Comparative wood anatomy of Andromedeae s.s., Gaultherieae, Lyonieae and Oxydendreae (Vaccinioideae, Ericaceae s.l.)

The wood anatomical structure of 11 out of 13 genera from four tribes of the Vaccinioideae, namely Andromedeae s.s. , Gaultherieae, Lyonieae and Oxydendreae (Ericaceae s.l. ), is described using light and scanning electron microscopy. Several features of the secondary xylem support the tribal classification based on molecular data: arrangement of vessel-ray pitting, height of multiseriate rays and the shape of the body ray cells. Oxydendreae are clearly defined from the other representatives by various wood anatomical features. Gaultherieae can be distinguished from Lyonieae by differences in vessel perforation plates, vessel-ray pitting, height and structure of multiseriate rays, and occurrence of prismatic crystals, but the wood of Andromedeae s.s. is similar to Gaultherieae. Moreover, Andromedeae s.s. , Oxydendreae and Vaccinieae are characterized by their pith structure, whereas considerable variation in the pith cells is found in Lyonieae and Gaultherieae.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 161–179.     

Comparative wood anatomy of epacrids (Styphelioideae,Ericaceae s.L.)

The wood anatomy of 16 of the 37 genera within the epacrids (Styphelioideae, Ericaceae s.l.) is investigated by light and scanning electron microscopy. Several features in the secondary xylem occur consistently at the tribal level: arrangement of vessel-ray pits, distribution of axial parenchyma, ray width, and the presence and location of crystals. The primitive nature of Prionoteae and Archerieae is supported by the presence of scalariform perforation plates with many bars and scalariform to opposite vessel pitting. The wood structure of Oligarrheneae is similar to that of Styphelieae, but the very narrow vessel elements, exclusively uniseriate rays and the lack of prismatic crystals in Oligarrheneae distinguish these two tribes. The secondary xylem of Monotoca tamariscina indicates that it does not fit in Styphelieae; a position within Oligarrheneae is possible. Like most Cosmelieae, all Richeeae are characterized by exclusively scalariform perforation plates with many bars, a very high vessel density and paratracheal parenchyma, although they clearly differ in ray width (exclusively uniseriate rays in Cosmelieae vs. uniseriate and wide multiseriate rays in Richeeae). Several wood anatomical features confirm the inclusion of epacrids in Ericaceae s.l. Furthermore, there are significant ecological implications. The small vessel diameter and high vessel frequency in many epacrids are indicative of a high conductive safety to avoid embolism caused by freeze-thaw cycles, while the replacement of scalariform by simple vessel perforation plates and an increase in vessel diameter would suggest an increased conductive efficiency, which is especially found in mesic temperate or tropical Styphelieae.     

Relationships within balsaminoid Ericales: a wood anatomical approach

Wood samples of 49 specimens representing 31 species and 11 genera of woody balsaminoids, i.e., Balsaminaceae, Marcgraviaceae, Pellicieraceae, and Tetrameristaceae, were investigated using light microscopy and scanning electron microscopy. The wood structure of Marcgraviaceae, Pellicieraceae, and Tetrameristaceae is characterized by radial vessel multiples with simple perforation plates, alternate vessel pitting, apotracheal and paratracheal parenchyma, septate libriform fibers, and the presence of raphides in ray cells. Tetrameristaceae and Pellicieraceae are found to be closely related based on the occurrence of unilaterally compound vessel-ray pitting and multiseriate rays with long uniseriate ends. The narrow rays in Pelliciera are characteristic of this genus, but a broader concept of Tetrameristaceae including Pelliciera is favored. Within Marcgraviaceae, wide rays (more than five-seriate) are typical of the genus Marcgravia. Furthermore, there is evidence that the impact of altitude and habit plays an important role in the wood structure of this family. The wood structure of Balsaminaceae cannot be compared systematically with other balsaminoids because of their secondary woodiness. Balsaminaceae wood strongly differs due to the presence of exclusively upright ray cells in Impatiens niamniamensis, the absence of rays in Impatiens arguta, and the occurrence of several additional paedomorphic features in both species.     

First record of Cercidiphylloxylon(Cercidiphyllaceae)from the Palaeocene of Fushun,NE China

Cercidiphylloxylon spenceri(Brett)Pearson is described from the Lizigou Formation,Palaeocene in China.The growth rings are distinct; pores are diffuse,solitary,with somewhat angular outlines in cross section;vessel elements long with long scalariform perforation plates; intervessel pitting is opposite to scalariform; fibertracheids are present; axial parenchyma is scarce; rays are mostly biseriate and heterogeneous.All wood characters of the fossil specimen fall into the range of those of extant Cercidiphyllum(Cercidiphyllaceae).The finding is one of the earliest fossil wood records of Cercidiphyllaceae.     

