• Login
    View Item 
    •   Oxy Scholar Home
    • Biology
    • Biology URC Student Scholarship
    • View Item
    •   Oxy Scholar Home
    • Biology
    • Biology URC Student Scholarship
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Root Structure and Function in Epiphytic Orchids Cam-Van Huynh

    Thumbnail
    Author
    Huynh, Cam-Van
    Issue
    urc_student; urc_student
    Date
    2007-01-01 0:00
    Metadata
    Show full item record
    URI
    https://scholar.oxy.edu/handle/20.500.12711/391
    Abstract
    Plants in the Orchidaceae (the orchid family) have evolved in diverse and physically stressful habitats (Benzing et. al, 1982). Epiphytic orchids, which grow on other plants in tree canopies, are especially susceptible to dehydration because their roots are on bare branches or in leaf litter rather than actual soil. In seasonally dry rainforests these epiphytic orchids face the challenges of water stress and nutrient acquisition. In response to these constraints the aerial roots of epiphytic orchids have developed a specialized spongy ?multilayered epidermis? called the velamen. The velamen is formed from epidermal cells and is extremely porous allowing rapid water movement towards the exodermis, where water can next enter the cortex (Figure 1). This structure assists with water uptake and is speculated to aid in water retention and possibly nutrient acquisition. In order to determine the role of the velamen in water uptake, aerial roots of various orchid species with the velamen intact and with the velamen removed were tested for saturation and water loss. The number of velamen layers was also compared to leaf thickness, an index of shoot desiccation tolerance. Hand-cut sections were examined microscopically for a variety of orchid species from Costa Rica and a shaded greenhouse at Occidental College in order to determine if there is a correlation between leaf thickness and the number of velamen layers
    Collections
    • Biology URC Student Scholarship

    Browse

    All of Oxy ScholarCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsJournal TitleJournal IssueThis CollectionBy Issue DateAuthorsTitlesSubjectsJournal TitleJournal Issue

    My Account

    LoginRegister

    DSpace software copyright © 2002-2021  DuraSpace
    Contact Us | Send Feedback
    DSpace Express is a service operated by 
    Atmire NV