Dicotyledonous Families Research Articles

An annotated list of ornamentals naturally found infected by Brevipalpus mite-transmitted viruses

The first cases of ornamental plants found infected by Brevipalpus transmitted viruses (BTV) were described in the 1990's from the region of Piracicaba, State of São Paulo, Brazil; subsequent cases were from other regions in the country and other American countries. Currently, 37 ornamental plant species (for the sake of simplicity, orchids being considered as a single species), belonging to 18 families of dicotyledons, have been reported hosting BTV. Because of the non systemic type of infection of these viruses, the localized diseases they cause are unimportant usually, but they have the potential to cause economic losses if severe outbreaks of Brevipalpus mite populations occur. Some ornamentals may serve as reservoirs to BTV known to cause serious damage to food crops as Citrus leprosis virus- cytoplasmic type (CiLV-C), passion fruit green spot virus (PFGSV) and Coffee ringspot virus (CoRSV).

Dark septate endophyte and arbuscular mycorrhizal status of vegetation colonizing a bottomland hardwood forest after a 100 year flood

Levels of arbuscular mycorrhizal (AM) colonization and dark septate endophyte (DSE) colonization were assessed in the vegetation recolonizing a remnant bottomland hardwood forest in north central Texas following a 100 year flood. Thirty seven plant species representing 21 dicotyledonous and 2 montocotyledonous families established following floodwater recession. AM and/or DSE were found in all species. AM colonization was found in 31 out of the 37 species assessed including both monocotyledonous families (Poaceae and Cyperaceae) and 17 out of 21 dicotyledonous families (Acanthaceae, Asteraceae, Boraginaceae, Cucurbitaceae, Euphorbiaceae, Lamiaceae, Loganiaceae, Lythraceae, Malvaceae, Onagraceae, Pedaliaceae, Ranunculaceae, Sapindaceae, Scrophulariaceae, Solanaceae, Verbanaceae and Violaceae). DSE were found in 31 out of 37 species assessed including both monocotyledonous families and 15 out of 21 dicotyledonous families (Amaranthaceae, Asteraceae, Boraginaceae, Brassicaceae, Cucurbitaceae, Euphorbiaceae, Lamiaceae, Lythraceae, Malvaceae, Pedaliaceae, Phytolaccaceae, Polygonaceae, Ranunculaceae, Sapindaceae, Scrophulariaceae and Violaceae). There were no detectable differences in AM or DSE colonization levels among wetland indicator groups ( p > 0.05). Levels of DSE colonization were negatively correlated with vesicular colonization and hyphal colonization for the obligate wetland species. There were no other significant relationships between AM and DSE colonization detected. Spearman rank order correlation coefficients did not differ significantly among wetland indicatory category for any level of AM or DSE colonization.

Seed dispersal systems in the New Zealand flora

Abstract Knowledge of the dispersal mechanisms used by plants is important in phylogenetic, ecological, biogeographical, and conservation studies. Here we attempt to assign dispersal mechanisms to the entire flora-2595 plant species of the New Zealand Botanical Region. Anemochory is the most frequent dispersal mechanism, utilised by 79% of species. The next most frequent mechanisms are endozoochory (33%), hydrochory (28%), epizoochory (26%), and ballistic (8%). Polychory is common, particularly in monocotyledonous and dicotyledonous families and hydrochorous, epizoochorous, and ballistically dispersed species. Epizoochory is more common in New Zealand than in other regions, and species using this dispersal mechanism are over-represented among threatened species. Frugivory is less common than previously reported, and is under-represented among threatened species. Some mechanisms are poorly known, and entanglement and capsulivory are dispersal mechanisms apparently unique to New Zealand. Dispersal mechanisms reflective of New Zealand's distinctive assemblages of large flightless birds and reptiles are not apparent. A pattern of reduction in dispersal-related structures is evident in some genera. The mechanisms utilised by some species are ambiguous. Thus there remains a need for further investigation of the dispersal mechanisms utilised by plants in New Zealand.

