Tag Archives: Parkwood Inside/Out

The elms are flowering

This is an article I wrote for the February issue of the Parkwood Inside/Out. We are planning trash cleanups on March 28th and a hike, and will be participating in the costume parade downtown on March 21st and other events for Durham Creek Week 2015. Check this website for announcements and all events will also be posted at:

Creek Week Events

Parkwood’s elms are blooming

Red maples dotting the still bare landscape with blots of crimson are one of the first signs that spring is here, but elms are among the first trees to flower. These prominent trees might be less appreciated because an elm in flower is stormy grey or lime green. Winged elms are the most common species, especially in central Parkwood, but there are slippery elms along the streams and probably American elms, and there are scattered Eurasian ornamentals. The most prominent and beautiful elm I know of in the area is the classically fountain-shaped tree on Highway 54, across from . Because its limbs are all high above the ground, it is hard to identify the species.

Elms, especially American elms, are beloved for the fountain or vaselike shape of mature trees, and there is a graceful symmetry to elms generally. Their leaves and branches alternate, creating an airy lattice effect. The straight veins in their oval leaves, double toothed like a pruning saw, are straight and parallel, but elms also have a very unsymmetric feature – the leaf bases are lopsided, especially in American and slippery elms. Elms have thin, elegant branches, strengthened by very tough wood, and the bark of some species can be twisted into rope. They produce wind pollinated bisexual flowers in early spring, developing into small seeds with a circular flange that drift with the wind several weeks later. The elms generally like moist soil, but winged elms seem to grow in drier soil as well.

The massive, spreading elm in front of Carrboro’s Town Hall could be an American elm (it is big enough for a plaque, yet nothing identifies the species), and I think there are labelled American elms in the Coker Arboretum at UNC. American or white elms are around, but are less common after the arrival of Dutch Elm Disease, a fungus that came to the US around 1930, and is spread by introduced and native beetles that bore in elms. Many elms have been killed, especially American elms, but this seems to be a little less catastrophic than the introduction of chestnut blight and emerald ash borer beetles, and the disease can be managed. American elms are large trees with furrowed bark, brownish leaf buds, and their leaves and stems aren’t very hairy, or less so than slippery elms. Their seeds have some hairiness, while the seeds of slippery elms lack hairs. Both American and slippery elms have large, sandpaperlike leaves, but American elms have greenish flowers, unlike slippery elms. Because their wood is so strong and resistant to splitting, and grips screws tightly, American elms have been used to make things like sports equipment, boats, flooring, crates, and kitchen cutting blocks. Many were planted for landscaping in the northeast, though they grow throughout the eastern USA. In A Natural History of Trees, botanist and nature writer Donald Culross Peattie wrote “If you want to be recalled for something that you do, you will be well advised to do it under an [American] Elm – a great Elm, for such a tree outlives the generations of men; the burning issues of today are the ashes of tomorrow, but a noble Elm is a verity that does not change with time. And although Elms too are mortal, great ones are remembered as long after they are gone as are great men.”

Slippery elms are similar to American elms, but smaller and less vaselike. They have been called red elms, having hairy, reddish leaf buds and reddish flowers, as well as hairy twigs. Their inner bark is slippery and becomes mucouslike when chewed. This inner bark was used to make tea and flour and was used for a variety of internal and external problems and still has an FDA approved medical use. American elm bark was used medicinally by Native American groups.

Winged elms are named for the cork flanges that line their twigs to varying degrees. Sweetgums usually aren’t as winged as elms and their leaves are very different. Winged elms leaves are smaller, smoother, and more symmetrical than those of other elms, and large trees have light brown bark. I think these are the first elms to flower, with brownish flowers that turn into silvery, hairy seeds. As with most trees, winged elms grow a lot when they first leaf out in spring, delicately etched leaves surging forth from the twig tips at a fast clip. The tiny, silky looking new leaves hang as if limp, but are actually strangely stiff. Snow, ice, and maybe hurricanes smashed many of the spindly young loblollies behind the Fire Station around 2002, leaving winged elms, ash, and a few surviving pines as the dominant tall trees, to be replaced themselves by oaks, hickories, and beech in coming decades.

