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PubMed1986

Stomatal responses to humidity in selected conifers.

Stomatal response to changes in leaf-to-air water vapor pressure difference (D) was studied in needles of the current year's shoot of three-year-old seedlings of Picea sitchensis (Bong.) Carr., Pinus contorta Dougl. ex Loud., Larix x eurolepis Henry, and Pinus sylvestris L. Both eight-week- and ten-month-old shoots of P. sylvestris were studied. Stomata of all the species responded by closing to some degree as D was increased over the range 0.4-2.0 kPa. Ten-month-old shoots of P. sylvestris showed the smallest reduction (7.5%), and shoots of P. sitchensis the largest reduction (64.6%) in stomatal conductance. However, in no species was stomatal closure sufficient to cause a reduction in transpiration (E) as D increased. Net photosynthesis (A) declined linearly as D was increased and as a result the ratio of E/A increased linearly in all species. Only the stomata of P. contorta and L. x eurolepis behaved in an 'optimal' way, i.e., estimated values of dEdA were approximately constant as D increased. For P. sylvestris, shoots of both ages, dE/dA increased markedly with D, whereas in P. sitchensis it declined. Explanation of these data does not require a mechanism of stomatal closure involving a site that senses the vapor pressure deficit outside the leaf. However, it is unlikely that a simple 'feedback' response involving bulk leaf water potential can explain the responses measured because changes in needle water potential were less than 0.1 MPa during an experiment.

Journal Article↗

PubMed2000

Characterization of Pin m III cDNA in western white pine.

Maximum accumulation of Pin m III protein in western white pine (Pinus monticola Dougl. ex D. Don) needles occurred during the winter months. To characterize Pin m III, an expression cDNA library from poly(A)+ mRNA of needles was immunoscreened and the full length cDNA was cloned. An open reading frame of 486 bases encodes a protein of 161 amino acid residues with a molecular mass of 18 kD and a predicted isoelectric point of 5.5. The deduced amino acid sequence had some similarities (37%) with an intracellular pathogenesis-related (PR) protein from garden asparagus (Asparagus officinalis L.) and the major pollen allergen from white birch (Betula verrucosa J. F. Ehrh.), which are members of the ribonuclease-like PR-10 family. Phylogenetic analysis provided circumstantial evidence that Pin m III may be grouped with intracellular PRs from asparagus and potato (Solanum tuberosum L.), while the allergens formed another subgroup. Northern analysis showed that the Pin m III gene was preferentially expressed during cold acclimation with the highest expression in the fall and winter months, preceding the peak of Pin m III protein accumulation. Tissue specificity expression analysis indicated that the gene was strongly expressed in roots and twigs. Higher amounts of the homologous protein (Pin l I) and its transcript accumulated in sugar pine (Pinus lambertiana Dougl.) needles infected with blister rust compared with healthy needles.

Journal Article↗

PubMed2000

Relationship between carbohydrate concentration and root growth potential in coniferous seedlings from three climates during cold hardening and dehardening.

Greenhouse-cultured, container-grown seedlings of Aleppo pine (Pinus halepensis Mill.), radiata pine (Pinus radiata D. Don), and interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) were cold acclimated and deacclimated in growth chambers over 24 weeks. Needle and root cold hardiness and root growth potential (RGP) were measured weekly. Root, needle and stem analyses for soluble sugars and starch were performed biweekly. In all tissues, there was a close correspondence between cold hardiness and the absolute concentration of soluble sugars, as well as between the increase and decrease in concentration of soluble sugars during cold hardening and dehardening, respectively, supporting the theory that soluble sugars function as cryoprotectants in plant tissues. The magnitude of starch concentration did not parallel the magnitude of the cold hardiness attained, and changes in starch concentration were related to production and consumption factors, rather than timing of changes in cold hardiness. The rise and fall of RGP paralleled the rise and fall of total carbohydrate concentration in roots. The behavior of the three species was surprisingly similar, considering the different climates to which they are adapted.

Carbohydrates↗

PubMed2001

Photosynthesis and carbon allocation of six boreal tree species grown in understory and open conditions.

