Search

The genus Arbutus (Ericaceae) has been traditionally used in folk medicine due to its phytomedicinal properties, especially Arbutus pavarii Pamp. However, this plant has not been evaluated for its efficacy, quality, and consistency to support the traditional uses, potentially in treating diabetes. Despite previous studies that revealed the biological activities of A. pavarii as antioxidant and α-glucosidase inhibitory agents, scientific reports on the bioactive compounds that contribute to its health benefits are still scarce. Therefore, this research focused on the evaluation of antioxidant and α-glucosidase inhibitory activities of the methanol crude extracts and various fractions of the leaf and stem bark, as well as on metabolite profiling of the methanol crude extracts. The extracts and fractions were evaluated for total phenolic (TPC) and total flavonoid (TFC) contents, as well as the DPPH free radical scavenging, ferric reducing antioxidant power (FRAP), and α-glucosidase inhibitory activities. Methanol crude extracts of the leaf and stem bark were then subjected to UHPLC–ESI–MS/MS. To the best of our knowledge, the comparative evaluation of the antioxidant and α-glucosidase inhibitory activities of the leaf and stem bark of A. pavarii, as well as of the respective solvent fractions, is reported herein for the first time. Out of these extracts, the methanolic crude extracts and polar fractions (ethyl acetate and butanol fractions) showed significant bioactivities. The DPPH free radical and α-glucosidase inhibitions was highest in the leaf ethyl acetate fraction, with IC50 of 6.39 and 4.93 µg/mL, respectively, while the leaf methanol crude extract and butanol fraction exhibited the highest FRAP with 82.95 and 82.17 mmol Fe (II)/g extract. The UHPLC–ESI–MS/MS analysis resulted in the putative identification of a total of 76 compounds from the leaf and stem bark, comprising a large proportion of plant phenolics (flavonoids and phenolic acids), terpenoids, and fatty acid derivatives. Results from the present study showed that the different parts of A. pavarii had potent antioxidant and α-glucosidase inhibitory activities, which could potentially prevent oxidative damage or diabetes-related problems. These findings may strengthen the traditional claim on the medicinal value of A. pavarii.

Strawberry tree (Arbutus unedo L.), an evergreen shrub/small tree of the family Ericaceae, is a main constituent of the Mediterranean basin flora; although it is also found in southwestern Prance, Macaronesia, and Ireland. The small fruits are edible but mostly used for preparation of preserves and jams, and for liquors such as the Portuguese traditional "aguardente de medronho". Traditionally cultivated by small farmers, often in consociation with Quercus sp., strawberry tree is presently emerging as a new important fruit crop cultivated in large orchards by modern export-oriented enterprises. This change of paradigm requires a growing role of plant breeding, upstream of the production process. Genomic tools for this species are mostly limited to the chloroplast genome sequence and to genomic data described in this work. In order to identify strawberry tree microsatellite (SSR) loci we performed partial genome next-generation sequencing using the Ion Torrent technology. The sequenced similar to 24.6M nucleotides resulted in the identification of 1185 microsatellite markers mostly constituted by dinucleotide motifs. The relative amount of microsatellite dinucleotide motifs (AG/CT - 71.7%, AC/GT - 20.5%, AT/AT - 2.9%, and CG/CG - 0.3%) is similar to the one observed in other Ericaceae species. Among a tested sample of 40 SSR primer pairs, 20 amplified well-defined PCR products, 12 (30%) were validated as polymorphic. Used in our collaborative project for molecular identification of selected and improved clones, the identified SSR loci constitute a strong tool for a large panoply of applied and fundamental studies of this emerging fruit crop. Pluriannual Funding Program of the Portuguese National Foundation for Science and Technology info:eu-repo/semantics/publishedVersion

In addition to nutrients, plant foods contain compounds that may provide additional health benefits improving the quality of life. Species from Arbutus genus (Ericaceae) represent a promising source of healthy phytochemicals. Bioactive compounds including such as anthocyanins, iridoids, phenols, triterpenes, sterols, and fatty acids are reported from Arbutus species. Some Arbutus species revealed promising biological activities including antioxidant, anti-inflammatory, anti-proliferative, anti-diabetic, and antimicrobial activities, and deserve for that reason further consideration for new drug discovery. However, only few species are investigated scientifically for their chemical profile and biological activities. The aim of this article is to summarize the current knowledge of the components and biological properties of Arbutus species common in Mediterranean area, as well as the future prospects on their applications as potentially valuable products.

