Wood anatomy of Polygonaceae: analysis of a family with exceptional wood diversity

Quantitative and qualitative data are presented for woods of 30 species of woody Polygonaceae. Wood features that ally Polygonaceae with Plumbaginaceae include nonbordered perforation plates, storeying in narrow vessels and axial parenchyma, septate or nucleate fibres, vasicentric parenchyma, pith bundles that undergo secondary growth, silica bodies, and ability to form successive cambia. These features are consistent with pairing of Plumbaginaceae and Polygonaceae as sister families. Wood features that ally Polygonaceae with Rhabdodendraceae include nonbordered perforation plates, presence of vestured pits in vessels, presence of silica bodies and dark-staining compounds in ray cells, and ability to form successive cambia. Of the features listed above, nonbordered perforation plates and ability to form successive cambia may be symplesiomorphies basic to Caryophyllales sensu lato . The other features are more likely to be synapomorphies. Wood data thus support molecular cladograms that show the three families near the base of Caryophyllales s.l. Chambered crystals are common to three genera of the family and may indicate relationship. Ray histology suggests secondary woodiness in Antigonon, Atraphaxis, Bilderdykia, Dedeckera, Eriogonum, Harfordia, Muehlenbeckia, Polygonum , and Rumex . Other genera of the family show little or no evidence of secondary woodiness. Molecular data are needed to confirm this interpretation and to clarify the controversial systematic groupings within the family proposed by various authors. Vessel features of Polygonaceae (lumen diameter, element length, density, degree of grouping) show an extraordinary range from xeromorphy to mesomorphy, indicating that wood has played a key role in ecological and habital shifts within the family; the diversity in ecology and habit are correlated with quantitative wood data.  © 2003 The Linnean Society of London. Botanical Journal of the Linnean Society , 2003, 141 , 25−51.     

Vestured pits and vestured vessel member walls in some Indian dicotyledonous woods

NAIR, M. N. B. AND MOHAN RAM, H. Y., 1989. Vestured pits and vestured vessel member walls in some Indian dicotyledonous woods. The woods of 144 taxa belonging to 38 families of angiosperms were examined for vestured pits and vestured vessel member walls using scanning electron microscopy. Vestured pits are present in 66 taxa (belonging to ten families) and vestured vessel member walls occur in only six taxa (belonging to three families). In Ehretiaceae and Euphorbiaceae vestures are present only in certain vessel members. In Wrighlia tinctoria , perforation plates containing vestures have been observed in addition to the presence of vestured pits. A classification of vestured pits based on their morphology and distribution is proposed by us. In all the types of vestured pits, vestures are present on the margin of the outer pit aperture or on the pit chamber wall. Occasionally, they are present in the pit canal, on the margin and in the vicinity of the inner pit aperture and rarely over the inner walls of the vessel members. The functions of vestured pits are not clear, although several suggestions are made. Whether or not these structures affect wood processing is not presently understood. It appears that vestured pits and vestured vessel member walls have diagnostic rather than phylogenetic value.     

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.     

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.     

Wood and bark anatomy of Muntingiaceae: A phylogenetic comparison within Malvales s. l.

Quantitative and qualitative data on wood and bark anatomy are given for Muntingia calabura L. and Dicraspidia donnell-smithii Standley. These data are compared with phylogenetic schemes, based on DNA analysis, in which Muntingiaceae belong to the “dipterocarp clade” within Malvales. The data are consistent with this hypothesis, although Muntingiaceae lack pit vestures in vessels, which are seen in the other malvalean families (Cistaceae, Dipterocarpaceae, Neuradaceae, Sarcolaenaceae, Thymeleaceae), and this may represent a loss of pit vestures. All families of the dipterocarp clade agree with both genera of Muntingiaceae in having tracheids as the imperforate tracheary element type (at least ancestrally), although fiber-tracheids also occur in some Dipterocarpaceae and Thymeleaceae. The large size of some malvalean families (with attendant greater diversity in character states) and a paucity of wood studies in those families make for difficulty in comparison of features such as axial parenchyma and ray types with those of Muntingiaceae; character states of these features are consistent with placement of Muntingiaceae in the dipterocarp clade of Malvales. Banded phloem fibers in bark of Muntingiaceae are much like those of other Malvales. Wood of Muntingiaceae is highly mesomorphic according to quantitative vessel features.     