One-year-old seedlings of Abies balsamea (L.) Mill, Picea glauca (Moench) Voss, Pinus contorta Loudon, Betula papyrifera Marsh., Populus tremuloides Michx. and Populus balsamifera L. were transplanted in the spring, in pots, to the understory of a mixed P. tremuloides-P. balsamifera stand or to an adjacent open site. Growth and leaf characteristics were measured and photosynthetic light response curves determined in mid-August. Overall, the coniferous seedlings showed less photosynthetic plasticity in response to growth conditions than the deciduous species. Abies balsamea, P. glauca and B. papyrifera responded to the understory environment with higher leaf area ratios, and lower photosynthetic light saturation points and area-based leaf respiration relative to values for open-grown seedlings, while they matched or exceeded the height growth of open-grown seedlings. In contrast, seedlings of Pinus contorta, P. tremuloides and P. balsamifera displayed characteristics that were not conducive to survival in the understory. These characteristics included a high light saturation point and leaf dark respiration rate in P. contorta, and lower leaf area variables combined with higher carbon allocation to roots in P. tremuloides and P. balsamifera. By the second growing season, all seedlings of P. tremuloides and P. balsamifera growing in the understory had died.

Carbon↗

PubMed1988

Auxin and ethylene regulation of diameter growth in trees.

Recent studies on the phytohormonal regulation of seasonal cell-division activity in the cambium, primary-wall radial expansion of cambial derivatives, differentiation of xylem cells, and growth of the cortex in forest trees of the north temperate zone are reviewed. Indol-3-ylacetic acid (IAA, auxin) has been characterized by combined gas chromatography-mass spectrometry (GC-MS) in the cambial region of Abies balsamea, Pinus densiflora, Pinus sylvestris and Quercus robur. All of the evidence supports the hypothesis that developing leaves and extending shoots are primary sources of IAA. The rate of ethylene emanation varies among conifer species when adjoining phloem and cambial tissues are incubated in vitro. The cambium from young cuttings of Abies balsamea produces more ethylene than that from older cuttings. Ethylene production by seven-year-old Abies balsamea cambium is substantially increased in vitro when the tissue is provided with exogenous 1-aminocyclopropane-1-carboxylic acid and IAA. In response to elevated ethylene concentrations, cortex growth is accelerated in both hardwood and conifer seedlings. Ethrel (2-chloroethylphosphonic acid) increases ray size and ray-cell number and promotes traumatic resin-canal development in xylem. In Ulmus americana, endogenous ethylene concentrations are inversely correlated with cambial activity. Ethylene decreases vessel diameter in Acer negundo, Acer platanoides and Ulmus americana. Several studies suggest that ethylene has a role in regulating reaction-wood formation in both conifers and hardwoods.

Journal Article↗

PubMed1998

Chlorophyll synthesis in dark-grown pine primary needles

The pigment content of dark-grown primary needles of Pinus jeffreyi L. and Pinus sylvestris L. was determined by high-performance liquid chromatography. The state of protochlorophyllide a and of chlorophylls during dark growth were analyzed by in situ 77 K fluorescence spectroscopy. Both measurements unambiguously demonstrated that pine primary needles are able to synthesize chlorophyll in the dark. Norflurazon strongly inhibited both carotenoid and chlorophyll synthesis. Needles of plants treated with this inhibitor had low chlorophyll content, contained only traces of xanthophylls, and accumulated carotenoid precursors. The first form of chlorophyll detected in young pine needles grown in darkness had an emission maximum at 678 nm. Chlorophyll-protein complexes with in situ spectroscopic properties similar to those of fully green needles (685, 695, and 735 nm) later accumulated in untreated plants, whereas in norflurazon-treated plants the photosystem I emission at 735 nm was completely lacking. To better characterize the light-dependent chlorophyll biosynthetic pathway in pine needles, the 77 K fluorescence properties of in situ protochlorophyllide a spectral forms were studied. Photoactive and nonphotoactive protochlorophyllide a forms with emission properties similar to those reported for dark-grown angiosperms were found, but excitation spectra were substantially red shifted. Because of their lower chlorophyll content, norflurazon-treated plants were used to study the protochlorophyllide a photoreduction process triggered by one light flash. The first stable chlorophyllide photoproduct was a chlorophyllide a form emitting at 688 nm as in angiosperms. Further chlorophyllide a shifts usually observed in angiosperms were not detected. The rapid regeneration of photoactive protochlorophyllide a from nonphotoactive protochlorophyllide after one flash was demonstrated.

Journal Article↗

PubMed1990

Increases in Phosphorus Requirements for CO(2)-Enriched Pine Species.