Many animals chew on elm branches, leaves, and seeds, including opossums, rabbits, and bobwhites. The caterpillars that fed on elms are like a who’s who of moths and butterflies, including many of the moths you might see at your porchlights this spring. Double-toothed prominent moth caterpillars feed only on elms. They bite into a leaf and then rest there, so their jagged backs appear like the missing leaf edge. It is surprising that this camouflage works, since elm leaves are emerald green, but the caterpillars are pale seafoam blue and green.

English Ivy: Coming to a woods near you

This is an article I wrote for the January issue of the Parkwood Inside/Out, serving the Parkwood community, next to Northeast Creek in southern Durham.

English Ivy: Coming to a woods near you

Now that Parkwood’s green areas are bare, the full extent of the English ivy problem is plain to see. In places behind Newhall, Euclid, Revere, and between Highway 54 and Euclid ivy thickly covers the ground, smothering native vegetation, including the next generation of canopy trees, creating what might best be called “ivy deserts.” A few native and non-native plants do sprout through the ivy, including poison ivy, but the spring beauties, trout lilies, bluets, pink wood sorrel, pussytoes, and other flowers and forbs that should gild the forest floor are excluded. Ivy might affect invertebrates living in streams flowing through an ivy-filled woodland and change the soil, because ivy has nitrogen-rich leaves, a vital plant nutrient. It can carry bacterial leaf scorch, which infects trees such as maples, elms, and oaks. Ivy vines thickly festoon trees, which might make them more likely to fall, though there is some controversy, and less able to get to sunlight.

Once in the canopy, ivy gets enough sun to flower and produce clusters of black fruits, which birds spread into new areas. In my yard there is some ivy kept under control in pots, but in the last 10 years a lot of ivy has crept in through seeding. Without pests or diseases, cold weather is probably the main factor limiting ivy here, by preventing fruit production and temporarily stopping photosynthesis, an advantage evergreen ivy has over deciduous plants. For this reason, ivy is not a major problem further north, but it is rampant in the Pacific Northwest.

As its name suggests, common or English ivy (Hedera helix) is native to the continent of Europe, as well as the Middle East and north Africa, but it was introduced here starting in the 18th century. In its native range it is kept in check and is a valuable food source for birds, some of the species that have become problematic introductions here, such as European starlings and house sparrows.

English ivy is in the same family as ginseng, so it is not a relative of poison ivy or Virginia creeper (in the cashew and grape families, respectively), but I thought it was related when I took a large cut stem and pressed it to my wrist to see what would happen, and my skin blistered, but less intensely than it would with poison ivy. I’m pretty sure it was an ivy stem, and not Virginia creeper, and some people do react to ivy, but from a different toxin than that in poison ivy.

Ivy has evergreen, palm-shaped leaves with three to five points in shade, but they become more lance-shaped in the sunny treetops. The vines appear hairy because of glue-producing roots, while vines high in the treetops lack roots. Stems can be almost a foot wide, and reportedly a 433 year old vine in Europe was more than 20” across. Ivy has tiny and inconspicuous yellowish flowers that appeal to insects with a short proboscis, such as flies, wasps, and moths. The resulting fruit, technically called a drupe, contains a few hard seeds and a toxic glycoside that sickens humans and can make birds vomit. Still, the fruits are nutritious and fatty, and are often eaten by robins, mockingbirds, and cedar waxwings. As with some other non-native plants, human disturbances, such as new roads, give ivy inroads into new areas. There is a lot of ivy in Parkwood now, but it is rare or nonexistent in intact woods nearby. Livestock and deer can apparently eat the leaves, but don’t appear to be making much of a dent in the problem. Non-native rats might be the main animal that can use an ivy desert.

Other than landscaping, people have used ivy for its antifungal and antibacterial properties and in dyeing, tanning, and varnish resin.

