Leaves of Three

Poison ivy has three leaflets, the center one has a longer stem.  Leaves have a central vein
with secondary veins branching off from it.  Young leaves are glossy, but older ones are variable
 and leaf margins are all over the place.

After a mild winter in the Mid-Atlantic, it's been a cool, damp spring.  This seems to have brought out a lot of growth in the understory.  Included in this lushness is plenty of poison ivy, Toxicodendron radicans, formerly, Rhus radicans.  As I have been doing some weeding I have been vigilant for ‘leaves of three’, the rhyme for identifying poison ivy.  But that is not the only plant out there that sports three leaflets. 

Following are some common plants that bare some resemblance to the dreaded poison ivy.  Probably the most common look alike in the Mid-Atlantic region is box elder, Acer negundo.  When I first encountered this tree I thought OMG it’s a  poison ivy tree!  This tree reseeds prolifically generating a myriad of seedlings with bright green leaves divided into three leaflets.  While superficially similar to poison ivy, on closer examination you can see that box elder has an opposite arrangement of leaves and branches, while those of poison ivy are alternate.

Box elder has three leaflets that appear very similar to
poison ivy, but branching is always opposite.  Leaf margins are variable

Here they are side-by-side.  Box elder seedling at top has opposite branching,
poison ivy in mid-frame is opposite.  The yellow flowers are green and gold,
  Chrysogonum virginianum.

A close second in my experience is Virginia creeper, Parthenocissus quinquefolia. This rambling and climbing vine has the same habit as poison ivy, but it usually have five leaflets rather than three.  The confusion comes because the younger shoots often sport leaves with three or sometimes four leaflets.  When I spot these I carefully trace the vine back a little ways to see if it also has leaves of five.  Some people have sensitivity to Virginia creeper, but the reaction is not as severe as the rash most people get from poison ivy. 

Virginia creeper is a vine with a similar habit as poison ivy. 
Most, but not all, leaves have 5 leaflets.

Another understory tree that has three leaflets is common hoptree or wafer ash, Ptelea trifoliata. This is not likely to be confused with poison ivy, although seedlings or growth from the base of the tree could cause some concern.  On the hoptree each leaflet does not have a distinct stem (petiolule), rather the leaf tapers sharply to the point of attachment.  While the leaflets of poison ivy are distinct with the central one considerably longer than the two lateral ones.  

Common hoptree grows well in shady locations not unlike poison ivy. 
Note how the leaflets lack distinct stems.

Aromatic sumac, Rhus aromatica, is less commonly encountered.  In the wild it is an upright shrub.  But in the landscape trade there is a shorter, spreading cultivar called ‘Grow Low’ that is becoming very popular.  When I’ve bumped into mine in the woodland edges I froze for a second until I noticed that the leaflets have different lobes and the leaflet stems (petiolules) are all the same length.  On poison ivy the middle leaflet has a longer stem than the other two.

The leaflets of aromatic sumac tend to have rounded lobes concentrated at the tips.

White avens, Geum canadense, has a number of leaf forms.  Some of its basal leaves can have three leaflets but they are not particularly glossy and are generally rough in texture.  Also this species grows in clumps, it is not viney.  

The younger leaves of white avens tend to have three leaflets.  To the lower left you
can see some of the more complex leaf forms.

Barren strawberry, Geum or Waldsteinia fragarioides and the non-native W. ternata, have leaves of three, but the leaf margins are more deeply toothed and the leaflet stems are all very short.

The glossy leaflets of barren strawberry appear to merge together looking
 more like lobes than separate leaflets.

  Mock strawberry, Potentilla  (or Duchesnia) indica, is another prolific ground cover with three leaflets.  It’s leaf margins are regularly toothed and it’s habit is different, spreading by stolons, not vining.  

The leaf surface of mock strawberry is much rougher in appearance than poison ivy.

Golden Alexanders, Zizia aurea, has leaflets that are twice divided, 3 sets of trifoliate leaflets (biternate).  The leaflets are ovate to lanceolate with finely toothed edges.  The long petioles may give the impression of young poison ivy stems.  

Leaflets of golden Alexanders can be seen in the circle at bottom right. 
Also present in this image is Virginia creeper and mock strawberry.

The native clematis, Virgin’s bower, Clematis virginiana, is a weak-stemmed vine with three part leaflets.  While you would want to routinely test the vine strength to distinguish it from poison ivy, an examination of the veins on the leaves would show the difference.  Virgin’s bower has a palmate pattern, with the major veins radiating from a single point; whereas poison ivy’s veins branch out along a central middle vein.  

The ribbed stems of virgin's bower are too weak to support itself
 and it needs something to climb on.