Pinus radiata D. Don (half-sib families 20010 and 20062) and Pinus caribaea var hondurensis (an open-pollinated family) were grown for 49 weeks at seven levels of phosphorus and at CO(2) concentrations of either 340 or 660 microliters per liter, to establish if the phosphorus requirements differed between the CO(2) concentrations and if mycorrhizal associations were affected. When soil phosphorus availability was low, phosphorus uptake was increased by elevated CO(2). This may have been related to changes in mycorrhizal competition. When the phosphorus concentration in the youngest fully expanded needles was above 600 milligrams per kilogram the shoot weight of all pine families was greater at high CO(2) due to increases in rates of photosynthesis. More dry weight was partitioned to the stems of P. radiata family 20010 and P. caribaea. At foliar phosphorus concentrations above 1000 milligrams per kilogram (P. radiata) and 700 milligrams per kilogram (P. caribaea), growth did not increase at 340 microliters of CO(2) per liter. Soluble sugar levels in the same needles mirrored the growth response, but the starch concentration declined with increasing phosphorus. At 660 microliters of CO(2) per liter, shoot weight and soluble sugar concentrations were still increasing up to a foliar P concentration of 1800 milligrams per kilogram for P. radiata and 1600 milligrams per kilogram for P. caribaea. The starch concentrations did not decline. These results indicate that higher foliar phosphorus concentrations are required to realize the maximum growth potential of pines at elevated CO(2).

Journal Article↗

PubMed2006

Mortality gradients within and among dominant plant populations as barometers of ecosystem change during extreme drought.

Understanding patterns of plant population mortality during extreme weather events is important to conservation planners because the frequency of such events is expected to increase, creating the need to integrate climatic uncertainty into management. Dominant plants provide habitat and ecosystem structure, so changes in their distribution can be expected to have cascading effects on entire communities. Observing areas that respond quickly to climate fluctuations provides foresight into future ecological changes and will help prioritize conservation efforts. We investigated patterns of mortality in six dominant plant species during a drought in the southwestern United States. We quantified population mortality for each species across its regional distribution and tested hypotheses to identify ecological stress gradients for each species. Our results revealed three major patterns: (1) dominant species from diverse habitat types (i.e., riparian, chaparral, and low- to high-elevation forests) exhibited significant mortality, indicating that the effects of drought were widespread; (2) average mortality differed among dominant species (one-seed juniper[Juniperus monosperma (Engelm.) Sarg.] 3.3%; manzanita[Arctostaphylos pungens Kunth], 14.6%; quaking aspen[Populus tremuloides Michx.], 15.4%; ponderosa pine[Pinus ponderosa P. & C. Lawson], 15.9%; Fremont cottonwood[Populus fremontii S. Wats.], 20.7%; and pinyon pine[Pinus edulis Engelm.], 41.4%); (3) all dominant species showed localized patterns of very high mortality (24-100%) consistent with water stress gradients. Land managers should plan for climatic uncertainty by promoting tree recruitment in rare habitat types, alleviating unnatural levels of competition on dominant plants, and conserving sites across water stress gradients. High-stress sites, such as those we examined, have conservation value as barometers of change and because they may harbor genotypes that are adapted to climatic extremes.

Arizona↗

PubMed1997

Survey of microsatellite DNA in pine.

A large insert genomic library from eastern white pine (Pinus strobus) was probed for the microsatellite motifs (AC)n and (AG)n, all 10 trinucleotide motifs, and 22 of the 33 possible tetranucleotide motifs. For comparison with a species from a different subgenus, a loblolly pine (Pinus taeda) genomic library was also probed with the same set of di- and tri-nucleotide repeats and 11 of the tetranucleotide repeats. The four most abundant microsatellite motifs in both species were (AC)n, (AG)n, (AAT)n, and (ATC)n, which as a group accounted for over half the microsatellite sites investigated. The two dinucleotide repeats were the most abundant microsatellite motifs tested in both species, each at 2-4.5 sites/megabase pair (Mbp), but the two trinucleotide motifs were nearly as abundant and are considered good candidates for pine microsatellite marker development efforts. Eastern white pine had more than twice as many (AC)n as (AG)n loci, in contrast with loblolly pine and most other plant species in which (AG)n is more abundant. In both pine species the minimum estimated genome density for all microsatellites, excluding (AT)n repeats, was 16 sites/Mbp.

DNA, Plant↗

PubMed1977

Tree host range and world distribution of the extomycorrhizal fungus Pisolithus tinctorius.

