MNHS Bird & Naturewalks will begin again in April.

See page 4 for details.

Public Is Invited

Spring 2005 Newsletter

Thursday, June 9, 6:00 PM

We’ll carpool from the Hermann Fine Arts Center

parking lotWe’re trying again – a rain delay field trip

from last fall. Aka the ‘Big NaturalBridge’, this natural bridge is in western

Washington County and is a dedicated StateNature Preserve. The 20 minute easy walkto the bridge is an enjoyable way to spend a

June evening in itself.

Presenter: John Hoopengarner, Executive Director of the

Muskingum Watershed Conservancy District This presentation will be a great opportunity to learn about the impacts and benefits of the14 MWCD reservoirs in reducing flood damage over the past 70 years, including the flood of 2005.

Thursday, April 14, 7:00 PM Selby Hall, Rm 143 Marietta College

Presenter: Nicole CavenderNicole Cavender, an ecologist at The Wilds, will provide background on the Wilds and then discuss some of her Restoration Ecology projects, such as creating and introducing various habitats and restoring woodlands. Some methods may be applicable to private lands as well.

Thursday, May 12, 7:00 PM Selby Hall, Rm 143

Marietta College

Marietta Natural History Society

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Landscape Restoration

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Web Threads

The following recipe for deer repellant was submitted by a reader of Backyard Living magazine – if it works onWisconsin deer will it work on southeastern Ohio deer? 1 egg 1 tablespoon dish detergent ½ cup milk 1 gallon water 1 tablespoon cooking oilBeat egg and milk together, then add cooking oil and detergent. Add mixture to water and stir or shake well. Store in acovered 1-gallon container (be sure to label). Apply liquid to plants (except for food plants) using a spray bottle. Reapply every 2 weeks or after heavy rains. ...Charlotte Schmidt, St. Germain, WI

Dinner with the speakers

We will meet at 5:00 at the Levee House RestaurantCheck first with Diane (373-8031), Marilyn (373-3372) or Elsa (373-5285). to be sure speaker will be there. Members should make their own reservations.

Garlic Mustard – opposite, broadlyheart-shaped leaves withscalloped edges with odor of garlic; stem 4” to 4 ft. tall; racemes of small 4-petaled flowers. Give it an inch and you will probably lose a mile of spring wildflowers. Woodland biennial. (Spring 1999)

Poison Hemlock – Will be growing more in the open – fencelines, streambanks, roadbanks. Somewhat attractive lacey dark green foliage and then it starts to grow, and grow and grow – up to 5 ft. tall. Stem usually has purple splotches. Flat-topped clusters of very small white 5-petaled flowers. Foliage and stem have rank odor – and Socrates was made to drink a potion made from this plant. Biennial. (Winter 2001)

Nothing is so rare as a day in May unless it is a day in Maywithout laying eyes on an exotic plant species. If you are nottaking action, invasive species are probably gaining on you. While you are enjoying a southeastern Ohio springtime, pleasebe alert for the following Spring Bandits that disrupt ecosystemfunctionality and displace native plant species. (See theindicated newsletters for more information.)

Dame’s Rocket – Another member of the mustard family. Opposite, rather coarse long arrow-shaped leaves; up to 3 ft. tall. Racemes of white-to-pink-to-purple 4- petaled flowers. May remind you of wild phlox from a distance but phlox has 5 petals. Woodland biennial but most often on stream terraces. (Spring 2003)

Indian Strawberry – is apparent all year andgrows in variety of habitats. (Summer 2001)

Indian Strawberry (Destroy) Yellow flowers Evergreen Forms a mat on ground Wild Strawberry (Keep & enjoy) White flowers Dies to ground each year Runners grow from a crown

If any of these are seen on your land, I recommend youhand-pull immediately. If garlic mustard or dame’srocket, bag the plants if they have started to flower orare in seed. If on a neighbor’s property, warn themthese Bandits are at large so they can deal with themwisely.

Biologist’s bailiwick. Pay a visit to the web site of Dr. DavidMcShaffrey, member of the Marietta College Department ofBiology and periodic presenter at the MNHS. Dave has aninteresting assortment of information and links on his Home Page.The Packyderm Web is available to help people learn aboutbiological diversity; or maybe you might like to view resources ondragonflies. You can learn about the ‘radar frog’ and a really uglycaterpillar, or visit the Home Pages of the various courses Daveteaches, including the one for Biological Imaging which includes anumber of portfolios of biological photography. Take a tour atwww.marietta.edu/~mcshaffd/.

