Wood anatomy of theSarraceniaceae; ecological and evolutionary implications

The wood of theSarraceniaceae has a considerable number of primitive features including scalariform perforation plates, long and oblique end walls, scalariform lateral wall pitting, solitary vessels, tracheids with scalariform pitting, and diffuse axial parenchyma. Vessel elements in the genusHeliamphora have the greatest number of primitive features, while vessel elements inDarlingtonia andSarracenia appear to have modifications relating to temperate climates. The wood anatomy suggests thatHeliamphora is growing in a habitat more similar to the original habitat for the family thanDarlingtonia andSarracenia. The wood of theSarraceniaceae is similar to the wood of theTheales.     

Morphology and ontogeny of stem xylem elements inSarcandra glabra (Thunb.) Nakai (Chloranthaceae): Additional evidence for the occurrence of vessels

Very recentlySarcandra, which had long been known as the only vesselless genus in Chloranthaceae, was found by Carlquist to have vessels in root secondary xylem. The present study further shows on the basis of observations of the xylem ontogeny that vessels occur in stem metaxylem ofSarcandra glabra as well, thus offering additional evidence for the occurrence of vessels in the genus, virtually in all Chloranthaceae. Metaxylem elements of the stem are thicker than the other tracheary elements in general and have scalariform pittings at the end wall, and their ontogeny indicates that, as the surrounding cytoplasm disintegrates, pit membranes at the end wall disappear at least in some elements, resulting in a perforated end wall, i.e., vessel perforation. The present study further shows thatChloranthus spicatus, which is closely related toSarcandra, may have an incomplete perforation plate because of retaining membranes at places on the plate. An evolutionary state of the “vesselless” condition in Chloranthaceae is discussed.     

鹅掌楸属(木兰科)次生木质部导管穿孔板的比较研究

利用扫描电子显微镜对鹅掌楸属仅存的2个自然种鹅掌楸和北美鹅掌楸的次生木质部导管穿孔板特征进行了详细的研究。结果显示,鹅掌楸属的2个种均以梯状穿孔板为主,同时存在网状-梯状混合穿孔板。鹅掌楸和北美鹅掌楸的导管穿孔板具有明显差异:(1)鹅掌楸具网状穿孔板,而北美鹅掌楸没有观察到;(2)北美鹅掌楸具单穿孔板,而鹅掌楸在该实验中未发现;(3)北美鹅掌楸具有横隔较粗的梯状穿孔板且横隔数目较多;(4)鹅掌楸的导管穿孔板多数横隔较少;(5)北美鹅掌楸的穿孔板倾斜角度较大;(6)北美鹅掌楸具麻黄式穿孔板的存在,且有纹孔膜残留存在。研究认为,北美鹅掌楸导管分子穿孔板分化较鹅掌楸更为剧烈。     

Discovery of vessels in Tetracentron (Trochodendraceae) and its systematic significance

Through SEM observation, we found that there are vessels as well as tracheids in the secondary wood of Tetracentron sinense Oliv. The vessel elements are as narrow and as long as or slightly shorter than the tracheids and generally have 1 to 3 very long, or sometimes relatively short and oblique end-wall perforation plates; such perforation plates are also present on the lateralwalls. The perforation plates of the vessels include scalariform and reticulate-scalariform types, with various degrees of membrane remnants present in the end walls.     