The natural occurrence of Pisolithus tinctorius has been confirmed in 33 countries of the world and in 38 states in the United States. This ectomycorrhizal fungus is found associated with various tree species in nurseries, urban areas, orchards, forests, and strip-mined spoils. Experiments have proved that this fungal symbiont forms ectomycorrhizae with Abies procera, Betula pendula, Carya illnoensis, 11 species of Eucalyptus, 30 species of Pinus, Pseudotsuga menziesii var. meniziesii, 2 species of Quercus, and Tsuga heterophylla. Pisolithus has also been reported growing under natural conditions in association with three additional species of Betula, two species of Eucalyptus, nine species of Pinus, and eight species of Quercus, Populus tremuloides, Pseudotsuga grandidenta, and Salix humilis. This fungal symbiont has great potential in forestation efforts because of (1) the availability of practical techniques for artificially introducing in into nursery soils; (2) its ability to improve tree survival and growth in the nursery and the field; (3) its near worldwide distribution on a variety of sites; and (4) its broad host range encompassing many of the world's most important tree species.

Basidiomycota↗

PubMed2004

Antibacterial and antifungal effects of essential oils from coniferous trees.

Essential oils have potential biological effects, i.e., antibiotic, anticarcinogenic, and sedative effects during stress. In the present study, we investigated the antibacterial and antifungal effects of essential oils extracted from the coniferous species Pinus densiflora, Pinus koraiensis, and Chamaecyparis obtusa, because their biological activities have not been yet elucidated. The essential oils were quantified using gas chromatography and identified in gas chromatography-mass spectrometric analysis. Simultaneously, antibacterial and antifungal assays were performed using the essential oils distilled from the needles of coniferous trees. The major components and the percentage of each essential oil were: 19.33% beta-thujene in P. densiflora; 10.49% alpha-pinene in P. koraiensis; 10.88% bornyl acetate in C. obtusa. The essential oils from P. densiflora and C. obtusa have antibacterial effects, whereas essential oils from P. koraiensis and C. obtusa have antifungal effects. These results indicate that the essential oils from the three coniferous trees, which have mild antimicrobial properties, can inhibit the growth of gram-positive and gram-negative bacteria and fungi.

Anti-Bacterial Agents↗

PubMed1997

Biotransformation of the fungal toxin fomannoxin by conifer cell cultures.

Fomannoxin [(+/-)-5-Formyl-2-isopropenyl-2,3-dihydrobenzofurane] is a phytotoxic secondary metabolite, which is produced by the forest pathogenic basidiomycete Heterobasidion annosum during the infection process. Fomannoxin shows growth-inhibiting effects on callus and suspension cultures of conifer cells. By investigating the interaction of the phytotoxin with Pinus sylvestris cells a detoxification of fomannoxin was detected, presumably as a defense reaction of the plant cells. Undifferentiated green cell lines of Pinus sylvestris were used as target cells. To provide rac-fomannoxin as a substrate a simple method for the chemical synthesis was developed. It was found that the aromatic aldehyde group is reduced by the plant cells producing the non-toxic fomannoxin alcohol which was isolated and identified by spectroscopy. After longer incubation times, also fomannoxin acid-beta-glucoside could be isolated as another detoxification metabolite. For comparison this glucoside was also synthesized.

Antifungal Agents↗

PubMed2003

Joint effects of elevated levels of ultraviolet-B radiation, carbon dioxide and ozone on plants.

There is growing interest regarding the joint effects of elevated levels of surface ultraviolet B (UV-B) radiation, carbon dioxide (CO2) and ozone (O3) on plants. Our current knowledge of this subject is too limited to draw any specific conclusions, although one might state that such effects are likely to be highly species dependent and may be more than additive, additive or less than additive. There are a number of uncertainties associated with the experimental protocols used and the conclusions reached in many studies. Nevertheless, in North America, there appear to be genotypes of three monocot crop species (Avena sativa L., Oryza sativa L. and Sorghum vulgare L.); six dicot crops (Cucumis sativus L., Lactuca sativa L., Lycopersicon esculentum Mill., Phaseolus vulgaris L., Pisum sativum L. and Solanum tuberosum L.) and two conifer species (Pinus ponderosa Dougl. and Pinus taeda L.) that may be considered sensitive to the joint effects of elevated levels of UV-B, CO2 and O3. However, to provide a more reliable assessment or validation of the predictions, future research must consider the concept of plant response surfaces and describe them more fully in numerical terms. Achieving that objective will require close cooperation among a number of scientists representing geographic locations with known spatial and temporal differences in UV-B, CO2 and O3 to conduct experiments under their site-specific conditions, using common plant materials and experimental protocols.

