Species of Cheilymenia, Coprobia, and Scutellinia of the Ciliarieae (Humariaceae) are studied by electron microscopy. They share the same type of ascosporogenesis, although only Cheilymenia and Coprobia form spore sheaths on their ascospores, and epispore layers are formed after the primary wall is deposited between spore-delimiting membranes. The manner of formation of epispore layers is very similar to that in the genus Aleuria. Gradual condensation of the secondary wall material in the perisporic sac is consistently found. Globular bodies with rodlet contents are found in the perisporic sac of Cheilymenia and are different from those found in Aleuria. Vacuolation occurs in the perisporic sac, within which ornaments are almost completely formed. During the condensation of secondary wall material, a translucent zone similar to that commonly found in Ascobolus and other coprophilous fungi is formed between the epispore layer and the ornaments.
{"title":"Ultrastructural Investigation of Humariaceae (Pezizales, Ascomycetes). II. Ascosporogenesis in Selected Genera of the Ciliarieae","authors":"Chi-Guang Wu, J. Kimbrough","doi":"10.1086/337903","DOIUrl":"https://doi.org/10.1086/337903","url":null,"abstract":"Species of Cheilymenia, Coprobia, and Scutellinia of the Ciliarieae (Humariaceae) are studied by electron microscopy. They share the same type of ascosporogenesis, although only Cheilymenia and Coprobia form spore sheaths on their ascospores, and epispore layers are formed after the primary wall is deposited between spore-delimiting membranes. The manner of formation of epispore layers is very similar to that in the genus Aleuria. Gradual condensation of the secondary wall material in the perisporic sac is consistently found. Globular bodies with rodlet contents are found in the perisporic sac of Cheilymenia and are different from those found in Aleuria. Vacuolation occurs in the perisporic sac, within which ornaments are almost completely formed. During the condensation of secondary wall material, a translucent zone similar to that commonly found in Ascobolus and other coprophilous fungi is formed between the epispore layer and the ornaments.","PeriodicalId":9213,"journal":{"name":"Botanical Gazette","volume":"152 1","pages":"421 - 438"},"PeriodicalIF":0.0,"publicationDate":"1991-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60238650","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}
Responses in net photosynthesis (A) and stomatal conductance to water vapor (g) in two Sonoran desert herbaceous perennials exposed to atypical conditions of variable sunlight were compared to previously documented responses in subalpine herbs that grow in an environment of extreme sunlight variability. In the desert herb Penstemon parryi, little variation in g (< 80 mmol m-2 s-1) or xylem pressure potential (ψ) was observed during periods of sunlight variability, although A varied substantially. This response was consistent with those subalpine plants that also maintained relatively constant ψ during sun/shade periods. ψ differed significantly between sun and shade periods in the desert herb Ambrosia ambrosioides (-1.65 vs. -1.36 MPa, respectively), and reductions in g during shade were as rapid (24.5 mmol m-2 s-1min-1) as observed in subalpine species with similarly variable ψ. However, recovery in g during sun periods occurred at a rate well below that measured in subalpine herbs. Thus, alterations in g did not closely correspond to variations in A and sunlight in this desert herb. This response pattern was unlike any measured in 22 subalpine species previously studied. Rapid recovery in g during sun periods that follow shade has likely been selected for in subalpine herbs that are exposed daily to sunlight variability. Such a response can substantially increase carbon gain. We suggest that the benefits of a strong tracking response in g to variations in A and sunlight are not realized in desert environments with relatively constant solar regimes. However, rapid stomatal closure during shade periods does insure higher water use efficiency and the potential for recovery in ψ in this desert herb.