Spring Bandits – by Marilyn Ortt

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Recycled Paper 100% Post-Consumer

ShadowlandThe lunar eclipse on April 24 is a penumbraleclipse visible from most of the Western Hemisphere. A penumbral eclipse is one in which the moon passes through the Earth’s penumbra, the partial shadow outside the main shadow (the ‘umbra’) of our planet.The eclipse will appear as a shading across thenorthern half of the Moon, beginning at 3:55 AM andpeaking around daybreak. The further westward theobserver, the longer the eclipse will be visible. Why nottake a look– What else do you have scheduled in yourPDA for this time?

Insect IncenseHow happy is the lowly skunkWho never burns mosquito punk;Whose perfume pungent keeps at bayAll insect pests which come his way.

-B. R. Weimer

Page 4 Marietta Natural History Society Spring 2005

Marietta City Bird WalksCommune with nature to start your

Tuesdays, from 6:30 to7:30 AM Leader: Lynn Barnhart

April 19 at Kroger Wetlandmeet at parking lot

April 26 at Buckeye Parkmeet near picnic shelter

May 3 at Oak Grove Cemeterymeet at American Legion entrance

May 10 at Jackson Parkmeet near old pool

Wear comfortable shoes and dress for the weather. Binoculars

would be useful but are not necessary.

Seeds: Starting life anew by Steven R. Spilatro In this article we will continue the story of seeds, now asthey enter a growing season and start a new life. The restraints of dormancy will need to bebroken, freeing the stored food reserves to bemobilized for use by the seed’s tiny embryo.Once reanimated, the growing points of the embryo willpush upward and downward, creating shoots and roots,and eventually a new plant. Signals that say ‘it’s time to break dormancy’ are thewarmth and moisture of spring, although alone these arenot always enough. Rehydration of the seed tissues isessential to growth. Dormant seeds are usually verydesiccated, with a moisture content below about 15% byweight. The tissues of a seed act much like a dry sponge,drawing in water rapidly from the surrounding environment. Some seeds contain carbohydrates called‘galactomannans’ which swell tremendously asthey absorb water and exert pressure on theseed coat. These are notably abundant in seedsof legumes, such as the common honeylocust. ‘Guargum’, a commercial thickening agent, is a galactomannanpurified from the seeds of the legume Cyamopsistetragonoloba. Guar gum can be found in manyfoods – look for it in the ingredients list on such foodsas ice cream and non-dairy whipped toppings. The hardest of seed coats, even acorn and walnut,offer little resistance to germination once rehydration hasbegun. The pressure of the swelling seed will rupturethe seed coat and free the embryo to the world. Seeds that mature in the spring, such as those ofmaple, elm and willow, will begin to germinate shortly afterfalling upon suitable soils. In an urban area with apredominance of maple trees, like ours, their seedshelicopter across the landscape in late spring and laysiege to untended lawns and freshly tilled gardens. Rapidgermination and growth allow these trees to establishthemselves before the return of dry or cold seasons. Yet, immediate germination would be a poor strategy forspecies whose seeds mature in the summer or fall, sinceyoung seedlings are poorly outfitted to withstand the rigorsof drought and cold temperature. Better to wait these outuntil next spring. In order to delay germination, most seeds have other prerequisites for germination. These may be linked to the mechanisms of their dispersal, or to environmental cues that signal the passage of time and seasons. Temperate plants often produce seeds that displaythermodormancy, a resistance to germination above a certain temperature. This is most likely an adaptation that prevents germination during the dog-days of summerwhen periodic drought would threaten survival of a seedling.Passing through a freeze-thaw cycle is necessary for someseeds to germinate, marking the passing of winter and thearrival of a new growing season. For this reason ‘winter wheat’ is planted in late fall, preparing the seeds for germination in the spring.

Dormancy of seeds can be regulated by internalmechanisms that record the passing of time. In the

case of the common cocklebur, gradual leachingof chemical inhibitors out of the seeds isnecessary. Sometimes further development of

the embryo or changes in the levels of hormonesmay be required.

The hard outer seed coat of some seeds must bebreached before germination can begin. Such is the case

for many native legumes, such as blacklocust and clover,and members of the mallow, morning-glory and nightshade families. Mechanical abrasion of their seedcoats is required for germination. This might occur asseeds tumble down a rocky stream, are attacked bymicroorganisms, insects and animals, or stressed by

repeated freeze-thaw cycles. A thorough scouring byacids in the digestive tract of birds or animalsdoes the trick for some seeds, such as those of

cherry. Many seeds respond to the length of the day(called the 'photoperiod' by plant physiologists)

to monitor arrival of the appropriate season for growth. Eastern hemlock and birch produce 'long-day' seeds,which only germinate when the day-length exceeds acertain minimum. This is a good reason to heed well the

instructions on a seed packet concerning therecommended planting depth. Seeds such aslettuce will not germinate in the dark.