Floristic analysis of the evergreen broad-leaved forest community from Jiulianshan National Nature Reserve in Jiangxi Province, China

Floristic composition of the evergreen broad-leaved forest in Jiulianshan Mountain was analyzed based on field investigations and community ecology. The community is rich in species diversity, with 144 spermatophyte families including 379 genera and 647 species, in which there are 6 gymnosperm families including 8 genera and 9 species, 21 monocotyledon families including 77 genera and 116 species, and 117 dicotyledon families including 294 genera and 522 species. Dominant families of the flora are Fagaceae, Lauraceae, Aquifoliaceae, Rosaceae, Ternstroemiaceae, Theaceae, Rubiaceae, Moraceae and Euphoarbiaceae, most of which are of tropical & subtropical distribution. As for family systematic distribution, the ratio of tropical & subtropical to temperate genera is 100:62.8 in 142 genera of 16 families. As for generic distribution in field investigation data, the tropical & subtropical areal type accounts for the majority of genera, in which there are 205 genera belonging to the tropical & subtropical areal type, 131 genera belonging to the temperate areal type, 35 genera belonging to the cosmopolitan areal type and 8 genera belonging to the endemic-to-China areal type. The ratio of the tropical & subtropical to temperate genera was 100:63.9. Floristic composition of the evergreen forest community in Jiulianshan and the typical species of the zonal flora will provide a scientific foundation for stand rehabilitation and stand establishment approximating a natural evergreen broad-leaved forest community. This study also indicates that the sample data based on community research are valid and convenient for floristic and environmental analysis of the evergreen broad-leaved forest community from the Jiulianshan Mountain.

Fossil leaf-impressions from the Late Tertiary sediments of Mahuadanr Valley, Latehar District, Jharkhand, India

Morphotaxonomical study of the leaf impressions collected from the Late Tertiary sediments of Mahuadanr Valley, Jharkhand, India has been done. The comparison of morphological features between the fossils and extant taxa revealed the occurrence of 13 species of 5 dicotyledonous families. On the basis of present assemblage, the palaeoclimate and phytogeography of Mahuadanr area during the Late Tertiary have been deduced. Present distribution of all the modern comparable species of the fossils indicates that these are presently found to grow in the tropical forests of the Himalayan foot hills, central India, south India and adjoining area of the Mahuadanr Valley, suggesting a mixed, mesophytic type of forest was flourishing in and around the fossil locality during the sedimentation. As most of the comparable species are found now-a-days in the vicinity of fossil locality of Mahuadanr it indicates that same flora has continued till now which suggests that there has been no marked climatic change in the area since the Late Tertiary time.

Structural, biochemical, and physiological characterization of photosynthesis in two C4 subspecies of Tecticornia indica and the C3 species Tecticornia pergranulata (Chenopodiaceae)

Among dicotyledon families, Chenopodiaceae has the most C(4) species and the greatest diversity in structural forms of C(4). In subfamily Salicornioideae, C(4) photosynthesis has, so far, only been found in the genus Halosarcia which is now included in the broadly circumscribed Tecticornia. Comparative anatomical, cytochemical, and physiological studies on these taxa, which have near-aphyllous photosynthetic shoots, show that T. pergranulata is C(3), and that two subspecies of T. indica (bidens and indica) are C(4) (Kranz-tecticornoid type). In T. pergranulata, the stems have two layers of chlorenchyma cells surrounding the centrally located water storage tissue. The two subspecies of T. indica have Kranz anatomy in reduced leaves and in the fleshy stem cortex. They are NAD-malic enzyme-type C(4) species, with mesophyll chloroplasts having reduced grana, characteristic of this subtype. The Kranz-tecticornoid-type anatomy is unique among C(4) types in the family in having groups of chlorenchymatous cells separated by a network of large colourless cells (which may provide mechanical support or optimize the distribution of radiation in the tissue), and in having peripheral vascular bundles with the phloem side facing the bundle sheath cells. Also, the bundle sheath cells have chloroplasts in a centrifugal position, which is atypical for C(4) dicots. Fluorescence analyses in fresh sections indicate that all non-lignified cell walls have ferulic acid, a cell wall cross-linker. Structural-functional relationships of C(4) photosynthesis in T. indica are discussed. Recent molecular studies show that the C(4) taxa in Tecticornia form a monophyletic group, with incorporation of the Australian endemic genera of Salicornioideae, including Halosarcia, Pachycornia, Sclerostegia, and Tegicornia, into Tecticornia.

