Tree of the Week: Silverbell (Halesia diptera)

Our tree of the week is the silverbell (Halesia diptera). Silverbells were among the first plants included in the arboretum catalogue. Since 1985, there have been 12 individual plantings, 11 of which were donated by local resident Jack Price. Today, only three survive.

 

 

In February of 1985, Jack Price donated five trees. Our three remaining silverbells are from this bunch, which makes them more than 35 years old. They were planted together, in a row, toward the bottom of a slope, near the arboretum drainage channel.

 

 

It just so happens that all three trees have terrible posture. Two of the trees lean heavily toward the south. In 2021, this location receives a fare amount of sun. However, the landscape has changed significantly since 1985, with the loss of old on-site native oaks that covered this area in shade.

 

 

All three trees have slender trunks with fissured, rough bark.

  

If you can train them properly, silverbells make excellent shade trees. They are small trees with big green leaves.

The dark green leaves have an ovate shape and a pointed tip. The upper surface is smooth to the touch.

Underneath, leaves are pale green and smooth. The leaf pictured measures approximately 6 inches in length, with the petiole included.

Edges are subtly serrated.

In the month of July, our three silverbells show an abundance of immature fruits, and what interesting fruits they are!

 

 

Fruits appear singly or in clumps. They are bulbous with wavy ridges. The species name diptera is a reference to the unusual fruit shape: the four wavy ridges divide into two sets of wings, making the fruit "two-winged".

 

A nice little branch was snipped for measurements.

 

Immature fruits are more than an inch in length.

 

Fruits are less than an inch wide. In the fall, these fruits will dry out and turn brown. This past winter, a handful of persistent fruits were collected and planted, but we didn't have any luck with germination. With such an abundance of fruit this year, we will necessarily try our luck again.

 

 

You can see flowers from these trees on an older blog post, found here.  

 

For more information about this species, please consult the following online sources:

Louisiana Plant Identification and Interactive Virtual Tours (LSU AgCenter) 

Texas A&M University (Aggie Horticulture)

North Carolina State University Extension 

Tree of the Week: Silverbell (Halesia diptera)

There are three silverbells in the collection. They were donated by Jack Price in 1985, making them at minimum 35 years old. Despite their age, these trees remain short in stature. This week they are covered in numerous pretty white flowers.

Autumn Landscapes

On the west side of Hamilton Hall, looking into the arboretum

North side of the arboretum

The trees still have their leaves: dappled sunlight on a sunny day.

Western edge of the arboretum: this is the sidewalk that runs between the Student Union Building and Cline Hall.

Persimmons (Diospyros virginiana) are ready to eat. Go for the wrinkled ones. 

The sweet gum (Liquidambar styraciflua) has been the stand-out fall foliage specimen.

The silverbell (Halesia diptera) is one of the few trees showing its fall colors.

Bright orange leaves of Halesia diptera

What's in Bloom?

It's the first day of spring. Trees are blooming. Vines are blooming. Wildflowers are blooming. Flowers are easy to find this time of year. Some flowers are large and hard to miss, attracting the eye with brilliant hues. Other flowers are subtle, small and white. And other flowers don't look like flowers at all; they look like 'weeds'. Below we have a small selection of the great variety of plants in bloom.

The red buckeye (Aesculus pavia) is still in bloom, with even more flowers this week. The red flowers contrast with the green foliage, forcing us to notice them.

The bees notice them, too

In contrast to the red buckeye, the silverbell (Halesia diptera) produces a small, inconspicuous flower. We used a clipboard for a backdrop to more easily see the flowers.

Looking up, the silverbell flowers are more obvious.

The crossvine (Bignonia capreolata) produces red-orange flowers, in the shape of a trumpet.

Even though they are brilliantly colored, crossvine flowers are easy to miss because the vine climbs up high. This vine has grown happily with a loblolly pine (Pinus taeda).

This is the first iris bloom of the season in the arboretum. This particular plant (Iris fulva) is a volunteer, growing in a drier spot than it should be, suggesting that the sprinklers have been doing a good job in this part of the arboretum.

Iris fulva detail

Additional Louisiana irises have opened up in the wetland.

Senecio glabellus is one of those 'weedy' looking wildflowers. It grows happily in wet areas. The flower smells like honey.

We are holding off on mowing the grass in the arboretum because of plants like the daisy fleabane (Erigeron sp.). They are truly wild, growing wherever they please. There are several healthy patches in the arboretum. And, like the Senecio, they have a pleasant smell. Enjoy them while you can!

Halesia diptera