PRESENCE OF VESSELS IN WOOD OF SARCANDRA (CHLORANTHACEAE); COMMENTS ON VESSEL ORIGINS IN ANGIOSPERMS

Sarcandra is the only genus of Chloranthaceae hitherto thought to be vesselless. Study of liquid-preserved material of S. glabra revealed that in root secondary xylem some tracheary elements are wider in diameter and have markedly scalariform end walls combined with circular pits on lateral walls. Examination of these wider tracheary elements with scanning electron microscope (SEM) demonstrated various degrees of pit membrane absence in the end walls. Commonly a few threadlike fibrils traverse the pits (perforations); these as well as intact nature of pit membranes in pits at ends of some perforation plates are evidence that lack of pit membranes does not result from damage during processing. Some perforations lack any remnants of pit membranes. Although perforation plates and therefore vessels are present in Sarcandra roots, no perforations were observed in tracheary elements of stems or lignotubers. Further, stem tracheids do not have the prominently scalariform end walls that the vessel elements in roots do. Presence of vessels in Sarcandra removes at least one (probably several) hypothetical events of vessel origin that must be postulated to account for known patterns of vessel distribution in angiosperms, assuming that they are primitively vesselless. Seven (perhaps fewer) vessel origin events in angiosperms could account for these patterns; two of those events (Nelumbo and monocotyledons) are different from the others in nature. Widely accepted data on trends of vessel specialization in woody dicotyledons yield an unappreciated implication: vessel specialization has happened in a highly polyphyletic manner in dicotyledons, and therefore multiple vessel origins represent a logical extension backward in time. If a group of vesselless dictyoledons ancestral to other angiosperms existed, they can be hypothesized to have had a relatively homogeneous floral plan now that Sarcandra-like plants no longer need be imagined within that group. Sarcandra and other Chloranthaceae show that the borderline between vessel absence and presence is less sharp than generally appreciated.     

Comparative wood anatomy ofCoriaria

Wood anatomy ofCoriaria was surveyed to clarify generic features on the basis of 14 species collected from various regions of the World to cover the whole range of geographic distribution and habitual variation. Wood anatomy ofcoriaria is considerably uniform, and the species share a combination of the following features: 1) pores are thin-walled, polygonal in outline and mostly in multiples; 2) vessel elements and libriform fibers are very short; 3) perforation plates are exclusively simple; 4) intervessel pits are alternate; 5) vascular tracheids are present; 6) wood parenchyma is vasicentric and sometimes confluent; 7) rays are heterogeneous and large. Its species differ in several characters, such as distinctness of growth rings, pore size, pore patterns, type and abundance of wood parenchyma, and distinctness of storied structure. Comparisons among species indicate that the species of the Northern Hemisphere show a tendency toward having semi-ring porosity, while those of the Southern and Western Hemisphere have diffuse porosity. The other infrageneric variations appear to be related to different habits of the species rather than to geographic distribution. Small trees mostly have confluent and vasicentric parenchyma composed of fusiform cells and distinctly storied tissues, while shrubs and herbs have less abundant parenchyma which is vasicentric and comprises strands of two to four cells and indistinctly storied tissues.     

Wood anatomy of Gentianaceae, tribe Helieae, in relation to ecology, habit, systematics, and sample diameter

Twenty collections representing one species each ofSymbolanthus andTachia, and 17 species ofMacrocarpaea were studied by means of light microscopy and scanning electron microscopy (SEM). Wood details show that the three genera form a coherent group;Tachia differs from the others in only a few minor characters. Because the species studied form a natural group, wood variations within Helieae offer the basis for correlations and interpretations with respect to habit and ecology. Diameter of stems studied proves to be an important variable that must be taken into account. Correlations with stem diameter include wider vessels in outer wood of wider samples. This would correspond to deeper penetration of reliable water tables by roots of helioid trees or large shrubs. Ray height decreases with increase in stem diameter, an indication of paedomorphosis. Rays of all species are paedomorphic in histology by virtue of relative paucity or even absence of procumbent cells in multiseriate rays. Pseusoscalariform lateral wall pitting of vessels is also a feature characteristic of paedomorphosis. The assemblage of paedomorphic features correlates well with the conclusion, reached by authors who used cladistic methods, that Gentianaceae other than Gentianeae are derived from suffrutescent prennials. The Mesomorphy Ratio, which incorporates three vessel features, correlates with leaf length and with stem diameter. All Helieae are mesophytic, but to various degrees. Septate fiber-tracheids, where present, are typically near vessels and form a substitute for or an addendum to vasicentric axial parenchyma as a mechanism for photosynthate storage. Vestured pits occur on lateral wall pits of vessels of all Helieae, but not on the fibertracheids. Vestured pits show diversity withinMacrocarpaea, a feature of possible systematic significance.     

