Halesia tetraptera

Since the last few posts have been about Central Park Zoo, I'll stay there for a bit longer, at least to talk about Halesia tetraptera, or Carolina silverbell.

Carolina silverbell is a small understory flowering tree that can ultimately reach a size of 30-40 feet (there's a larger one on the north side of Central Park bandshell, too). It has a lemony fall color that is evident in these photos, and in mid-spring the plant is covered with white bell-shaped flowers.

But today, and even after the leaves have fallen, the notable characteristic that remains is the seedpods. Tetraptera literally means four-winged and refers to the four flattened corners of the seedpod. Halesia is named for a botanist, Stephen Hales.

Brugmansia

Central Park Zoo has a great collection of moderately hardy plants - the horticulturist there who oversees the grounds is always pushing the zonal limits for different species. I always love to see what he has growing there.


Brugmansia is one of these plants. Native to South America, this plant typically thrives in frost-free climates but has tolerated the Manhattan climate, for now.


Of course, it thrives in a warmer climate. For comparison to the above Central Park plant, here's shot of one growing in Barcelona:

Brugmansia is in the Solanaceae family, or the nightshade family. It is related to tomatoes, potatoes and some peppers. But, it's also related to some highly toxic plants and this species can be fatal if ingested in the wrong doses.


It's poison can have psychotropic effects, but it's toxicity makes ingesting the plant a very dangerous gamble. It has been used in shamanic practices by people from Peru and Amazonia.


Brugmansia is named for a botanist, Sebald Justin Brugmans.

Sugar Maple and a Brief Explanation of Fall Color

When it comes to fall color, the sugar maple (Acer saccharum) may be king.



This specimen is turning yellow, but you can find sugar maples turn fiery orange and red as well.

A commenter asked earlier this week why leaves turn different colors in the fall, and now I'm going to attempt to answer in just a few short sentences....


Most people know that chlorophyll is the chemical compound in plants that is necessary for photosynthesis (the production of sugars and carbon dioxide in a plant). Chlorophyll is also a pigment that absorbs the blue and yellow colors from sunlight, making plants appear green. The more chlorophyll in a plant, the more green it appears (and also, the more energy it produces and in some cases, the faster it grows -- it's generally why green-leaved plants grow faster than their variegated counterparts).

In the fall - as the days become shorter and colder - a membrane grows between the twig and the leaf petiole which clogs up the flow of sugars and water between the leaf and the rest of the tree. This eventually prevents the chlorophyll from being productive and the compound breaks down.

That's where carotenes and anthocyanins - two other pigments in leaves - come in to play. These pigments exist in the leaf all year, but are overpowered by the presence of chlorophyll until autumn. The former absorbs blue-green and blue light, which means that the presence of carotene - once the chlorophyll is gone - can make a leaf look yellow. Anthocyanins absorb blue, blue-green and green light, which makes a leaf appear red. The amount of anthocyanins and carotene varies among species (and in the case of sugar maples, they vary among individual plants).


So now, when you see a tree that has yellow fall color, you can impress your friends by observing that said tree must have a high concentration of carotene. I'm sure they'll be fascinated!

Back to sugar maples, briefly. Sugar maples of course are responsible for maple syrup and, as the common name would imply, the tree's sap is quite sweet. They are also very hard-wooded trees and the lumber is used for basketball court floors, pool cues and bowling pins.

My students struggle with discerning differences between sugar, silver, Norway and red maples. I'll post some of these other species in the days to come. The important characteristics to look for in sugar maples are a smooth or entire leaf margin and furrowed bark. While Norway maples also have entire margins, their bark is more stripey (and the leaf petiole exudes a white milky substance). Unlike sugar maples, red maples have serrated edges and silver maples have deep leaf sinuses.

Acer comes from a Latin word for sharp - referring to the hard wood, which could be utilized to make spears. Saccharum means 'sugar' - like saccharine.

Yellowwood

Autumn really is a wonderful time of year for tree watching. Not just for the aesthetic pleasure of seeing various trees' leaves change from green to yellow, orange or red, but also because while this change is taking place, different trees will begin to reveal themselves to you.