{"title":"Gas Exchange Responses to Variable Sunlight in Two Sonoran Desert Herbs: Comparison with Subalpine Species","authors":"A. Knapp, W. K. Smith","doi":"10.1086/337889","DOIUrl":"https://doi.org/10.1086/337889","url":null,"abstract":"Responses in net photosynthesis (A) and stomatal conductance to water vapor (g) in two Sonoran desert herbaceous perennials exposed to atypical conditions of variable sunlight were compared to previously documented responses in subalpine herbs that grow in an environment of extreme sunlight variability. In the desert herb Penstemon parryi, little variation in g (< 80 mmol m-2 s-1) or xylem pressure potential (ψ) was observed during periods of sunlight variability, although A varied substantially. This response was consistent with those subalpine plants that also maintained relatively constant ψ during sun/shade periods. ψ differed significantly between sun and shade periods in the desert herb Ambrosia ambrosioides (-1.65 vs. -1.36 MPa, respectively), and reductions in g during shade were as rapid (24.5 mmol m-2 s-1min-1) as observed in subalpine species with similarly variable ψ. However, recovery in g during sun periods occurred at a rate well below that measured in subalpine herbs. Thus, alterations in g did not closely correspond to variations in A and sunlight in this desert herb. This response pattern was unlike any measured in 22 subalpine species previously studied. Rapid recovery in g during sun periods that follow shade has likely been selected for in subalpine herbs that are exposed daily to sunlight variability. Such a response can substantially increase carbon gain. We suggest that the benefits of a strong tracking response in g to variations in A and sunlight are not realized in desert environments with relatively constant solar regimes. However, rapid stomatal closure during shade periods does insure higher water use efficiency and the potential for recovery in ψ in this desert herb.","PeriodicalId":9213,"journal":{"name":"Botanical Gazette","volume":"152 1","pages":"269 - 274"},"PeriodicalIF":0.0,"publicationDate":"1991-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60238323","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}
Wall structure in the water-conducting cells of Rhynia gwynne-vaughanii and Asteroxylon mackiei from the Lower Devonian Rhynie Chert was examined and compared using thin sections and scanning electron microscopy of etched sections. Although the internal thickenings of these cells are superficially similar in both plants, there are significant differences in other aspects of wall structure. The tracheids of A. mackiei are shown to be of a basic type (G-type) that is common in some early land plant fossils such as zosterophylls and lycopods, and they are comparable to protoxylem elements in some extant `pteridophytes'. The "tracheids" of R. gwynne-vaughanii are more similar to another kind of water-conducting cell (S-type) that combines certain features of tracheids and moss hydroids. The S-type cell is known from two other Lower Devonian sporophytes, Stockmansella langii and Huvenia kleui, supporting recent suggestions that these three taxa form a natural group. S-type cells are also found in the gametophyte Sciadophyton sp. as well as two taxa, Sennicaulis hippocrepiformis and Taeniocrada dubia, for which reproductive structures are unknown. The water-conducting tissues of other early land plants are briefly reviewed and detailed reconstructions of the S-type and G-type cell are provided. A preliminary cladistic analysis focusing on the Rhyniophytina of Banks results in the recognition of a `protracheophyte' grade, as well as a small clade, the Rhyniaceae, comprising Rhynia, Stockmansella, and Huvenia. If the tracheid-like features of S-type and G-type cells are regarded as homologous, then the Rhyniaceae are resolved as the basal clade that forms the sister group to all other tracheophytes. The occurrence of a more or less isomorphic alternation of generations in some Devonian `protracheophytes' and the Rhyniaceae implies that the gametophytes of all extant `pteridophytes' are phylogenetically reduced.
