Pityostrobus mcmurrayensis sp.nov., a permineralized pinaceous cone from the Cretaceous of Alberta

1981 ◽  
Vol 59 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Ruth A. Stockey
Keyword(s):  
Early Cretaceous ◽  
Vascular Tissue ◽  
Secondary Xylem ◽  
Resin Canal ◽  
Seed Structure ◽  
Thin Sections ◽  
Mcmurray Formation ◽  
Cone Axis ◽  
Resin Canals ◽  
Cone Scale

A new pinaceous species is described from the Early Cretaceous (Albian) McMurray Formation of Alberta. The cone is partially lignitic with permineralized ovules, 13 cm long × 4 cm wide, and occurs in a siliceous sandstone matrix. Thin sections were made after embedding with bioplastic and infiltration of cut faces with epoxy. Externally the helically arranged flattened cone scales resemble those of extant Picea. Scales bear two inverted, winged ovules containing shrunken nucellar and megagametophyte tissue. The cone axis is slender and contains small wedges of secondary xylem lacking resin canals. Vascularization of the cone–scale complex is similar to the non-Pinus species of the Pinaceae with bract and scale traces separate at their origins. One large abaxial resin canal, 1 mm in diameter, accompanies the traces out into the scale for 1 cm before branching. Two large bundles of sclerenchyma accompany the scale vascular tissue and may have served to open the cone at maturity. The bract, small and triangular in outline, has a terete trace and two lateral resin canals. Cone and seed structure are closely comparable to fossil pinaceous genera Pseudoaraucaria and Pityostrobus and the non-Pinus genera of the extant Pinaceae.

Seasonal Variation in Traumatic Resin Canal Formation in Chamaecyparis Obtusa Phloem

IAWA Journal ◽  
1998 ◽  
Vol 19 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Keiko Kuroda
Keyword(s):  
Annual Ring ◽  
Stem Canker ◽  
Chamaecyparis Obtusa ◽  
Resin Canal ◽  
Annual Rings ◽  
Secondary Phloem ◽  
Resinous Stem Canker ◽  
Traumatic Resin Canals ◽  
Resin Canals ◽  
Artificial Wounding

Trunks of Chamaecyparis obtusa were injured to examine seasonal differences in traumatic resin canal formation in secondary phloem. Even after wounding during winter, differentiation of axial parenchyma into epithelium was initiated, and vertical resin canals formed. After winter wounding, resin canal development was slower and the tangential extent of resin canals was narrower than after spring wounding, and it took one to two months until resin secretion began. After spring wounding, the sites of resin canal formation were the 1- and 2-year-old annual rings of phloem. In August, the location of resin canal formation shifted into the current and 1-year-old annual ring. Resin canals never formed in secondary phloem areas that were 3 or more years old. In C. obtusa trunks that are affected by the resinous stem canker, numerous tangentiallines of resin canals are found throughout the phloem, not just recent and 1- to 2-year-old phloem. The present research indicates that these many lines of resin canals were not formed at one time, and that the stimuli that induce traumatic resin canals must occur repeatedly over many years. The data on artificial wounding effects are useful for understanding resinous stem canker.

Analysis of Turee Microscopic Cuaracters for Separating the Wood of Pinus Contorta and P. Ponderosa

IAWA Journal ◽  
2003 ◽  
Vol 24 (3) ◽  
pp. 257-267
Author(s):  
Alex C. Wiedenhoeft ◽  
Regis B. Miller ◽  
Terra J. Theim
Keyword(s):  
Pinus Ponderosa ◽  
Pinus Contorta ◽  
Resin Canal ◽  
Diagnostic Character ◽  
Resin Canals

Three microscopic characters were evaluated for the identification of Pinus contorta and Pinus ponderosa. The tangential diameter of the resin canals, including the epithelium, was compared to the tangential diameter of the entire resin canal complex. The latter measurement was shown to give diagnostic results for these species. Data from the examination of ray composition do not support previously published methods for separating P. contorta and P. ponderosa. The presence or absence of small elongate crystals in the subsidiary parenchyma of the resin canal complexes was shown to be the most powerful diagnostic character for separating the wood of these species.