For instance, the entry to Central Park near the 5th Avenue stop on the NR train has never slowed my pace very much. If I enter the park here, I usually rush down to the nearby pond (the one where we saw our friend taking a dip last August) and then begin to meander through the landscape.

But on Saturday, this yellow tree caught my eye before I'd even entered the park.


When I neared the tree I quickly realized it was yellowwood (or Cladrastis kentukea, or C. lutea). I was delighted. I love this tree, but until now I have only been able to show students a smallish specimen near the magnolias behind the Met, or the larger one in Jefferson Market Garden.



Yellowwood are fairly easy to identify. They have a pinnately compound leaf with leaflets quite larger than a honey locust, sophora or black locust. More specifically, the terminal leaflet is always broader in shape than the lateral leaflets. It is almost spatula-shaped, where the lateral ones are simple footballs.



Like those other trees with pinnately compound leaves, Cladrastis is in the Fabaceae or pea family (also considered the Leguminosae family). And, like other members of that family, the tree has long, pendulous sweetpea-like flowers in the late spring.


The bark is gray and smooth. If one were to trim a branch and look at the cut, they would see yellow heartwood, thus the common name.


Cladrastis comes from the Greek words klados (branch) and thraustos (fragile). clearly refers to a native range. The other species name, lutea, means yellow.

Central Park, Yesterday

Yesterday I had brunch with some friends on the upper west side. It was kind of a perfect afternoon. The night before I had had a dinner party at my apartment, which meant the entire day was spent cooking or cleaning or trying to figure out how to seat eight people to dinner with an apartment that sorely lacks the required furnishings. By Sunday afternoon I was more than ready to be served by someone else. What made it better was that one of the group had juice with the waitstaff and we evidently had free refills on Prosecco.

Leaving brunch at five in the afternoon, I decided to walk through the park, and try to catch something in bloom to blog about. Or at least find a nice specimen of tree that caught my imagination. I wasn't finding much I hadn't already covered, and then, at the pond I saw this:


Yep, he was swimming in the pond. At first, he was doing a breast stroke in the water, and I had to watch 'cause I was curious how deep the water was. When he stopped and stood up, you could see that either he was very, very tall or the water was a mere 3' deep.



Perhaps most amusing though, were the reactions among the people in the park, as well as those gawking from Central Park South. A lot of them were mad. Energetically mad. The woman near me called 311 to complain, and others began to speculate on whether or not he was crazy (granted, that was my first thought too, though watching him for even a moment made it clear he was simply enjoying a cold dip on a hot August day).

The whole spectacle also illustrated something about how city dwellers understand (or don't) the idea of nature. As 'natural' as Central Park may seem, it's still - evidently to many - a museum, or a set piece. As if this man was going to 'mess up' the pond -- sort of like the pond is that parlor room that no one ever uses. I understand, of course, that the Central Park Conservancy can't *let* people swim in the pond, but it was a little bit sad that people didn't connect this pond to a 'real' pond that people can and do swim in. I suppose it illustrates that even people who don't know a thing about landscape architecture or Olmsted still know that this park is not natural, not 'real.'

...Or they're all just busybodies stuck in the city on a summer weekend!

Clethra alnifolia

Right near the oakleaf hydrangea from Wednesday's post, stands a Clethra alnifolia, or summersweet or sweet pepperbush, preparing to bloom.


Clethra is a native, summer-flowering, disease-resistant, fragrant shrub with lovely red fall color. So as a result it's clearly a wonderful plant to have on your palette. The one drawback it does have is that it's very late to leaf out. Your lilacs will be in bloom and bulbs will be popping out of the ground, but if you don't know any better, all you'll do is obsess over whether or not that damn clethra has died on you. It hasn't; it just likes to sleep in, so to speak. This is hardly a dealbreaker - the plant is too lovely not to use. Just forewarn skittish clients, or tuck it further back on a border so other things can mask it's bareness in the spring.



Clethra is literally the Greek name for alder (which I suppose is confusing for Greek people learning plants) and alnifolia is Latin for Alnus (alder) like foliage.

