Page 10 spacer Botanic Garden News spacer Fall 98
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Rare Native Plants, continued

(Continued from page 9)
conditions around a known population of the green dragon, Sanders set out with topographic maps in hand to find other populations in Hampshire County. She located seven populations in Hatfield, Hadley, and Northampton, five of which had not previously been known. During her search, she made an even more surprising discovery, the first known population of hybrids between jack-in-the-pulpit and green dragon. Interspecific hybridization sometimes occurs in new or marginal habitat and eventually may lead to the development of new species.
    While human activity is often a factor in the decline or extinction of native plant species, some species appear to be inherently "extinction-prone." Former Smith biology professor Alan H. Bornbusch and two of his students, Lesley A. Swender '93 and Deborah L. Hoogerwerf '93, examined genetic variation in one of Massachusetts' rarest native plants, the ram's head lady's slipper (Cypripedium arietinum), and its more common relative, the pink lady's slipper (Cypripedium acaule). In populations of both orchid species they found extremely low levels of genetic variation, a condition that often leads to the decline of a species. But while human impacts such as habitat destruction and collecting may have led to fragmentation of populations and loss of genetic variation in the ram's head lady's slipper, Bornbusch, Swender, and Hoogerwerf believe that certain aspects of the species' reproductive biology such as low flowering success and lack of nectar to reward pollinators may also be factors in the decline of this species. Even isolation of populations during long periods of glaciation may have led to the loss of genetic variability in both species long before the arrival of humans in North America.
    While field botanists often study rare species in hopes of preserving or restoring declining populations, documenting rare plant populations can have broader implications. Sometimes studying such rare species can aid biologists in identifying unusual habitats and ecosystem types. In 1993 Smith graduate student Sarah Cooper-Ellis MA '94 examined the bryophyte flora in four tracts of old-growth forest in western Massachusetts. Her study included mosses and liverworts growing on the ground or on rock outcrops, as well as on the bark of old trees. She identified
  74 moss and 18 liverwort species in the study plots and produced a list of 24 bryophyte species she determined to be useful indicators of old-growth forest, information that will be useful in further efforts to identify old-growth stands around New England and elsewhere.
    Smith College faculty have played central roles in teaching about plant conservation and in directing and conducting research related to the subject. For example, Professor C. John Burk has taught plant ecology, plant systematics, conservation of natural resources, and biogeography at Smith for over 30 years, integrating into his courses research in the Lyman Conservatory and field trips to local natural sites where students learn to identify native plant species and appreciate the variety of native flora. The staff of the Botanic Garden has long been involved in growing, propagating, and distributing plant species that are threatened to varying degrees in their natural habitats, and other members of the Department of Biological Sciences have for many years taught courses that stress the function, structure, ecology, and diversity of plants.
    Although I am experiencing a sinking sensation standing here in this Conway marsh, I am nevertheless optimistic about the prospects for the northern adder's-tongue fern and for many other endangered plant species that grow wild in New England and elsewhere. While they are often tiny and occupy seemingly insignificant niches in the biosphere, they have much to teach us about how natural communities work and how easily they may be disrupted.
    Perhaps the single greatest challenge to humankind in the new century will be to slow or reverse the decline of species on Planet Earth that we have witnessed in recent decades. Whether in the laboratory, in the greenhouse, or in the wild, the students, faculty, and staff of the Botanic Garden of Smith College will continue to play a role in that effort. decoration

Bibliography

Bornbusch, A. H., L. A. Swender and D. L. Hoogerwerf. 1994.
Genetic variation in Massachusetts populations of Cypripedium arietinum R. Brown in Ait. and C. acaule Ait. (Orchidaceae). Rhodora 96:354-369.

Cooper-Ellis, S. 1994. Ecology and distribution of bryophytes in
old-growth forests of western Massachusetts. Master's Thesis, Smith College.

_______. 1998. Bryophytes in old-growth forests of western
Massachusetts. Journal of the Torrey Botanical Society 125(2):117-132.

McMaster, R. T. 1994. Ecology, reproductive biology and
population genetics of Ophioglossum vulgatum (Ophioglossaceae) in Massachusetts. Rhodora 96:259-286.

_______. 1996. Vegetative reproduction observed in
Ophioglossum pusillum Rafinesque. American Fern Journal 86:58-60.

Sanders, L. L. 1989. On the occurrence of Arisaema dracontium
in Hampshire County, Massachusetts. Rhodora 91:339-341.

_______ and C. J. Burk. 1992. A naturally-occurring population
of putative Arisaema triphyllum subsp. stewardsonii x A. dracontium hybrids in Massachusetts. Rhodora 94:340-347.
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