DOCSLIB.ORG

Determining Spatial Distribution of Toxicodendron Diversilobum

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Determining Spatial Distribution of Toxicodendron Diversilobum Determining Spatial Distribution of Toxicodendron diversilobum Colin Pryor1,2 and Michael Techler1 1Department of Geography and Planning, CSU Chico 2Department of Geologic and Environmental Science, CSU Chico Abstract Introduction Methods & Materials spatial analysis. A Near analysis was done Conclusions to determine the distance from each poison oak individual to the nearest disturbance, Western poison oak (Toxicodendron The distribution of western poison oak To explore the relationship between and nearest source of surface water. Slope Riparian vegetation type has a very diversilobum) has one of the widest (Toxicodendron diversilobum) comprises a the distribution of poison oak and three and aspect for each individual was high density of poison oak possibly due to geographic ranges of any native wider range of environmental conditions spatial variables, poison oak individuals determined from a Digital Elevation Model its close association with surface water, and Californian shrub. It is found under a than any other California shrub. The were sampled in three distinct areas of of Butte County. The area of each increased activity of animals which play a greater variety of soil conditions, purpose of this study is to identify a spatial Upper Bidwell Park, Chico, CA. The vegetation type within each transect was role in seed dispersal. The similar densities temperature, and rainfall ranges than any relationship between the location of poison variables being explored were distance to a calculated to get a density of poison oak by of mix oak and valley oak vegetation types other Californian shrub. Poison oak is also oak individuals in relation to: vegetation disturbance (road or trail), distance to a vegetation type. are expected because their habitat cover type, disturbed areas, and surface unique in its ability to grow in extreme surface water source (ephemeral or characteristics are very similar in stand water. In a foothill environment in northern shade, and full-sun. A useful structural perennial stream), and dominant vegetation Statistical analysis was done using density and understory vegetation California, poison oak individuals within adaptation of poison oak is its ability to type. Individuals were classified as IBM SPSS. For all statistical tests, an alpha composition. belt transects were recorded in a GPS. A grow as a climbing vine with presence of a climbing or non-climbing and recorded value of 0.05 was used. It can be concluded that the large portion of the analysis had a spatial support, instead of as a shrub. with a GPS waypoint. morphological adaptation of vining poison component and was done in a Geographic Proximity to disturbed areas and Poison oak individuals were sampled oak is most common near large trees that Information System (GIS). A measure of surface water can strongly influence the Results using a 10 meter wide belt transect located create a high amount of canopy closure. density by vegetation cover type, and composition of vegetation found at any within either a valley oak, blue oak, or mix Poison oak of both growth forms is more distances from each poison oak individual site. Disturbed areas can create edge effects oak dominated vegetation type as identified There is a strong association between common in low-sloping areas in close (N=308) to the nearest disturbance, and that influence the hydrology, insolation, from a vegetation map of Upper Bidwell climbing poison oak, riparian, and mixed proximity to disturbed areas and sources of nearest surface water source was calculated and nutrient cycling at a site. Edge effects Park. Transects were identified using oak vegetation types. From nonparametric surface water, even if the source is in a GIS. The slope and aspect at each offer a unique opportunity for plants to Google Earth, and chosen to capture a tests, the distribution of values for the ephemeral. individual was also analyzed. exploit these conditions if they can adapt to range of gradients (i.e. elevation, distance variables: distance to water, distance to Poison oak of both growth forms is the differences. Different habitats offer to water). disturbance, and slope are significantly more commonly present in close proximity different variables that can be exploited by associated with growth form of poison oak. to a disturbed area and in low-sloping areas species with particular adaptation traits. Waypoints were exported from the Riparian vegetation type has a significantly near surface water sources. Riparian and This study explored the spatial distribution DeLorme PN-40 GPS and brought into higher density of poison oak individuals per mixed oak vegetation types are correlated of climbing and non-climbing poison oak ESRI’s ArcMap. Trails, roads, and streams square kilometer than any other type, while with vining poison oak. individuals in relation to disturbances and not traced in the field were drawn in mix oak and valley oak types have nearly sources of surface water. The influence of Google Earth, and brought into ArcMap for identical densities. dominant vegetation type and slope were also examined. Figures 1, 2, 3: Distribution of poison oak individuals in transects. Survey transects with disturbance and surface Figure 5: Density of poison oak individuals by vegetation cover type water features included on (individuals/sq km). (N=308). top of vegetation cover type basemap. Figure 4: Legend for Figures 1,2, and 3. Figure 6: Flowchart of process to calculate distance from poison oak Fig. 4 individuals to a disturbance. Made in ArcGIS ModelBuilder. Figure 7: Flowchart of process used to get vegetation type area by Fig. 1 Fig. 2 Fig. 3 transect. .