PALEOCENE DICOTYLEDONOUS TREES FROM BIG BEND NATIONAL PARK,TEXAS: VARIABILITY IN WOOD TYPES COMMON IN THE LATE CRETACEOUS AND EARLY TERTIARY,AND ECOLOGICAL INFERENCES

Paraphyllanthoxylon abbottii n. sp. and cf. Plataninium haydenii Felix from the Paleocene Black Peaks Formation, Big Bend National Park, Texas, are the first Paleocene dicotyledonous woods described from North America. Both represent wood types common in the Cretaceous. There are 30 logs of Paraphyllanthoxylon abbottii; it is rare that a single locality has such as large number of petrified dicotyledonous logs with a similar structural pattern, and the variability in mature wood structure can be documented. Paraphyllanthoxylon abbottii has a combination of features that occurs in many dicotyledonous families, but it is most similar to genera of Burseraceae. The Big Bend Paraphyllanthoxylon trees lack distinct growth rings, which suggests they grew in a climate without marked seasonality; they have high (10–74) vulnerability indices; such high values occur in extant tropical trees. The type species of Paraphyllanthoxylon, P. arizonense Bailey was reexamined, and its quantitative features are described. Aplectotremas Serlin of Albian age from the Edwards Limestone has anatomy like Paraphyllanthoxylon, and most probably is wood from a tree. The wood designated cf. Plataninium haydenii Felix resembles extant Platanaceae but differs in having exclusively scalariform perforation plates. Comparison of this wood with other platanoid woods suggests that in platanoid woods there has been a shortening of vessel elements and a decrease in the frequency of scalariform perforation plates from the Cretaceous through the Tertiary. These changes are consistent with the Baileyan model for specialization in tracheary elements.     

Scalariform-to-simple transition in vessel perforation plates triggered by differences in climate during the evolution of Adoxaceae

Background and Aims Angiosperms with simple vessel perforations have evolved many times independently of species having scalariform perforations, but detailed studies to understand why these transitions in wood evolution have happened are lacking. We focus on the striking difference in wood anatomy between two closely related genera of Adoxaceae, Viburnum and Sambucus, and link the anatomical divergence with climatic and physiological insights.Methods After performing wood anatomical observations, we used a molecular phylogenetic framework to estimate divergence times for 127 Adoxaceae species. The conditions under which the genera diversified were estimated using ancestral area reconstruction and optimization of ancestral climates, and xylem-specific conductivity measurements were performed.Key Results Viburnum, characterized by scalariform vessel perforations (ancestral), diversified earlier than Sambucus, having simple perforations (derived). Ancestral climate reconstruction analyses point to cold temperate preference for Viburnum and warm temperate for Sambucus. This is reflected in the xylem-specific conductivity rates of the co-occurring species investigated, showing that Viburnum lantana has rates much lower than Sambucus nigra.Conclusions The lack of selective pressure for high conductive efficiency during early diversification of Viburnum and the potentially adaptive value of scalariform perforations in frost-prone cold temperate climates have led to retention of the ancestral vessel perforation type, while higher temperatures during early diversification of Sambucus have triggered the evolution of simple vessel perforations, allowing more efficient long-distance water transport.     

国产对囊蕨亚科(蹄盖蕨科)植物的管状分子

利用扫描电镜观察了国产蹄盖蕨科(Athyriaceae)对囊蕨亚科(Deparioideae)10种植物及双盖蕨属(Diplazium Sw.)3种植物根状茎的管状分子。结果显示, 这些管状分子端壁和侧壁的形态及结构分别相同且侧壁具有穿孔板(多穿孔板)。根据穿孔板的形态特征, 将该亚科的管状分子分为5种类型: (1)梯状穿孔板, 无穿孔的二型性现象; (2)梯状穿孔板, 有穿孔的二型性现象; (3)网状穿孔板; (4)梯状-网状混合的穿孔板; (5)大孔状穿孔板。按照纹孔膜残留的程度又可分为3种: 部分区域有完整的纹孔膜、残留呈网状或线状以及很少或无纹孔膜残留。结合前人的研究资料, 发现蕨类植物的管状分子与被子植物的导管分子在形态和输导机理上存在明显差异, 管胞和导管分子不能仅仅根据纹孔膜的存在与否来确定, 而应根据穿孔板存在于端壁还是侧壁进行判断, 即穿孔板仅存在于端壁的管状分子为导管分子; 端壁和侧壁形态及结构分别相同, 有或无穿孔板的管状分子为管胞。由此可以推测蕨类植物和裸子植物中输导水分和矿物质的管状分子主要为管胞。单叶双盖蕨属(Triblemma(J. Sm.) Ching)与双盖蕨属管状分子的特征并不相似, 显示了将单叶双盖蕨属从双盖蕨属独立出来归入对囊蕨亚科的合理性。根据管状分子的特征, 推测假蹄盖蕨属(Athyriopsis Ching)和蛾眉蕨属(Lunathyrium Koidz.)可能是比较进化的属, 而介蕨属 (Dryoathyrium Ching)相对比较原始, 单叶双盖蕨属的系统位置应介于假蹄盖蕨属与介蕨属之间。     

