| Efforts to Save an Endangered Species - Echinacea laevigata
(Smooth Coneflower) |
James E. Arnold
South Carolina Botanical Garden
Clemson, South Carolina |
Lonette G. Edwards
USDA Forest Service &
Department of Biological Sciences
Clemson University |
Timothy P Spira
Department of Biological Sciences
Clemson University |
Joan L. Walker
Southern Research Station
USDA Forest Service
Department of Forest Resources
Clemson University |
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The South Carolina Botanical Garden contains living collections of several
rare plants. Among these, Echinacea laevigata (Boynton and Beadle)
Blake is federally listed as endangered. The Garden staff and plant ecologists
from the USDA Forest Service's Endangered and Threatened Species in Southern
Forests Research Work Unit have been cooperating on a research project involving
this rare species. Botanical Gardens play an indispensable role not only
in research, but also in the education of students, visitors, the citizens
of South Carolina, and others regarding natural resources.
Research
Echinacea laevigata (Asteraceae), is a perennial herb. Originally
reported to occur in eight states, the current range is limited to Virginia,
North Carolina and South Carolina and Georgia. Little is known of the life
history or the basic biology of any stage in the life cycle of E. laevigata
. Aerial shoots arise from underground rhizomes as basal rosettes of glabrous
leaves (hence, the common name, Smooth Coneflower) or as flowering, leafy
stems. A single rhizome can have various combinations of the above, and
may be connected to as many as a dozen (or more) above-ground parts. Flowering
rosettes usually produce a solitary head of perfect disk and pistallate
ray florets between May and August. Ray petals are pink to pale purple (infrequently
white) and drooping.
The attractive inflorescence and prominance
of plants along roadsides and open, sunny areas led people to uproot entire
plants from the wild. Collection of plants from natural populations was
a significant factor in placing this species on the national list of endangered
species. South Carolina recognizes the federal listing for this species.
The SC Botanical Garden and the Endangered Species Research Work Unit applied
for and were granted permission by the US Department of Interior's Fish
and Wildlife Service, the South Carolina Non-Game and Heritage Trust Program,
and the US Forest Service to conduct basic research projects on E. laevigata
plants maintained in Garden facilities. In addition to other Forest Service
research on E. laevigata , pilot studies are also being conducted
to determine: 1. the potential of E. laevigata for vegetative reproduction
and 2. the optimal time of year for such events. Results are very encouraging.
As suspected, E. laevigata has the potential to produce physiologically independent
plants from a single mother plant when the rosettes are severed from each
other; and from rhizome cuttings which include roots. In the second part
of this study, rhizome segments were taken early in the growing season and
again in late summer. In general, more new plants developed from cuttings
made later in the year, then from cuttings taken at the start of the growing
season. Although applications of exogenous hormone (indole-butyric acid,
or IBA) were effective in small contrations (i.e., treated segments developed
both shoots and roots); controls (no hormone treatment) also developed into
plants.
Among other on-going projects at the South Carolina Botanical Garden, the
Forest Service's Clemson unit has been conductiog research to determine
what environmental factors are necessary for successful seed germination
of additional rare plant species, as well as seedling growth and establishment
of E. laevigata . Plants were grown outside under shade cloth of
varying densities in order to measure effects of light intensity on growth
and development (including flowering).
The Forest Service sought not only facilities of the South Carolina Botanical
Garden, but also its wide expertise in horticulture and plant research.
Research alone, however, will not recover rare, endangered or threatened
species. Education, an on-going activity at the Garden, is also a vital
tool. In its Smooth Coneflower Recovery Plan (The U.S. Fish and Wildlife
Service. 1995. Atlanta, GA) the FWS identifies this and other activites
as important to the conservation of Echinacea laevigata . The Botanical
Garden in its collaboration with the Forest Service, Clemson University,
and private industry is uniquely suited to further address at least three
(if not more) of these targets: 1. "conduct research on the biology
of the species that includes (...sun/shade...asexual reproduction via rhizomes,
conditions and requirements for seedling...survival, etc)."; 2. "maintain
cultivated sources for the species"; and 3. "(encourage and assist)
nurseries in the development of cultivated stock". Public education
about the need for conservation efforts can also include outdoor exhibits
(which the Garden has) of other commercially available native coneflowers
and equally attractive flowering plants with a similar appearance. Successful
conservation efforts are collaborative ventures; the SC Botanical Garden
and the US Forest Service have initiated just such an association.
Last Updated 7/16/98