Saturday, February 23, 2013

More Winter Trees

Since it is still a little early to start creating the beds for the vegetable garden I've had time to take a closer look at some of the trees out back.  With the leaf buds beginning to swell there is enough information on the twigs to do some identification.  Our new property is blessed with a number of hickory trees.  In my last post I showed a photo of the terminal bud of a Mockernut Hickory (Carya alba).  This past week I found that there were at least two other species of hickories.

The Pignut has smaller leaf scars than the Mockernut.

The first one I noticed had a much more ovate terminal bud than the Mockernut Hickory, and the leaf scars were more like a rounded off equilateral triangle.  Again, I turned to Trees of New York State for help in narrowing down the choices.  Based on the detailed descriptions in the text I feel pretty confident that this one is a Pignut Hickory, Carya glabra.

Not far from the Pignut was another type of hickory.  The leaf scars on this one were triangular with raised edges.  What stands out is the bright yellow buds and the orangy color of the year old twigs.  This one was easy to find in the key since only Bitternut Hickory, Carya cordiformis, has the yellow leaf buds.

Yellow leaf buds and the raised leaf scars indicate that this is a Bitternut Hickory

As I was taking these photos I noticed some branches where the leaf buds were opposite on another on the twig, rather than on alternate sides moving along the twig.  There are only 6 genera of native trees with this opposite branching:  Maples, Ash, Catalpa, Buckeye, Dogwood and Viburnum.  When I see this opposite branching pattern I usually think of maples, but the terminal leaf buds on this branch were not as pronounced as on maples.  To help with this ID challenge I turned to The Tree Identification Book, by George Symonds.  A quick review of the twig photos brought me to this being some type of Ash tree.  I'm pretty sure that this is a White Ash, Fraxinus americana.  I settled on that because the twigs were smooth and not fuzzy (F. pensylvanica); and the leaf scars are concave at the top rather than straight across (F. nigra).

White Ash has smooth, hairless twigs, a blunt terminal bud and the leaf scars are concave at the top (arrow).

 An easy tree to identify in the field is the American Beech, Fagus grandifolia.  In this photo you can see the elongated leaf buds.  Other indicators over the winter are the persistent dried leaves and the smooth gray bark.
Leaf buds of the American Beech 'stick out'.
Looking down at the ground level I had been perplexed by a small leafy plant that was just sprouting up last fall.  I was unfamiliar with it and just assumed that it was badly confused by the warm weather.  As I was deciding on plants to order for this spring I came across a description of a spring ephemeral that matched up with this little plant.  This appears to be Toothwort, Dentaria diphylla.  I will need to keep an eye out for the little 4-petaled white flowers this spring.  I only found one patch, but I hope I have some others.

Toothwort, a spring ephemeral is a member of the Mustard (Brassicacae) Family.

While walking back to the house I noticed a lot of little white flowers blooming in the lawn.  Many aspects of this plant were familiar, but I could not put a name to it.  I ended up digging one up for closer examination with a hand lens.  The flowers had 4 petals so I immediately thought of the mustard family.  I ended up using Gleason and Conquist to key it out as Cardamine hirsuta, Hairy Bittercress.  This is an Old World plant that is now found in 2/3 of the US.  It is a winter annual that germinates in the fall and overwinters as a rosette.  It blooms from early spring and through the summer.  While edible, the leaves on mine are very small, so it would take a lot if picking to make a salad.

Hairy Bittercress has tiny hairs on the leaves and petioles visible with a hand lens.

Monday, February 4, 2013

Early Spring???

This winter has been schizophrenic.  Bouts of snow followed by brief warm-ups.  Last Tuesday, January 29th, it was well over 60 degrees here in Washington County, MD.  We have had Snow Drops, Galanthus nevalis, blooming since Christmas day but I had seen no signs of pollinators.  That is until the 29th when the little flowers were being swarmed by honey bees.

How many bees do you see here?  I counted 6.

Can someone ID these bees for me?
I assume these are European Honey bees from a local hive, but to be honest I don't know that much about bee ID.  I was surprised to see so many bees out this time of year.  I only hope they have someplace warm to return to as the temperatures dipped back below freezing two days later.

"Buds naked, rusty-brown-tomentose; bundle scars 5-7"

While I was out photographing the Snow Drops I decided to see if there were any other early signs of spring.  Walking through the woods I found no early blooms, but I did see some swelling leaf buds.  I noticed that the terminal buds of the PawPaw Trees, Asimina triloba, were getting pliable.  While I remembered their location from the fall, I just wanted to double check the ID using a plant manual.  I needed to do the ID based on the twigs and bark.  On Google Books I found a very nice resource for identifying trees in the Northeast US: Trees of New York State .  It has several identification keys based on leaves, flowers and fruits, as well as one that focuses on the appearance of twigs and leaf scars.  There are also detailed descriptions of each of the tree species.  The description in the key confirmed that this was one of the PawPaw trees.

This image close-up shows the 5 bundle
scars where a leaf had been attached.

Looking at things like bundle scars can be very useful in identifying trees, especially in winter when there not much else to go on.  The bundle scars are left over from where the vascular bundles of the twig and leaf meet.

Encouraged by my success with the PawPaw I found another tree with distinctive leaf and bundle scars.  On this tree the leaf scars were large and 3-lobed, almost like a stylized human skull.  The bundle scars were clustered in arcs, one cluster in each lobe.  Using the key I was able to narrow it down to a Hickory (Carya) of some sort.  I needed to go to the detailed descriptions and accompanying botanical drawings to finally settle on Mockernut Hickory, Carya alba (formerly C. tomentosa).

"Twigs very stout pale lenticellate pubescent reddish brown turning gray the second season.
Leaf scars inversely 3 lobed, the bundle scars in marginal clusters.
Terminal bud reddish brown or yellowish usually tomentose 1/3 to 3/4 of an inch long."  [from "Trees of New York"] 

There are plenty more trees to identify in the woods here, so I should put on my boots and get out there to see what I can learn before the leaves start popping out.