Load more

Recommended publications
  • Allergic Contact Dermatitis to Plants: Understanding The
    Document downloaded from http://http://www.actasdermo.org, day 06/09/2012. This copy is for personal use. Any transmission of this document by any media or format is strictly prohibited. Actas Dermosifiliogr. 2012;103(6):456---477 REVIEW Allergic Contact Dermatitis to Plants: Understanding the ଝ Chemistry will Help our Diagnostic Approach a,∗ b a a E. Rozas-Munoz,˜ J.P. Lepoittevin, R.M. Pujol, A. Giménez-Arnau a Department of Dermatology, Hospital del Mar. Parc de Salut Mar, Barcelona, Spain b Dermatochemistry Laboratory, Institut of Chemistry, University of Strasbourg, Strasbourg, France Received 12 April 2011; accepted 29 July 2011 Available online 10 August 2012 KEYWORDS Abstract Allergic contact dermatitis due to plants is common. Potentially allergenic plants and plant products are found in many everyday environments, such as the home, the garden, Contact dermatitis; Plants; the workplace, and recreational settings. By improving our knowledge of allergenic plant- ␣-Methylene-␥- derived chemical compounds, we will be better positioned to identify novel allergens. We butyrolactone; review the most relevant chemical allergens that contribute to plant allergic contact dermatitis Quinones; and propose a clinical classification system based on 5 major families of chemical sensitiz- ␣ ␥ Terpenes; ers: -methylene- -butyrolactones, quinones, phenol derivatives, terpenes, and miscellaneous Phenols structures (disulfides, isothiocyanates, and polyacetylenic derivates). We also describe the dif- ferent clinical pictures of plant allergic contact dermatitis and review currently available patch test materials. A better understanding of the specific allergens involved in plant allergic contact dermatitis will help to predict cross-reactivity between different plant species or families. © 2011 Elsevier España, S.L. and AEDV.
    [Show full text]
  • Toxicodendron Diversilobum (Torr
    A WEED REPORT from the book Weed Control in Natural Areas in the Western United States This WEED REPORT does not constitute a formal recommendation. When using herbicides always read the label, and when in doubt consult your farm advisor or county agent. This WEED REPORT is an excerpt from the book Weed Control in Natural Areas in the Western United States and is available wholesale through the UC Weed Research & Information Center (wric.ucdavis.edu) or retail through the Western Society of Weed Science (wsweedscience.org) or the California Invasive Species Council (cal-ipc.org). Toxicodendron diversilobum (Torr. & A. Gray) E. Greene Pacific poison-oak Family: Anacardiaceae Range: Baja California to British Columbia. West of the Cascade Range in Washington and Oregon; ubiquitous in California west of the Sierra Nevada. Also along the western side of Nevada. Habitat: Mixed evergreen forests, woodlands, chaparral, coastal sage scrub, and riparian zones. It is one of the most widespread shrubs in California. It generally occurs on acid soils, but is not limited to any particular soil type, texture or drainage pattern. Pacific poison-oak is typically found at less than 5,000 ft elevation and grows on all aspects. It can tolerate drought, fire, and low temperatures. Origin: Native to the Pacific Coast of the western United States from British Columbia to Baja California. Impacts: One of the most hazardous native plants in the western states. It can be problematic wherever people are likely to contact the plant such as along trails or during brush removal around homes, along rights-of-way, fire breaks, construction sites, etc.