五味子科比较木材解剖及其系统学意义

在光学显微镜和扫描电镜下观察了南五味子属Kadsura 7种21个样品和五昧子属Schisandra 8种14个样品的木材解剖特征,结果表明次生木质部的导管分子类型、导管一射线间纹孔的排列方式、射线类型、射线细胞形状等性状在科的水平上很稳定,这些共同特征都支持五味子科Schisandraceae是比较自然的类群。在五昧子科中发现木材导管单生、具梯状穿孔板、导管壁具梯形排列的纹孔以及木射线异型等原始性状,支持五味子科在被子植物中的原始地位。此外,该科木材还具有单穿孔板导管、导管次生壁具螺纹加厚、具分隔纤维等较为特化的性状状态,这种性状进化水平的异等级现象,使五味子科表现出不同进化水平性状的镶嵌组合。根据木材解剖性状对五味子科进行UPGMA聚类分析,所得结果显示南五昧子属和五味子属在木材解剖特征方面有一定的交叉和重叠,这与分子系统学的结论一致,表明这两个属关系密切,可能起源于共同的祖先。通过比较五昧子科与八角科Illiciaceae的木材解剖特征,进一步证明两个科的亲缘关系很近,不支持将五味子科从八角目Illiciales中独立出来成立五味子目Schisandrales的观点。     

The fossil record of Cunoniaceae: new evidence from Late Cretaceous wood of Antarctica?

Fossil angiosperm wood from Upper Cretaceous sediments of Livingston Island and James Ross Island in the northern Antarctic Peninsula region is identified as having the combination of anatomical characters most similar to modern Cunoniaceae. The material is characterised by predominantly solitary vessels, opposite to scalariform intervessel pitting, scalariform perforation plates, heterocellular multiseriate and homocellular uniseriate rays, diffuse axial parenchyma. Anatomically, the specimens conform most closely to the fossil organ genus Weinmannioxylon Petriella which has been placed within the Cunoniaceae. The presence of Weinmannioxylon in Late Cretaceous sediments suggests that taxa within or stem taxa to the Cunoniaceae might have been a notable component of the forest vegetation that covered the Antarctic Peninsula during the Late Mesozoic and may therefore represent the earliest record of this family.     

First record of Cercidiphylloxylon (Cercidiphyllaceae) from the Palaeocene of Fushun,NE China

Abstract Cercidiphylloxylon spenceri (Brett) Pearson is described from the Lizigou Formation, Palaeocene in China. The growth rings are distinct; pores are diffuse, solitary, with somewhat angular outlines in cross section; vessel elements long with long scalariform perforation plates; intervessel pitting is opposite to scalariform; fiber‐tracheids are present; axial parenchyma is scarce; rays are mostly biseriate and heterogeneous. All wood characters of the fossil specimen fall into the range of those of extant Cercidiphyllum (Cercidiphyllaceae). The finding is one of the earliest fossil wood records of Cercidiphyllaceae.     

WOOD ANATOMY OF THE NEW GENUS MANGLIETIASTRUM LAW OF MAGNOLIACEAE FROM CHINA IN RELATION TO ALLIED GENERA

The present paper contributes the knowledge of wood structure of Manglie- tiastrum sinicum Law, a new monotypic genus of the family Magnoliaceae. The anatomical feature of this wood is described as follows: Diffuse-porous wood ; pores 15-25 per sq. mm, solitary or in radial multiples of 3- 4 (may be up to 6) pore cluster also occur but rare, more or less angular in shape, perforation plates scalariform, with 6-12 bors (may be up to 17), generally 7-8 or 10, intervascular pittings scalariform with fine spiral thickenings; vessel elements 748-1224, generally 876 longl wood rays heterogeneous, type IIA with 1-2, sometimes 3-4 rows of upright cells on both margins, uniserate rays 3-7 cells (may be up to 13) or 193-230u high, the multiseriate rays 3-5 cells or 68-119.2u wide, and 16-22 cells or 340-748u height; oil cells absent, fiber-tracheids 0.8-2.8 mm, generally 1.5 mm long; wood parenchma terminal, narrow banded (generally 7-8 cells wide, may be up to 12), rarely scanty paratracheal.     

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).     