Several plant-derived natural products have been used in clinical phase for applications in neurological, cardiovascular, and inflammatory diseases. Arbutus andrachne L. (Ericacea) is an evergreen shrub native to the Mediterranean region. Traditionally, the fruits and leaves of Arbutus tree are well known and used as antiseptics, diuretics, blood tonic, and laxatives.Data regarding the biological effects of compounds derived from the Lebanese Arbutus andrachne are not available. In the present work, we studied the antioxidant activity of methanol extracts of leaves, fruits, and roots of the plant against electrolysis; together with their effects on the cardiodynamics of isolated perfused rabbit hearts.In vitro electrolysis of the different root, leaves, and fruits methanol extracts was evaluated by the amount of free radicals that has been reduced by increasing the concentration of root extracts ranging from 0.5 to 2 mg after 1, 2, 3, and 4 min. Left ventricular pressure (LVP), heart rate (HR), and coronary flow (CR) were investigated in isolated rabbit heart after administration of 0.5, 1, 2, and 2 mg of each methanol extracts plotted against time (0, 0.5, 1.5, 5, and 10 min), according to the Langendorff method. Lipid peroxidation study was performed by the colorimetric method on myocard tissue after incubation with 500 μl of the different methanol extracts. The amount of MDA was determined at 500 nm absorbance after 5 min incubation.Among the different methanol extracts, the roots showed the highest in vitro antioxidant activity, particularly observed at concentration of 2 mg which completely inhibits free radical generation after 4 min. LVP decreases by 32% at the dose of 2 mg of root extracts after 5 min. No significant effect was observed by the three tested extracts on the heart rate. The three methanol extracts did not show any significant effect on the coronary flow. Moreover, the roots show an increase in the coronary flow at a concentration of 1 and 2 mg/ml during 1 min. Electrolysis on heart tissue treated with the roots extracts shows a decrease in the MDA level from 70.51 ± 6.71 to 48.58 ± 4.15 nmole/g of tissue.Methanol extracts of the roots possess antihypertensive effect that may result from its ability to decrease the LVP together with its protective role by inhibiting free radical generation and significantly decreasing the MDA level of heart tissue.

© 2016 John Wiley & Sons Ltd Mesophyll conductance to CO2(gm) may respond to light either through regulated dynamic mechanisms or due to anatomical and structural factors. At low light, some layers of cells in the leaf cross-section approach photocompensation and contribute minimally to bulk leaf photosynthesis and little to whole leaf gm(gm,leaf). Thus, the bulk gm,leafwill appear to respond to light despite being based upon cells having an anatomically fixed mesophyll conductance. Such behaviour was observed in species with contrasting leaf structure using the variable J or stable isotope method of measuring gm,leaf. A species with bifacial structure, Arbutus × ‘Marina’, and an isobilateral species, Triticum durum L., had contrasting responses of gm,leafupon varying adaxial or abaxial illumination. Anatomical observations, when coupled with the proposed model of gm,leafto photosynthetic photon flux density (PPFD) response, successfully represented the observed gas exchange data. The theoretical and observed evidence that gm,leafapparently responds to light has large implications for how gm,leafvalues are interpreted, particularly limitation analyses, and indicates the importance of measuring gmunder full light saturation. Responses of gm,leafto the environment should be treated as an emergent property of a distributed 3D structure, and not solely a leaf area-based phenomenon.

