraron esta disminución en la germinación. Discutimos la importancia de la sensibilidad al calor y a la desecación en las semillas dispersadas por los osos para la germinación exitosa en el chaparral mésico y árido, tanto en el chaparral recién quemado como en el que está en las etapas finales de sucesión.     

Recovery and germinability of native seed fed to cattle

Using livestock as seed dispersal agents may be an effective method for increasing species diversity on degraded and previously seeded rangelands. We quantified seed passage and recovery rates, and post-passage germinability of Wyoming big sagebrush ( Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young), bottlebrush squirreltail ( Elymus elymoides [Raf.] Swezey), and gooseberry globemallow ( Sphaeralcea grossulariaefolia [H. & A.] Rydb.) by feeding Holstein heifers seeds of each species at 3 levels (15,000; 30,000; and 60,000 seeds) over a period of 3 weeks. One-kg fecal samples were collected 1, 2, 3, and 4 days after seed ingestion. Undamaged seeds were extracted from the samples and tested for germinability. Globemallow had the highest percentage of recovered, undamaged seed, followed by squirreltail and sagebrush. Globemallow and sagebrush seed passage was highest on Day 1, after which seed numbers dropped sharply. Squirreltail passage and recovery were more consistent through time, with higher seed recovery at lower seed feeding levels. Post-passage germinability was highest for squirreltail and globemallow on Day 1. Sagebrush germination was negligible. Differences in physical seed properties (size, shape, and seed coat) likely influenced interspecies variation in passage, recovery, and germinability. Globemallow and squirreltail seeds may be suited for livestock dispersal, but sagebrush seeds are not.     

Utah plant novelties in Cymopterus and Penstemon

Cymopterus higginsii and Penstemon atwoodii are named and described from materials collected in the Kaiparowits Plateau vicinity of eastern Kane County, Utah. Habitat, distribution, and probable affinities are outlined.     

Studies in nearctic desert sand dune Orthoptera. Part XV: Eremogeography of Spaniacris with bioecological notes

Four decades of the author's records indicate that Spaniacris deserticola (Bruner) is confined within the periphery of the Colorado Desert. It is usually found, near or within a few hundred feet of sea level, marking the shore line of ancient Lake Cahuilla (except for the Dale Lake record). The preferred host plant is Coldenia palmeri growing on the lower fringes of bajadas, with C. plicata on drift sand being second in preference. Spaniacris can tolerate sand and rock temperatures of 60 C. (believed to be a maximum for Colorado Desert life). Mating takes place at that and lower temperatures. When they are disturbed while on the tops of host plants, their flight is low and direct and of short duration, and they come to rest on the torrid soil for long periods of time. The female, much larger than the male, can sustain the male in flight while mating. The study verified spatial longevity of Spaniacris at Indio, California, after approximately 70 years and for the Kane Springs area after 52 years.     

Temporal distribution,seed damage and notes on the natural history of Acanthoscelides quadridentatus and Acanthoscelides winderi (Coleoptera: Chrysomelidae: Bruchinae) on their host plant,Mimosa setosa var. paludosa (Fabaceae: Mimosoideae), in the Brazilian Cerrado

The seed beetles, Acanthoscelides quadridentatus and Acanthoscelides winderi are here recorded for the first time feeding on seeds of Mimosa setosa var. paludosa in the Brazilian Cerrado. Our main aims were to describe the temporal distribution, seed damage, and notes on the natural history of these two species on their host plant. We hypothesised that: (a) healthy seeds from infested fruits would have worse germination rate than healthy seeds from noninfested fruits, and (b) females of seed beetles would lay more eggs on large fruits. We made field observations and an experimental field study with the presence of seed beetles versus their exclusion on plants. Results revealed that seed beetles are synchronised with fruiting, with a temporal partitioning in occurrence. Attacked seeds did not germinate, whereas healthy seeds from infested fruits had worse germination rate than healthy seeds from noninfested fruits. Females of seed beetles laid more eggs on large fruits. These results suggest that seed beetles avoid competition through a temporal partitioning curcial for their coexistence, and select large fruits to oviposit as these fruits probably provide more food resource for their offspring. Furthermore, plants might perceive seed beetles’ damage and then reduce resource allocation on infested fruits.