Wood structure of Aegiceras corniculatum and its ecological adaptations to salinities

We describe the wood structure of Aegiceras corniculatum and its differences under various soil salinities. This species had diffuse-porous wood with poorly defined growth rings. Vessels which had single perforations occurred abundantly and in multiples and were storeyed. Intervascular pits between contiguous vessels were alternate bordered ones while half-bordered pit-pairs existed between both vessel-ray and vessel-parenchyma. Homogenous xylem rays were multiseriate and uniseriate. Fiber-tracheids with bordered pits often had thinner walls. Xylem parenchyma cells were scant and distributed diffusely and paratracheally. Differences in the structural and quantitative characters of vessels, xylem rays and fiber-tracheids under diverse soil salinities are described. This revised version was published online in August 2006 with corrections to the Cover Date.     

A review of the platanaceous woods from the Eocene paratropical rainforest of south-east England

Small diameter pyritized axes, commonly referred to as 'twigs', of fossil platanaceous wood are described from the Lower Eocene London Clay Formation of south-east England. These twigs are characterized by solitary vessels with scalariform perforation plates, opposite intervessel pits, and tall, multiseriate rays that dilate in the phloem region. The wood anatomy supports close relationship to members of extant Platanaceae and the material is placed in the organ genus Plataninium Unger erected for fossil woods with close anatomical similarity to Platanus L. This material supplements the fossil record of platanaceous type wood from the Eocene London Clay and documents the first record of Plataninium decipiens Brett in the twig flora.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 181–191.     

The Ecological Secondary Xylem Anatomy of 7 Desert Species of Leguminosae

The wood anatomy of 7 species (Ammopiptanthus mongolicus, Amorpha fruticosa, Halimodendron halodendron, Hedysarum mongolicum. Hedysarum scoparium, Lespedeza bicolor and Robinia pseudoacacia)of Leguminosae, which grow in desert regions of Northern China, is described in details. A comparative study on the quantitative wood anatomical characters among the species is made. Except some anatomical characters in A. fruticosa were larger in vessel diameter, thin walled in vessels and libriform fibres, all the rest six species showed a general similarities:vessel frequency/sq, mm very numerous and percentage of multiple vessels high; vessel elements very short, perforations simple and in almost horizontal end walls, intervessel bordered pits alternate and vestured; libriform fibres very short, and usually with thickened walls, and with simple pits; average ray height very low, and with multiseriate as well as uniseriate. However, there are differences in other characters, e. g. vessel distribution, percentage of solitary vessels; spiral thickenings present or absent; amount of axial parenchyma and distribution; ray frequency and type; crystals present or absent, and crystal distribution, if present. According to these anatomical diversities, a key to the identification of the 7 species is given. In this article, the relation between the structure of wood and the environmental influences has been discussed.     

KLEINODENDRON AND XYLEM ANATOMY OF CLUYTIEAE (EUPHORBIACEAE)

Kleinodendron, a new genus of Euphorbiaceae, was assigned by Smith and Downs to the tribe Cluytieae. A xylem anatomical survey indicates that there are no objections to this placement. Woods of Cluytieae are diverse but may be characterized generally by having pores which average less than 80 μ in diameter and which are well divided between solitary and radial multiple distributions in the same species; simple vessel perforations; alternate intervascular pitting; fiber-tracheids and libriform wood fibers; exclusively uniseriate, or uniseriate and biseriate heterocellular vascular rays in the same species; uniseriate “bridges” linking superposed biseriate ray segments; diffuse, diffuse-in-aggregates, and scanty vasicentric axial parenchyma, sometimes in the same species; and crystal rhomboids. That Microdesmis and Pogonophora diverge sharply from these generalizations in having scalariform vessel perforations and broad vascular rays, is an indication that they may not be closely related to other genera in Cluytieae.     

The Secondary Xylem Anatomy of 6 Desert Plants of Caragana

The structures of secondary xylem of 6 species of Caragana, which grow in desert regions of Northwest of China, are described in details. The main quantitative characters are compared with species. And a key to the identification of wood structures of 6 species is given. The main similarities of secondary xylem of these 6 species are as follows: vessels per mm2 very numerous, percentage of multiple vessels high; vessel elements very short, perforations simple and in almost horizontal end walls; intervessel bordered pits alternate and vestured, and vessels with spiral thickenings. Libriform fibres are very short, and usually with thick end walls, and with simple pits. Rays are heigh to very low, and with multiseriate and uniseriate, and with heterogeneous type Ⅰ and Ⅱ. In addition, there are differences in other characters, e.g. vessel distribution, amount of axial parenchyma and distribution, ray frequency, crystals present or absent, and crystal distribution, if present. These differences can be used as the anatomical characters to identify the wood structures of the 6 species. In this article we also discuss the relation between the structure of xylem elements and the environmental influences.     

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.     