{"title":"Water-Conducting Cells in Early Fossil Land Plants: Implications for the Early Evolution of Tracheophytes","authors":"P. Kenrick, P. Crane","doi":"10.1086/337897","DOIUrl":"https://doi.org/10.1086/337897","url":null,"abstract":"Wall structure in the water-conducting cells of Rhynia gwynne-vaughanii and Asteroxylon mackiei from the Lower Devonian Rhynie Chert was examined and compared using thin sections and scanning electron microscopy of etched sections. Although the internal thickenings of these cells are superficially similar in both plants, there are significant differences in other aspects of wall structure. The tracheids of A. mackiei are shown to be of a basic type (G-type) that is common in some early land plant fossils such as zosterophylls and lycopods, and they are comparable to protoxylem elements in some extant `pteridophytes'. The \"tracheids\" of R. gwynne-vaughanii are more similar to another kind of water-conducting cell (S-type) that combines certain features of tracheids and moss hydroids. The S-type cell is known from two other Lower Devonian sporophytes, Stockmansella langii and Huvenia kleui, supporting recent suggestions that these three taxa form a natural group. S-type cells are also found in the gametophyte Sciadophyton sp. as well as two taxa, Sennicaulis hippocrepiformis and Taeniocrada dubia, for which reproductive structures are unknown. The water-conducting tissues of other early land plants are briefly reviewed and detailed reconstructions of the S-type and G-type cell are provided. A preliminary cladistic analysis focusing on the Rhyniophytina of Banks results in the recognition of a `protracheophyte' grade, as well as a small clade, the Rhyniaceae, comprising Rhynia, Stockmansella, and Huvenia. If the tracheid-like features of S-type and G-type cells are regarded as homologous, then the Rhyniaceae are resolved as the basal clade that forms the sister group to all other tracheophytes. The occurrence of a more or less isomorphic alternation of generations in some Devonian `protracheophytes' and the Rhyniaceae implies that the gametophytes of all extant `pteridophytes' are phylogenetically reduced.","PeriodicalId":9213,"journal":{"name":"Botanical Gazette","volume":"152 1","pages":"335 - 356"},"PeriodicalIF":0.0,"publicationDate":"1991-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/337897","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60238606","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}
The development of the complex hierarchy of axillary buds in Vitis vinifera L. cv Cabernet Sauvignon is described. Developmental differences between lateral and compound buds and between the compound bud and the apex of the growing shoot are discussed. Differences include the position and timing of bud initiation, the position of the first uncommitted primordium and the timing of its differentiation, and the ability of the compound bud to overwinter in a dormant state. Evidence confirming the monopodial development of the grape shoot includes the persistence of first-order axillary buds in each leaf axil of this species regardless of the position of the node relative to inflorescence or tendril insertion, the uninterrupted plane of phyllotaxy in field-grown vines, and morphological evidence of the lateral origin of uncommitted primordia. The initiation and early development of tendril and inflorescence primordia are described, and evidence supporting Bugnon's interpretation of these organs as shoot homologs is discussed. Shoot development in V. vinifera is interpreted as a highly modified form of distichous phyllotaxy in which each node bears a single leaf or modified leaf subtending an axillary bud or bud homolog. Some nodes bear foliage leaves subtending lateral buds; other nodes bear modified leaves (bracts) subtending bud homologs (tendrils or inflorescences). The unusual position of tendrils and inflorescences opposite the leaf results from the failure of the internodes separating bract-bearing nodes from leaf-bearing nodes to elongate.
介绍了赤霞珠葡萄(Vitis vinifera L. cv Cabernet Sauvignon)腋芽复杂层次结构的发育过程。讨论了侧芽与复芽之间以及复芽与生长期顶端之间的发育差异。差异包括芽形成的位置和时间，第一个未参与的原基的位置及其分化的时间，以及复合芽在休眠状态下越冬的能力。证实葡萄芽单足发育的证据包括:该物种的每个叶腋上都有一级腋芽，而与花序或卷须插入的节点无关;在田间生长的葡萄藤中，叶分结构的平面不间断;以及未投入的原基的侧向起源的形态学证据。描述了卷须和花序原基的起始和早期发育，并讨论了支持Bugnon将这些器官解释为茎同源物的证据。在葡萄树中，茎的发育被解释为一种高度变异的二分叶分制形式，其中每个节都有单叶或变异的叶，其下部有腋芽或同源芽。一些节生叶片对侧芽;其它节具修饰的叶(苞片)对着芽同源物(卷须或花序)。卷须和花序的不同寻常的位置相对于叶片是由于节间分离苞片节和叶片节的延长失败。
{"title":"Bud Development in Vitis vinifera L.","authors":"J. C. Morrison","doi":"10.1086/337894","DOIUrl":"https://doi.org/10.1086/337894","url":null,"abstract":"The development of the complex hierarchy of axillary buds in Vitis vinifera L. cv Cabernet Sauvignon is described. Developmental differences between lateral and compound buds and between the compound bud and the apex of the growing shoot are discussed. Differences include the position and timing of bud initiation, the position of the first uncommitted primordium and the timing of its differentiation, and the ability of the compound bud to overwinter in a dormant state. Evidence confirming the monopodial development of the grape shoot includes the persistence of first-order axillary buds in each leaf axil of this species regardless of the position of the node relative to inflorescence or tendril insertion, the