scholarly journals Resin canals in spruce (Picea abis /L./ Karst.) with the occurrence of reaction wood

2005 ◽  
Vol 53 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Vladimír Gryc ◽  
Petr Horáček
Keyword(s):  
Compression Wood ◽  
3D Models ◽  
Resin Canal ◽  
The Other ◽  
Stem Length ◽  
Reaction Wood ◽  
Spruce Wood ◽  
Other Hand ◽  
Resin Canals

The paper was aimed at the determination of variability of horizontal resin canal dimension in spruce wood in relation to the position in a spruce stem. Significant changes of dimensions in horizontal resin canal along the stem length and radius were found. On the basis obtained of results 3D models (for CW, OW, SWL and SWP zones) describing changes in resin canal dimensions in spruce in relation to the position in a stem were created. In the models, the resin canal dimension decreases with the height of a stem and on the other hand, with an increasing distance from the stem pith the dimension of resin canal increases. The importance of the paper consists in the enlargement of findings about the structure of spruce with compression wood.

Regeneration of vascular tissue through redifferentiation of interxylary phloem after complete girdling in Aquilaria sinensis

IAWA Journal ◽  
2021 ◽  
pp. 1-16
Author(s):  
Bei Luo ◽  
Arata Yoshinaga ◽  
Tatsuya Awano ◽  
Keiji Takabe ◽  
Takao Itoh
Keyword(s):  
Time Course ◽  
Potential Role ◽  
Vascular Tissue ◽  
Secondary Xylem ◽  
Vascular Cambium ◽  
Aquilaria Sinensis ◽  
Phloem Fibers ◽  
Interxylary Phloem ◽  
Time Course Study

Abstract We studied the time-course of stem response for six months following complete girdling in branches of Aquilaria sinensis to determine the potential role of interxylary phloem (IP) in this response. It was found that the vascular cambium, as well as its derivative secondary xylem and phloem, regenerated fully through redifferentiation of IP. We confirmed that vascular cambium regenerated within one month after girdling based on observation of new vessels, IP, and secondary phloem fibers. The time-course study showed that IPs made connections with each other, merged, and became larger through the proliferation of IPs parenchyma cells and the cleaving of secondary xylem in a narrow zone 400 to 1000 μm deep inside the girdled edge. This led to the formation of a complete circular sheath of vascular cambium, followed by the regeneration of vascular tissue. It is worth noting that the secondary xylem is regenerated always following the formation of a thick belt of wound xylem.

The effect of crown position and tree age on resin-canal density in Scots pine (Pinus sylvestris L.) needles

2001 ◽  
Vol 79 (11) ◽  
pp. 1257-1261 ◽  
Author(s):  
Jinxing Lin ◽  
D A Sampson ◽  
R Ceulemans
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Cross Sections ◽  
Resin Canal ◽  
Tree Age ◽  
Needle Length ◽  
Cross Sectional ◽  
Crown Position ◽  
The Cross ◽  
Resin Canals

Resin canals are an important taxonomic characteristic in conifers. In this paper we examined within- and between-needle variation of the cross-sectional number of resin canals in Scots pine (Pinus sylvestris L.). Variation within needles was determined from 12 free-hand sections taken along the whole length of foliage collected from a common crown position. The effect of crown location and tree age on resin-canal density was also examined from the midpoint cross sections of 450 Scots pine needles collected from interior and exterior locations from the top, middle, and bottom of 25 crowns of trees ranging in age from 8 to 70 years. Within-needle resin-canal density varied with needle length. Two resin canals were typical for the basal and the terminal needle cross sections. There were 3.2 and 8.6 resin canals for cross sections taken from 10 and 30% of the needle length from the basal sheath, respectively. Resin-canal density was largest, and relatively constant, between 30 and 80% of the needle length. We found significant differences in the cross-sectional number of needle resin canals, as influenced by crown positions and tree age. Resin-canal density increased with foliage height. Foliage from the top one-third of crowns had significantly more resin canals than foliage from the bottom. Foliage collected from the crown interior (proximal to the stem) had fewer resin canals than samples from the crown edge. Resin-canal density increased from 7.1 to 10.3 as tree age increased from 8 to 70 years. These results suggest that crown position and tree age need to be incorporated into the sampling protocols used to establish species standards in resin-canal density, at least for Scots pine, if meaningful comparisons are to be made.Key words: resin canal, needle age, crown position, needle anatomy, Pinus sylvestris.