    [Show full text]
  • Poison Ivy (Toxicodendron Radicans) DESCRIPTION
    Weed Identification and Control Sheet: www.goodoak.com/weeds Poison Ivy (Toxicodendron radicans) DESCRIPTION: Poison ivy is a native woody vine and member of the sumac family. It can be found in shady and sunny sites rambling along the ground, forming a small shrub, or climbing up trees. The vines attach to surfaces by means of thin aerial roots which grow along the length of the stem. The plant always has three leaflets which are often serrated. Usually these leaflets have one dominant lobe, giving the outer two leaves the appearance of mittens with the central leaf resembling a mitten with two thumbs. Young leaves are often dark green or maroonish, and the attractive fall foliage can range from brick to fire- engine red. Poison ivy is generally not considered a threat to native plant communities, in fact, the white berries provide winter food for birds and deer relish the foliage. Though harmless to most animals, many humans are allergic to the urushiol (yoo-roo-shee-ol) oil produced by the plant which results in itching, inflammation and blisters. This oil is found in all parts of the plant during all times of the year. This oil can also be spread by contact with clothing, shoes, pets or equipment that have touched poison ivy weeks or months after initial contact. It can even be transmitted in the air when poison ivy is burned, which presents a severe risk if inhaled and has been known to result in hospitalization and death. Though some people are not alleargic to the oil, its important to wear pants, long sleeves and gloves when working around poison ivy since the allergy can develop af- ter repeated exposures to urushiol.
    [Show full text]
  • Assessing Restoration Potential of Fragmented and Degraded Fagaceae Forests in Meghalaya, North-East India
    Article Assessing Restoration Potential of Fragmented and Degraded Fagaceae Forests in Meghalaya, North-East India Prem Prakash Singh 1,2,* , Tamalika Chakraborty 3, Anna Dermann 4 , Florian Dermann 4, Dibyendu Adhikari 1, Purna B. Gurung 1, Saroj Kanta Barik 1,2, Jürgen Bauhus 4 , Fabian Ewald Fassnacht 5, Daniel C. Dey 6, Christine Rösch 7 and Somidh Saha 4,7,* 1 Department of Botany, North-Eastern Hill University, Shillong 793022, India; [email protected] (D.A.); [email protected] (P.B.G.); [email protected] (S.K.B.) 2 CSIR-National Botanical Research Institute, Council of Scientific & Industrial Research, Rana Pratap Marg, Lucknow 226001, Uttar Pradesh, India 3 Institute of Forest Ecosystems, Thünen Institute, Alfred-Möller-Str. 1, House number 41/42, D-16225 Eberswalde, Germany; [email protected] 4 Chair of Silviculture, University of Freiburg, Tennenbacherstr. 4, D-79085 Freiburg, Germany; anna-fl[email protected] (A.D.); fl[email protected] (F.D.); [email protected] (J.B.) 5 Institute for Geography and Geoecology, Karlsruhe Institute of Technology, Kaiserstr. 12, D-76131 Karlsruhe, Germany; [email protected] 6 Northern Research Station, USDA Forest Service, 202 Natural Resources Building, Columbia, MO 65211-7260, USA; [email protected] 7 Institute for Technology Assessment and Systems Analysis, Karlsruhe Institute of Technology, Karlstr. 11, D-76133 Karlsruhe, Germany; [email protected] * Correspondence: prem12fl[email protected] (P.P.S.); [email protected] (S.S.) Received: 5 August 2020; Accepted: 16 September 2020; Published: 19 September 2020 Abstract: The montane subtropical broad-leaved humid forests of Meghalaya (Northeast India) are highly diverse and situated at the transition zone between the Eastern Himalayas and Indo-Burma biodiversity hotspots.
    [Show full text]
  • Non-Native Invasive Plants of the City of Alexandria, Virginia
    March 1, 2019 Non-Native Invasive Plants of the City of Alexandria, Virginia Non-native invasive plants have increasingly become a major threat to natural areas, parks, forests, and wetlands by displacing native species and wildlife and significantly degrading habitats. Today, they are considered the greatest threat to natural areas and global biodiversity, second only to habitat loss resulting from development and urbanization (Vitousek et al. 1996, Pimentel et al. 2005). The Virginia Department of Conservation and Recreation has identified 90 non-native invasive plants that threaten natural areas and lands in Virginia (Heffernan et al. 2014) and Swearingen et al. (2010) include 80 plants from a list of nearly 280 non-native invasive plant species documented within the mid- Atlantic region. Largely overlapping with these and other regional lists are 116 species that were documented in the City of Alexandria, Virginia during vegetation surveys and natural resource assessments by the City of Alexandria Dept. of Recreation, Parks, and Cultural Activities (RPCA), Natural Lands Management Section. This list is not regulatory but serves as an educational reference informing those with concerns about non-native invasive plants in the City of Alexandria and vicinity, including taking action to prevent the further spread of these species by not planting them. Exotic species are those that are not native to a particular place or habitat as a result of human intervention. A non-native invasive plant is here defined as one that exhibits some degree of invasiveness, whether dominant and widespread in a particular habitat or landscape or much less common but long-lived and extremely persistent in places where it occurs.