Controlling English ivy and other non-native plants is a good New Year’s resolution. Many non-natives can be grown without causing too much trouble for native vegetation and the neighbors. There are more controllable non-natives, such as the groundcovers Vinca minor and Vinca major (they are similar, but V. major is larger and possibly more difficult to keep in check), which only spread vegetatively, but they spread a lot in shade. There are also many native alternatives. Crossvine is an evergreen vine with showy spring flowers that attract hummingbirds. Yellow jessamine is also evergreen and showy. Virginia creeper is a pretty deciduous vine with red fall foliage and dark blue berries. There are several evergreen groundcovers, such as doghobble, Galax, and partridgeberries (common in Parkwood).

Get to know some local pines

This is an article I wrote for the April issue of the Inside/Out. The loblolly pines are done ‘flowering,’ but yellow jasmine is still blooming in pinewoods and there is more to see under the pines.

Parkwood under the pines

I used to discount the pinewoods that are so abundant around here as pretty dull and barren, but pines can grow on you. This month the sky will be hazy with clouds of pollen (winged, like the seeds) for about two weeks, much of it probably wafting from loblolly pines. Their glistening needles seem so green in the intensifying sunlight, before the softer greens of hardwoods emerge. There are three or four pines native to Parkwood and another two that aren’t quite native.

The most abundant pine is the loblolly pine, Pinus taeda (taeda refers to torches). Their seeds sprout wherever there is bare, sunny ground, but loblolly probably refers to temporary puddles. Loblollies have relatively long needles, usually three in a fasicle, a bundle of needles that is actually a tiny branch, and rough dark gray and reddish bark. The cones are large and prickly. Most of Parkwood’s pines are still relatively small, but loblollies can grow 115′ tall, five feet across, and live more than 200 years. There used to be some around three feet across behind Racliff Circle, and there are still some very large pines on low ground by the Ball Field and behind Ace Hardware.

Shortleaf pines are common, but their ranks are much fewer than the loblollies. Shortleaf pines usually grow on hills and have short needles, two or three to a sheath, the smallest cones, and smooth brownish bark furrowed into large rectangles. They have small, but spreading dark green parasol-like crowns, reminding me of a Japanese painting, supported by sturdy, angular branches. Unlike loblollies, shortleaf stumps can re-sprout when young. Shortleaf pines can grow up to 150′ tall and 3-4 feet across, and like loblollies are an important timber tree. Their scientific name is P. echinata, probably referring to the hedgehog-like spines on their cones.

There are a few Virginia pines (P. virginiana) around, but they are more common west and north. They are also called scrub pines and often form thickets of small trees, though they can get 60′ tall. The needles come in twos, and curl. The cones are small and cling to branches years after the seeds have all fallen out. Overall they have a bristlely appearance with weathered and broken old branches and flakey brown bark, but their airy branches arch gracefully. There are a few behind Parkwood Elementary’s ballfield.

Pond pines resemble loblollies, but have slightly shorter needles on easily broken twigs and small, round, and not very prickly cones. There might be some around here, but they are more common east. They are called pond pines because they like moist ground and their scientific name, P. serotina, meaning late, probably refers to how the pinecones are held for years. Virginia pines and pond pines aren’t often cut for wood.

North Carolina’s state tree, the longleaf pine, is typical of the Sandhills and might never have grown in Parkwood naturally. They have needles so long they are woven into baskets and saplings have a strange, grasslike form. Longleaf pines are adapted to survive fires, so they form pine savannas when periodic fires are allowed to burn, killing the hardwoods. These majestic pines aren’t limited to wet soil, but P. palustris refers to marshes.

Eastern white pines are common Christmas trees and can last at least several years if planted here, though they are native to the Appalachians and north, where old growth trees grew over 200′ tall. They do grow naturally in one spot nearby, the White Pines Preserve in Chatham County ( triangleland.org/what-we-do/nature-preserves/white-pines-nature-preserve ), where they found shelter on a north-facing slope along the Deep River after the ice ages. White pines have soft bluish needles coming in fives and unusual long thornless cones (and they are called P. strobus, strobus meaning pinecone). The branches form whorls around the trunk. White pines are cut for timber, but are softer than southern yellow pines like loblolly.