Uvae ursi folium (Arctostaphylos uva ursi, Ericaceae) is the best known and most widely used herbal urinary antiseptic. In traditional medicine, other Ericaceae species are also used for the treatment of urinary tract infections. The present study investigates antimicrobial activity of five species of Ericaceae family native to the Balkan Peninsula: Arbutus unedo, Bruckenthalia spiculifolia, Calluna vulgaris, Erica arborea and Erica carnea. Ethanolic extracts were tested against 10 different gram-positive and gram-negative bacteria by the disc diffusion technique, where standard tetracycline, streptomycin and penicillin discs and discs containing crystal violet (1 mg/ml) and solvent (70.0% v/v ethanol) were used as controls. The most prominent antibacterial effect was achieved on Staphylococcus aureus with extracts of Calluna vulgaris and Erica carnea. Tested samples showed no activity against the gram-negative strains Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae. Inhibitory effects on the growth of gram-positive bacteria were more potent. The exception is Arbutus unedo ethanol extract which exhibited certain activity against a laboratory strain of wild Escherichia coli. Antimicrobial activity of the ethanolic extracts against 10 tested strains of bacteria in disc diffusion assay was generally weak, even for sample in which HPLC determination confirmed the presence of arbutin (secondary metabolite responsible for most of the antibacterial activity of Uvaeursi folium). Najpoznatiji i najviše korišćeni biljni uroantiseptik je list uve, Uvaeursi folium (Arctostaphylos uva ursi, Ericaceae). U tradicionalnoj medicini često se i druge vrste familije Ericaceae spominju u lečenju urinarnih infekcija. Provera antimikrobne aktivnosti izvršena je za sledeće biljne vrste ove familije koje samostalno rastu u flori Balkanskog poluostrva: Arbutus unedo, Bruckentalia spiculifolia, Calluna vulgaris, Erica arborea i Erica carnea. Antimikrobna aktivnost etanolnih ekstrakata listova ispitivana je diskdifuzionom metodom, korišćenjem 10 sojeva gram pozitivnih i gram negativnih bakterija, pri čemu su kao kontrole korišćeni standardni diskovi tetraciklina, streptomicina i penicilina, kao i diskovi sa rastvorom kristalvioleta (1 mg/ml) i rastvarača (70.0% v/v etanol). Pseudomonas aeruginosa, Escherichia coli i Klebsiella pneumoniae nisu osetljive ni na jedan od ispitivanih ekstrakata. Kao najbolji rezultati mogu se izdvojiti aktivnosti ekstrakta Calluna vulgaris i Erica carnea na bakterijski soj Staphylococcus aureus. Testirani uzorci uglavnom ispoljavaju antimikrobnu aktivnost prema gram pozitivnim sojevima. Izuzetak je etanolni ekstrakt vrste Arbutus unedo, koji ispoljava određenu antimikrobnu aktivnost prema laboratorijskom soju Escherichia coli. Antimikrobna aktivnost etanolnih ekstrakata prema 10 testiranih bakterijskih sojeva u diskdifuzionoj metodi je veoma slaba, čak i za uzorak za koji je HPLC analizom utvrđeno prisustvo arbutina (sekundarni metabolit odgovoran za uroantiseptično dejstvo lista uve).

Se describe e ilustra a Arbutus bicolor S. González, M. González et P. D. Sørensen, sp. nov., especie relacionada con A. xalapensis H.B.K., que ha sido por largo tiempo identificada erróneamente como A. glandulosa M. Martens & Galeotti, un sinónimo de esta última. Se diferencia de A. xalapensis por tener las ramillas y pecíolos densamente glandular pubescentes, las hojas marcadamente bicolores con envés blanquecino a ocre pálido debido a la presencia de indumento denso y uniforme de pelos apretadamente crespos, las hojas de color rojo intenso en la senescencia, así como las flores de color rosa o raramente blanco. Arbutus bicolor está ampliamente distribuida en la Sierra Madre Occidental y el Eje Neovolcánico, alcanzando la vertiente occidental de la Sierra Madre Oriental. Se registran híbridos esporádicos con A. madrensis S. González, A. occidentalis McVaugh & Rosatti, A. tessellata Sørensen y A. xalapensis. Se incluye una clave para distinguir a A. bicolor de otras especies arbóreas de Arbutus de México.