四种番荔枝科(Annonaceae)植物导管分子及其穿孔板的比较观察

番荔枝科是被子植物基部类群,木兰目中最大的一个科。为了解暗罗属(Polyalthia)的海南暗罗(Polyalthia laui)、假鹰爪属(Desmos)的假鹰爪(Desmos chinensis)、紫玉盘属(Uvaria)的山椒子(Uvaria grandiflora)、瓜馥木属Fissistigma)的瓜馥木(Fissistigma oldhamii)四个种的导管与穿孔板的形态学特征,该研究利用扫描电子显微镜(SEM)对其导管分子及穿孔板形态进行观察,首次展示了这4属4种的导管分子与穿孔板的形态特征,并对其导管的长度与直径进行了分析与比较。结果表明:这四个种导管分子端壁均为单穿孔板,部分穿孔板具尾,不同种在导管与穿孔板形态上具有明显的差异;长度与直径的统计学分析显示其种间差异极显著,导管长度与直径的相关性分析显示其没有相关性。综合导管的形态学特征与统计学分析结果,该研究认为在这四个种中,假鹰爪的导管分子直径与长度变化幅度都不大,长度较短,直径最大,穿孔板平截,不具尾或具小尾,其导管分子处于较高的演化水平。     

Distribution of scalariform and simple perforation plates within the vessel network in secondary xylem of Araliaceae and its implications for wood evolution

The distribution of scalariform and simple perforation plates along vessels in Arthrophyllum otopyrenum, Meryta tenuifolia, and Polyscias multijuga (Araliaceae) is examined. In all three species, most vessels bear simple perforation plates only, but the combination of simple and scalariform perforation plates in variable ratios also occurs. Aggregated arrangement of scalariform perforation plates along the vessels was statistically confirmed in some vessel portions. The scalariform perforation plates occur mostly in narrow vessels that are grouped in multiples. Within the clade represented by Polyscias and Arthrophyllum, the evolutionary transition from scalariform to simple perforation plates is realized as the gradual elimination of vessels or vessel portions with scalariform perforation plates, but is not accompanied by a gradual decrease of the number of bars per perforation plate. The narrow vessels that are grouped in vessel multiples are likely to retain the ability to develop scalariform plates, which could promote the evolution from simple to scalariform perforation plates as is the case within Meryta.     

Effects of elevated CO<Subscript>2</Subscript> and nitrogen on wood structure related to water transport in seedlings of two deciduous broad-leaved tree species

Wood structure might be altered through the physiological responses to atmospheric carbon dioxide concentration ([CO₂]) and nitrogen (N) deposition. We investigated growth, water relations and wood structure of 1-year-old seedlings of two deciduous broad-leaved tree species, Quercus mongolica (oak, a ring-porous species) and Alnus hirsuta (alder, a diffuse-porous species and N₂–fixer), grown under a factorial combination of two levels of [CO₂] (36 and 72 Pa) and nitrogen supply (N; low and high) for 141 days in phytotron chambers. In oak, there was no significant effect of [CO₂] on wood structure, although elevated [CO₂] tended to decrease stomatal conductance (g _s) and increased water use efficiency regardless of the N treatment. However, high N supply increased root biomass and induced wider earlywood and larger vessels in the secondary xylem in stems, leading to increased hydraulic conductance. In alder, there was significant interactive effect of [CO₂] and N on vessel density, and high N supply increased the mean vessel area. Our results suggest that wood structures related to water transport were not markedly altered, although elevated [CO₂] induced changes in physiological parameters such as g _s and biomass allocation, and that N fertilization had more pronounced effects on non-N₂-fixing oak than on N₂-fixing alder.     