银缕梅木材解剖特征及其系统学意义

报道了银缕梅（ShaniodendronsubaequaleM.B.Deng,H.T.Wei＆X,Q,Wang）木材的解剖学特征,通过比较研究支持将银缕梅（“小叶金缕梅”HamamelissubaeqalisH.T.Chang）从金缕梅属（族）中分出的处理,其合适的系统位置应归入弗特吉族。     

我国南部5种冷杉植物木材的比较解剖学研究

应用光学显微镜和扫描电子显微镜对分布于我国南部的5种冷杉属(Abies)植物,即资源冷杉(A．ziyuanensis)、大院冷杉(A.dayuanensis)、梵净山冷杉(A.fanjingshanensis)、元宝山冷杉(A.yuanbaoshanensis)和台湾冷杉(Akawakamii)的木材结构进行了研究。从管胞分子长度、管胞分子直径、射线高度、射线频率、纹孔类型、交叉场纹孔类型、交又场纹孔数目等方面,比较了它们木材解剖特征的差异。结果表明：大院冷杉和资源冷杉在射线频率、管胞直径、管胞长度、交叉场纹孔数目方面都很类似;元宝山冷杉在管胞直径与射线长度方面与其它冷杉有显著差异。在纹孔类型、交叉场纹孔类型方面,几种冷杉都是一致的。在交叉场纹孔数目方面,大院冷杉、资源冷杉较少,而梵净山冷杉、元宝山冷杉和台湾冷杉较多。我国南部这5种冷杉的木材解剖特征与分布在华北、东北及青藏高原上冷杉的木材非常类似。为了便于区别这5种木材,根据木材解剖特征编制了检索表。     

Contribution of vegetative anatomy to the systematics of the Zygophyllaceae R.Br

SHEAHAN, M. C. & CUTLER, D. F., 1993. Contribution of vegetative anatomy to the systematics of the Zygophyllaceae R.Br. The Zygophyllaceae sensu lato are a heterogeneous family of trees, shrubs and herbs growing in arid and semi-arid areas of the world. There has been disagreement about the systematic status of some groups within the family, and the position of Balanites has also been disputed. The vegetative anatomy of the family was examined to see if it could throw light on current systems of classification. The anatomy of 37 species in 19 genera is described, and the results of tests of C₄ activity in 27 species are given. There is anatomical evidence to support the exclusion of Balanites into a separate family, and some groups (Engler's Peganoideae and Nitrarioideae) have characteristics which set them apart from the rest of the family. This is in accordance with other analyses of the family based on morphological, palynological and biochemical studies. There is also evidence that the tribuloid genera Tribulus, Kallstroemia and Kelleronia should be separated from the zygophylloid genera, at least at subfamily level; however, Neoluederitzia and Sisyndite should remain in the Zygophylloideae. Brief reference is made to relationships with other families in the Geraniales.     

Wood anatomy of Penaeaceae (Myrtales): comparative, phylogenetic, and ecological implications

Wood samples of stems, lignotubers, and roots of the majority of species of Penaeaceae were analyzed with respect to qualitative and quantitative features. Virtually no data have hitherto been presented on xylem features of this family, restricted to Cape Province, South Africa. Presence of vestured pits in vessels, septate crystalliferous parenchyma in wood, intraxylary phloem, predominantly erect ray cells in the typically narrow, multiseriate rays and in the uniseriate rays, and amorphous deposits in ray cells place Penaeaceae securely in Myrtales and help to define that order. By comparison of ecological preferences of the species, as observed during field work, with quantitative analysis of conductive tissue, close correspondence of the wood structure to habit and habitat is demonstrated.     

Wood and bark anatomy of Gnetutn gnemon L.

Quantitative and qualitative data are presented for seven collections representing two varieties (unlike in habit) of Gnetum gnemon. Tracheids are present, but abundant and intermixed with them are septate fibre-tracheids rich in starch. Axial parenchyma has been reported only once previously for the species. Axial parenchyma is in strands of 4–10 cells, is rich in starch, is primarily vasicentric (paratracheal) in distribution, less commonly diffuse. About equally common are simple and compound perforation plates; the latter are composed of from two to about ten bordered foraminate perforations, the shape of which may be altered by crowding or coalescence, but is clearly still foraminate. Lateral walls of vessels bear pits that are vestured around pit cavities, not facing the pit membrane. Rays are composed mostly of procumbent cells; the tangential walls bear bordered pits. Crystals, present in ray cells and (rarely) axial parenchyma vary widely in size. Crystalliferous sclereids with layered walls, starch-rich parenchyma, and gelatinous secondary phloem fibres are the main components of bark. Early stages in origin of successive vascular cambia in bark are newly described. When representative conditions are derived from study of large numbers of slides, the classical view that Gnetum vessels are unlike those of angiosperms is supported. Features of Gnetum gnemon wood are discussed in the light of ecology and conductive physiology.     