    [Show full text]
  • Toxicodendron Radicans) in the Free-Air Tyree
    February 2008 COMMENTS 585 Sotala, D. J., and C. M. Kirkpatrick. 1973. Foods of white- Schnitzer et al. (2008) contrast results from a recent tailed deer, Odocoileus virginianus,inMartinCounty, experimental study documenting increased growth of Indiana. American Midland Naturalist 89:281–286. Sperry, J. S., N. M. Holbrook, M. H. Zimmerman, and M. T. poison ivy (Toxicodendron radicans) in the free-air Tyree. 1987. Spring filling of xylem vessels in wild grapevine. carbon dioxide enrichment (FACE) facility in the Duke Plant Physiology 83:414–417. Forest, North Carolina (Mohan et al. 2006), to an Stiles, E. W. 1982. Fruit flags: two hypotheses. American uncontrolled observational study finding decreased Naturalist 120:500–509. Walters, M. B., and P. B. Reich. 2000. Seed size, nitrogen abundance of poison ivy in Wisconsin forests between supply and growth rate affect tree seedling survival in deep 1959 and 2005 (Londre´and Schnitzer 2006). Schnitzer et shade. Ecology 81:1887–1901. al. (2008) accurately point out that controlled field Ward, J. K., and J. Kelly. 2004. Scaling up evolutionary studies may not always emulate long-term responses in responses to elevated CO2: lessons from Arabidopsis. Ecology Letters 7:427–440. uncontrolled ‘‘real world’’ forests. The lack-of-change in WDNR (Wisconsin Department of Natural Resources). 2004. overall vine abundance in the Wisconsin forests is in Southern forest communities. Ecological landscapes of contrast to previous studies showing recent increases in Wisconsin—Ecosystem Management Planning Handbook, the abundance of vines in temperate (Myster and Pickett HB1805.1. Wisconsin Department of Natural Resources, Madison, Wisconsin, USA. 1992, Dillenburg et al.
    [Show full text]
  • What Is This Plant and Why Is This Japanese Artist Eating It? (From Page 196)
    Brief Toxicology Communications BRIEF TOXICOLOGY COMMUNICATIONS Since many aspects of clinical toxicology involve visual 3. A clinical question should accompany the image. clues, the editorial board of The Journal of Medical A clinical narrative must be included and will be Toxicology is pleased to announce a new section. published separately in the same issue. The nar- rative should include any pertinent pathophysi- 1. The focal point of this section is an image sup- ology, mechanisms, pharmacokinetics, and a ported by a clinical case or a vignette of informa- reference list. tion. This is not intended to replace case reports, 4. Text and image format must meet the criteria which are published elsewhere in the journal. listed on the Instructions for Authors at http:// Examples may include a physical finding, crea- jmt.pennpress.org/PennPress/journals/jmt/ ture, plant, chemical structure, medication vial or authorGuide.pdf bottle, ECG tracing, historical photo, etc. 5. Submissions should be sent directly to lesliedye@ 2. The submission should be no more than 500 earthlink.net words. What is this plant and why is this Japanese artist eating it? (From page 196) Lewis S. Nelson, MDa, Michael Balick, PhDb, Nieve Shere, MSb aNew York City Poison Control Center, New York, New York bThe New York Botanical Garden, Bronx, New York ANSWER/DISCUSSION: hyposensitization, allowing them to work intimately with the urushiol monomer without developing the pruritic and uncom- Japanese lacquer artists use an urushiol-based product derived fortable vesicular rash typical of poison ivy (allergic contact from Toxicodendron vernicifluum (the Japanese lacquer tree) to dermatitis) [2].
