BOWERS, JANICE E. (U.S. Geological Survey, 1675 W. Anklam Road, Tucson, AZ 85745). More flowers or new cladodes? Environmental correlates and biological consequences of sexual reproduction in a Sonoran Desert prickly pear cactus, Opuntia engelmannii. Bull. Torrey Bot. Club 123: 34-40. 1996.-Should a platyopuntia expend all aerolar meristems in flower production, no new cladodes could be produced, and further reproductive effort and vegetative growth would cease. To investigate the trade-off between flower and cladode production, the numbers of flowers, fruits, and cladodes were monitored for 4 years on 30 Opuntia engelmannii Saim-Dyck. plants on Tumamoc Hill, Tucson, Arizona. Plant size controlled the number of flowers initiated each spring. The proportion of flowers that developed (i.e., did not abort) was perhaps determined by December-February rainfall in the months before bloom, with more being developed in the wettest years. Models based on different ratios of initiated cladodes to initiated flowers demonstrated that continued high investment in flowers and fruits would eventually terminate reproduction altogether; therefore periods of high sexual reproduction should alternate with periods of high vegetative growth. In the first 3 years of this study, the ratio of new cladodes to initiated flowers was low, showing a high investment in sexual reproduction. As suggested by the model, the population recouped this investment in the fourth year, when the number of new cladodes was nearly 3 times the 1992-1994 mean, and the number of initiated flowers was only 73% of the 3-year mean.
(美国地质调查局，1675年)。安克兰路，图森，85745)。更多的花还是新的枝?索诺兰沙漠仙人掌(Opuntia engelmannii)有性繁殖的环境因素和生物学后果。公牛。托里机器人。俱乐部123:34-40。1996.-如果一个扁桃花在花的生产中消耗了所有的气枝分生组织，就不能产生新的枝，进一步的繁殖努力和营养生长就会停止。为了研究花与枝的平衡关系，对30株恩格尔曼尼(Opuntia engelmannii sam - dyck)的花、果和枝的数量进行了4年的监测。亚利桑那州图森市图马莫克山上的植物。植株大小控制着每年春天开花的数量。开花(即不流产)的比例可能是由开花前几个月的12月至2月的降雨量决定的，在最潮湿的年份开花的比例更多。基于不同初始枝与初始花比例的模型表明，持续对花和果实的高投入最终将完全终止生殖;因此，有性繁殖期应与营养生长期交替进行。在本研究的前3年，新枝与初始花的比例很低，表明有性繁殖的投入很高。模型表明，种群在第四年就收回了投资，新枝数几乎是1992-1994年平均值的3倍，而初始花数仅为3年平均值的73%。
{"title":"More flowers or new cladodes? Environmental correlates and biological consequences of sexual reproduction in a Sonoran Desert prickly pear cactus, Opuntia engelmannii","authors":"J. E. Bowers","doi":"10.2307/2996304","DOIUrl":"https://doi.org/10.2307/2996304","url":null,"abstract":"BOWERS, JANICE E. (U.S. Geological Survey, 1675 W. Anklam Road, Tucson, AZ 85745). More flowers or new cladodes? Environmental correlates and biological consequences of sexual reproduction in a Sonoran Desert prickly pear cactus, Opuntia engelmannii. Bull. Torrey Bot. Club 123: 34-40. 1996.-Should a platyopuntia expend all aerolar meristems in flower production, no new cladodes could be produced, and further reproductive effort and vegetative growth would cease. To investigate the trade-off between flower and cladode production, the numbers of flowers, fruits, and cladodes were monitored for 4 years on 30 Opuntia engelmannii Saim-Dyck. plants on Tumamoc Hill, Tucson, Arizona. Plant size controlled the number of flowers initiated each spring. The proportion of flowers that developed (i.e., did not abort) was perhaps determined by December-February rainfall in the months before bloom, with more being developed in the wettest years. Models based on different ratios of initiated cladodes to initiated flowers demonstrated that continued high investment in flowers and fruits would eventually terminate reproduction altogether; therefore periods of high sexual reproduction should alternate with periods of high vegetative growth. In the first 3 years of this study, the ratio of new cladodes to initiated flowers was low, showing a high investment in sexual reproduction. As suggested by the model, the population recouped this investment in the fourth year, when the number of new cladodes was nearly 3 times the 1992-1994 mean, and the number of initiated flowers was only 73% of the 3-year mean.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996304","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68405534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The European Garden Flora: A Manual for the Identification of Plants Cultivated in Europe Both Out-of-Doors and Under Glass. 1995. Volume 4: Dicotyledons (Part II): Dilleniaceae to Krameriaceae.","authors":"R. Barneby, J. Cullen","doi":"10.2307/2996310","DOIUrl":"https://doi.org/10.2307/2996310","url":null,"abstract":"","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996310","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68405190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Nature's Champion: B. W. Wells, Tar Heel Ecologist.","authors":"J. Snyder, J. R. Troyer","doi":"10.2307/2996311","DOIUrl":"https://doi.org/10.2307/2996311","url":null,"abstract":"","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996311","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68405201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CRAWFORD, D. J. (Department of Plant Biology, The Ohio State University, Columbus, OH 43210), E. LANDOLT (Geobotanisches Institut ETH, Zurichbergstrasse 38, CH-8044, Zurich, Switzerland) AND D. H. LES (Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269). An allozyme study of two sibling species of Lemna (Lemnaceae) with comments on their morphology, ecology and distribution. Bull. Torrey Bot. Club 123: 1-6. 1996.-Enzyme electrophoresis was employed to examine divergence between Lemna mninuta H.B.&K. and L. valdiviana Phil., two nearly indistinguishable species comprising sect. Uninerves of Lemna. Fifteen presumptive loci were resolved for 25 clones of Lemna minuta and 26 of L. valdiviana. Genetic identity between the two species is 0.70, which is near the mean value for congeneric species of flowering plants, but is much higher than values reported for other species of Lemnaceae. With the exception of two clones, the taxonomic designations of the strains correlated with monomorphism for alternative alleles at two MDH loci. The two species are highly differentiated at two other loci as well. Although the taxa are morphologically similar, they differ in geographic distribution, flavonoid chemistry, and certain physiological and ecological attributes. The relatively high identity at allozyme loci compared to other Lemnaceae suggests that L. minuta and L. valdiviana are closely related and recently diverged sister species.