Arbutus herpetica Roxburgh (1832a) ascribed this binomial to Colebrooke and made reference to Hardwicke���s ��� Arbutus doubtful���. Before Roxburgh���s publication appeared, however, Wallich had already referred to Arbutus herpetica and Hardwicke���s drawing in describing Andromeda ovalifolia from Nepal. Wallich noted that the two did not agree in all respects. For simplicity, below I treat Arbutus herpetica as a synonym of Lyonia ovalifolia (Wall.) Drude, but Judd (1981), recognised a number of varieties to capture the variability of the species, and Arbutus herpetica probably is closest to his var. cordata. Below, I select the Hardwicke drawing no. 36 in the Natural History Museum set as the type of Arbutus herpetica. There is a similar drawing in the Plants of India set (Vol. VII no. 24)., Published as part of Turner, Ian M., 2015, The botanical legacy of Thomas Hardwicke's journey to Srinagar in 1796, pp. 1-25 in European Journal of Taxonomy 108 on page 16, DOI: 10.5852/ejt.2015.108, http://zenodo.org/record/3779322, {"references":["Roxburgh W. 1832 a. Flora Indica. Second edition. Volume 2. W. Thacker & Co., Calcutta.","Judd W. S. 1981. A monograph of Lyonia (Ericaceae). Journal of the Arnold Arboretum 62: 63 - 209."]}

Pacific madrone (Arbutus menziesii) is a broadleaf evergreen tree native to western North America that has been in decline for the past 30 years. A fungus has been isolated and was verified as the cause of cankers on dying trees. It was determined to belong in the genus Fusicoccum, an asexual state of Botryosphaeria. This genus in both its sexual and asexual states commonly causes canker diseases of deciduous woody plants. Using morphological and molecular data the fungus causing cankers on Pacific madrone is characterized, described and illustrated as a new species of Fusicoccum, F. arbuti D.F. Farr & M. Elliott sp. nov. No sexual state is known for F. arbuti. Evidence from the literature, cultures and specimens suggests that F. arbuti, often mistakenly identified as Nattrassia mangiferae, has been causing madrone canker since at least 1968. Authentic isolates of Nattrassia mangiferae as the synanamorph Scytalidium dimidiatum were sequenced and determined to be different from Fusicoccum arbuti and to belong in Botryosphaeria/Fusicoccum. In addition to molecular sequence data, the morphology of the pycnidial and arthric conidial states of Nattrassia mangiferae/ Scytalidium dimidiatum resembles that of Fusicoccum. Therefore the correct name for Nattrassia mangiferae and its numerous synonyms (Dothiorella mangiferae, Torula dimidata, Scytilidium dimidiatum, Fusicoccum eucalypti, Hendersonula toruloidea, H. cypria, Exosporina fawcetii, H. agathidia, and S. lignicola) is Fusicoccum dimidiatum (Penz.) D.F. Farr, comb. nov.

This study examined the vascular effect of Arbutus leaves (aqueous extract) and described the isolation of several fractions responsible for their vasorelaxant activity. The aqueous extract (AE) of leaves was tested on rat aortic rings precontracted with 0.1 µm noradrenaline. At 10−2 g/L, AE produced an endothelium dependent relaxation of 66% ± 5%, (n = 8). The leaves of Arbutus were then extracted successively with different solvents and the methanol extract was the most active. When tannins (primarily condensed tannins) were precipitated from the methanol extract, they showed a strong vasorelaxant activity (87% ± 4%, n = 5), whereas the elimination of tannins in the methanol extract reduced significantly its vasorelaxant activity (42% ± 8%, n = 8, p < 0.005). The methanol extract was further separated semi-preparatively by reversed-phase HPLC. Four fractions (Fr2, Fr3, Fr4 and Fr6) were the most active and produced 88% ± 2% (n = 5), 75% ± 6% (n = 5), 76% ± 3% (n = 7) and 77% ± 3% (n = 10) relaxation, respectively. These four fractions mainly correspond to polyphenol compounds. Analysis of Fr6 indicated that this fraction contained catechin gallate. In conclusion, the vasorelaxant activity of Arbutus is likely to be due to polyphenol compounds, primarily condensed tannins and catechin gallate. Copyright © 2004 John Wiley & Sons, Ltd.

