A tall nut tree

There's a tree I walk by on my way to work every day.  The branches are all very high, so I can't get much of a look at the leaves.  But this is that time of year they call "fall," which means the leaves fall down to where I can get a better look at them.  Here are some photos:

Two from September 16:

One from October 4:

So we know we've got pinnately compound leaves, and The Tree Identification Book suggests pecan, hickory, walnut, ash, ailanthus, sumac, mountain ash, and box elder.  Now I am acquainted with ash, ailanthus, sumac, and box elder, and this is not one of those.  Another clue is that it has nuts.  They look kind of like tennis balls, with the bright greenish color, though they are a little smaller than tennis balls.  Mountain ash is not a nut tree, so that leaves us with pecan, hickory, and walnut.  The Sibley Guide to Trees tells us that these are related kinds of trees, in family Juglandaceae.  

So, which kind could it be?  The top picture shows 11 leaflets on a leaf, and the bottom one shows 15. For species that we might find around here in a cultivated environment, The Sibley Guide to Trees lists the following numbers of leaflets:

Black walnut: 15-23

Butternut: 11-17

Japanese walnut: 11-17

English walnut: 7-9

Shagbark hickory: 5-7

Pecan: 11-17

Bitternut hickory: 7-11

So, based on the number of leaflets, it could be butternut, Japanese walnut, or pecan.

What about the nut? In the Juglandaceae section of The Sibley Guide to Trees, the following nuts seem to match the ones on the tree that I see: black walnut, English walnut, and shagbark hickory.  

I don't think it could be shagbark hickory because it does not have enough leaflets.  The butternut, Japanese walnut, and pecan nuts just aren't round enough.  

The book says that English walnut has toothless leaves.  Clearly these leaves are toothed.  So I'm thinking maybe it's a black walnut.  Maybe the leaf with 11 leaflets was just a fluke.  Also, the book says black walnut is large, which fits -- this tree is pretty tall.   I'll have to go back and check out some more leaves.

Flowering sugar maple

A sugar maple at Sage Park is flowering now.

Ash

An ash tree by the river.

Star magnolia

This tree is quite near the tree I wrote about in my previous post.  I am wondering if this is a star magnolia.  It is different from the magnolia trees I usually see.  I think the ones I usually see are saucer magnolia.

Basswood bud

I think this is basswood, also known as linden. The reason I think that is because that's what I remember this tree being at other times of the year. (This is a tree at Sage, near the corner of a building.) When I look up picture of linden or basswood buds, this is not what I see.  However, this is a bud opening up, which is different.  The pictures show closed reddish buds.  I should continue to watch this tree, to see if I continue to think it's basswood.

Norway maple flowering

The last two years, I tracked the progress of the Norway maple flowers as the emerged in the tree by my balcony.  For spring 2011, that's at Spring emerges in the Norway maple.  For 2012, it's at The Norway maple's March transformations.  That tracking came to an end on March 31, 2012, when they cut down the tree I had been watching.

I don't know if it's because I tracked it closely the past two years, or whether Norway maple just holds a special place in my heart anyway, but I thought it was beautiful when I saw this:

That was April 12. In 2011, that was how the Norway looked April 20.  In 2012, it looked that way March 23.

Now, the Norway maples are fully flowering.

April 25:

April 26:

Cherry blossoms

Cherry trees are blossoming now.

Weeping cherry at RPI near VCC, April 24:

Cherry on 14th Street, near Hutton Street, April 26:

Emergence of the crabapple leaves

It was so exciting when I saw the first trace of leaves of the season  -- the little folded up green on the crabapple trees.  On April 9, I saw no sign of leaves on the crabapple trees.  On April 10, I was home sick and did not see the trees.  When I returned to the office on April 11, there they were! I was jubilant!  Ever since then, I've been watching their progression.

April 12:

April 15:

April 16:

April 17:

April 18:

April 23:

April 25:

Magnolia blossoms

The magnolia tree by the Greene Building is starting to blossom.

Is this a red maple?

This tree seems somewhat like a red maple, based on the color of the spring buds and the autumn leaves.  But the leaves are smaller than what I see on other red maples.  Is it something else? An amur maple? A hybrid?

April 9:

April 18:

Red maples flowering in April

April 4:

April 12:

April 17: