Saturday, May 29, 2010

Tulip tree

The first time I remember seeing a tulip tree (Liriodendron tulipifera) was during a family trip to Virginia. I didn't think that it grew as far north as Massachusetts. I was quite wrong. It's far from common, but it is occasionally planted as a landscape tree, and can survive. When I started at my current job a couple of years ago, I realized when spring came that there was a big specimen growing right next to the parking lot.

It's impossible to fit the whole tree into one picture from the parking lot.

The tulip tree, aka yellow poplar, is a native of much of the United States east of the Mississippi, more common in the southeast but obviously capable of growing as far north as Massachusetts - though we are on the extreme northern edge of its range. It's a very distinctive and remarkable tree. In sheer size, it can be one of the largest trees in eastern North America, growing to more than 160 feet/50 meters tall in the more southern parts of its range. The leaves, flowers, and seeds are very distinctive and not easy to mistake for anything else once you get a close look at them.

The most distinctive feature of all, and the one that gives the tree its name, are the flowers. They are large and showy, a mixture of yellow, orange, and green, and shaped somewhat like tulips - hence the name for the tree. Unfortunately, the flowers tend to be mostly on the middle and upper branches of the tree, so it can be difficult to get a good closeup, especially on a fairly large tree.

Tulip tree flowers - pale yellow and orange in color

The name for the tree may come not only from the shape of the flowers themselves, but also from the shape of the leaves. They have a similar shape to the outline of some types of tulip flowers when seen from the side. They also look a little like maple leaves, but they have 4 lobes rather than the 5 or 3 lobes that maple leaves have. Tulip tree leaves lack a middle lobe of the type that gives maple leaves a "tip" in the center.

Closer view of Tulip tree leaves - 4 lobes total, no central lobe

Tulip trees are related to magnolias, but they have no really close relatives (in the same genus) in North America. Their closest relative is in fact a native of China - Liriodendron chinense. It may seem bizarre that the closest relative of a plant native to the eastern USA is found in China, on the opposite side of the northern hemisphere, but in fact many plants from both eastern and western North America have close relatives in China and other parts of eastern Asia. For tens of millions of years, the two continents have apparently been exchanging plant and animal species through several different means - dry land bridges or bridges of closely-spaced islands caused by either lower sea levels or geological activity, or by migrating birds and wind-blown seeds. In the distant past, tens of millions of years ago, it was also apparently easier for Asia and North America to exchange plant species because the world's climate was both warmer and wetter, so even the high arctic latitudes where the two continents came closest too each other were covered with temperate or even subtropical forests, rich in plant species that could migrate in both directions. In more recent times, the two continents have been temporarily joined by a land bridge during ice ages, but that land bridge was frigid tundra, which allowed animals - including humans - to move between the continents, but was only useful to plants that were adapted to the coldest tundra conditions - which eliminates most trees!

Saturday, May 22, 2010

Garden geography

One of the things that I find interesting about gardening is something that many gardeners probably don't think very much about - where the plants in the garden originally came from. Most garden plants, whether flowers, herbs, or vegetables, have been selectively bred to some degree to produce larger flowers or leaves or roots, but most of them still have a lot in common with their wild ancestors. So, in a sense, even an average suburban garden is a sort of herbarium or botanical garden with specimens that originate in various parts of the world. Here are just a few samples from my particular garden:

Dicentra eximia - Wild bleeding heart; native to
eastern United States, mainly Appalachian mountains

Syringa vulgaris - Common lilac; native to the
Balkan peninsula of southeastern Europe

Podophyllum peltatum - Mayapple; native to
eastern United States

Cercis canadensis - Eastern redbud; native to
eastern United States (but not Canada, in spite of the name)

Centaurea cyanus - Cornflower or Bachelor's button; native to
most parts of Europe

Rosa carolina - Pasture rose or Carolina rose; native
to eastern United States and southeastern Canada

Rudbeckia hirta - Black-eyed susan; native to
central and eastern United States and Canada

Athyrium niponicum - Japanese painted fern; native to
Japan (duh!), northern China, Korea, Taiwan

Leucanthemum x superbum - Shasta daisy; hybrid of two species
native to Europe -- with Apis mellifera - Honey bee; native to parts of Asia,
Africa, and Europe

Dicentra spectabilis - Bleeding heart or Lyre-flower; native to
southeastern Siberia, northern China, Korea, and Japan

Rhododendron maximum - Great rhododendron; native to
eastern United States and southeastern Canada

You may notice that all of these plants are natives of either eastern North America, Europe, or the northern China-Korea-Japan area. This isn't an accident - the northeastern part of the United States has a type of climate sometimes known as humid continental. There are three large areas of land on earth that have this climate:

Image from here on Wikipedia - see this article.

The native ranges of most of the common (and quite a few of the less common) garden plants that grow in the northeastern United States fall mostly within one of these three zones.

Wednesday, May 19, 2010


Tired at all hours of the day. Tired enough to barely keep my eyes open sometimes. Tired enough to go in and out of a near-sleep state in front of my computer at work, in which my eyes are open but I am not conscious of my surroundings. Tired for no apparent reason. Tired in spite of getting enough sleep. Tired in spite of not being particularly stressed. Tired in spite of not feeling sick in any other way. Mystery tired. Not too worried - it happens occasionally. Hope it goes away.

Monday, May 10, 2010

Wild turkey

As I was eating breakfast this morning, I saw a wild turkey in the backyard right outside the window, less than 10 feet away. By the time I got my camera, it was further away but I managed to get a couple of good photos:

I'm pretty sure this was a female - the males are considerably larger and have more reddish skin on their head and neck. They can fly, but only do so when they really have to, preferring to walk around. They often travel in groups, but this one was solitary.

Twenty years ago, wild turkeys were very rare in this part of Massachusetts, having been hunted or driven out by the 19th century. The first one in my town in more than 100 years was spotted 18 or 20 years ago. Now they are common enough that it's no surprise to see them, but this was still an unusually good opportunity to get a picture from pretty close up in good light - and from indoors, where my movement and noise wouldn't drive the bird away quickly.

Saturday, May 8, 2010

Tulips and other flowers of mid-spring

I was so happy to see the tulips actually get a chance to bloom this year instead of being eaten by deer that I took lots of photographs. There are plenty of other flowers that have been blooming over the past 10 days or so, and I didn't completely neglect them with the camera.

First, the tulips. Most of these photos were actually taken last weekend. Unfortunately, tulips are not very long-lasting flowers once they open, and virtually all of the flowers pictured here have dropped all of their petals. Today I clipped off a lot of the flower heads, because bare flower heads after the petals fall off look rather unattractive (in my opinion), plus if they actually produce seeds, this will use some of the sugar and other nutrients that the plants live on. If they don't produce seeds, more of the nutrients will go down into the bulb, resulting in a larger plant next year. Or so I've heard - I probably should check more closely to see if I'm wasting my time!

These first two pictures are two views of the same tulip. It is the only one with this color combination in the garden - I especially like the combination of colors when the flower is backlit.

Red and white striped tulip with colors that remind me of a candy cane. (It doesn't take much to remind me of one kind of junk food or another.) These I like how the outer "petals" flare out like little tongues. (The "outer petals" are actually sepals in tulips. For many kinds of flowers, the sepals are the green lobes that make up the outer covering of the flower before it opens, and which usually shrivel up or become inconspicuous after the flower opens and the petals come out. In tulips, however, the sepals change color to match the petals as the flower starts to open, and remain an important part of the flower until they drop off around the same time as the petals.)

Pinkish tulip with a lighter central area and sepals that flare out somewhat less than the previous flower.

Large yellow tulip with dark center - and a small spider crawling on the right side.

A tulip of the same type as the previous, except with a single red stripe.

Some type of pale blue iris - as you may have noticed, I'm not good at remembering the names of different varieties or cultivars! All I know is that I got this at a local garden club sale, and that it is a short variety, with the the flowers no more than 6-8 inches above the ground and the leaves not much taller.

A closeup of the flowers of an azalea or dwarf rhododendron (I can't remember which) in front of the house. Notice the bee at work gathering nectar from the flower in the center - I believe this is a honey bee.

A broader view of the same azalea along the walkway to the front door of Dad's house (the house where I spent most of my childhood and have lived for some of my adult years as well.)

A cluster of pink tulips, with some white and red tulips in front of them (kind of washed out from the late afternoon sunlight glaring off the white flowers). The pale blue irises are at upper left, further from the camera than the tulips - you can see how they are pretty short.

An azalea bush with reddish flowers to the left, pink and mixed pink and white tulips to the right. There are a mix of lower-growing plants, including a few blue anemones to the left, a few purplish grape hyacinths to the right, the plant with the gray-colored foliage whose name I can never remember, and a bunch of lily-of-the valley sprouting just about everywhere it can. (Lily of the Valley spreads itself all too well by underground runners. Mom planted it years ago against her better judgment in a location a few feet to the left of the left edge of this photo, and surrounded it with a plastic barrier 6 inches deep to prevent it from spreading as recommended in the garden books. This worked for 2 or 3 years, but then its underground runners found some little breach and it has been spreading to a wider part of the garden each year.)

A patriotic grouping of flowers - red azalea bush, white candytuft (Iberis sempervirens), and blue anemones.

A nice ensemble photo, with 5 colors of tulip (multiple pinks and purples, 2 white with a little red, and a single solid red and single pale-pink/yellow) growing along with bleeding hearts (background), candytuft (lower left), and yellow alyssum (right). An azalea bush is just above the alyssum, but this one has not started to flower yet.

Pink, purple, and red tulips again, along with bleeding hearts and alyssum, and the pale blue irises (which were hidden behind another some of the tulips in the previous picture.)

Sunday, May 2, 2010

Garden: Least Wanted #1, Poison Ivy

Weeds are something that every gardener has to deal with. My own attitude toward weeds is not as always as hostile as that of the typical gardener. My mom, from whom I learned a lot of what I know about gardening, preferred a garden style that was somewhere between strictly formal, with no plants tolerated out of place, and natural or wildflower, where everything except the most noxious weeds are allowed to grow naturally. Her view tended to be that wildflowers and natural offspring of deliberately cultivated plants were welcome as long as 1) they didn't grow too big or crowd or choke out nearby plants, 2) they didn't look too unattractive or out of place - obviously a subjective judgment, but most garden choices have to be subjective. Taking care of the same garden for my father later, I followed a somewhat similar pattern, except that I err more on the side of giving things a chance to grow. Sometimes this "erring" is costly. Dad mildly but firmly informs me that I need to get more ruthless rather than waiting until halfway through summer to see if those unidentified seedlings of April will turn out to be nice wildflowers, only to discover that they are fast-growing weeds with microscopic flowers that are threatening to devour whole flower beds by the end of June - by which point they have developed clumps of thick roots the size of carrots and need a considerable amount of effort to be removed without tearing out 3 or 4 surrounding plants with them.

In spite of my far too indulgent attitude toward many plants that turn out to be weeds, there are a very few weeds that even I loathe enough to want to eliminate on sight. At the very top of the list is Toxicodendron radicans, better known as poison ivy, the little three-leaved plant growing out of the cracks of the stone wall just beneath a branch from an evergreen shrub here:

It's also known as Rhus radicans, or "The three-leaved spawn of Satan",
though the latter term might just be mine.

This plant is unfortunately familiar to many, perhaps most, people living in the eastern half of the United States and Canada. It's actually not a bad plant in many respects - it is a native plant, its foliage looks reasonably attractive, its berries are eaten by several different species of birds, and it even gets nice red foliage before dropping its leaves in autumn. It has just one slight flaw from a human perspective - all parts of the plant are covered by an oily chemical called urushiol that causes a severe itching and burning rash in the majority of people. Any physical contact between human skin and any part of the plant causes, for most people, anything from a slightly itchy rash to severe swelling and blistering that resembles a fairly serious burn. Some people have no reaction as children, but develop the allergy as adults. Unlike some toxins, the body actually tends to become more sensitive to the oil the more times it is exposed to it. The oil is potent enough that touching objects that have touched the plant, such as clothing and tools, is usually enough to cause a reaction. The WORST thing to do is burn the plant, because this simply vaporizes the oil and can cause severe irritation inside the nasal passages and lungs if one inhales the vapors.