Pines are a prominent feature of the landscape because they are among the first trees to grow. Loblollies are the main pioneering pine around here, sometimes with shortleafs, and Virginia pines are first in other places, often on bare clay. These pines can’t stand shade, so if not disturbed by logging or fire, hardwoods eventually take over. Some flowers are common under the sighing and creaking pines. The flowers of yellow jasmine vines bedeck pine forests now. I have often found rare pink ladyslipper orchids shaded by pines [these flower in May], as well as downy rattlesnake plaintain (another orchid), yellow-eyed grass, Pipsissewa, pencil flower, and wild roses. Brown-headed nuthatches, talkative little birds that sound like squeak toys live in pines, as do pine warblers, and birds of prey nest there. On hot, dry days of late summer, the raspy, treefrog like calls of Robinson’s cicadas often resonate out of pines. Around the same time, it becomes hard to walk barefoot under the pines, because squirrels sit in favorite branches to eat green cones like corncobs and rain down thorny scales.

Notices: We met April 13th and our May meeting will be next Monday, the 5th, at the Mediterranean restaurant in the Parkwood Shopping Center, time TBA.

This week we are looking at the umbrella magnolias and pinxterflower azaleas, but see the listserve for those announcements.

Strange winter waterfowl

We are meeting Sunday, February 16th at 4pm to plan for Creek Week, and our regular meeting will be February 23rd, at 4pm in the same place.

Below is another article I originally wrote for the Parkwood Inside/Out.

Strange winter waterfowl

Many unusual water birds winter in North Carolina. My favorite place to look for them is Crabtree Lake in [Cary], which is large enough to attract many birds, but also small enough to find them and easily accessible. It can be hard to see migrants, because they are wary and often stay far from shore but they usually swim from danger rather than flying. Parkwood Lake is also a convenient place to look, and even small ponds attract migrants, in addition to the Canada geese and mallard ducks that live here all year. It is not very easy to see the waterfowl staying at the Jordan and Falls reservoirs.

Geese and mallards aren’t supposed to breed here, but captive birds that didn’t learn to migrate were released, creating resident populations. Migratory geese swell the local population in winter, and in the mid-90’s there were many migrants with neck tags in Parkwood, making it easy to get to know geese as individuals.

The first unusual migrants I saw were small black ducks in a tight flock in the water at Clermont one cloudy winter day years ago. They were black scoters; the males being jet black with bright orange bills and the females paler with dark bills. We are used to puddle or dabbling ducks like mallards paddling around, eating plant matter from the surface or as deep as their necks will reach, but many migrants, such as scoters are diving ducks, and swim underwater. Scoters dive for foods such as mussels and barnacles.

Other diving ducks I have seen outside of Parkwood. At a nearby beaver pond about the size of the Lotus Pond I saw what I thought was a long-tailed duck, but it took off fast when it saw me, and long-tails are one of the fastest flying ducks. Long-tailed ducks, or oldsquaws in older guides, are white with black wings and black and gray patches. Like penguins, they swim with their wings, and venture to great depths, after molluscs, crustaceans, and fish. Last winter I frequently saw buffleheads at a wastewater treatment lagoon at Falls Lake. Buffleheads are the smallest duck in the US, and have big heads and striking black and white plumage. They were with wood ducks, and both species nest in tree holes, unlike mallards. Wood ducks are here year-round, and winter is a good time to search for these very wary and colorful ducks, but they prefer creeks and swamps. Buffleheads resemble hooded mergansers, one of three mergansers that winter and sometimes breed in NC. These unducklike ducks have rakish crests and pointed bills they use to catch fish underwater. I’ve seen them at Crabtree, but they are uncommon and wary. A week ago I noticed that there were four ducks, as well as a large flock of geese, at the large stormwater retention pond across Renaissance Parkway from Southpoint Mall. I didn’t have binoculars, but one of the ducks had a white patch, so there could be a pair of hooded mergansers there right now.