梣属11种植物次生木质部附物纹孔的电镜观测

应用扫描电镜对梣属11种植物次生木质部导管附物纹孔的分布和形态进行了详细的观察,应用Carnoy2.0软件和扫描电子显微镜采集的照片,测定了附物纹孔丰富度指标和纹孔数量特征指标。电镜观察表明,梣属11种研究植物次生木质部导管分子侧壁附物纹孔的分布和形态变化较大,附物纹孔丰富度指标的统计描述进一步证实附物纹孔的分布变化大;3个附物纹孔丰富度指标分别与管间具缘纹孔数量特征指标的逐步回归分析表明,导管侧壁附物纹孔丰富度2个指标,即导管外纹孔口附物频率与导管纹孔腔附物频率随纹孔口面积百分比的增大而增大,推测梣属植物附物纹孔丰富度与纹孔几何构造及数量特征有关。研究认为,附物纹孔在梣属植物稳定存在,是可界定梣属植物的木材解剖性状。     

木槿5个种下类群木材的比较解剖学

根据木材结构观察,运用方差分析和数量分类方法,对木槿五个种下类群的种下分类和系统进化进行讨论。结果表明,木槿五个种下类群共同的特征是:半环孔材或环孔材。导管在横切面呈椭圆形,端壁水平或倾斜,单穿孔,导管分布频率相对较少,以复管孔为主,导管分子较短,直径较大。纤维均由大量的韧型纤维和极少量的纤维管胞组成。木射线为异型Ⅱa或异型Ⅱa和Ⅱb,中等射线密度或在紫花单瓣木槿为高密度(每1mm为12个),单列射线和多列射线均为低射线和细射线。聚类分析和PCD排序结果表明,木槿五个种下类群可分为2个亚种:牡丹木槿和紫花单瓣木槿,前者包括3个变型:雅致木槿、白花重瓣木槿和牡丹木槿,后者包括2个变型:紫花单瓣木槿和紫花重瓣木槿。从木材演化趋势看,紫花单瓣木槿是一个原始类群,该类群在早期分化出牡丹木槿,在晚期分化紫花重瓣木槿,而牡丹木槿又先后分化出雅致木槿和白花重瓣木槿。     

Wood anatomy of Krameriaceae with comparisons with Zygophyllaceae: phylesis, ecology and systematics

Wood of nine species of Krameria (including all clades proposed within the genus) reveals a few characters related to infrageneric systematics; most relate primarily to ecology and habit. Wood of Krameria closely fits quantitative data reported for desert shrubs. Lack of vessel grouping correlates with the presence of densely pitted tracheids. Wood xeromorphy in Krameria may relate in part to hemiparasitism. Tracheid presence may also account for relatively low vessel density. Wood anatomy of six species of Zygophyllaceae (including both genera of Morkillioideae) is compared with that of Krameriaceae because recent phylogenies propose that these two families comprise the order Zygophyllales. Several wood characters appear to represent synapomorphies reflecting this relationship. Differences in wood anatomy between Krameriaceae and Zygophyllaceae are believed to represent autapomorphies. Notable among these include Paedomorphic Type II rays (Krameriaceae), storying (Zygophyllaceae), presence of vestured pits (Zygophyllaceae), and differentiation into vasicentric tracheids and fibre-tracheids (Zygophyllaceae). The latter feature is referable to the concept of fibre-tracheid dimorphism. Recognition of Krameriaceae as separate from Zygophyllaceae is supported by wood characters. Wood of Zygophyllales does not conflict with the idea that the order belongs to rosids, with Malpighiaceae as the outgroup of Zygophyllales.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 257–270.     