In contrast, plants of arid regions often produceseeds that require short-days, a photoperiod that heralds

the passage of the dry season. Such seeds are ofteninhibited by light, since moisture is likely to be more

abundant below the surface. See Anew, page 5

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Squirrel Wars We generally perceive exotic species as unwelcomeimmigrants from other parts of the globe marauding ourecosystems, but little conceive of our native species asinvasive trouble makers elsewhere. Alas, such is the case for the North American greysquirrel, which over the last century has largely displacedthe native red squirrel in the United Kingdom. Certainlythe fecundity of the grey squirrel would suggest such apossibility. However, a recent study (Tomkins, et al., 2003, Ecol.Lett. 6:189) has found that its invasiveness is accentuatedthrough transmission of the parapoxvirus. The virus isharmless to the grey squirrel but causes fatal illness forthe red squirrel. This is another example of a virus‘jumping’ species and wreaking havoc, a lathe corona virus of SARS.

Suggestions,Comments or

Contributions forthe MNHSNewsletter?

Send them to theEditor:

625 5th St Marietta, OH45750 374-8778

spilatrs@marietta.edu

Molecular MimicrySpring – and the lovely green of chlorophyll is increasing exponentially. It is, of course, the chlorophyll molecule (below left) that absorbs the red, orange and blue rays of sunlight. Did you know that the green

chlorophyll molecule is very similar in structure to the red hemoglobin molecule (above right)? Both have a ring shaped molecular structure, with a magnesium atom in the center of chlorophyll and an iron atom in hemoglobin, which contribute to the different colors of the molecules.

Anew, con’t from page 4 Transformation of seed to plant begins with themobilization of the food reserves. Within minutes to hoursof seed hydration, enzymes are activated that willbreakdown the starch, protein and fat molecules held in thecotelydons and endosperm. The end-products are simplesugars and amino acids which are used by the embryo forgrowth and development. As growth initiates, the two poles of the embryo beginto elongate. At one end lies the hypocotyl, which elon-gates most rapidly to establish the root system of theseedling. A seedling’s first priority is to secure a supply ofwater, which drives the internal plumbing system of theplant to bring nutrients upward from the surrounding soil. Extending from the other end of the embryo is thecoleoptile, the immature stem. The coleoptile bends toform a small loop which is uses to push up through the soil. This protects the delicate shoot apex, the actual growingpoint of the stem, until the shoot reaches the surface. Upon emerging into open air, the coleoptile straightens tohold proudly skyward the apex, ready to form the stem andleaves of the sprout Young seedlings fill some special places in human diet. Sprouts of bean and alfalfa, today familiar offerings ofgrocery store produce departments, commonly accompanyAsian dishes and garnish salads. Beer production begins with barley seeds allowed to germinate for a few days – a short-life indeed. In aprocess known as malting, amylases activated as the seedrehydrates enzymatically 'chop' large carbohydrates intosmaller ones, which later can be readily extracted from thegrain. These sugars (barley malt) are combined with driedhops flowers to form the ‘‘wort’ later fermented by yeast. It is quite common among dicotyledonous plants, suchas legumes, for the cotyledons of the seed to be elevatedinto the air just below the shoot apex. These often turn green and form the first photosynthetic organ of the plant. They are sometimes mistaken for leaves, but are not, andthe cotyledons eventually wither and drop off after realleaves form on the shoot above. Very quickly a seed is transformed into a seedling.Mature roots develop as the hypocotyl burrows into thesoil, branching and becoming covered with small hair-likecells that absorb nutrients and water. Shoots launchskyward, expanding with branches and leaves to collectthe sunlight and carbon dioxide needed to sustain growth. Eventually, a plant will reach reproductive maturity.Annuals will flower several weeks after germination (somespecies of Brassica willflower in less than three).Trees often requireyears of growth beforebearing seeds, butmay then do so fordecades, producingmillions of seeds ina lifetime.

Invite a Friend to Join the Benefits of

Marietta Natural History Society Membership

Wood Thrush — Individual $15 L Monthly programs

River Otter — Family $25 L Field trips

Monarch — Friend $50 L Quarterly newsletter

Why not give a gift membership? L Educational experiences Mail check to address given below for kids and adults L Conservation Projects

The MNHS Missioni To foster awareness of and sensitivity to our environment and its biodiversityi To provide a place where people with these interests can gather for information and activityi To create a presence in our community representing these ideas

Marietta Natural History Society P.O. Box 1081 Marietta, Ohio 45750 (740) 373-5285