The most abundant winter visitor in the Triangle is the double-crested cormorant, which is not a duck. A few usually visit Parkwood Lake. Cormorants are dark and sit low in the water, with their orange bills up. They eat fish and, to make diving easier, their feathers are not very waterproof, so they periodically get out and hold their wings open to dry. There are flocks at the large reservoirs and they can be seen flying just above the water in ragged lines.

Handfuls of pied-billed grebes can be seen on most lakes. They are small ducklike birds with nondescript grayish fuzzy feathers and a dark bar on their bills. They also breed in NC and readily dive for prey such as crayfish.

American coots are pretty common. Coots are rails, chickenlike waterbirds, and are black and gray with stark white bills. They nod their heads as they swim in tight groups, and when they come on to the land at Clermont to eat vegetation and seeds. Coots sometimes breed in NC and are a prey of bald eagles, which have been seen at the Lake.

Vast flocks of pure white tundra swans and snow geese winter on the coast. One icy morning I saw a V of white birds in the cold blue sky far above Fayetteville Road, and they might have been swans or geese.

Now is the time to look, because the migrants will probably be all but gone by mid to late February.

The life and death of an ash tree

Our next meeting will be Sunday, January 26th at 4pm, to plan for Creek Week 2014 (March 15-22) and discuss some development issues, etc. Contact us for the address of the residence where we are meeting.

Below is an expanded version of an article I wrote for the January issue of the Parkwood Inside/Out. This giant ash tree grows beside the stream that flows from the corner of Barbee and 54, through Parkwood to NE Creek at the bridge on Grandale Road.

The life and death of an ash tree

An ash tree in Parkwood is one the largest I have come across. There are taller trees, but this ash is nearly four feet across, beating large ash in the wild bottomlands around NE Creek and the big ash in downtown Chapel Hill. Parkwood’s ash is a little south of McCormick Road, near the intersection with Auburndale, beside the stream in the common green area, and can be seen from the road. Ash trees usually have very straight trunks, but this giant leans southwest and has lost huge limbs to the force of wind or ice over its long life. It is hard to say why it leans. That section of woods is relatively young and this ash is the biggest tree there. It has pale bark, and as a reaction to tilting, it grows more on the leaning side, producing unusually deep 4” furrows, resembling a baleen whale’s throat or treads. In one place the bark is brown, probably from deer rubbing the velvet off their antlers. There are rows of holes created by yellow-bellied sapsuckers, woodpeckers that winter here and tap trees for sap.

During the growing season, the ash’s massive trunk is obscured by understory oaks, dogwoods, and black cherries. American beech, increasingly common in Parkwood, and Northern red oak saplings wait for the ash to fall. This is the only spot I know of where pawpaws grow inside Parkwood, though they are quite common as small riparian trees along NE Creek. The pawpaws probably would benefit from more light, though the site might still be a bit dry for them to produce their sweet bananalike fruit. There is a seemingly innocent sprig of English ivy, a plant which is taking over in nearby sections of the woods, and a Nandina bush with purple foliage, another non-native, but much less invasive. Partridgeberry, ‘wild onions,’ and grape ferns form the herb layer under the ash.

Each ash produces only male or female flowers, and this must be a male tree. Perhaps it is a parent of large ash on nearby Timmons Drive, or even throughout the area.

Our ash is probably a white ash. Green, pumpkin, and Carolina ash also grow in Durham. They look similar, all living up to their scientific name, Fraxinus, the Latin name for ash, which also means spear, and describes their typical soaring shape. Ash have leaves and twigs growing in pairs along a stem, and their pinnately compound leaves are made up of oval leaflets, resembling the leaves of walnuts, hickories, and locusts. In fall ash turn gold, orange, and purple. Ash saplings have smooth gray bark and mature trees have somewhat furrowed or rough bark, depending on the species.

