January 2010 Volume 84 Number 1 January 2010
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BotSoc News, January 2010 1 Volume 84 Number 1 January 2010 Georgia Botanical Society LL HAIL THE APPLE MAGGOT AAs Darwin so famously claimed 150 years ago, natural selection drives the origin of species. While IN THIS ISSUE: most of us think of evolutionary change as occurring over hundreds of thousands of years, eco- logical speciation (also known as reproductive isolation) can occur within just a few generations. In a recent commentary for the New York Times, evolutionary biologist Olivia Judson discusses Society News – how quickly populations of our native phytophagous insects become reproductively isolated after p2 colonizing introduced exotic plants. Thinking of these new species, Ms. Judson argues that just as we bemoan extinctions, we might also take time to celebrate the arrival of new species - and Book Review - to illustrate her point, offers up the apple maggot as reason enough for a party. p3 Rhagoletis pomonella, the apple maggot fly, is So why don’t we consider the apple special- in the process of splitting into two species. Until ists a new species? Because they aren’t quite all The Native the mid-1800s, R. pomonella was a hawthorn the way there. From time to time, flies reared Garden - on apple will come to hawthorn to mate. And fly: adults met at hawthorn fruits to mate and p4 lay eggs. But when apples were introduced to although the offspring of such a mating are North America, some less likely to survive, they haw flies found these aren’t inviable or sterile. Upcoming fruits attractive places to This means that there is Field Trips – gather and began to mate still a low level of “gene p6 and lay their eggs on ap- flow” - i.e., successful sex ples instead. Today, the - between the two groups. Field Trip population of flies that But because offspring from Report – like apples have become such matings have a sur- genetically distinct from vival disadvantage, it seems p11 those that like haw. likely that there will come There are a couple a time when the separation of reasons why. First, flies meet each other at will be complete, and we will be able to raise a fruits. Since most flies have a preference for one cheer of welcome for the newly speciated apple fruit over the other, haw-preferring flies tend to maggot. Yippee! meet other haw-preferring flies, and ditto for I can sense your excitement. And perhaps apple flies. that’s the real reason we don’t celebrate apple Second, these mating preferences are rein- maggots, or any of the other new species (and forced by differences in how well the flies survive. there are many we know about) that are in the Attributes that help maggots survive on haw are process of evolving. For when a new species different from those that promote survival on does appear, it’s just not that different from Photo of the apples. Apple trees produce fruits earlier than the old species. To evolve the flamboyant dif- apple maggot fly hawthorn, and apple-specialists must thus ferences that distinguish a swan from a duck, (Rhagoletis pomonella) or a human from a chimpanzee - that takes from Central Science emerge from their pupae earlier, or they risk Laboratory, Harpenden missing the fruit. Emergence is under genetic thousands, even millions, of years. Archive, British Crown, control, so you might expect that apple flies and And that is what we lose with extinction. bugwood.org. haw flies would have genes that predispose them to emerge at different times - and they do. As a Exerpted from “All Hail the Apple Maggot” consequence, if, say, an apple fly should happen by Olivia Judson (http://judson.blogs.nytimes. to go to a haw instead and mate with a haw fly, com/2008/11/18/all-hail-the-apple-maggot/). their offspring will have a mix of haw and apple genes. It will thus be poorly suited to both fruits and less likely to survive. 2 BotSoc News, January 2010 Society News 2010 FIELD TRIPS & WORKSHOPS We have an extensive and varied schedule We’ll continue to visit our state parks: Sweet- next year. There are several new locations: McIn- water Creek for spring wildflowers, Providence BotSoc News tosh Reserve in Carroll County, the Monastery of Canyon for Plumleaf Azela, and Stone Mountain is published seven times a year (Jan, Our Lady of the Holy Spirit in Rockdale County, park for trout lilies. And we’ll offer a series of full Mar, May, Jul, Sep, Paulding Forest in Paulding County, and the and half day trips in the Chattahoochee River Nov and for the Freeman trail in Lumpkin County. NRA throughout the flowering seasons. Spring Wildflower Pilgrimage). This year we are offering several North Plant inventories will continue at Redtop Submission deadline Carolina trips, one for a weekend and