Development of mucilage cells of Araucaria angustifolia (Araucariaceae)

The roles of mucilage cells were investigated through morphological and cytological analysis during leaf development in young Araucaria angustifolia plants. Differentiation began in leaf primordia in the shoot apex, when the young cells underwent a greater increase in volume in comparison with other mesophyll cells. The mucilage polysaccharides were synthesized by dictyosomes, from where they were taken by large vesicles and released into a cavity formed by detachment of the tonoplast, which was separated from the cytoplasm. At the end of differentiation, the cell was completely filled with mucilage, a gel consisting of a denser reticular structure surrounding less dense regions. The nucleus and cytoplasm were degenerated in mature cells. The A. angustifolia mucilage cells presented some cytological resemblances to the mucilage cells of members of some dicotyledonous families; however, differences in the dictyosomes and the secretion route were observed. Translocation and water storage of solutes was suggested by the use of the hydroxy pyrenetrisulfonic acid tri-sodium salt apoplastic tracer. The tonoplast detachment, dechromatinization, nuclear condensation, and general degeneration of the membrane systems observed during maturity indicated a programmed cell death process, one not yet described for angiosperm mucilage cells.

Structural and histochemical characterisation of the colleters of Rodriguezia venusta (Orchidaceae)

Colleters are secretory structures present in many dicotyledon families, but they have not yet been reported for the Orchidaceae. However, the orchid Rodriguezia venusta was observed to possess secretory trichomes on the adaxial side of the bracts subtending floral buds that can be interpreted to be colleters. The present work describes the anatomy and histochemistry of these structures. These bracteal trichomes are multicellular, uniseriate, and densely spaced near the region where the bract attaches to the inflorescence. The secretions of these trichomes are mucilaginous and apparently exclusively constituted by carbohydrates, and they appear to act as a lubricant that facilitates the young floral bud to slide over the bract as it grows. In light of these characteristics, it is proposed that these secretory trichomes should be considered to be ‘colleters’.

Stomatal Observations in Dicotyledons

Since 1998, research into more than 470 plant species from some 65 families, found growing in a unique protected area of Irano-Torany, has examined diverse aspects of their anatomical and structural features and has studied the ecological implications of these finding for each species. The present paper, as a part of this research, focuses on the stomatal characters of 326 species from 36 families of dicotyledons, the majority of which are herbaceous species. The stomatal density, guard cell lengths on the adaxial and abaxial leaf epidermis and the stomatal type in each family is described and the relationship between stomatal density and guard cell size is reviewed. The stomatal characteristics presented here are a valuable research resource, allowing; I) the identification of basic stomatal types in these plants, II) the facilitation of their taxonomic classification and III) constitution of a baseline data set against which to monitor and evaluate environmental changes at these sites of international conservation interest.

Root Structure and Functioning for Efficient Acquisition of Phosphorus: Matching Morphological and Physiological Traits

Global phosphorus (P) reserves are being depleted, with half-depletion predicted to occur between 2040 and 2060. Most of the P applied in fertilizers may be sorbed by soil, and not be available for plants lacking specific adaptations. On the severely P-impoverished soils of south-western Australia and the Cape region in South Africa, non-mycorrhizal species exhibit highly effective adaptations to acquire P. A wide range of these non-mycorrhizal species, belonging to two monocotyledonous and eight dicotyledonous families, produce root clusters. Non-mycorrhizal species with root clusters appear to be particularly effective at accessing P when its availability is extremely low. There is a need to develop crops that are highly effective at acquiring inorganic P (Pi) from P-sorbing soils. Traits such as those found in non-mycorrhizal root-cluster-bearing species in Australia, South Africa and other P-impoverished environments are highly desirable for future crops. Root clusters combine a specialized structure with a specialized metabolism. Native species with such traits could be domesticated or crossed with existing crop species. An alternative approach would be to develop future crops with root clusters based on knowledge of the genes involved in development and functioning of root clusters. Root clusters offer enormous potential for future research of both a fundamental and a strategic nature. New discoveries of the development and functioning of root clusters in both monocotyledonous and dicotyledonous families are essential to produce new crops with superior P-acquisition traits.