CRAWFORD, D. J.(俄亥俄州立大学植物生物系，Columbus, OH 43210)， E. LANDOLT (ETH Geobotanisches研究所，Zurichbergstrasse 38, CH-8044, Zurich, Switzerland) AND D. H. LES (Connecticut大学生态与进化生物学系，Storrs, CT 06269)。Lemna属两个兄弟种的同工酶研究及其形态、生态和分布。公牛。托里机器人。俱乐部123:1-6。1996.-酶电泳法测定了两种植物间的差异。和L. valdiviana Phil。，两个几乎不可区分的种，包括钩藓的节。对25个lena minuta无性系和26个L. valdiviana无性系的15个推定位点进行了解析。两种植物的遗传同源性为0.70，接近开花植物同类种的平均值，但远高于lemaceae其他物种的报道值。除两个克隆外，菌株的分类名称与两个MDH位点的备选等位基因的单态相关。这两个物种在另外两个位点也高度分化。虽然它们在形态上相似，但在地理分布、类黄酮化学和某些生理生态属性上存在差异。同工酶位点的同源性较其他lemaceae植物高，表明L. minuta和L. valdiviana亲缘关系近，是新近分化的姊妹种。
{"title":"An allozyme study of two sibling species of Lemna (Lemnaceae) with comments on their morphology, ecology and distribution","authors":"D. Crawford, E. Landolt, D. Les","doi":"10.2307/2996300","DOIUrl":"https://doi.org/10.2307/2996300","url":null,"abstract":"CRAWFORD, D. J. (Department of Plant Biology, The Ohio State University, Columbus, OH 43210), E. LANDOLT (Geobotanisches Institut ETH, Zurichbergstrasse 38, CH-8044, Zurich, Switzerland) AND D. H. LES (Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269). An allozyme study of two sibling species of Lemna (Lemnaceae) with comments on their morphology, ecology and distribution. Bull. Torrey Bot. Club 123: 1-6. 1996.-Enzyme electrophoresis was employed to examine divergence between Lemna mninuta H.B.&K. and L. valdiviana Phil., two nearly indistinguishable species comprising sect. Uninerves of Lemna. Fifteen presumptive loci were resolved for 25 clones of Lemna minuta and 26 of L. valdiviana. Genetic identity between the two species is 0.70, which is near the mean value for congeneric species of flowering plants, but is much higher than values reported for other species of Lemnaceae. With the exception of two clones, the taxonomic designations of the strains correlated with monomorphism for alternative alleles at two MDH loci. The two species are highly differentiated at two other loci as well. Although the taxa are morphologically similar, they differ in geographic distribution, flavonoid chemistry, and certain physiological and ecological attributes. The relatively high identity at allozyme loci compared to other Lemnaceae suggests that L. minuta and L. valdiviana are closely related and recently diverged sister species.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996300","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68405381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Life History Strategies of Florida Scrub Plants in Relation to Fire","authors":"E. Menges, Nancy Kohfeldt","doi":"10.2307/2996320","DOIUrl":"https://doi.org/10.2307/2996320","url":null,"abstract":"","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996320","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68405323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Quiescent Center in Aerial Roots of Orchids","authors":"V. Raghavan, C. Goh","doi":"10.2307/2996318","DOIUrl":"https://doi.org/10.2307/2996318","url":null,"abstract":"","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996318","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68405247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EHRENFELD, JOAN G., WEIXING ZHU AND WILLIAM F. J. PARSONS. (IMCS, Rutgers University, New Brunswick, NJ 08903). Above- and below-ground characteristics of persistent forest openings in the New Jersey Pinelands. Bull. Torrey Bot. Club. 122:298-305. 1995.-Openings in the pitch pine (Pinus rigida Mill.) forests of southern New Jersey may persist for decades. In five such openings, ranging in size from 22 to 223 m2, and their surrounding forest matrix, we characterized the vegetation, the forest floor, root biomass, soil chemistry and soil fungi. There was a much greater disparity between the openings and the forest matrix in the density of small ericad shrubs than in the number or basal area of the canopy trees, and this disparity was mirrored in the thickness of the litter and organic horizons, and in the total small root biomass. The matrix:gap ratios of total root biomass and of total soil fungal length were similar to the ratios for tree and large shrub densities. Extractable NH4-N, BrayP, pH, and soil moisture did not differ between the openings and matrix, but extractable N03-N was higher in the openings than the intact forest. We suggest that the shrubs may be an important factor in maintaining the differences between the openings and the matrix, by trapping litter, maintaining high root biomasses, and inhibiting decomposition. If the organic horizon is destroyed in a locally intense disturbance, the slow rate of invasion and growth of the shrubs into mineral soil may help perpetuate the opening for long periods of time.