uninterrupted plane of phyllotaxy in field-grown vines, and morphological evidence of the lateral origin of uncommitted primordia. The initiation and early development of tendril and inflorescence primordia are described, and evidence supporting Bugnon's interpretation of these organs as shoot homologs is discussed. Shoot development in V. vinifera is interpreted as a highly modified form of distichous phyllotaxy in which each node bears a single leaf or modified leaf subtending an axillary bud or bud homolog. Some nodes bear foliage leaves subtending lateral buds; other nodes bear modified leaves (bracts) subtending bud homologs (tendrils or inflorescences). The unusual position of tendrils and inflorescences opposite the leaf results from the failure of the internodes separating bract-bearing nodes from leaf-bearing nodes to elongate.","PeriodicalId":9213,"journal":{"name":"Botanical Gazette","volume":"152 1","pages":"304 - 315"},"PeriodicalIF":0.0,"publicationDate":"1991-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/337894","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60238448","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}
Hybrid embryo abortion at about 14 days after pollination (DAP) is typical of crosses between the cultivated lentil, Lens culinaris, and the wild species L. ervoides, regardless of the direction of the cross. Hybrid embryo abortion was also observed in crosses between the cultivated lentil and specific accessions of its wild progenitor, L. orientalis, and between these accessions and L. ervoides. The embryos of the parental lines of these three taxa reached the globular stage ca. 5 DAP; the cotyledons, shoot, and root primordia were observed ca. 10 DAP, and the immature seeds reached their final size ca. 14 DAP. The embryos were surrounded by a thin layer of endosperm that disappeared when the immature seeds reached their final size. The development of the hybrid embryos and endosperm was similar to that of the parental lines up to the globular stage; after this stage retarded development and progressive necrosis were detected. At 14 DAP the hybrid embryos contained smaller cotyledons, initiations of shoot and root primordia, and remnants of the endosperm. Through the use of embryo culture hybrid embryos can be grown into vegetatively normal plants that are partially fertile. The genus Lens is therefore proposed as a model system for the genetic analysis of hybrid embryo abortion.
{"title":"Anatomical Aspects of Hybrid Embryo Abortion in the Genus Lens L.","authors":"S. Abbo, G. Ladizinsky","doi":"10.1086/337895","DOIUrl":"https://doi.org/10.1086/337895","url":null,"abstract":"Hybrid embryo abortion at about 14 days after pollination (DAP) is typical of crosses between the cultivated lentil, Lens culinaris, and the wild species L. ervoides, regardless of the direction of the cross. Hybrid embryo abortion was also observed in crosses between the cultivated lentil and specific accessions of its wild progenitor, L. orientalis, and between these accessions and L. ervoides. The embryos of the parental lines of these three taxa reached the globular stage ca. 5 DAP; the cotyledons, shoot, and root primordia were observed ca. 10 DAP, and the immature seeds reached their final size ca. 14 DAP. The embryos were surrounded by a thin layer of endosperm that disappeared when the immature seeds reached their final size. The development of the hybrid embryos and endosperm was similar to that of the parental lines up to the globular stage; after this stage retarded development and progressive necrosis were detected. At 14 DAP the hybrid embryos contained smaller cotyledons, initiations of shoot and root primordia, and remnants of the endosperm. Through the use of embryo culture hybrid embryos can be grown into vegetatively normal plants that are partially fertile. The genus Lens is therefore proposed as a model system for the genetic analysis of hybrid embryo abortion.","PeriodicalId":9213,"journal":{"name":"Botanical Gazette","volume":"152 1","pages":"316 - 320"},"PeriodicalIF":0.0,"publicationDate":"1991-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60238490","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}
Haustoria in Cassytha pubescens R. Br. (Lauraceae) are initiated before the tissues of the stem are fully differentiated. The adhesive disk of the haustorium develops an "epithelium" of mostly unicellular, tightly packed trichomes that become folded at their tips upon contact with the host. The trichome initials are enveloped by microtubules prior to mitosis. The trichomes secrete adhesive polysaccharide material that contains fragments of the disintegrated cuticle. During formation of the trichomes the epicuticular wax originally covering the stem is shed. The wedge-shaped intrusive organ develops inside the hypodermis from the third cell layer of cortical chlorenchyma. The origin of the intrusive organ is independent of the position of the vascular bundles. Dissolution of cell walls in front of the intrusive organ occurs but penetration of the host seems mainly dependent on turgor pressure and extension growth. Most of the starch stored in the adhesive disk before the intrusive phase is used during penetration. The outer part of the storage tissue then forms a collapsed zone as a response to cambial activity.