Comparative anatomy of intervessel pits in two mangrove species growing along a natural salinity gradient in Gazi bay, Kenya

BACKGROUND AND AIMS: According to the air-seeding hypothesis, embolism vulnerability in xylem elements is linked directly to bordered pit structure and functioning. To elucidate the adaptive potential of intervessel pits towards fluctuating environmental conditions, two mangrove species with a distinct ecological distribution growing along a natural salinity gradient were investigated. METHODS: Scanning and transmission electron microscopic observations were conducted to obtain qualitative and quantitative characteristics of alternate intervessel pits in A. marina and scalariform intervessel pits in Rhizophora mucronata. Wood samples from three to six trees were collected at seven and five sites for A. marina and R. mucronata, respectively, with considerable differences between sites in soil water salinity. KEY RESULTS: Vestured pits without visible pores in the pit membrane were observed in A. marina, the mangrove species with the widest geographical distribution on global as well as local scale. Their thick pit membranes (on average 370 nm) and minute pit apertures may contribute to reduced vulnerability to cavitation of this highly salt-tolerant species. The smaller ecological distribution of R. mucronata was in accordance with wide pit apertures and a slightly higher pitfield fraction (67 % vs. 60 % in A. marina). Nonetheless, its outer pit apertures were observed to be funnel-shaped shielding non-porous pit membranes. No trends in intervessel pit size were observed with increasing soil water salinity of the site. CONCLUSIONS: The contrasting ecological distribution of two mangrove species was reflected in the geometry and pit membrane characteristics of their intervessel pits. Within species, intervessel pit size seemed to be independent of spatial variations in environmental conditions and was only weakly correlated with vessel diameter. Further research on pit formation and function has to clarify the large variations in intervessel pit size within trees and even within single vessels.     

Systematic and phylogenetic value of wood anatomy in Heteromorpheae (Apiaceae,Apioideae)

The wood anatomy of all four woody genera of the tribe Heteromorpheae (Apiaceae, subfamily Apioideae) has been described and compared, based on 40 wood samples (representing nine species of Anginon, one species of Glia, three species of Heteromorpha and two species of Polemannia). The four genera were found to be relatively similar in their wood anatomy. Helical thickenings on the vessel walls occur in all species investigated and appear to represent an ancestral character state and a symplesiomorphy for the tribes Bupleurieae and Heteromorpheae. Each of four genera has a diagnostically different combination of character states relating to the diameter of vessels, size of intervessel pits, length of fibres, presence and arrangement of banded axial parenchyma, size of rays and ray cells, and presence of septate fibres and crystals in the ray cells. The occurrence of marginal axial parenchyma in Anginon and Glia may be an additional synapomorphy for these taxa. Variation in the wood anatomy of 31 samples from nine species of Anginon is not correlated with habitat (Fynbos or Succulent Karoo Biomes), but instead appears to reflect adaptations to seasonal aridity found in both ecosystems. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 569–583.     

Wood anatomy and hydraulic architecture of stems and twigs of some Mediterranean trees and shrubs along a mesic-xeric gradient

Woody species populating the major Mediterranean ecosystems in the world are characterized by different levels of adaptation to the seasonal Mediterranean climate conditions. Many species of these ecosystems show wood features that allow high efficiency of transport when water is available, while maintaining hydraulic safety during drought periods. This study focuses on the anatomy of juvenile and mature wood of some species representative of continuous sequences of Mediterranean vegetation formations according to gradients of water availability, from xeric to relatively mesic: Cistus monspeliensis L., Rhamnus alaternus L., Myrtus communis L., Pistacia lentiscus L., Olea europaea L., Quercus ilex L., Fraxinus ornus L. and Ostrya carpinifolia L. Twigwood collected in Southern Italy was anatomically compared with the stemwood of the same species represented in the reference slide collection of the National Herbarium of the Netherlands (Lw). The “hydraulic distance” between the wood of main stems and twigs was estimated on the basis of suites of anatomical features related to water efficiency/safety. Although some attributes (i.e. porosity and type of imperforate tracheary elements) were similar in young twigs and older rings, other traits (i.e. vessel frequency and size) evidenced the different hydraulic properties of twig and stemwood. The difference between juvenile and mature structures was large in the species of the mesic end of the gradient while it was relatively small in those more xeric. This tendency is in agreement with the habit gradient from medium-sized trees to small evergreen/drought deciduous shrubs according to decreasing water availability in Mediterranean vegetation types.     