White ash is the most economically valuable ash. High-quality baseball bats are made from white ash, as well as other objects requiring lightweight, strong wood with a spring, like oars, lacrosse sticks, musical instruments, furniture, and bowling lanes. It is also an easy to split, hot burning firewood. White ash has been used to relieve fevers, sores, and snake bites, as a laxative, and as an aphrodisiac, among other medicinal uses. Ash have a long history in mythology, for example the Norse axis mundi/world tree Yggdrasil is supposed to have been an ash, and according to folklore snakes don’t like ash trees. White ash likes well-drained, but not very dry soil and is one of the first trees to sprout in abandoned fields. White and green ash can tolerate shade as seedlings, waiting for their chance to shoot into the canopy when an old tree dies. The big snowstorm that left two feet of snow and ice and other bouts of freezing rain have knocked down most of the young pines behind the Parkwood Volunteer Fire Station, leaving a woods of only ash and winged elm in places. Pumpkin and Carolina ash like wet habitats, and ash are one of the main trees in swamps and bottomlands. Ash trees can be seen next to the Parkwood Association office, where there used to be a trailer, and at the Parkwood Convenience Store, at the corner of Seaton and Revere. Ash of some kind can be found on most streets in Parkwood and are common throughout the Triangle.

Late last summer I watched big pale green, red, and yellow hornworms on an ash sapling at Falls Lake. These were waved sphinx moth caterpillars, but the red markings were unusual. Usually their larvae don’t have any red coloration, but these were mostly red with yellow markings when small and then mostly green, but with red heads, horns, and markings. A few other sphinxes feed on ash, as do caterpillars of black and yellow Eastern tiger swallowtails. These green caterpillars have fake eyes complete with angry eyebrows, to mimic snakes, and if that fails, they can send out bright orange ‘horns’ that emit a smelly fluid. The big, shiny black rhinoceros or unicorn beetles sometimes found under streetlights at the Parkwood Shopping Center also eat ash. Ash have wind-pollinated flowers in early spring, but honeybees and other insects sometimes harvest pollen from male flowers. The winged seeds, or keys, of ash trees are eaten by weevils, mice, and birds such as wood ducks, turkeys, and purple finches. Large ash often have hollows where birds and squirrels can nest. Our ash seems to house a colony of big black ants, judging from the seemingly arboreal ants walking along its trunk last summer. Deer and rabbits eat the leaves while beavers like ash bark. Ash growing around the beaver impoundments on Grandale or elsewhere could host mistletoe.

Native beetles and two species of dayflying moth that mimic wasps bore into living or dead ash trees, but a new ash-boring beetle from East Asia is on its way to killing virtually all ash. Emerald ash borer or EAB reached Michigan in the 90’s, probably in shipping materials. It wasn’t noticed until 2002 and has since spread throughout the Eastern US and Canada, in part because people violated quarantines on firewood and other products. Their grubs tunnel under the bark of trees as small as 1” across, and since these are non-native animals, they come in out of control numbers that girdle our naïve ash, killing them within a few years of colonization. A good online resource to check out is www.emeraldashborer.info .

Earlier this summer emerald ash borers crossed into Granville County from a pocket across the border in Virginia and a quarantine was imposed (see http://www.ncforestservice.gov/forest_health/fh_eabfaq.htm ). This is likely to be the end for Parkwood’s great ash in the near future, when the emerald ash borer gets to Durham, on its own power or by hitching a ride, and a great many beetles could come from it. There is cause for hope – some ash seem to have survived the borer up north, introduced Asian and native parasitoid wasps could help control the beetle, and individual trees can be protected with insecticides that are relatively safe for the environment. Emerald ash borer has a big ecological and economic impact, and even harms human health, so communities in the Triangle should prepare.

You can read more about emerald ash borer in my article in the February issue of Carolina Gardener magazine (www.carolinagardener.com).