The list of trifoliate plants seems to go on and on.  After I thought I had this pretty well wrapped up I took another look and noticed the leaves of Jack-in-the-pulpit, Arisaema atrorubens, and that reminded me of the trilliums.  These can be recognized by their relatively large leaf size and regular arrangement of leaves.  Arisaema leaves are in a ‘T’ arrangement and those of trilliums are arranged in a regular triangle pattern (120 deg apart).  Can you think of any more poison ivy look-alikes to be on the watch for?

Not all plans work out

Three years ago we cleared out a section of garden that was over run by English ivy.  The plan was to put in some new native species as well as watching to see what would sprout up from the soil that had been covered with ivy for a number of years.  To the newly cleared space I put in some goatsbeard (Aruncus dioicus), and a strawberry bush (Euonymus americanus).  As a ground cover I got a bunch of Virginia jumpseed (Persicaria virginiana), which looked like the 'Lance Corporal' cultivar, with reddish chevrons on each leaf. These were followed up the following spring with American alumroot (Heuchera americana), Indian pink (Spigelia marilandica) and Solomon's seal (Polygonatum biflorum).

A jumbled mass.  Blue lobelia is recognizable on the left with spent flower stems of the alumroot.  The glossy leaves of Solomon's seal are evident on the right.  In the center you can make out the red flowers of the jumpseed, but the leaves are barely discernible.

Over the next 3 seasons I let the plantings develop without much interference, except for pulling out Japanese honeysuckle and garlic mustard.  Additional species that cropped up included natives like white avens (Geum canadense) and great blue lobelia (Lobelia siphilitica) as well as introduced species like mock strawberry (Duchesnea indica) and a cultivated species of columbine that had been reseeding itself for a number of years through the ivy.

In September as the flowers of the jumpseed are opening up,
something goes after the leaves, eventually skeletonizing them.

While it was interesting to see 'new' plants coming in, the overall planting was too chaotic to look good as a whole.  One problem with the new scheme was that the goatsbeard gets tattered by mid-summer if it gets too dry.  This can be fixed with a little more care and watering through the season. Also the long flower stems of the alumroot add to the confusion. The biggest disappointment was the jumpseed.  It looks nice early in the season with its striped leaves, but by late summer the leaves are decimated by some insects.  What remains is a jumble of wiry stems going every which-way that detracts from the spikes of red flowers.

After letting this area go for several years and not seeing any improvement I decided it was time to make it a little more formal by adding more defined layers to the garden.  While a random planting works in the distance, close up the human eye is looking for more defined structure and order.  In general, lower plants will go in the foreground, near the stepping stones.  Medium sized perennials go to the middle and the bushy goatsbeard stays in the back.  This new planting will be easier to maintain because it will be easier to identify the 'weedy' plants over a background of low sedges than it was before.

First I removed as much of the jumpseed as I could see.  Then I pulled out any encroaching English ivy and honeysuckle.  I also pulled out some native trees that seeded in, like butternut and box elder.  The lower-growing alumroot was already near the path.  For additional low-growing plants, I transplanted several species of sedges from elsewhere on the property.  Their lower stature, defined form, and contrasting texture will help show off the taller perennials.

Here's the garden after removing the jumpseed.  The back right is dominated by two goatsbeard, and the fencing is getting covered with virgin's bower (Clematis virginiana) that was planted in 2013.

In the foreground is one of the sedges I moved into the garden.
It could be Carex laxiculmis but I won't be sure until it blooms.
Also shown here are Alumroot and white avens,
at top with its deep red autumn color.

Since the Indian pinks don't like to be moved I left them in place and instead transplanted all the columbine to the middle ground.

The Solomon's seal was doing well, but they were getting hidden by the jumpseed.  I put some sedges around the Solomon's seal to give them some vertical space.

One of the sedges I chose has 1/4-1/2" wide blades and  grows in clumps about a foot wide.  These went in along the path and are scattered with the perennials to provide some height variation. Also it's evergreen so it will be around all year.  The white avens that is indigenous to this site has deeply lobed leaves that blend well with the alumroot.  The avens can get lanky and will benefit from some cutting back late in the season.

The other sedge is also clumping but has very thin, light green blades.  I'm pretty sure this is rosey sedge (Carex rosea).  It grows very well on partly sunny to shady sites.

The strawberry bush is known for these brightly colored seed pods in early fall.
Where the branches are touching the ground I am seeing new roots forming.
I'll separate these from the parent plant next season.  This is an easy way to propagate this shrub.

This unknown columbine was planted by a previous owner and
has been reseeding itself for a number of years.  Definitely not a native, but it looks good here.