Summary • We tested the hypothesis that unavoidably soft young leaves, which are therefore vulnerable to herbivory, should rely heavily on chemical defense to avoid overconsumption by herbivores. • Along with area lost to herbivores, parameters related to chemical and mechanical defense were monitored in two evergreen Mediterranean sclerophylls (Arbutus unedo and Arbutus andrachne) during spring and early summer, when newly growing and old leaves co-occur on the same branches. • During the lag phase of growth, young leaves were soft, rich in phenolics and gallotannins (up to 50% and 14% w/w, respectively) and highly astringent. During this period, the main consumer, a cricket (Poecilimon sp., Phaneropterinae) fed almost exclusively on the much tougher old leaves, which were low in phenolics (16%), gallotannins (6%) and astringency. During the rapid phase of leaf expansion, toughness increased and phenolics, gallotannins and astringency dropped to levels characteristic of old leaves. At that time, a shift in insect preferences towards young leaves was evident. Nitrogen content was independent of leaf age. • We conclude that leaf toughness is less important than chemical composition in the Arbutus–Poecilimon system, where gallotannins may play a decisive role.

This study aims at the determination of some physical and chemical characteristics of strawberry-tree fruit (Arbutus unedo L.), a typical Mediterranean climate species, namely of the Portuguese region of Algarve. It intends to be a contribution to its valorization and other applications following research by other scientists and local development associations as far as a better quality of alcoholic distillate of arbutus berry is concerned. Arbutus berry appears to be a good source of vitamins, namely niacin, ascorbic acid and β -carotene (content of 9.1, 346.3 and 70.9 mg/100 g, respectively), organic acids (nearly 9%), total sugars (c. 42%) and tannins (1.75 mg g−1).

The fruits and leaves of Arbutus species are well known in folk medicine as antiseptics, diuretics, and laxatives in many parts of Turkey. Some chemical properties including pH, soluble solid content, titratable acidity, protein, moisture, ash, ascorbic acid, fructose, glucose, sucrose, total phenols, total antioxidant activity, and minerals were determined in fully matured Arbutus unedo L. and Arbutus andrachnae L. fruits collected from different sites of Canakkale, Turkey in 2006 and 2007. Total soluble solids, titratable acidity, protein, moisture, and ash content of A. unedo and A. andrachnae berries were on average 16.0% and 14.0%, 0.4% and 0.6%, 2.38% and 3.77%, 47.21% and 38.21%, and 2.82% and 4.35%, respectively. The mean values of ascorbic acid were 270.50 mg/100 g for A. unedo and 140.30 mg/100 g for A. andrachnae, which suggested that Arbutus berries contain high amounts of vitamin C. In the strawberry tree fruits, fructose and glucose were determined to be the major sugars. The analysis showed that fructose and glucose occurred in concentrations of 24.09% and 19.09%, respectively. However, ripe A. andrachnae fruits contained small amounts of fructose (4.12%), glucose (2.73%), and sucrose (0.16%) detectable by high-performance liquid chromatography analysis. The general order of abundance of the minerals was KCaPMgNa in whole fruit of the strawberry tree. The chemical composition of Arbutus fruits indicates that the fruits are good sources of minerals and ascorbic acid and that they are high in phenolics and antioxidant capacity and low in soluble sugars, especially A. andrachnae. The data should be useful for research purposes and for compiling local food composition tables. In view of its chemical composition, the use of Arbutus fruits in some food products may be suggested.

Several Mediterranean shrubs, both autochthonous and naturalized, have been traditionally used as food, flavouring and/or spicing agents, and as phytopharmaceuticals. The interest around ‘natural’ and ‘biological’ products is steadily increasing in developed countries. Therefore, it seems reasonable to screen some shrubs with regard to the actual information about their content of phytochemicals, in relation to both real and putative beneficial properties, and with particular concern to their ‘antioxidant’ power. Moreover, striking molecules from the examined shrubs are compared according to their occurrence in the various genera. Also, their structures and structure/activity relationship are discussed in the light of possible practical application.