    [Show full text]
  • Intriguing World of Weeds Iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
    Intriguing World of Weeds iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii Poison-Ivy/Poison-Oak/Poison-Sumac-The Virulent Weeds 1 LARRY W. MITICH2 I I; INTRODUCTION I, ii The word poison entered the English language in 1387 as 'poysoun" (18), and in Memoirs ofAmerican Academy of Arts and Sciences, v. 1, 1785, the word poison-ivy was used for the first time: "Poison ivy ... produces the same kind of inflammation and eruptions . as poison wood tree" (18). · The first known reference to poison-ivy, Toxicodendron radicans (L.) Ktze., dates from the 7th century in China and the 10th century in Japan. Since Toxicodendron species do not grow in Europe, the plants re­ mained unknown to Western civiliza­ tion until explorers visited the New World seven centuries later (7). Capt. John Smith (1579-1631) wrote the first description of poison-ivy and origi­ nated its common name; he noted a similarity in the climbing habit of They used that name for a shrub of the Southern States, North American poison-ivy to English with crenately-lobed, very pubescent leaflets (1). ivy (Hedera helix L.) (7). Toxicodendron, a pre-Linnaean name, was not accepted Joseph Pitton de Tournefort (1656-1708) established at the generic level by Linnaeus. Tournefort limited the the genus for poison-ivy in lnstitutiones rei herbariae, v. genus to ternate-leaved plants, thus omitting such close 1, p. 610, 1700 (7). The name is from the Latin for poison­ relatives of poison-ivy as poison-sumac and the oriental ous tree (9). lacquer tree (7). The lacquer tree has been known for In 1635 Jacques Philippe Cornut ( 1601-1651) wrote the first book on Canadian botany (Canadensium Plantarum thousands of years, and descriptions of the inflammations aliarumque nondum editarum historia, Parisiis [Paris]).
    [Show full text]
  • Draft Plant Propagation Protocol
    Plant Propagation Protocol for Toxicodendron diversilobum ESRM 412 – Native Plant Production TAXONOMY Family Names Family Anacardiaceae Scientific Name: Family Sumac Family Common Name: Scientific Names Genus: Toxicodendron Species: diversilobum Species Mill. Authority: Variety: n/a Sub-species: n/a Cultivar: n/a Authority for n/a Variety/Sub -species: Common Rhus diversiloba, Poison Oak Synonym: Common Pacific poison oak Name: Species Code: TODI GENERAL INFORMATION Geographical range: Ecological Poison oak occurs from British Columbia to Baja California, primarily west of distribution: the cascade mountain range. It is very prominent in California west of the Mojave and Sierra Nevada.(1) Climate and Poison-oak is found in elevations less than 5,000 ft. (1) elevation range Local habitat Douglas-fir, Ponderosa pine, Hemlock- Sitka spruce, Redwood, Western and hardwoods, and Chaparral. Poison-oak occurs in mixed evergreen forests, abundance; woodlands, chaparral, coastal sage scrub, and riparian zones (1). may include commonly associated species Plant strategy According to the U.S Forest Service, poison-oak is considered a facultative seral type / species. successional stage: Plant Poison-oak has many stems and can be seen as shrub or vine. As a shrub it can characteristi reach heights of 2-6 ft. However, the vine steams reach 10-30 ft and cs occasionally seen reaching 100 ft. Leaves resemble oak leaves with 3-5 rounded to ovate, toothed or lobed leaflets. The fruits are white drupes (1). Flowers are male and female, found on different plants. (1) PROPAGATION DETAILS Ecotype: n/a Propagation Plants Goal: Propagation Seed Method: Product Type: This propagation is designed for 3-gal container product type.
    [Show full text]
  • Appendix E - Plants and Wildlife
    Appendix E - Plants and Wildlife Blue Ridge NWR Plant Lists Table E-15. Blue Ridge NWR – Plants Scientific Name Common Name Family Abies concolor white fir Pinaceae Adenostoma fasciculatum chamise Rosaceae Amsinckia sp. fiddleneck Boraginaceae Arctostaphylos patula greenleaf manzanita Ericaceae Arctostaphylos viscida viscid manzanita Ericaceae Asclepias californica California milkweed Apocynaceae Asclepias fascicularis narrow-leaf milkweed Apocynaceae Bromus diandrus ripgut grass Poaceae Bromus hordeaceus soft chess Poaceae Bromus madritensis subsp. rubens red brome Poaceae Calocedrus decurrens California incense-cedar Cupressaceae Ceanothus leucodermis chaparral whitethorn Rhamnaceae Cercocarpus betuloides birch-leaved cercocarpus Rosaceae Chamaebatia foliolosa mountain misery Rosaceae Chlorogalum pomeridianum wavy-leaved