Genetic Structure of Field Populations of Begomoviruses and of Their Vector Bemisia tabaci in Pakistan

ABSTRACT The genetic structure of field populations of begomoviruses and their whitefly vector Bemisia tabaci in Pakistan was analyzed. Begomoviruses and B. tabaci populations were sampled from different crops and weeds in different locations in Punjab and Sindh provinces, in areas where cotton leaf curl disease (CLCuD) occurs or does not occur. Phylogenetic analysis based on nucleotide sequences of the intergenic region in the viral DNA-A provided evidence of two clusters of isolates: viruses isolated from species in the family Malvaceae, and viruses isolated from other dicotyledon families. Analysis of the capsid protein (CP) open reading frame grouped isolates into three geographical clusters, corresponding to isolates collected in Punjab, Sindh, or both provinces. Random amplified polymorphic DNA analyses of the B. tabaci population showed that intrapopulation diversity was high at both the local and regional scales. Sequence analysis of the mitocondrial cytochrome oxydase I (mt COI) gene showed that the B. tabaci population was structured into at least three genetic lineages corresponding to the previously described Indian, Southeast Asian, and Mediterranean-African clades. The Indian clade was present only in Punjab, the Mediterranean-African only in Sindh, and the Southeast Asian in both provinces. B. tabaci haplotypes of the Indian clade were found only in the Punjab, where CLCuD occurs. Hence, the geographical distribution of virus and vector genotypes may be correlated, because similar phylogenetic relationships were detected for the viral CP and the vector mt COI genes.

Influence of elevated CO2 and ultraviolet-B radiation levels on floral nectar production: a nectary-morphological perspective

Investigations of the effects of two global events – elevated CO2 levels and enhanced ultraviolet-B (UV-B) radiation – on floral nectar production are reviewed from twelve dicotyledonous families. Furthermore, to allow comparisons between nectary morphology and nectar production in treated plants of these fifteen species, new data on floral nectary structure are provided for Malcolmia maritima (L.) R. Br. (Brassicaceae) and Scabiosa columbaria L. (Dipsacaceae). All but the last taxon possessed mesenchymatic floral nectaries with surface stomata. Few clear relationships existed between nectary morphology and various physiological responses to CO2 or UV-B enrichment, indicating that species responded notwithstanding nectary structure itself. Overall, nectar-solute concentration was least affected by elevated CO2 or UV-B radiation; consequently, changes in nectar volume were responsible for differences in nectar-sugar production per flower. Three species of Fabaceae experienced no change in floral nectar production upon exposure to elevated CO2. To date, no study of enhanced UV-B radiation reported a consistent reduction in floral nectar production; three species of Brassicaceae responded differently, but various levels of ozone depletion were simulated. Experimentation with more taxa – including those possessing nectary types such as septal (gynopleural) nectaries (e.g. many monocotyledons) or aggregations of glandular trichomes – and expanding such physiological studies to species possessing extrafloral nectaries, are recommended.

Spondylostrobus F.Mueller: operculate fruits of an extinct dicotyledon from the mid-Tertiary of Australia

Spondylostrobus F.Mueller, which accommodates operculate fruit-stones reported only from the mid-Tertiary of Australia, is redefined on the basis of type and other specimens of the type species, S. smythii F.Mueller, and of specimens included in S. rozefeldsii sp. nov. The globose to ellipsoidal fruits have 3–6 locules symmetrically disposed around a massive fibrous axis. Each locule has a single anatropous ovule, axile placentation, and a dorsal germination operculum that extends from near the base to the apex. In possessing these characters Spondylostrobus more closely resembles operculate fruits within the tribe Spondiadeae (Anacardiaceae) than operculate fruits of other dicotyledonous families. Spondylostrobus has widespread distribution in Oligocene–Miocene sediments of eastern Australia. At many localities it is associated with fruit-stones having affinities with extant taxa that now occur in rainforests, monsoonal forests, and fringing communities of northern Australia.

Phylogeny and Biogeography of the Styracaceae

The dicotyledonous family Styracaceae is distributed among all the major Tertiary mixed‐mesophytic forest refugia of the Northern Hemisphere. To infer the biogeographical history of the family and its significance for models of Northern Hemisphere historical biogeography, the phylogeny of the Styracaceae was estimated from separate and combined analyses of three DNA sequence data sets (chloroplast trnL intron/trnL‐trnF spacer, chloroplast rbcL gene, ITS region of nuclear ribosomal DNA) and a morphological data set of 47 characters. Up to 15 samples of other families of Ericales sensu the Angiosperm Phylogeny Group were employed as outgroups. The results strongly support the monophyly of the family. Dispersal‐vicariance analysis and Fitch parsimony optimization support a Eurasian origin of the Styracaceae, with subsequent dispersion to the Americas. This scenario is consistent with a hypothesized European origin for the family based on the fossil record. The eastern Asian–eastern North American disjunct genus Halesia is not supported as monophyletic. The sole Asian species of this genus groups with the Asian genus Rehderodendron, whereas the two North American species most often form parts of polytomies with other genera. The generally nested placement of the warm‐temperate deciduous species of Styrax within the amphi‐Pacific tropical evergreen group is consistent with an initial spread of the genus across the North Atlantic land bridge as part of the Eocene boreotropical flora and subsequent intercontinental dispersion of derived warm‐temperate‐adapted elements.