Arbutus andrachne Linnaeus, Systema Naturae, ed. 10, 2: 1024. 1759. ["Habitat in Oriente."] Sp. Pl., ed. 2, 1: 566 (1762). RCN: 3108. Neotype (Turland & Cafferty in Cafferty & Jarvis in Taxon 51: 752. 2003 [2002]): Greece. Fl. Graeca Exsiccata, " in monte Pentelico Atticae", April, Orphanides 78 (BM-000576313). Current name: Arbutus andrachne L. (Ericaceae)., Published as part of Jarvis, Charlie, 2007, Chapter 7: Linnaean Plant Names and their Types (part A), pp. 252-342 in Order out of Chaos. Linnaean Plant Types and their Types, London :Linnaean Society of London in association with the Natural History Museum on page 309, DOI: 10.5281/zenodo.291971

Arbutus unedo Linnaeus, Species Plantarum 1: 395. 1753. "Habitat in Europa australi." RCN: 3107. Lectotype (Chamberlain in Jarvis & al., Regnum Veg. 127: 20. 1993): Herb. Clifford: 163, Arbutus 1 (BM-000628452). Generitype of Arbutus Linnaeus (vide Hitchcock, Prop. Brit. Bot.: 154. 1929). Current name: Arbutus unedo L. (Ericaceae)., Published as part of Jarvis, Charlie, 2007, Chapter 7: Linnaean Plant Names and their Types (part A), pp. 252-342 in Order out of Chaos. Linnaean Plant Types and their Types, London :Linnaean Society of London in association with the Natural History Museum on page 309, DOI: 10.5281/zenodo.291971

Arbutus unedo L. (Ericaceae) is used in oriental Morocco to treat arterial hypertension. We studied its vasodilator effect and mechanisms of action in vitro. The root aqueous extract of Arbutus (0.25 mg/mL) produced a relaxation of noradrenaline-precontracted ring preparations of rat aorta with intact endothelium. Relaxation by Arbutus did not occur in specimens without endothelium and was inhibited by pretreatment with 100 μM NG-methyl-L-arginine (L-NMA), 10 μM methylene blue or 50 μM 1H-[1,2,4] oxadiazolo [4,3-a] quinoxaline-1-one (ODQ) but not by 10 μM atropine. These results suggest that Arbutus produces an endothelium-dependent relaxation of the isolated rat aorta which may be mediated mainly by a stimulation of the endothelial nitric oxide synthase by mechanisms other than activation of muscarinic receptors. Copyright © 2002 John Wiley & Sons, Ltd.

Mature flowering Arbutus texana trees were successfully micropropagated from shoot tips. Optimum shoot proliferation was achieved on a basal medium consisting of WPM salts, MS vitamins, and sucrose supplemented with 11.1 or 22.2 μm BA and no auxin. Microcuttings rooted readily when pulsed with 6.1 μm IBA for 1 week and transferred to auxin-free medium. The addition of charcoal to the rooting medium improved root branching and elongation but suppressed root formation. Chemical names used: N-(phenylmethyl)-1H-purin-6-amine (BA); indole-3-butyric acid (IBA).