Acclimatization↗

PubMed2004

Ground-dwelling ant fauna of sites with high levels of copper.

Richness and diversity of ant species are related to environmental factors such as vegetation, soil, presence of heavy metals, and insecticides, which allow the use of the assemblage members as terrestrial indicators of environmental conservation status. This study presents the results of ground ants surveyed in Minas do Camaquã in the municipality of Cacapava do Sul (Camaquã Basin), State of Rio Grande do Sul. Collections were performed in four sites, which high levels of copper in the soil, three of which--a mine, a liquid reject, and a solid reject-, had sparse or no plant cover, and one site where Pinus has been used for rehabilitation. Parque das Guaritas was the control site, since it presented normal levels of copper and a dense savanna cover. For each site, three transect lines extending 100 m were draw, and at each 10 m sardine baits were distributed; after two hours the ants present were collected. Hand collections in all five sites were performed during one hour (capture effort). A total of 51 species belonging to 17 genera were collected. The control site was the richest in ant species (r = 45). Sites with high level of copper and poor plant cover presented the lowest richness: mine (r = 14), solid reject (r = 15), and liquid reject (r = 16). In contrast, the site planted with Pinus presented an increment in richness (r = 24) of ground-dwelling ants, suggesting a reahabilitation process.

Animals↗

PubMed2006

Tree species effects on decomposition and forest floor dynamics in a common garden.

We studied the effects of tree species on leaf litter decomposition and forest floor dynamics in a common garden experiment of 14 tree species (Abies alba, Acer platanoides, Acer pseudoplatanus, Betula pendula, Carpinus betulus, Fagus sylvatica, Larix decidua, Picea abies, Pinus nigra, Pinus sylvestris, Pseudotsuga menziesii, Quercus robur, Quercus rubra, and Tilia cordata) in southwestern Poland. We used three simultaneous litter bag experiments to tease apart species effects on decomposition via leaf litter chemistry vs. effects on the decomposition environment. Decomposition rates of litter in its plot of origin were negatively correlated with litter lignin and positively correlated with mean annual soil temperature (MAT(soil)) across species. Likewise, decomposition of a common litter type across all plots was positively associated with MAT(soil), and decomposition of litter from all plots in a common plot was negatively related to litter lignin but positively related to litter Ca. Taken together, these results indicate that tree species influenced microbial decomposition primarily via differences in litter lignin (and secondarily, via differences in litter Ca), with high-lignin (and low-Ca) species decomposing most slowly, and by affecting MAT(soil), with warmer plots exhibiting more rapid decomposition. In addition to litter bag experiments, we examined forest floor dynamics in each plot by mass balance, since earthworms were a known component of these forest stands and their access to litter in litter bags was limited. Forest floor removal rates estimated from mass balance were positively related to leaf litter Ca (and unrelated to decay rates obtained using litter bags). Litter Ca, in turn, was positively related to the abundance of earthworms, particularly Lumbricus terrestris. Thus, while species influence microbially mediated decomposition primarily through differences in litter lignin, differences among species in litter Ca are most important in determining species effects on forest floor leaf litter dynamics among these 14 tree species, apparently because of the influence of litter Ca on earthworm activity. The overall influence of these tree species on leaf litter decomposition via effects on both microbial and faunal processing will only become clear when we can quantify the decay dynamics of litter that is translocated belowground by earthworms.

Analysis of Variance↗

PubMed1986

A comparison of internal standards for plant cytophotometry.