So here's the garden after clean-up and planting.  It looks a little sad now since leaves are falling off and the plants are settling in for winter.

Weeded and replanted, we'll see what happens next year.

If all the transplants come back and the weeds don't return in force the new garden may look something like this overlay drawing.

As drawn here the goatsbeard, Indian pinks, and columbine are shown in bloom.

The sedges and alumroot line the stepping stones, from lower right to upper left.

An August Drive: Skyline Drive and the Blue Ridge Parkway

August isn't only for pulling stilt grass.  If you don't take some time off to enjoy nature, it could drive you crazy.  With that in mind, we took some time off and headed south to Asheville, NC for a couple of days via Skyline Drive and the Blue Ridge Parkway.  These were beautiful drives with terrific overlooks, lots of green and many plants in bloom.  Not surprising, but these are not great roads if you are try to get somewhere by a given time, so we did have to bail out by mid-afternoon each day.  Here are some of the natural highlights we saw travelling the backbone of the Blue Ridge Mountains.

Thunder storm moving up the Shenandoah Valley south of Luray, VA. 

Mounds of blooming virgin's bower were a common
sight along the route.  This particular photo was
taken near Cherokee, NC.

We started at the northern end of skyline Drive in Front Royal, VA.  All along the way we saw numerous wildflowers in bloom.  Plants we could ID at 35 mph were eastern Joe Pye weed (Eutrochium dubium), several species of sunflowers (Helianthus sp.), wild bergamont (Monarda fistulosa), threadleaf coreopsis (Coreopsis verticillata) and tons of virgin's bower (Clematis virginiana).  We did manage to finish Skyline Drive then jump out to I-81 to get down to Marion, VA so that we would have an easy drive into Asheville the next day.


Later on in the trip we drove the southern end of the Blue Ridge Parkway near Cherokee, NC.  Here we saw similar plants in bloom but maybe different species from further north.  A couple that I feel pretty sure about here was spotted Joe Pye weed (E. maculatum) and thin-leaved sunflower (Helianthus decapetalus).

This spotted Joe Pye weed was growing on a steep slope next to
the Blue Ridge parkway.  The leaf shape and the purple stem are
clues that this is, in fact, E. maculatum.

While I didn't ID this sunflower on-site, I think it is thin-leaved
sunflower (H. decapetalus).  Some clues are the large teeth
on the serrated leaf, the long bracts under the flower head
and the purplish stem.

View to the northwest from near the Craggy Gardens visitor center.

One of the last botanical stops on the trip was at Craggy Gardens, near Mount Mitchell, the highest peak east of the Mississippi.  Among the plants noted there was Mountain ash (Sorbus americana) with its long pinnate leaves and large clusters of orange berries.  The plant that impressed me the most here was hairy alum root (Heuchera villosa).  The bloom period for it is mid-August into early fall.  This is a species that I have been growing for a while at home, but this was the first time I have seen large quantities growing in the wild.

These Alum Root were growing out of a north-facing rock wall
at the Craggy Gardens visitor center. 

This thistle patch was popular with the butterflies.
Here's one of the few Monarchs we encountered.

In addition to the plants, we did come across some interesting animals.  We had a small bear cross the road in front of us on Skyline Drive (no chance to take a photo).  We saw a lot of eastern swallowtails (Papilio glaucus), but only a couple of Monarchs.

The craziest insect we saw was a fast moving caterpillar which I believe to be of a pipevine swallow tail (Battus philenor).  I'm not sure where it was headed, I didn't notice any pipevine nearby, but it could have been in the undergrowth.

This pipevine swallowtail caterpillar was racing across a retaining wall at a scenic outlook
on I-81 from TN to NC.  It's fleshy antennae were waving around wildly.

Fall's Second Season

Even though all the blossoms are gone there are still sights to delight the eye in the fall garden.  Rather than the purples and golds of aster and goldenrod flowers, we get whites and silvers from the seeds and seed heads of many of these same plants.  The lower angle of the winter sun magnifies this effect, causing them to nearly glow with reflected light.

This photo was taken on a mid-November morning.  Some of the plants from
left to right are little bluestem, New England aster, purple top (grass) and Canada goldenrod.

Sweet everlasting, Pseudognaphallium obtussifolium, has a particularly long-lasting presence in the garden.  Even after the seeds are dispersed the white, star-like sepals remain intact well into January.  This plant is an annual and depends on this seed finding a spot on the ground to continue its presence in the garden.

The spent flowers of sweet everlasting show off well in front of a dark back ground.
Mixed in here are the seed stalks of the native grass, purple top, Tridens flavus.