Granted, poison ivy is far from the only plant that can cause a severe and painful reaction for people who simply touch it. Quite a few plants have urushiol - in the United States alone, there are two species of Poison oak and one of Poison sumac that cause similar, or sometimes even more severe effects. Some tropical regions have a number of plants that cause much more severe reactions than poison ivy or its relatives. Different people have different levels of both sensitivity and severity of reaction.

Still, in the northeastern United States, these other plants are non-existent or rare, while poison ivy grows abundantly and lushly in exactly the kind of places where people are likely to encounter it - in gardens, along the edges of yards, along sidewalks and streets, up the sides of trees and shrubs. It's a plant that thrives along the edges of land disturbed by human activity, and therefore many more people will literally come into contact with it than would be the case for a plant that grows mainly in deep woods or swamps. Many of these people will have a reaction that will range from merely irritating to quite painful and even debilitating (though temporary).

Poison ivy usually grows as a vine, either growing up trees, shrubs, rocks, fences, and buildings, or spreading along the ground. Sometimes it will grow more like a shrub. Its most characteristic feature is the leaves in clusters of three, with the middle leaf extended on a petiole (leaf-stalk) while the leaves on either side have little or no leaf-stalk. The leaves typically have a "shiny" and oily appearance, and they are often have a dark reddish hue when they are first emerging:
Growing along the ground with newest growth at upper right.

The stems or vines of poison ivy have just as much oil as the leaves. They are characterized by a distinctly "hairy" appearance when they climb up objects, especially as they get older and thicker:
"Hairy" poison ivy vine growing up chain link fence among other types of vine.
Note the reddish leaves emerging from the upper portions - this was a couple of weeks ago.

Unfortunately the "hairiness" is not nearly as obvious on young vines, and poison ivy also grows along the ground and as a shrub - in which case the stems often have no root hairs at all, since the hairs are used to cling on the objects to support the plant's growth upward.

1 year old stem with some root hairs, but mostly smooth.

There are several other plants that can be confused with poison ivy, especially if you are as paranoid about it as I am.

For example, there's Virginia creeper:

It has five rather than three leaves, but when the plant is growing three leaves sometimes emerge before the other two, making it look very similar to poison ivy. It's not related to poison ivy at all - it's actually a pretty close relative of grapes. In spite of a certain vague resemblance of leaf shape, it is not related to another well-known plant. It's not safe for everyone - it actually produces a different chemical that can cause bad allergic reactions in some people, but for a smaller percentage of the population than poison ivy. I've never had a bad reaction after years of weeding it with bare hands, and I'm really hoping that it stays that way.

Virginia creeper leaves have a similar oily shine to those of poison ivy, and the two plants are both vines that often grow right alongside each other. Below is part of the stone wall between the proper garden and the weed-rich waste area behind it. Poison ivy is growing over the stones toward the left, Virginia creeper toward the right. One branch of the poison ivy extends toward the right and is intermixed with the Virginia creeper. This gives some idea of how one could mix the two up if one is not constantly paying close attention.

Even the bare stems look similar. Compare the Virginia bare creeper vine below with the bare Poison ivy vine earlier in this post.

Another one that can be confused with poison ivy is a very young hickory sapling, which has leaves which are reddish and a little oily looking when they are newly grown. The hickory leaves grow in groups of five, like Virginia creeper, but it's easy to miss the extra two leaves if you aren't looking closely. Unlike poison ivy, hickory tree leaves have fine "teeth" all around the edges, and have a different overall shape:

There are also several types of wild berries, such as blackberries, raspberries, and strawberries, that grow their leaves in groups of three and can look similar to poison ivy. Their leaves tend to have more "teeth" around the edge, though.

So, Poison ivy is my personal most hated weed. When it comes the natural ecosystem as a whole, though, there are plenty that are worse ....