soap-plant Agavaceae Cirsium sp. thistle Asteraceae Clarkia sp. clarkia Onagraceae Cynosurus echinatus bristly dogtail grass Poaceae Dendromecon rigida bush poppy Papaveraceae Dudleya sp. dudleya Crassulaceae Boraginaceae Eriodictyon californicum California yerba santa [Hydrophyllaceae] Eriogonum sp. wild buckwheat Polygonaceae Frangula californica subsp. cuspidata California coffee-berry Rhamnaceae Juncus sp. rush Juncaceae Lonicera sp. honeysuckle Caprifoliaceae Marah fabacea California man-root Cucurbitaceae Phrymaceae Mimulus viscidus viscid monkeyflower [Scrophulariaceae] Orobanche sp. broomrape Orobanchaceae Pinus lambertiana sugar pine Pinaceae Pinus ponderosa ponderosa pine Pinaceae Populus fremontii Fremont’s
    [Show full text]
  • Systemic Contact Dermatitis from Herbal and Homeopathic Preparations Used for Herpes Virus Treatment
    Acta Derm Venereol 2004; 84: 223–226 CLINICAL REPORT Systemic Contact Dermatitis from Herbal and Homeopathic Preparations Used for Herpes Virus Treatment Carla CARDINALI1, Stefano FRANCALANCI1,2, Barbara GIOMI1, Marzia CAPRONI1, Achille SERTOLI2 and Paolo FABBRI1 1II Dermatological Clinic and 2U.O. Allergological Unit, Department of Dermatological Sciences, University of Florence, Italy Systemic contact dermatitis may occur in contact- Allergic contact dermatitis due to Rhus toxicoden- sensitized individuals when they are exposed to haptens dron, in a phytotherapeutic preparation, has been orally, transcutaneously, intravenously or by inhalation. described already in two patients. One had used it as an We report the case of a woman developing a diffuse skin ointment for the treatment of muscoloskeletal aches eruption after the topical use of Rhus toxicodendron and the other for herpes lesions on the upper lip (6). alcoholic extract and the oral introduction of a We report here the case of a woman who developed a homeopathic preparation of the same substance for diffuse skin reaction after the topical use of an alcoholic herpes treatment. An open test, performed with the extract of Rhus toxicodendron and the oral introduc- Rhus toxicodendron tincture, showed an erythemato- tion of a 7CH preparation in pellet form of the same oedematous response at 48 h and vesicular reaction at substance (see Discussion for explanation of the 96 h that was still present after 7 days. Patch test with homeopathic nomenclature). 65% ethyl alcohol gave negative results. The open test performed, as control, in eight healthy informed subjects CASE REPORT revealed negative responses to Rhus tincture application.
    [Show full text]
  • Observations on Functional Wood Histology of Vines and Lianas Sherwin Carlquist Pomona College; Rancho Santa Ana Botanic Garden
    Aliso: A Journal of Systematic and Evolutionary Botany Volume 11 | Issue 2 Article 3 1985 Observations on Functional Wood Histology of Vines and Lianas Sherwin Carlquist Pomona College; Rancho Santa Ana Botanic Garden Follow this and additional works at: http://scholarship.claremont.edu/aliso Part of the Botany Commons Recommended Citation Carlquist, Sherwin (1985) "Observations on Functional Wood Histology of Vines and Lianas," Aliso: A Journal of Systematic and Evolutionary Botany: Vol. 11: Iss. 2, Article 3. Available at: http://scholarship.claremont.edu/aliso/vol11/iss2/3 ALISO 11(2), 1985, pp. 139-157 OBSERVATIONS ON FUNCTIONAL WOOD HISTOLOGY OF VINES AND LlANAS: VESSEL DIMORPHISM, TRACHEIDS, V ASICENTRIC TRACHEIDS, NARROW VESSELS, AND PARENCHYMA SHERWIN CARLQUIST Rancho Santa Ana Botanic Garden and Department of Biology, Pomona College Claremont, California 91711 ABSTRACT Types of xylem histology in vines, rather than types of cambial activity and xylem conformation, form the focus of this survey. Scandent plants are high in conductive capability, but therefore have highly vulnerable hydrosystems; this survey attempts to see what kinds of adaptations exist for safety and in which taxa. A review of scandent dicotyledons reveals that a high proportion possesses vasi­ centric tracheids (22 families) or true tracheids (24 families); the majority of scandent families falls in these categories. Other features for which listings are given include vascular tracheids, fibriform vessel elements, helical sculpture in vessels, starch-rich parenchyma adjacent to vessels, and other parenchyma distributions. The high vulnerability of wide vessels is held to be countered by various mechanisms. True tracheids and vasicentric tracheids potentially safeguard the hydrosystem by serving when large vessels are embolized.
    [Show full text]