Bestimmung des Schleimgehaltes myxospermer Diasporen verschiedener Angiospermenfamilien

The mucilage content of structurally differing myxospermatic diaspores from 49 species belonging to 19 families ofAngiospermae has been determined by applying various extraction procedures. The results demonstrate no obvious relationship between the size, mucilage quantity, and the swelling factor of the diaspores studied. Furthermore, mucilage producing structures and structural peculiarities of the mucilages themselves are elaborated.

     

国产对囊蕨亚科（蹄盖蕨科）植物的管状分子

利用扫描电镜观察了国产蹄盖蕨科（Athyriaceae）对囊蕨亚科（Deparioideae）10种植物及双盖蕨属（Diplazium Sw．）3种植物根状茎的管状分子。结果显示,这些管状分子端壁和侧壁的形态及结构分别相同且侧壁具有穿孔板（多穿孔板）。根据穿孔板的形态特征,将该亚科的管状分子分为5种类型：（1）梯状穿孔板,无穿孔的二型性现象：（2）梯状穿孔板,有穿孔的二型性现象：（3）网状穿孔板：（4）梯状-网状混合的穿孔板：（5）大孔状穿孔板。按照纹孔膜残留的程度又可分为3种：部分区域有完整的纹孔膜、残留呈网状或线状以及很少或无纹孔膜残留。结合前人的研究资料,发现蕨类植物的管状分子与被子植物的导管分子在形态和输导机理上存在明显差异,管胞和导管分子不能仅仅根据纹孔膜的存在与否来确定,而应根据穿孔板存在于端壁还是侧壁进行判断,即穿孔板仅存在于端壁的管状分子为导管分子：端壁和侧壁形态及结构分别相同,有或无穿孔板的管状分子为管胞。由此可以推测蕨类植物和裸子植物中输导水分和矿物质的管状分子主要为管胞。单叶双盖蕨属（Triblemma（J．Sm．）Ching）与双盖蕨属管状分子的特征并不相似,显示了将单叶双盖蕨属从双盖蕨属独立出来归人对囊蕨亚科的合理性。根据管状分子的特征,推测假蹄盖蕨属（Athyriopsis Ching）和蛾眉蕨属（Lunathyrium Koidz．）可能是比较进化的属,而介蕨属（Dryoathyrium Ching）相对比较原始,单叶双盖蕨属的系统位置应介于假蹄盖蕨属与介蕨属之间。     

Wood and stem anatomy of Lardizabalaceae, with comments on the vining habit, ecology and systematics

CARLQUIST, S., 1984. Wood and stem anatomy of Lardizabalaceae, with comments on the vining habit, ecology and systematics. Qualitative and quantitative data, based mostly upon liquid-preserved specimens, are presented for Akebia, Roquila, Decaisnea, Holbodia, Lardizabala, Sinofranchetia and Stauntonia . Because Decaisnea is a shrub whereas the other genera are vines, anatomical differences attributable to the scandent habit can be considered. These include exceptionally wide vessels, a high proportion of vessels to tracheids (or other imperforate trdcheary elements) as seen in transection, simple perforation plates, multiseriate rays which are wide and tall, and pith which is partly or wholly sclerenchymatous. With respect to ecology, two features are discussed: spirals in narrower vessels may relate to adaptation to freezing in the species of colder areas, and crystalliferous sclereids seem adapted in morphology and position to deterrence of phytophagous insects or herbivores. The wood may provide mechanisms for maintaining conduction even if wider vessels are deactivated temporarily by formation of air embolisms. Wood and stem anatomy of Lardizabalaceae compare closely to those of Berberidaceae and of Clematis (Ranunculaceae), as well as to other families of Berberidales. Decaisnea is more primitive than these in having consistently sralariform perforation plates and in having scalariform pitting on lateral walls of vessels. A tentative listing of anatomical features which may correspond to generic limits is given.     