Virgin's bower, Clematis virginiana, is one of our native clematises.  It has a very long vining habit, growing to about 20 feet in sunny location in one season.  Many consider it weedy because its thin stems go just about anywhere.  I like it because it does a good job of covering  fences  with foliage without becoming heavy and damaging like the exotic sweet autumn clematis.  The flowers in the second half of summer are small and rather subtle compared to many cultivated clematises.  Where this plant shines (or glows) is in the fall when the feathery seed heads form.  

After the fluffy white seeds of New York ironweed are dispersed
these rust colored capsules will remain for several months.

Another fall star is New York ironweed, Vernonia novebaracensis.  By the end of October the magenta flowers are all gone, replaced with the rust-colored seed heads.  As winter wears on these breakdown and become less fluffy; however the star-like sepals remain into the new year.




Besides all these flowering plants, the grasses also make a graceful contribution to the fall and winter garden.  Last fall I wrote a blog post about fall grasses.  I won't go into a lot of detail again, only to say that some of them really do use the winter light to great effect, such as pink muhly (Muhlenbergia capilaris) and little bluestem (Schizachyrium scoparium).

Little bluestem also takes on a distinct copper hue that makes it easy to spot at a distance.  Northern sea oats (Chasmantheum latifolium) also has a distinctive form with its dangling seed heads and rich brown hues.  Also on the property I have several large patches of deer tongue grass (see last fall's post).  What I noticed this year was that, while not particularly beautiful in form, the stiff dried leaves made a very pleasant rustling sound when there was just a little breeze.

While leaving perennials and grasses standing over the winter offers some visual interest to an otherwise flat landscape, it is also a good practice for the ecologically minded gardener.  Seed heads left standing provide food for migrating and non-migrating birds.  Standing twigs provide winter cover for many small animals and insects.  The larvae of many butterflies over winter in the leaf litter.  Many insect predators overwinter in the ground cover.  By providing space for them you will have a leg up come spring on your pest control.  (There are situations were fall clean up is advised, particularly for plants battling a fungal or bacterial infection where spores can overwinter in the leaf layer.)

Appreciating plants in the fall is not just an outdoor activity.  We brought in a few to enjoy as a table center piece.  While pretty this has proven to get a little messy.  The seeds  on the little bluestem stick quite tightly to the table cloth and the hosta seed head is still shedding seeds.  Our biggest problem is that our cat likes to get in and rearrange things, even the spiny branches of the invasive wineberry (Rubus phoenicolasius).

Some of the plants from left to right, Northern sea oats, a wineberry stem, little bluestem,
false indigo pods, tall ornamental garlic, hosta and wild bergamot.

New Seeds for 2012

I just got in my 2012 seed order from Prairie Moon Nursery.  I'm only trying five new plants this year, but as I noted in my last post, I have another half dozen from last year already started.  The plants that I will be trying this year are:

Agastache foeniculum, Blue Giant Hyssop, a mid-western native that is often grown as an annual or short-lived perennial in New England.  I normally would have gone with the species native to this area, A. scrophulariifolia, the Purple Giant Hyssop, but this plant can get a bit too large for a residential setting, reaching 6-7'.  The Giant Blue Hyssop usually grows to about 3', a more manageable size for a suburban landscape.

Agastache scrophulariifolia in mid-October at
Garden in the Woods, Framingham, MA.  This was a small one,
others nearby were well over 6' tall.

Chamaecrista (formerly Cassia) fasiculata, Partridge Pea, is an annual that grows on poor well-drained soils.  It is often used as a temporary ground cover when establishing a meadow planting and has been recommended for use on roadsides.  As with other legumes, Partridge Pea help fix nitrogen into the soil.

Clematis virginiana, Woodbine, is a common woodland vine in the Eastern US.  I would like to try it under my Norway Maple, as a complement to the Virginia Creeper that is doing so well.  While it reseeds itself easily in the wild, it is more difficult to start indoors.

Lilium philadelphicum, Wood Lily, is a beautiful native lily that, while geographically wide spread, has seen its numbers diminished.  This is due in part to harvesting of flowers from the wild.  This may also be a tricky one to grow from seeds, but that will have to do until I find a good commercial source for the bulbs.

Solidago ulmifolia, Elm-leaved Goldenrod, is another shade-tolerant perennial.  I had such good results last year from the Blue-stemmed Goldenrod (S. caesia), that I thought I would try another woodland goldenrod for comparison.

Since I don't have any plants to show off yet, here's a photo showing each of the five seeds.

Clock-wise from upper left: Agastache foeniculum, Chamaecrista fasiculata,
Clematis virginiana, Lilium philadelphicum, and Solidago ulmifolia.

I need to start the cold stratification for the Lily and Clematis right away!