Study on the pathway of glycinebetaine biosynthesis in a monocotyledonous grass, Aneurolepidium chinense, grown in semiarid area

In some higher plants, glycinebetaine is known to be synthesized and accumulated in cells in response to salt stress or drought stress. Glycinebetaine is a compatible solute and acts as an excellent osmoprotectant. High levels of glycinebetaine are present in leaves of diverse families of dicotyledons and of some monocotyledons. The pathway of glycinebetaine biosynthesis in higher plants is as follows: Choline ? Betaine aldehyde ? Glycinebetaine. The first step is catalyzed by choline monooxygenase (CMO), being recently purified and characterized. The final step is catalyzed by betaine aldehyde dehydrogenase (BADH), which has been well characterized. Existence of BADH isozymes was suggested in spinach, mangrove, sorghum and barleys, and we reported that all those monocotyledonous plants have BADHs with a C-terminal tripeptide SKL that is known to be a signal for targeting preproteins to microbodies. We cloned and characterized a new type of sheep grass (Aneurolepidium chinense) BADH gene more homologous with dicotyledonous BADHs. Differential expression pattern was observed between the two types of sheep grass BADH genes under various stresses. Although the SKL type of BADH gene was inducible in sheep grass leaves, the new type of BADH gene was expressed constitutively under both heat and salt stresses. We also examine the localization of the new type of BADH protein. Furthermore we examine, whether or not sheep grass has chloroplastic CMO to protect photosynthetic machineries under heat or salt stresses.

ANÁLISIS FLORÍSTICO Y FITOGEOGRÁFICO DE UN BOSQUE SECUNDARIO PLUVIAL ANDINO, CORDILLERA CENTRAL (ANTIOQUIA, COLOMBIA)

Giraldo-Canas, D. 2001. Floristic and phytogeographical analysis of the Andean secondary wet forest, Central Cordillera (Antioquia, Colombia). Darwiniana 39(3-4): 187-199. A detailed floristic inventory as well as a preliminary phytogeographical analysis was conducted in an Andean secondary wet forest of NW of Colombia, in order to know the vascular species richness and the phytogeographical relationships. The floristic inventory revealed the presence of 712 vascular species distributed among 129 families, of which 17 belong to ferns and allies, with 69 species and 30 genera; 18 monocotyledon families, with 153 species and 87 genera, and 94 dicotyledon families, with 490 species and 290 genera. The best-represented plant families are Melastomataceae (36 species), Rubiaceae (36), Orchidaceae (30), Asteraceae (28), Poaceae (28), Piperaceae (24), Araceae (23), Fabaceae (20), Clusiaceae (18), Moraceae (18), Gesneriaceae (17), Mimosaceae (16), Solanaceae (15), Acanthaceae (14), and Polypodiaceae (13). The richest genera are Piper (17 species), Ficus (11), Psychotria (11), Inga (10), Anthurium (9), Miconia (9), Peperomia (7), Asplenium (6), Blechnum (6), Clidemia (6), Costus (6), Mikania (6), Selaginella (6), and Solanum (6). Regarding life forms, herbs are the best represented with 344 species (48,2%), followed by shrubs and trees (291 species, 41%), lianas (62 species, 8,7%), palms (12 species, 1,7%) and by arborescent herbs (3 species, 0,4%). There are 101 epiphytic or hemiepiphytic species belonging to 23 families. The richest families in epiphytes are Orchidaceae (23 species), Araceae (10), Bromeliaceae (8), Piperaceae (7) and Gesneriaceae (6), while the most common epiphytic genera are Peperomia (7 species), Anthurium (6), Elaphoglossum (5), Huperzia (4) and Trichomanes (4). There are 9 endemic species (1,3%). Some of the species collected are new to science or are new records for the flora of NW of South America. Nine species and 3 genera exhibit a disjunct distribution. The analyzed forest is floristically similar to lowland Neotropical forests. The phytogeographic analysis shows that 62,4% of the genera are neotropical, 25,8% are pantropical, 10% are cosmopolitan, 1,8% are holarctic, and that 15 genera have a tropical amphipacific distribution. Nine genera are confined to South America. Although the area studied was strongly modified, only 8 species are introduced or naturalized. The frequency of disturbances, such as fire, grazing, cutting, selective cutting, abandoned cultivat fields, maintains the area at early successional stages.