Plant cell nuclei were compared with chicken erythrocyte nuclei for use as internal standards for microspectrophotometry. The amount of DNA per nucleus and the coefficient of variation for measurement of individual nuclei were determined for cells from dormant embryos of Pinus taeda and Pinus coulteri, from onion root tips and from chicken erythrocytes. The chicken erythrocytes had the least variability and thus were best suited for use as a standard. Onion root tips were least suitable, with a coefficient of variation 2 1/2 times that of erythrocytes. Although onion root tips have been used as an internal standard in other studies, their mitotic activity, in contrast with the nonreplication of DNA of mature erythrocytes, is reflected in a broad distribution of nuclei with values in the 2C-4C range. Coulter pine mature embryos were at the 3C level, whether dry or hydrated, while loblolly pine embryos were in the 2C state. This confirms previous reports. The coefficient of variability for the pine embryo cells was 1 1/2 times that of erythrocytes for nonhydrated seeds and twice the erythrocyte value for hydrated seeds. The larger 2C values for pine (26 pg for P. taeda and 17 pg for P. coulteri) are closer to values expected for many plant species than the 3 pg level of the chicken erythrocytes. Dormant P. taeda embryo cells (2C) are suggested as an alternative where the experimental material has large DNA values and/or chicken erythrocytes are difficult to procure. Large sample size is recommended for the plant materials if they are to be used as internal standards in Feulgen cytophotometry.

Allium↗

PubMed1999

Two highly divergent 5S rDNA unit size classes occur in composite tandem array in European larch (Larix decidua Mill.) and Japanese larch (Larix kaempferi (Lamb.) Carr.).

The 5S ribosomal DNA unit structure and organization have been investigated in Larix decidua and Larix kaempferi using selective amplification of gene and spacer, sequence analysis and homologous probe hybridization. Two highly divergent unit size classes of approximately 650 and 870 bp were detected in both species. Sequence analysis in Larix decidua revealed that length variations occur in the middle spacer region and are the result of duplications (in the long spacers) and considerable sequence heterogeneity. Conversely, the transcribed region is of uniform length (120 bp), and the nucleotide sequence of one Larix decidua clone is similar to that reported for other gymnosperms. Sequence comparison of the larch spacers with two other Pinaceae species (Pinus radiata and Picea glauca) showed that the 5' and 3' regions flanking the gene (40 and 60 bp, respectively) are quite conserved, suggesting a regulatory role. Moreover, a small element of about 70 bp located in the middle spacer region was found to be common to the larch long units and the six Pinus radiata spacer clones previously sequenced (64% sequence identity). The short and long unit size classes are mainly organized in composite tandem array(s) with evidence of extensive zones of strict alternation in both species. Mechanisms underlying this unusual association of divergent units in larch 5S rDNA arrays are discussed.

Base Sequence↗

PubMed2000

[Description, distribution, anatomy, chemical composition and uses of Mimosa tenuiflora(Fabaceae-Mimosoideae) in Mexico].

Because of some catastrophic events which occurred in Mexico during the 1980 decade, the utilization of "tepescohuite" bark against skin wounds and burns was popularized. The media manipulated the lack of available information about its medical properties and gave erroneous information to the society propagating a lot of myths. Therefore, the aim of this paper is to determine its taxonomic identity and to study the distribution, bark and wood anatomy of this species, and to determine its actual and historic uses, and the compilation of the information about bark pharmacology and toxicity. Its taxonomic identity is established as Mimosa tenuiflora (Willd.) Poir. (Fabaceae-Mimosoideae). It blooms and fructifies from November to June, occurring in Mexico (the states of Oaxaca and Chiapas), Guatemala, Honduras, El Salvador, Nicaragua, Panama, Colombia, Venezuela and Brazil, at altitudes of 0-1110 (-1520) m. In Mexico, it is found in dry forests, thorny thickets, Pinus and Pinus-Quercus forests, and in M. tenuiflora pure thickets, along roads and in resting or abandoned culture lands. This species has an aggregate distribution in the forests and a uniform one in the thickets. It presents a mean density of 9 individuals per m2, with 0.45 of frequency per quadrat and 1.69 m2 of mean coverture, and it has a wide range of tolerance to climatic and edaphic factors, confirming their invasive character. Regionally, the wood is used as fuel and fence construction, and against skin wounds and burns (bark tea, powder and/or ointment), and diverse products, such as shampoos, creams, capsules, soaps, etc., are commercialized. The bark is wrinkled, reddish-brown to grey, fibrous texture, 0.5-1.5 mm thick, resinous and with an astringent odor and flavor, and with a great quantity of tannins. The wood presents extremely short vessel elements, with alternate areolate punctuations, and simple perforated plates, vasicentric axial parenchima, confluent stripes, uniseriated rays, extremely short, fine and very short libriform fibres. The bark contains tannins, saponins, an alkaloide fraction, lipids, phytosterols, glucosides, xylose, rhamnose, arabinose, lupeol, methoxychalcones, and kukulkanins.

Mexico↗