Evidence for intergeneric incompatibility in ferns

The archegonial mucilage ofAthyrium filix-femina andA. distentifolium paralyses spermatozoids ofDryopteris filix-mas (and in one caseD. inaequalis) before they penetrate the archegonial venter. The archegonial mucilage ofDryopteris filix-mas has a weak positive chemotactic influence on the spermatozoids of the twoAthyrium species. The spermatozoids ofDryopteris were never observed in the archegonia ofAthyrium. Incompatibility was not observed within and between the twoAthyrium species, withinDryopteris filix-mas or betweenAthyrium filix-femina and twoAsplenium species.Contribution No. 327.     

WOOD ANATOMY OF ILLICIUM (ILLICIACEAE): PHYLOGENETIC,ECOLOGICAL, AND FUNCTIONAL INTERPRETATIONS

Quantitative and qualitative features are reported for 23 collections of ten species of Illicium, sole genus of Illiciaceae. Vessel elements are long, thin-walled, and angular; perforation plates are scalariform and range from long to moderately long; vessel-ray pitting is scalariform to opposite. Tracheids bear fully bordered pits. Axial parenchyma is sparse, abaxial to vessels with some diffuse cells also present. Rays are both multiseriate and uniseriate; the former are lacking near the pith in some species. No erect sheathing cells are present on multiseriate rays, and procumbent cells become more abundant as stems increase in size. Four species from montane subequatorial highlands lack growth rings and helical sculpture in vessels; the remainder of Illicium species have these features. Notably narrow vessels and large numbers of vessels per sq. mm characterize the temperate species from northern limits for the genus, I. anisatum, I. floridanum, and I. parviflorum. Greater vessel density offers redundancy and greater safety and is correlated with greater frost and possibly greater fluctuation in moisture availability. These two ecological features are probably also related to the narrow vessel diameter, which may retard entry of air embolisms (lowered air entry values) in accord with the physiological considerations of Slatyer. Reduction of number of bars per perforation plate within Illicium is also correlated with the more northerly climates. An additional hypothesis for evolution of shorter vessel elements in dicotyledons is introduced: if, as claimed by Slatyer, air embolisms in vessels tend to stop at ends of vessel elements and thus do not disable entire vessels, shorter vessel elements would maximally localize air embolisms. Presence of helical sculpture and other forms of relief within vessels has been difficult to explain in conifers and dicotyledons; such features might help resist cavitations by increasing adhesion of water molecules to cell walls (hydration).     

Xylem structure and water transport in a twiner,a scrambler,and a shrub of Lonicera (Caprifoliaceae)

Summary Wood structure and function was investigated in different growth forms of temperate honeysuckles (Lonicera spp.). All three species had many narrow vessels and relatively few wide ones, with the measured K _h (flow rate/pressure gradient) approximately 24–55% of the theoretical K _h predicted by Poiseuille's law. Only the twiner, Lonicera japonica, had some vessels greater than 50 m in diameter. The twiner also had the narrowest stem xylem diameters, suggesting the greater maximum vessel diameter hydraulically compensated for narrow stems. Conversely, the free-standing shrub, L. maackii, had the greatest annual increments of xylem but the least percent conductive xylem implying that a great portion of the wood was involved with mechanical support. The scrambler, L, sempervirens had low maximum vessel diameter, high Huber values (= xylem area/leaf area), and low specific conductivities (= measured K _h/xylem area), much like the shrub. The greatest vessel frequency occurred in the scrambler (901 vessels · mm^-2), the highest thus far recorded in vines. The lowest Huber value and highest specific conductivity occurred in the twiner, suggesting little self-support but relatively efficient water conduction. LSC (= measured K _h/leaf area) and maximum vessel diameter of Lonicera vines were near the low end of the range for vines in general.     

Nectar flow and pollinators' efficiency in two co-occurring species ofCapparis (Capparaceae) in Israel

Two closely related species ofCapparis, C. ovata andC. spinosa, which are exposed to the same pollination environment were studied. The nectar volume and concentration ofC. ovata are higher than inC. spinosa. Both species have similar pollination efficiency, but the relative contribution of each pollinator is different.C. ovata is pollinated mainly hy hawkmoths while the principal pollinators inC. spinosa are bees.