Wood and bark anatomy of lianoid Indomalesian and Asiatic species of Gnetum

Quantitative and qualitative data on wood and bark are offered for 11 species of lianoid Indomalesian and Asiatic species of Gnetum section Cylindrostachys. Material of roots was studied for two species, material of an underground stem for one species, and stem material was studied for all species; wood from inside and outside of a large stem of G. montanum was analysed (quantitative data do not change with age in this species). Roots have shorter, narrower vessel elements, more numerous per mm², compared with those of stems; these trends run counter to those in dicotyledons. Roots and underground stems have more abundant parenchyma and less abundant sclerenchyma than do stems. Parenchyma of both roots and stems is rich in starch. All of the species studied here have both fibre-tracheids and tracheids, but tracheids are not distributed vasicentrically as they are in dicotyledons. Tori are reported for tracheary elements of three species studied here. Vasicentric axial parenchyma (which usually is thick-walled) is present in all species; thick or thin-walled diffuse or diffuse-in-aggregates apotracheal parenchyma is present in almost all of the species studied. Rays are mostly dimorphic in size, but show various conditions with respect to wall thickness, sclerenchyma presence, and crystal presence. As in other lianoid species of Gnetum, the species of the present study show origin of lateral meristem activity in parenchyma of the innermost cortex. Cortex and bark of the species studied here are relatively uniform in distribution of gelatinous fibres, nests of sclereids, the cylinder of brachysclereids that extends around the stem, and sclerenchymatous phelloderm. Laticifers were observed in bark of only two species studied. Although a few species characters are evident, the species that comprise Section cylindrostachys differ from each other mostly in degree rather than in presence or absence character state distributions. Secretory cavities are newly reported for the genus.     

Systematic anatomy of Oceanopapaver, a monotypic genus of the Gapparaceae from New Caledonia

Evidence from vegetative anatomy, reproductive morphology, and palynology does not support a relationship of Oceanopapaver with Cistaceae, Cruciferae, Flacourtiaceae, Papaveraceae, and Tiliaceae, but suggests placement of the genus in Capparaceae. The apparent occurrence of myrosin cells, among other features, effectively excludes all of the aforenoted families except Capparaceae and Cruciferae. However, multicellular non-glandular trichomes, bracteate inflorescences, sepals and petals each occasionally other than four per flower, presence of an androgynophore, numerous stamens, tricolporate and binucleate pollen, the unilocular mature ovary, the stipitate fruit, and the exotegmic seed in Oceanopapaver favour Capparaceae over Cruciferae. Floral histology and vasculature provide no clues about the relationships of Oceanopapaver. A few features are anomalous, most notably the presence of secretory canals and secretory cells in the genus versus their absence in Capparaceae and their rarity in Cruciferae, the trichomic floral nectary in the genus versus the massive, non-trichomic nectaries in these two families, and the straight embryo in the genus versus the more or less curved or folded embryo in the two families. The fleshy endosperm in Oceanopapaver has counterparts in a few Capparaceae, contrary to previous claims that endosperm is absent or scanty in this family. The report of stamen fascicle traces for Oceanopapaver is the first for Capparaceae, but these should be sought elsewhere in the family. Within Capparaceae the genus fits best in Capparoideae compared to Cleomoideae or the nine other very restrictive subfamilies variously proposed for Capparaceae. There is no justification for the monotypic segregate Oceanopapaveraceae. The phylogenetic and functional anatomy of vegetative and reproductive structures is discussed.     

Wood day capacitance is related to water content,wood density,and anatomy across 30 temperate tree species

Water released from wood during transpiration (capacitance) can meaningfully affect daily water use and drought response. To provide context for better understanding of capacitance mechanisms, we investigated links between capacitance and wood anatomy. On twigs of 30 temperate angiosperm tree species, we measured day capacitance (between predawn and midday), water content, wood density, and anatomical traits, that is, vessel dimensions, tissue fractions, and vessel–tissue contact fractions (fraction of vessel circumference in contact with other tissues). Across all species, wood density (WD) and predawn lumen volumetric water content (VWC_L-pd) together were the strongest predictors of day capacitance (r²_adj = .44). Vessel–tissue contact fractions explained an additional ~10% of the variation in day capacitance. Regression models were not improved by including tissue lumen fractions. Among diffuse-porous species, VWC_L-pd and vessel–ray contact fraction together were the best predictors of day capacitance, whereas among semi/ring-porous species, VWC_L-pd, WD and vessel–fibre contact fraction were the best predictors. At predawn, wood was less than fully saturated for all species (lumen relative water content = 0.52 ± 0.17). Our findings imply that day capacitance depends on the amount of stored water, tissue connectivity and the bulk wood properties arising from WD (e.g., elasticity), rather than the fraction of any particular tissue.