For the angiosperm dominants of northern California’s mixed evergreen forests, this study compares the display of photosynthetic tissue within leaves and along branches, and examines the correspondence between these morphological attributes and the known environmental tolerances of these species. Measurements were made on both sun and shade saplings of six species: Arbutusmenziesii (Ericaceae), Chrysolepischrysophylla (Fagaceae), Lithocarpusdensiflorus (Fagaceae), Quercuschrysolepis (Fagaceae), Quercuswislizenii (Fagaceae), and Umbellulariacalifornica (Lauraceae). All species had sclerophyllous leaves with thick epidermal walls, but species differed in leaf specific weight, thickness of mesophyll tissues and in the presence of a hypodermis, crystals, secretory idioblasts, epicuticular deposits, and trichomes. The leaves of Arbutus were 2 – 5 times larger than those of Chrysolepis, Lithocarpus and Umbellularia and 4 – 10 times larger than those of both Quercus species. Together with differences in branch architecture, these leaf traits divide the species into groups corresponding to environmental tolerances. Shade-tolerant Chrysolepis, Lithocarpus, and Umbellularia had longer leaf lifespans and less palisade tissue, leaf area, and crown mass per volume than the intermediate to intolerant Arbutus and Quercus. Having smaller leaves, Quercus branches had more branch mass per leaf area and per palisade volume than other species, whereas Arbutus had less than other species. These differences in display of photosynthetic tissue should contribute to greater growth for Quercus relative to the other species under high light and limited water, for Arbutus under high light and water availability, and for Chrysolepis, Lithocarpus, and Umbellularia under limiting light levels.

Leaf anatomy of a species from the island of Badija on the east Adriatic coast of Yugoslavia, that has been determined as Arbutus andrachne L., was investigated using light and scanning electron microscopy and compared with that of a typical form of Arbutus andrachne L. from Greece, Arbutus unedo L. and Arbutus andrachnoides Link., well known as a hybrid between A. unedo and A. andrachne. The Arbutus taxon from the east Adriatic coast of Yugoslavia was found to be closest in leaf anatomy to the hybrid A. andrachnoides but not identical with it.

The morphological boundaries between Arbutus xalapensis and A. glandulosa are diffuse. Many individuals share traits of both species. The character most commonly used to distinguish the species is the presence of glandular hairs in A. glandulosa. Comparisons in the field of the number of colonies and level of defoliation by Eucheira socialis (Lepidoptera, Pieridae), an Arbutus-specific herbivore, showed that the damage is greater for glabrous than pilose trees and greater for pilose than glandular trees. Additionally, the geographic distribution of glandular trees is strongly correlated with that of E. socialis while that of non-glandular trees is not. We suggest that the glandular and non-glandular forms could belong to one single polymorphic species in which the glandular characteristic is maintained by differential herbivory. CLASSIFICATION OF THE Mexican species of Arbutus (Ericaceae) has proven to be a difficult task. Standley (1924) described seven species, though he acknowledged that all could be variants of A. xalapensis H.B.K.: "The Mexican plants of this genus are extremely variable and

Four hundred and eighty plants in northern California from 27 taxa in the Ericaceae and 5 in the Pyrolaceae were surveyed for presence of ectomycorrhizae, arbutoid, or ericoid mycorrhizae between September 1977 and April 1978. Of these, 337 in the Ericaceae and 8 in the Pyrolaceae had one or more types of mycorrhizae.At least 88% of the plants of larger shrubs or trees (Arbutus menziesii or Arctostaphylos spp.) were mycorrhizal in various locations in northern California. Of the plants in the remaining twenty-two taxa that were mycorrhizal, 67–100% had ectomycorrhizae or arbutoid mycorrhizae. Twenty-three taxa of ericaceous or pyrolaceous plants in the genera Cassiope, Gaultheria, Kalmia, Ledum, Leucothoe, Phyllodoce, Rhododendron, Vaccinium, Pyrola, and Chimaphila were also mycorrhizal. The type and abundance of mycorrhizae appear to depend on as yet undefined ecological factors.Ectomycorrhizae (including the Cenococcum type) or ericoid mycorrhizae are reported for the first time in Arbutus, most Arctostaphylos spp., Gaultheria shallon, Kalmia polifolia, Ledum glandulosum var. columbianum, Leucothoe davisiae, Rhododendron macrophyllum, Vaccinium arbuscula, V. ovatum, V. scoparium, Chimaphila menziesii, and Pyrola picta f. picta.