two for Mountain State Park. is February 1 for the a day each. March issue. We have scheduled two workshops: one on Subscriptions You have an opportunity to spend Memo- geology, entitled Rocks ‘n’ Bots and one on the are included with rial Day weekend walking and botanizing in the Environments of the Piedmont. Advance regis- membership. mountains. tration will be required for both. Website: www.gabotsoc.org We’re continuing to broaden the days on We hope to offer a herbarium tour at UGA in which we offer trips with several more weekday Athens in late February, but are unable to con- Editorial Office trips and a few Sunday or Sunday afternoon firm the date as of press time. Please continue Jean Smith trips. to check the web site www.gabotsoc.org for the 1135 Barwick Hill Rd Comer, GA 30629 latest information. We’ll also send out an email ph 706.783.2308 We’re returning to old favorites too - the when we have more information. email: Pocket at Pigeon Mountain, the Lake Winfield jss2holly@ Scott Loop, Ocmulgee Bottomlands, and Oaky Maureen Donohue, windstream.net Woods in Houston County. Field Trip Chair © 2010 Georgia Bo- tanical Society a private nonprofit organization under IRS 501(c)3. Founded in 1926. NATIVE GARDENING IN THE SOUTHEAST SATURDAY, FEBRUARY 13, 2010 CHATTAHOOCHEE TECHNICAL COLLEGE The Georgia Native Plant Society (GNPS) invites all Georgia Botanical Society members to attend their 15th Plant Symposium at a special rate of $50. Among the topics to be presented are native vines, hollies, trilliums, plant identification, plant propagation, plant communities, and climate change and plant phenology. Download a registration form and more information from their website (www.gnps.org) or call 770-343-6000. BotSoc News, January 2010 Book Review Wicked Plants: The Weed that Killed Lincoln’s Mother and Other Botanical Atrocities reviewed by The term “natural” applied to various foods in Bob Linn grocery stores and elsewhere is often seen as an assurance of a more nutritious and healthful prod- Abraham Lincoln’s mother uct. However, as the recent book Wicked Plants: Nancy Hanks (and the exam- the Weed that Killed Lincoln’s Mother and Other ple used in the book’s subtitle) Botanical Atrocities by Amy Stewart makes clear, died from “milk sickness” after the word “natural” often means just the opposite of drinking milk that had been healthful. While few plants are as vicious as Audrey tainted with white snakeroot II in the cult movie Little Shop of Horrors, wild (Eupatorium rugosum; now plants can summon defenses against predators just known as Agertina altissima). as animals can. In truth, it’s a jungle out there. In fact, several other members of the Lincoln family as well as neighbors died from the same source. It Wicked Plants: The Plants have evolved mechanisms like colorful Weed that Killed blooms and strong scents to attract friends (like bees is probably just chance that Abe himself was Lincoln’s Mother and other pollinators) but also use strategies like the not killed. White snakeroot is kin to Joe Pye and Other Botani- irritating oils in poison ivy to keep potential foes weed (E. purpureum), a plant reputed to have cal Atrocities medicinal value. away. Often, plants with attractive blooms can have written by Amy very unattractive side effects. For example, monks- Stewart hood (Aconitum napellus) is a beautiful wildflower Stewart’s book does much more than simply that is also extremely toxic. Gardeners are advised report on poisonous plants. She also includes illustrated by short chapters on psychoactive plants, car- Briony Morrow- to wear gloves around the plant and its carrot-like Cribbs root is deadly when eaten. In 2004, the Canadian nivorous plants, and destructive plants (think actor Andre Noble died after eating monkshood on kudzu). All of this is done in brief informative Hardcover a hike. chapters that make this an entertaining book 22 pages to browse. Algonquin Books of Chapel Hill While Aconitum napellus is a European native, other Chapel Hill, NC Aconitum species grow in the US, both in the wild One serious idea that comes out of Stewart’s 2009 and as hybrids for gardens. They are all poisonous discussions is the idea that “natural” is not to some degree. Of interest is the fact that Aconitum a useful word when applied to supposedly is part of the Ranunculaceae (buttercup) family and healthful products. Nature is filled with incred- that its roots can be mistaken for horseradish. Not ible beauty as well as unbelievable ugliness only is the plant deadly, it’s tricky. and with both beneficial plants and deadly ones. Sometimes people take herbal remedies Recent scholarship has suggested that the Lewis and because they are labeled “natural,” but what Clark expedition was nearly ruined by a wild plant.