{"title":"Anatomy and Ultrastructure of the Haustorium of Cassytha pubescens R. Br. I. The Adhesive Disk","authors":"H. Heide-Jørgensen","doi":"10.1086/337896","DOIUrl":"https://doi.org/10.1086/337896","url":null,"abstract":"Haustoria in Cassytha pubescens R. Br. (Lauraceae) are initiated before the tissues of the stem are fully differentiated. The adhesive disk of the haustorium develops an \"epithelium\" of mostly unicellular, tightly packed trichomes that become folded at their tips upon contact with the host. The trichome initials are enveloped by microtubules prior to mitosis. The trichomes secrete adhesive polysaccharide material that contains fragments of the disintegrated cuticle. During formation of the trichomes the epicuticular wax originally covering the stem is shed. The wedge-shaped intrusive organ develops inside the hypodermis from the third cell layer of cortical chlorenchyma. The origin of the intrusive organ is independent of the position of the vascular bundles. Dissolution of cell walls in front of the intrusive organ occurs but penetration of the host seems mainly dependent on turgor pressure and extension growth. Most of the starch stored in the adhesive disk before the intrusive phase is used during penetration. The outer part of the storage tissue then forms a collapsed zone as a response to cambial activity.","PeriodicalId":9213,"journal":{"name":"Botanical Gazette","volume":"152 1","pages":"321 - 334"},"PeriodicalIF":0.0,"publicationDate":"1991-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/337896","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60238596","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}
The extinct trochodendraceous genus Nordenskioldia, well represented in the Paleocene of the Northern Hemisphere, is documented for the first time from the Neogene, based upon infructescences, fruits, associated twigs, and foliage from the Miocene of Idaho, Washington, and southern British Columbia. The infructescences and fruits, assigned to Nordenskioldia interglacialis (Hollick) comb. nov., are very similar to Paleocene N. borealis, but differ in ranging to a higher number of carpels per fruit and in being less regularly dehiscent. The leaves, Zizyphoides auriculata (Heer) comb. nov., formerly attributed to Populus and Cocculus, are clearly congeneric with the leaves associated with Nordenskioldia in Paleocene deposits. Zizyphoides auriculata leaves differ from Paleocene Z. flabellum in having generally more prominent dentations along the margin and a broader divergence of the lateral primary veins. Excellent preservation of the Miocene material reveals features not preserved in the Paleocene specimens, and in particular, lignified fruitlets clearly show aborted ovules in addition to the single mature seed. Infructescences of Trochodendron are also documented from the same Miocene localities at which N. interglacialis occurs. The close similarities between Paleocene and Miocene species of Nordenskioldia, and also between the Miocene and extant species of Trochodendron, suggest relative stasis in the morphological evolution of the Trochodendraceae over intervals of up to 45 million years.