Woods of the Vitaceae—fossil and modern

Vitaceoxylon tiffneyi gen. et sp. nov. and Vitaceoxylon carlquistii sp. nov. from the Middle Eocene Clarno formation are the oldest known woods with characteristics of the Vitaceae. They are characterized by a tendency to two diameter classes of vessels, wide and tall rays, and a high proportion of their area is vessel. Other characteristics include septate imperforate elements, scanty paratracheal to vasicentric parenchyma, idioblasts in the rays, crowded alternate intervessel pitting, and vessel-parenchyma pits with reduced borders. Wood anatomy of the major extant genera of Vitaceae was examined and compared to the fossils. Features of secondary xylem useful for distinguishing between genera in the Vitaceae include vessel size and arrangement (two distinct diameter classes or not, radial multiples or tendency to tangential multiples), vessel pitting (scalariform or alternate), crystal type (prismatic, druses, and/or raphides) and location (in chambered parenchyma and/or ray parenchyma), cambial variants (present or absent). Wood anatomy supports the proposed close relationship of Cissus to Cayratia. Pronounced vessel dimorphism occurs in temperate Vitaceae; cambial variant structure occurs in tropical Vitaceae. Despite their conformity with Vitaceae at the family level, the two fossil woods are not comparable to any one extant genus. This contrasts with the Vitaceae seeds from Clarno, all of which are referable to extant genera. Two new combinations for fossil woods of the Vitaceae are proposed: Vitaceoxylon ampelopsoides (Schönfeld) comb. nov., and Vitaceoxylon megyazoense (Greguss) comb. nov.     

Two early Eocene vines from south-east England

Small diameter pyritized axes, commonly referred to as 'twigs', of fossil vitaceous and menispermaceous wood from the Lower Eocene, London Clay Formation of south-east England are described here for the first time. The vitaceous twigs, which represent the earliest known occurrence of fossil Vitaceae wood, are characterized by large diameter, solitary vessels, tall wide rays which dilate in the phloem region, scalariform intervessel pits and simple perforation plates. The wood anatomy supports a close relationship to the Vitaceae and in particular the genus Rhoicissus Planch. The menispermaceous twigs are characterized by medium to moderately large vessels, simple perforation plates, alternate intervascular pitting and very broad and high rays. The anatomical characters support a close relationship to the Menispermaceae and in particular the genera Tinomiscium Miers and Coscinium Colebr. However, as these fossil twigs are not exactly similar to any particular genus they have been placed in the organ genus, Vitacexoylon Wheeler and LaPasha and Menispermoxylon Vozenin-Serra, Privé-Gill & Ginsburg, with which, respectively, they have the greatest similarity. These specimens were studied using reflected light- and scanning electron microscopy.     

Systematic and phylogenetic implications of the wood anatomy of six Neotropical genera of Primulaceae

Our main goals were to identify diagnostic characters at the species, genus, and subfamily levels, find anatomical features with potential for future morphological and molecular (combined) phylogenetic analyses, and to reconstruct the evolution of wood anatomical characters in two subfamilies of Primulaceae in a molecular phylogenetic framework. We investigated twenty-seven species from the woody Myrsinoideae (4 genera) and Theophrastoideae (2 genera) using scanning electron, light, and epifluorescence microscopy. Samples were prepared using standard protocols. Based on the wood anatomical characters, we were able to identify synapomorphies and to detect evolutionary trends of interest for the genera and subfamilies. Both subfamilies share the presence of diffuse porosity, simple perforation plates, septate fibres, and scanty paratracheal axial parenchyma. Theophrastoideae species have rays?>?10 cells wide and short (<?350 µm) vessel elements, and Myrsinoideae have breakdown areas in rays and longer vessel elements. Ardisia and Stylogyne have scalariform intervessel pits, Myrsine exhibit breakdown areas in rays, and two Cybianthus species from subgenus Weilgetia have distinguishing features (e.g., scalariform perforation plate in C. nemoralis and the absence of rays in C. densiflorus). Overall, when combining characters, we were able to segregate the Neotropical Primulaceae subfamilies and genera from each other and from the subfamily Maesoideae based on wood anatomy.     

蜈蚣草导管分子的观察

对蜈蚣草(Pteris vittata)叶轴中导管分子进行了观察。结果表明,其导管分子十分细长,均具长、且十分倾斜的梯状穿孔板,穿孔没有纹孔膜的残余,与侧壁上的梯纹纹孔有着明显的差异。     

蜈蚣草导管分子的观察

对蜈蚣草(Pteris vittata)叶轴中导管分子进行了观察。结果表明,其导管分子十分细长,均具长、且十分倾斜的梯状穿孔板,穿孔没有纹孔膜的残余,与侧壁上的梯纹纹孔有着明显的差异。