Sweetbay Magnolia

Not far from yesterday’s sawtooth oak in central park stands another diminutive beauty (and this one isn’t even invasive!), the sweetbay magnolia, or Magnolia virginiana.

Magnolia virginiana is more Elinor Dashwood than Marianne -- the two sisters from Jane Austin's Sense and Sensibility. It’s the less outrageous counterpart to Magnolia soulangiana. The white flowers are smaller and they never cast a profusion of blossoms over the entire tree, like the floral frenzy of the saucer magnolia in early spring.

But, while you don’t have a riot of color and perfume when sweetbay magnolia is in season, you do have a slow burn. Sweetbay magnolia sets a steady pace that means it will bloom for months in the summer, as opposed to the ephemeral display of the saucer magnolia. This is demonstrated in the above photo and the following two. Above, you see a flower bud and below, a flower that is just about to open.

In tandem with buds forming and opening, you have fully-open blossoms like the one below. The flowers are creamy-white, similiar to Magnolia stellata, perhaps, but less strappy and flimsy. They are lovely flowers -- and fragrant, too -- but you need to get a bit closer to this plant to appreciate its beauty. Much like Elinor.

Sawtooth Oak

This sawtooth oak, Quercus acutissima is growing in one of my favorite parts of the park -- the area behind the Met by the magnolias I've discussed in the past. There's almost always such a nice mix of activity here; people strolling from the Met or picnicking on the lawn near the Alexander Hamilton statue, runners making their way along the loop or dads walking their son or daughter home from a little league game on the nearby ballfields.


And I do love this oak, subtly standing sentry on all this activity. Which is why I was so dismayed to learn that invasive.org has listed it as a problem plant. Apparently, it has begun to spread from ornamental plantings into forests along the east coast. That fact will keep me from planting this tree in the future, but it won't stop me from blogging a little bit more about it.



Sawtooth oak, as you can see from the photo above, is an apt name for a tree with such leaves. Small, hairlike spines along the leaf margin look much like the blade of a saw. Their glossy, strappy shape create a unique canopy, too.



Below, immature acorns have started to form. They will not fall for another 18 months or so.

Carpinus caroliniana

Well, I'd love to say that I went for a walk in Central Park yesterday, during one of are extremely rare sunny June days. And that while I was on this walk, I took this photo of Carpinus caroliniana, or American hornbeam.

But I'd be lying. 'Cause the only really nice day was on a Thursday, and I, well I have a job.

This was actually shot last summer, around this time of year. It is in Central Park, next to the loop road as it circles back north from Central Park South, rising in grade before you see Wollman Rink on your right.

I do love this tree, though. Usually multistemmed, it has a broad elegant habit and okay(ish) fall color. Of course the bark is the real attraction. Smooth and gray, it has a sinewy look, which accounts for its other common name, musclewood (or ironwood).

Central Park's Lilac Walk

It always bothered me that I had such dreary photos of Japanese Lilac Tree posted on this blog. It's a lovely tree, but the photos I took at Sarah Roosevelt Park were, well honestly, a bit dismal.

So, when I was in the Sheep Meadow last Sunday - on what may very well be our *only* sunny day in June - and I saw these beautiful, sparkling specimens, I decided to do another post on Syringa reticulata and the Lilac Walk in Central Park. In fact, it was only when I looked up the link to my previous post on this species did I realize that I wrote it exactly a year ago.


The path you see above is the Lilac Walk in Central Park. As the name suggests, the path is planted with various species of lilacs, including Syringa vulgaris, S. reticulata and S. patula. From April until June this little part of Central Park has something in bloom.


The Lilac Walk is only 39 years old -- it was created in 1970 by philanthropist Nell Singer, who passed away in 2006. The path itself leads to a (currently defunct) concession stand that was once called Mineral Springs. The site was originally conceived as a concession (and will be once again -- the Central Park Conservancy has an outstanding RFP for a Shake Shack type venue) in the late 19th Century. It was called Mineral Springs because, just as now, people were very into fresh 'high end' waters and would-be reformers thought touting the benefits of spring water would lure people away from the evils of alcohol!

Personally, it looks like a great spot for a glass of white wine.