Endophytic fungi of some halophytes from an estuarine mangrove forest

Four halophytes belonging to three dicotyledon families, Acanthaceae, Aizoaceae and Chenopodiaceae, were screened for the presence of fungal endophytes. Thirty-six species of fungi, including some sterile forms, were isolated. Camarosporium species showed some degree of host preference as they were the dominant endophytes of the halophytes of Chenopodiaceae but were absent from the other halophytes. Some genera such as Colletotrichum, Phomopsis, Phyllosticta and Sporormiella were ubiquitous.

Further contribution to the Siwalik flora from the Koilabas area, western Nepal

The present study on fossil plants comprising well-preserved leaf and fruit impressions from the Siwalik sediments exposed near Koilabas in western Nepal is the first detailed and systematic work. The floral assemblage recovered from these sediments is impoverished both in quality and quantity as constituted by 25 species belonging to 22 genera and 15 dicotyledonous families of angiosperms. This assemblage adds significant data to the Siwalik Palaeobotany. On the basis of present assemblage as well as already known data from the area, the palaeoclimate, palaeoecology, and phytogeography of the area during the Mio-Pliocene in the Himalayan foothills have been deduced. The significance of the physiognomic characters of the fossil leaves in relation to climate has also been discussed.

Floral Morphology and Anatomy of Bonnetiaceae

DICKISON, W. C. (Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 275993280) and A. L. WEITZMAN (Department of Botany, Smithsonian Institution, Washington, DC 20560). Floral morphology and anatomy of Bonnetiaceae. J. Torrey Bot. Soc. 125:268-286. 1998.-A detailed study of floral morphology and anatomy of three genera comprising a narrowly circumscribed dicotyledonous family Bonnetiaceae is presented. Flowers are subtended by bracteoles and possess a perianth that is clearly differentiated into a 5-parted calyx and corolla composed of rather thick members. The androecium contains numerous stamens that are united at the base to form a short tube or collar or the stamens are pentadelphous and grouped at the base into five bundles that are positioned in the petal planes. Stamen fascicle traces are reported for the first time in flowers of Bonnetiaceae and are shown to originate close to, or adnate to, the median petal trace. Occasionally, two fascicle bundles arise side by side from a common gap as double bundles. Anther morphology and attachment is variable. Ploiarium possesses nectariferous discs that alternate with the stamen clusters. The presence of nectariferous tissue in Archytaea is variable. Nectaries can be supplied by double bundles, supporting the view that the nectaries of Plioarium and Archytaea represent transformed stamens. Gynoecia are compound, superior, and 3-carpellate or 5-carpellate. Styles range from divided to the base to undivided, and uniformly have a papillate stigma and a central canal filled with transfusion tissue. Placentation changes from axile to essentially parietal at midlevel of the ovary. Ovules are bitegmic, and contrasted with the putatively closely related Theaceae in which the elongated inner integument forms the micropyle, the outer integument projects well beyond the inner one. In addition to the degree of style fusion and carpel number, other important differences among genera of Bonnetiaceae are found in anther wall structure and floral vascular patterns. Major features of variation in the floral vascular system relate to the number and degree of independence of sepallary and petal traces; degree of independence of the androecial vascularization; the organization of the central ovarian vascular system; and the condition of the stylar vasculature. Comparisons are made among the flowers of Bonnetiaceae, Theaceae and Cluisiaceae.

Vestures in Woody Plants: A Review

Vestures are defined as mostly branched or irregularly shaped protuberances on the inner surface of the secondary wall of wood incIuding the surface of the wall lining the pit cavity. Based on a survey of literature, vestures in softwoods and hardwoods are discussed. Data on the chemical composition, ontogeny and possible functions are limited and partly contradictory. A preliminary list of dicotyledonous families is given in which vestures have been reported to occur. No general morphological cIassification of the different types of vestures (and 'warts') has been accepted at present. The taxonomie and diagnostic value of this polyphyletic character can be considerable but should be evaluated for each individual taxonomie group. It is not cIear whether all types of vestures and warts are homologous; both structures remain poorly understood.