Survival of tanoak (Lithocarpus densiflorus) and Pacific madrone (Arbutus menziesii) seedlings was studied in order to interpret succession in conifer hardwood forests and to determine ways to suppress establishment of these species. Seed protected from rodents and birds, and unprotected seed was sown in clearcuts and in conifer stands 40 to 200+ years old. Second-year survival rates of tanoak seedlings were high (50–70%) in exposed clearcuts and conifer stands. Seed predators appear to be of prime importance in limiting tanoak establishment. Survival rates of Pacific madrone seedlings on the same sites as the tanoak were low (0–8%), and many factors caused mortality. Seedlings of both species grew slowly; after 3 years, average tanoak height was only 6.0 to 14.0 cm, average madrone height 2.0 to 6.0 cm.

Alkane analyses of Arbutus (Ericaceae) leaves of the three species (A. texana, A. menziesii and A. arizonica) native to the United States show that two morphologically overlapping but allopatric taxa (A. texana and A. menziesii) have substantially different alkane profiles at the unusually low C., level. These data supply additional evidence supporting continued recognition of them as separate species.

Two species of the genus Arbutus, A. unedo L. and A. andrachne L. are found in Europe (Polunin and Eveard 1976). While A. andrachne is confined to Eastern Mediterranean countries, A. unedo (the strawberry tree) occurs throughout the entire Mediterranean region, the southwest of Europe and as far north as southwest Ireland. In the Iberian Peninsula A. unedo is a widespread shrub (or a small tree to 12 m) most common in upland or mountainous regions and less frequent in the Central Plateau (Lazaro 1921).

Arbutus uva-ursi, spec. nov. 4. Arbutus caulibus procumbentibus, foliis integerrimis. Fl. lapp. 162. t.6. f.3. Fl. suec. 339. Mat. med. 211. Hort. cliff. 163. Roy. lugdb. 440. Hall. helv. 415. Uva ursi. Clus. hist. 1. p. 63. Radix idaea putata & Uva ursi. Bauh. hist. 1. p. 524. Arbutus noveboracensibus Bearberry. Cold. nov. 104. Habitat in Europa frigida, Canada . ���, Published as part of Linnaeus, Carolus, 1753, Species plantarum: exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas, Stockholm :Laurentius Salvius on page 395, DOI: 10.5281/zenodo.3931989

Arbutus alpina, spec. nov. 3. Arbutus caulis procumbentibus, foliis rugosis serratis. Fl. lapp. 161. Fl. suec. 340. Hort. cliff. 163. Roy. lugdb. 440. Hall. helv. 415. Vitis idaea foliis oblongis albicantibus. Bauh. pin. 470. Vitis idaea. Clus. hist. 1. 61. Habitat in Alpibus Lapponiae , Helvetiae , Sibiriae . ���, Published as part of Linnaeus, Carolus, 1753, Species plantarum: exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas, Stockholm :Laurentius Salvius on page 395, DOI: 10.5281/zenodo.3931989

Arbutus acadiensis, spec. nov. 2. Arbutus caulibus procumbentibus, foliis ovatis subserratis, floribus sparsis, baccis polyspermis. Vitis idaea acadiensis, foliis alterni. Tournef. inst. - - Habitat in Acadia . ���, Published as part of Linnaeus, Carolus, 1753, Species plantarum: exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas, Stockholm :Laurentius Salvius on page 395, DOI: 10.5281/zenodo.3931989

Arbutus unedo, spec. nov. 1. Arbutus caule erecto, foliis glabris serratis, baccis polyspermis. Hort. cliff. 163. Roy. lugdb. 440. Sauv. monsp. 59. Arbutus folio serrato. Bauh. pin. 460. Arbutus. Cam. epit. 168. Habitat in Europa australi. ��� Baccae polyspermae tuberculis seminum exasperatae., Published as part of Linnaeus, Carolus, 1753, Species plantarum: exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas, Stockholm :Laurentius Salvius on page 395, DOI: 10.5281/zenodo.3931989

Arbutus tessellata Sorensen, described and illustrated, is a tree distinguished chiefly by its checkered bark and long, spreading, glandular hairs on the petioles and young twigs and is recognized as distinct from A. glandulosa Martens & Galeotti.