{"title":"Nordenskioldia and Trochodendron (Trochodendraceae) from the Miocene of Northwestern North America","authors":"S. Manchester, P. Crane, D. Dilcher","doi":"10.1086/337898","DOIUrl":"https://doi.org/10.1086/337898","url":null,"abstract":"The extinct trochodendraceous genus Nordenskioldia, well represented in the Paleocene of the Northern Hemisphere, is documented for the first time from the Neogene, based upon infructescences, fruits, associated twigs, and foliage from the Miocene of Idaho, Washington, and southern British Columbia. The infructescences and fruits, assigned to Nordenskioldia interglacialis (Hollick) comb. nov., are very similar to Paleocene N. borealis, but differ in ranging to a higher number of carpels per fruit and in being less regularly dehiscent. The leaves, Zizyphoides auriculata (Heer) comb. nov., formerly attributed to Populus and Cocculus, are clearly congeneric with the leaves associated with Nordenskioldia in Paleocene deposits. Zizyphoides auriculata leaves differ from Paleocene Z. flabellum in having generally more prominent dentations along the margin and a broader divergence of the lateral primary veins. Excellent preservation of the Miocene material reveals features not preserved in the Paleocene specimens, and in particular, lignified fruitlets clearly show aborted ovules in addition to the single mature seed. Infructescences of Trochodendron are also documented from the same Miocene localities at which N. interglacialis occurs. The close similarities between Paleocene and Miocene species of Nordenskioldia, and also between the Miocene and extant species of Trochodendron, suggest relative stasis in the morphological evolution of the Trochodendraceae over intervals of up to 45 million years.","PeriodicalId":9213,"journal":{"name":"Botanical Gazette","volume":"152 1","pages":"357 - 368"},"PeriodicalIF":0.0,"publicationDate":"1991-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60238155","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}
Ecophysiological responses to drought and a 3-cm rain were measured in seven C3 forb and five C4 grass species on a tallgrass prairie in northeastern Kansas. In general, midday leaf water potentials and conductances increased after rain to a greater extent in the C3 forbs, although exceptions occurred. In particular, the deeply rooted Silphium laciniatum showed little or no change in water potential and three of the five grass species exhibited no change in conductance. Although the above differences in species and life-form responses were noted, few of the species exhibited signs of severe stress at the height of the drought, emphasizing the degree to which both C3 forbs and C4 grasses are adapted to occasional severe droughts in the prairies of North America.
{"title":"Ecophysiological Responses of C3 Forbs and C4 Grasses to Drought and Rain on a Tallgrass Prairie in Northeastern Kansas","authors":"C. Martin, F. Harris, F. Norman","doi":"10.1086/337887","DOIUrl":"https://doi.org/10.1086/337887","url":null,"abstract":"Ecophysiological responses to drought and a 3-cm rain were measured in seven C3 forb and five C4 grass species on a tallgrass prairie in northeastern Kansas. In general, midday leaf water potentials and conductances increased after rain to a greater extent in the C3 forbs, although exceptions occurred. In particular, the deeply rooted Silphium laciniatum showed little or no change in water potential and three of the five grass species exhibited no change in conductance. Although the above differences in species and life-form responses were noted, few of the species exhibited signs of severe stress at the height of the drought, emphasizing the degree to which both C3 forbs and C4 grasses are adapted to occasional severe droughts in the prairies of North America.","PeriodicalId":9213,"journal":{"name":"Botanical Gazette","volume":"152 1","pages":"257 - 262"},"PeriodicalIF":0.0,"publicationDate":"1991-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60238301","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}
Pub Date : 1991-09-01DOI: 10.1086/botanicalgazette.152.3.2995222
Paul, E. Lester
TERABAYASE[I, .: Vernation Potterns in Celtidaceae and Ulmaceae (Urticales), and thelr Evolutionary and Systematic Implications SHUMA, J.C. AND M.V.S. RAJU: TS the Wild Oat Embryv Mvnocotylvus ? HOZUMI, K. AND N. KURACE:I: Estimation of Semonal Changes ln Translocation RaXs in Leaxres of a Japanese Larch Stand SUZUE, M.5 L. JOSHI ANTD S.NOSE:IRO: Tetracentron wood from the Mlocene of Noto :Peninsula, Cental Japan, with a Short Revision of Homoxylic Fossil Woods WATANTABE, M.F. M. WATANABE, T. EATO, K. HARADA ND M. SETZURI: Composltion of Cyclic Peptide Toxins among Strains of Microwstis asrugtnosa (Blue-green algae cya}wobacXria) AWASTEI, D.K., R. RAWAT, A. KEMAR AND V. KUMAR: Light and Seanning Electron MiGroscopic Studiss of Flower Development in lindenbergia msrostshya Benth (Serophulariaceae) SHIBAOKA, T.: Rapid Plant Movemen Triggered by Action Potentials KAWANO, S.: The Life C:ycle of MiMchondria rl the Trne Slime Mould, Physarum Polyceghalum