Geometric analysis of intrusive growth of wood fibres in Robinia pseudoacacia

IAWA Journal ◽  
2018 ◽  
Vol 39 (2) ◽  
pp. 191-208 ◽  
Author(s):  
Anna B. Wilczek ◽  
Muhammad Iqbal ◽  
Wieslaw Wloch ◽  
Marcin Klisz
Keyword(s):  
Secondary Xylem ◽  
Robinia Pseudoacacia ◽  
Geometric Analysis ◽  
Cell Types ◽  
Vascular Cambium ◽  
Tangential Plane ◽  
Intrusive Growth ◽  
Thin Sections ◽  
Growing Cell ◽  
Vessel Elements

ABSTRACTAll cell types of the secondary xylem arise from the meristematic cells (initials) of the vascular cambium and grow under mechanical constraints emerging from the circular-symmetrical geometry that characterises many tree trunks. The course of intrusive growth of cambial initials has been elucidated, but is yet to be described in the case of xylem fibres. This study explains the geometry of intrusive growth of the secondary xylem fibres in the trunk ofRobinia pseudoacacia.Long series of serial semi-thin sections of the vascular cambium and the differentiating secondary xylem were analysed. Since fibres grow in close vicinity to expanding cells of the derivatives of the vascular cambium, we assumed that they have similar growth conditions. Dealing with the cylindrical tissue of the vascular cambium in a previous study, we used a circularly symmetrical equation for describing the growth mechanism of cambial initials. Like the cambial initials, some of the cambial derivatives differentiating into the various cell types composing the secondary xylem also exhibit intrusive growth between the tangential walls of adjacent cells. As seen in cross sections of the cambium, intrusively growing initials form slanted walls by a gradual transformation of tangential (periclinal) walls into radial (anticlinal) walls. Similarly, the intrusive growth of xylem fibres manifests initially as slants, which are formed due to axial growth of the growing cell tips along the tangential walls of adjacent cells. During this process, the tangential walls of adjacent cells are partly separated and dislocated from the tangential plane. The final shape of xylem fibres, or that of vessel elements and axial parenchyma cells, depends upon the ratio of their intrusiveversussymplastic growths in the axial, circumferential and radial directions.

BRIEF COMMENTS ON THE NOMENCLATURE OF SOFTWOOD AXIAL RESIN CANALS AND THEIR ASSOCIATED CELLS

IAWA Journal ◽  
2002 ◽  
Vol 23 (3) ◽  
pp. 299-303 ◽  
Author(s):  
Alex C. Wiedenhoeft ◽  
Regis B. Miller
Keyword(s):  
Intercellular Space ◽  
Resin Canal ◽  
Subsidiary Cells ◽  
Standard Terms ◽  
Resin Canals

The terminology related to axial resin canals in conifers is briefly reviewed, standard terms are clarified and a new term is proposed. The definitions proposed are intended primarily for light microscopic observations. All the cells and spaces of an axial resin canal as differentiated from the axial tracheids are collectively referred to as the resin canal complex. The resin canal is the intercellular space itself, and the epithelium is the uniseriate layer of cells lining the canal. We propose the term subsidiary cells to include all cells exterior to the epithelium, which may be subsidiary parenchyma and /or strand tracheids.

