Aquatic Plants of Pennsylvania

Aquatic Plants of Pennsylvania: A Complete Reference Guide

TIMOTHY A. BLOCK
ANN FOWLER RHOADS
Illustrations by Anna Aniśko
Copyright Date: 2011
Pages: 320
https://www.jstor.org/stable/j.ctt3fhdnn
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  • Book Info
    Aquatic Plants of Pennsylvania
    Book Description:

    From the Delaware River to the shores of Lake Erie, Pennsylvania's diverse watery habitats are home to more than 200 species of aquatic plants. In Aquatic Plants of Pennsylvania: A Complete Reference Guide, botanists Timothy A. Block and Ann Fowler Rhoads have assembled the first identification guide specific to the Keystone State yet useful throughout the Mid Atlantic region. Organized and written in a way that will make information easily accessible to specialists and nonspecialists alike, the book highlights the diversity and vital ecological importance of this group of plants, providing photographs, illustrations, descriptions, and identification keys for all emergent, floating-leaved, and submergent aquatic plants found in the Commonwealth. An introductory chapter on aquatic plant ecology covers topics such as evolution, form, and reproduction of aquatic plants, vegetation zones, types of aquatic ecosystems, and rare and endangered species. Information on invasive plants, such as Eurasian water-milfoil and curly pondweed, that threaten Pennsylvania's aquatic ecosystems will be especially useful to watershed organizations, citizen monitoring projects, lake managers, and natural resource agency personnel. An illustrated identification key guides the reader through a series of steps to properly identify a specimen based on its characteristics. Each of the more than 200 listings provides a plant's taxonomy, detailed description, distribution map, and expert botanical illustrations. Many also include color photographs of the plants in their natural habitats.

    eISBN: 978-0-8122-0504-6
    Subjects: Botany & Plant Sciences

Table of Contents

  1. Front Matter
    (pp. i-iv)
  2. Table of Contents
    (pp. v-vi)
  3. Tables and Figures
    (pp. vii-viii)
  4. Preface
    (pp. ix-x)
  5. Acknowledgments
    (pp. xi-xii)
  6. Chapter 1. Evolution and Ecology
    (pp. 1-20)

    It’s not always easy to decide what to include in a list of aquatic plants. We treat 194 macrophytes (large plants) here, including 178 flowering plants, 2 horsetails, 2 ferns, 5 quillworts, 3 mosses, 2 liverworts, and 2 Charophyte algae. Phytoplankton and filamentous algae are not included. Macrophytes range from plants that grow with their roots under water but most of their stems, leaves, flowers, and fruits above the water surface—the emergent flora—to species that are completely submergent.

    The difficulty in choosing what to include arises because of the flexibility of some species, which can grow as emergents...

  7. Chapter 2. Identification Keys for the Aquatic Plants of Pennsylvania
    (pp. 21-28)

    The keys in this book are designed to guide the user through a series of decisions leading to proper identification. At each step of the key, the user must examine a characteristic or characteristics of the plant and decide which of a pair of corresponding statements best fits the specimen in question. Each statement and its corresponding member are preceded by the same capital letter(s). There are a few simple rules that, if followed carefully, should ease the task of arriving at a correct identification.

    1. Read each statement of a pair carefully and thoroughly before deciding which best fits the...

  8. Chapter 3. Emergent Plants
    (pp. 29-142)

    Emergent species grow in shallow water at the margins of lakes or streams. These species are rooted below the water surface, but the stems, leaves, and flowers are mostly above the surface. Emergent plants often form a continuous band at the edge of the water at depths to about 1 m; the width of the emergent zone depends on the slope of the lake bottom.

    Arrow-arum is one of several emergent aquatic plants with large, arrow-shaped leaves. The plants consist of a cluster of long-petioled leaves that grow from buried vertical rhizomes. The strongly veined leaf blades are 5–20...

  9. Chapter 4. Floating-leaf Plants
    (pp. 143-162)

    This group of species is characterized by leaves that float on the water surface, although some members may also have underwater leaves. Flowering typically occurs at or just above the surface of the water.

    The floating-hearts are rooted aquatics with a long stem that bears leaves and flowers at the water surface. Although the floating leaves look superficially like those of water-lily, the plants are not closely related at all. The flowers have 5 fused petals and 5 stamens attached to the corolla tube. The fruit is a capsule.

    A. flowering stem with a single leaf at the base of...

  10. Chapter 5. Thalloid and/or Tiny Floating Plants
    (pp. 163-182)

    Plants in this group have a reduced structure lacking well-defined stems and leaves, or have tiny floating stems with minute leaves. They are small plants that float at or just below the water surface, or in a few cases grow attached to submerged rocks or other solid surfaces. Included in this group are flowering plants (the duckweeds and riverweed), and non-flowering plants including aquatic liverworts and a fern.

    The aquatic liverworts are small floating plants that may also exist stranded on exposed mud. They are described as thalloid because they lack true roots, stems, or leaves; they also lack specialized...

  11. Chapter 6. Submergent Leafy-stemmed Plants
    (pp. 183-240)

    This group of species grows rooted in the lake bottom or attached to rocks or other solid underwater surfaces. Their stems bear numerous leaves, most of which are beneath the water surface, but some at the stem tip may be floating. The group includes aquatic mosses and flowering plants. Flowering and fruiting occur underwater, at the water surface, or on short emergent stem tips.

    In our work in lakes, ponds, and streams we have observed several aquatic mosses. They are included here because they might be confused with vascular plants on first glance. However, mosses differ from vascular plants in...

  12. Chapter 7. Submergent Rosette-forming Plants
    (pp. 241-254)

    Plants in this group are rooted in the lake bed and form a basal rosette of leaves. The group includes flowering plants and the quillworts, which reproduce by spores. In the flowering species an erect, leafless, flowering stem arises from the basal rosette, and flowers are usually borne above the water surface.

    Sterile (non-flowering) rosettes of species other than those treated in this section may be present at some sites. These are very difficult to identify although leaf venation and leaf shape may provide some clues. See additional comments under arrowheads, especially Sagittaria rigida and Sagittaria graminea.

    Mudmat is a...

  13. Chapter 8. Submergent Plants with Finely Divided Leaves
    (pp. 255-290)

    The characteristic that defines this group is submergent leaves that are divided into fine, capillary segments. The plants may be either free-floating or rooted. Most are completely submergent, but stem tips or flowering stems of some species extend above the water surface.

    Most bladderworts are found in low nutrient environments such as oligotrophic lakes and bogs. These native carnivorous plants trap tiny aquatic invertebrates in small bladders (traps) on their leaves (Figure 8.1). The small sac-like traps have a suction-operated mechanism that is triggered by sensitive hairs at the base of the trap door. When a small aquatic invertebrate comes...

  14. Glossary
    (pp. 291-294)
  15. References and Sources
    (pp. 295-298)
  16. Appendix: Taxonomic List of Plants Included
    (pp. 299-304)
  17. Index
    (pp. 305-308)