{"title":"Above- and below-ground characteristics of persistent forest openings in the New Jersey Pinelands' 2","authors":"J. Ehrenfeld, Weixing Zhu, W. Parsons","doi":"10.2307/2996321","DOIUrl":"https://doi.org/10.2307/2996321","url":null,"abstract":"EHRENFELD, JOAN G., WEIXING ZHU AND WILLIAM F. J. PARSONS. (IMCS, Rutgers University, New Brunswick, NJ 08903). Above- and below-ground characteristics of persistent forest openings in the New Jersey Pinelands. Bull. Torrey Bot. Club. 122:298-305. 1995.-Openings in the pitch pine (Pinus rigida Mill.) forests of southern New Jersey may persist for decades. In five such openings, ranging in size from 22 to 223 m2, and their surrounding forest matrix, we characterized the vegetation, the forest floor, root biomass, soil chemistry and soil fungi. There was a much greater disparity between the openings and the forest matrix in the density of small ericad shrubs than in the number or basal area of the canopy trees, and this disparity was mirrored in the thickness of the litter and organic horizons, and in the total small root biomass. The matrix:gap ratios of total root biomass and of total soil fungal length were similar to the ratios for tree and large shrub densities. Extractable NH4-N, BrayP, pH, and soil moisture did not differ between the openings and matrix, but extractable N03-N was higher in the openings than the intact forest. We suggest that the shrubs may be an important factor in maintaining the differences between the openings and the matrix, by trapping litter, maintaining high root biomasses, and inhibiting decomposition. If the organic horizon is destroyed in a locally intense disturbance, the slow rate of invasion and growth of the shrubs into mineral soil may help perpetuate the opening for long periods of time.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996321","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68405378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
sequentially to simulated March-October temperatures in incubators or (3) exposed to 25/15 or 30/15?C for 24 and 12 weeks, respectively. As seeds entered dormancy, they first lost the ability to germinate at 15/6?C and then at higher temperatures. Buried seeds exposed to seasonal temperature changes for 28 months in the nonheated greenhouse exhibited an annual dormancy/nondormancy cycle, with full dormancy occurring in September-November. Seeds came out of dormancy in winter (December-March), and they germinated to 8596% in light at simulated habitat temperatures from mid-April until July. Although 20-50% of the seeds germinated in darkness at simulated habitat temperatures in spring (March-June), only 2% of them germinated while buried in soil in the nonheated greenhouse. Thus, seeds have the potential to form a persistent seed bank.
{"title":"Role of temperature in the germination ecology of the summer annual Bidens polylepis Blake (Asteraceae)","authors":"C. Baskin, J. Baskin, E. W. Chester","doi":"10.2307/2996319","DOIUrl":"https://doi.org/10.2307/2996319","url":null,"abstract":"sequentially to simulated March-October temperatures in incubators or (3) exposed to 25/15 or 30/15?C for 24 and 12 weeks, respectively. As seeds entered dormancy, they first lost the ability to germinate at 15/6?C and then at higher temperatures. Buried seeds exposed to seasonal temperature changes for 28 months in the nonheated greenhouse exhibited an annual dormancy/nondormancy cycle, with full dormancy occurring in September-November. Seeds came out of dormancy in winter (December-March), and they germinated to 8596% in light at simulated habitat temperatures from mid-April until July. Although 20-50% of the seeds germinated in darkness at simulated habitat temperatures in spring (March-June), only 2% of them germinated while buried in soil in the nonheated greenhouse. Thus, seeds have the potential to form a persistent seed bank.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996319","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68405262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Embryo Growth in Tuberous Corydalis Species","authors":"M. Lidén, Rutger Staaf","doi":"10.2307/2996323","DOIUrl":"https://doi.org/10.2307/2996323","url":null,"abstract":"","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996323","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68405841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Flora and Vegetation of \"Las Piedritas\" and the Margin of Laguna Caceres, Puerto Suarez, Bolivian Pantanal","authors":"R. Frey","doi":"10.2307/2996324","DOIUrl":"https://doi.org/10.2307/2996324","url":null,"abstract":"","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996324","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68405856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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