The opening and shedding mechanism of the female cones of Pinus radiata

1964 ◽  
Vol 12 (2) ◽  
pp. 125 ◽  
Author(s):  
R Allen ◽  
AB Wardrop
Keyword(s):  
Pinus Radiata ◽  
Radial Growth ◽  
Secondary Wall ◽  
Vascular Tissue ◽  
Middle Layer ◽  
Cell Axis ◽  
Vascular Connection ◽  
Differential Shrinkage ◽  
Longitudinal Cell ◽  
Cone Scale

The opening of the female cones of P. radiata has been shown to result from differential shrinkage between the adaxial vascular tissue and the abaxial sclerenchyma of the cone scale. The organization of the secondary wall of the tracheids typically consists of three helically organized concentric layers. In the outer and inner layers the microfibrillar orientation is approximately transverse, and in the middle layer the helix makes an angle of c. 40° with the longitudinal cell axis. In the sclerenchyma the secondary wall consists of wide layers in which the microfibrils of the lamellae are almost transverse to the longitudinal cell axis, alternating with narrow layers in which the microfibrils of the lamellae are almost parallel to the cell axis. Opening is preceded by a severance of the vascular connection between the cone and the stem or branch by the occlusion of the lurnina of the tracheids of the peduncle with resin. As radial growth of the stem proceeds, small fissures develop between the xylem of the stem or branch and that of the cone peduncle. The fissures become filled with resin and there is a progressive erosion of the tracheids of the peduncle until ultimately the xylem of the peduncle is separated from that of the stem or branch.

Carboniferous pteridosperm studies: morphology and anatomy of Schopfiastrum decussatum

1972 ◽  
Vol 50 (12) ◽  
pp. 2649-2658 ◽  
Author(s):  
Gar W. Rothwell ◽  
Thomas N. Taylor
Keyword(s):  
Secondary Xylem ◽  
Vascular Cambium ◽  
Secondary Phloem ◽  
Outer Cortex ◽  
Southern Illinois ◽  
Leaf Arrangement ◽  
Resin Canals ◽  
Inner Cortex

The monostelic seed fern Schopfiastrum decussatum Andrews is described from a specimen collected at a Middle Pennsylvanian petrifaction locality in southern Illinois. The specimen measures 24 cm long and is about 1.1 cm in diameter. Two petioles are attached to the axis and abundant foliar material is also present. Leaf arrangement is alternate and distichous. The stem consists of an exarch protostele surrounded by a prominent zone of secondary xylem. Secondary phloem and a vascular cambium are also preserved. The cortex is characterized by an undulating outer epidermal zone consisting of alternating ridges and furrows; internally this zone is delimited by conspicuous lacunae. Sclerenchyma bands occur in the outer cortex, with prominent resin canals present in the inner cortex. The fronds are represented by dichotomizing rachides, primary pinnae, and laminar pinnules. Features of the plant are compared to those of other Carboniferous pteridosperms, and a reconstruction of Schopfiastrum is included.

Differentiation of Secondary Xylem After Girdling

IAWA Journal ◽  
1988 ◽  
Vol 9 (4) ◽  
pp. 375-383 ◽  
Author(s):  
Li Zhengli ◽  
Cui Keming
Keyword(s):  
Large Scale ◽  
Vascular Tissue ◽  
Secondary Xylem ◽  
Living Cells ◽  
Growth Season ◽  
Meristematic Tissue ◽  
Continuous Growth ◽  
Parenchyma Cells

Under favourable growth season and by suitable technical means, regeneration and continuous growth of new bark after girdling has been observed in many trees. Differentiation of the secondary xylem varies after arteficial treatment. Thus , the authors consider that (1) under appropriate conditions most trees could be girdled on a large scale with subsequent new bark regeneration and continued growth, (2) after removal of the phloem the living cells of the secondary xylem, i.e., wood parenchyma cells, may function in transporting nutrients from the treecrown downwards, and (3) finally, after girdling or when cultured in vitro, both immature xylem and phloem can dedifferentiate into meristematic tissue that further develops vascular tissue.

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