[j]，李建军，李建军，等。野生燕麦胚的遗传变异及其系统意义[j]。苏苏，M.5 L. JOSHI, d . S.NOSE:IRO:来自日本中部诺托半岛茂新世的四环木，与同氧化石木材的短修订WATANTABE, M. f . M. WATANABE, T. EATO, K. HARADA和M. SETZURI:蓝绿藻微藻(Microwstis asrugtnosa)菌株中环肽毒素的组成SHIBAOKA, T.:动作电位触发的植物快速运动。KAWANO, S.:多绒泡菌(Physarum Polyceghalum)中线粒体的生命周期
{"title":"Back Matter","authors":"Paul, E. Lester","doi":"10.1086/botanicalgazette.152.3.2995222","DOIUrl":"https://doi.org/10.1086/botanicalgazette.152.3.2995222","url":null,"abstract":"TERABAYASE[I, .: Vernation Potterns in Celtidaceae and Ulmaceae (Urticales), and thelr Evolutionary and Systematic Implications SHUMA, J.C. AND M.V.S. RAJU: TS the Wild Oat Embryv Mvnocotylvus ? HOZUMI, K. AND N. KURACE:I: Estimation of Semonal Changes ln Translocation RaXs in Leaxres of a Japanese Larch Stand SUZUE, M.5 L. JOSHI ANTD S.NOSE:IRO: Tetracentron wood from the Mlocene of Noto :Peninsula, Cental Japan, with a Short Revision of Homoxylic Fossil Woods WATANTABE, M.F. M. WATANABE, T. EATO, K. HARADA ND M. SETZURI: Composltion of Cyclic Peptide Toxins among Strains of Microwstis asrugtnosa (Blue-green algae cya}wobacXria) AWASTEI, D.K., R. RAWAT, A. KEMAR AND V. KUMAR: Light and Seanning Electron MiGroscopic Studiss of Flower Development in lindenbergia msrostshya Benth (Serophulariaceae) SHIBAOKA, T.: Rapid Plant Movemen Triggered by Action Potentials KAWANO, S.: The Life C:ycle of MiMchondria rl the Trne Slime Mould, Physarum Polyceghalum","PeriodicalId":9213,"journal":{"name":"Botanical Gazette","volume":"152 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1991-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/botanicalgazette.152.3.2995222","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60890425","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}
Five types of fossil conifer foliage from the Upper Cretaceous Black Creek Formation of North Carolina have been reexamined from newly discovered material. The cuticular and gross morphology of Androvettia carolinensis, Brachyphyllum squammosum, Brachyphyllum sp., Geinitzia reichenbachii, and Moriconia cyclotoxon is described and illustrated. To determine the affinities of these nonreproductive remains, data for sixteen characters of leaf and cuticle morphology were gathered for the modern conifers and the fossil taxa and analyzed using Principal Components Analysis (PCA). Once characters were identified that caused known family members to sort into correct family groups with PCA, it was assumed that the fossil taxa scored for the same characters would cluster with family groupings, indicating affinities. This analysis indicates that A. carolinensis and Brachyphyllum sp. are members of the Hirmerellaceae and G. reichenbachii and B. squammosum are members of the Araucariaceae. The affinities of M. cyclotoxon are unresolved.
{"title":"Upper Cretaceous Conifer Leaf Fossils from the Black Creek Formation with an Assessment of Affinities Using Principal Components Analysis","authors":"Linda A. Raubeson, P. Gensel","doi":"10.1086/337900","DOIUrl":"https://doi.org/10.1086/337900","url":null,"abstract":"Five types of fossil conifer foliage from the Upper Cretaceous Black Creek Formation of North Carolina have been reexamined from newly discovered material. The cuticular and gross morphology of Androvettia carolinensis, Brachyphyllum squammosum, Brachyphyllum sp., Geinitzia reichenbachii, and Moriconia cyclotoxon is described and illustrated. To determine the affinities of these nonreproductive remains, data for sixteen characters of leaf and cuticle morphology were gathered for the modern conifers and the fossil taxa and analyzed using Principal Components Analysis (PCA). Once characters were identified that caused known family members to sort into correct family groups with PCA, it was assumed that the fossil taxa scored for the same characters would cluster with family groupings, indicating affinities. This analysis indicates that A. carolinensis and Brachyphyllum sp. are members of the Hirmerellaceae and G. reichenbachii and B. squammosum are members of the Araucariaceae. The affinities of M. cyclotoxon are unresolved.","PeriodicalId":9213,"journal":{"name":"Botanical Gazette","volume":"152 1","pages":"380 - 391"},"PeriodicalIF":0.0,"publicationDate":"1991-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/337900","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60238178","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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