Winterthur, Delaware is the legacy of Henry Francis du Pont, 1880-1969

Mt. Cuba, Hockessin, Delaware is that of the Lammot du Pont Copelands

 

 

I go out into the green in late July and August even in the hot humidity to catch the last of the summer flowers;

 

and to absorb the variety of greens.  I am certain they are a healing balm to the body, mind and soul of primates.  Among other species.

 

 

native Tiger lily (Lilium superbum)

a variety of native rose mallow (Hibiscus)

A variety of native oakleaf hydrangea

a variety of native day lily

native phlox and bugbane (Actaea racemosa)

native plumleaf azalea (Rhododendron prunifolium)

native plumleaf azalea (Rhododendron prunifolium)

a cultivar of native amsonia

lethally protected, still ripening fruit of the Hardy orange (Citrus trifoliata or Poncirus trifoliata) from the Far East

a native redbud tree in seed

cultivar of the Rose of Sharon (Hibiscus syriacus)

native bottlebrush buckeye (Aesculus parviflora) at the Jenkins Arboretum, Devon, PA

weeping European beech at Winterthur in late summer and early autumn

 

 

 

The tree which flowers when all other forms are dormant

 

I turned a corner at Winterthur  in late July and saw two common witch-hazels (Hamamelis virginiana).  One of 3 native N. American species.  Deciduous. Not tall.

 

A few days later,  I looked up near an entrance into the garden at Mt. Cuba; and saw two more.

 

 Common witch-hazel (Hamamelis virginiana)

 

 

The leaves of all the common witch-hazel trees were studded with galls – witch hazel cone gall made by the aphid, Hormaphis hamamelidis.

 

The galls look like teeth: cream/white, red, and black.  These colours denote different stages of the gall’s life.

 

 

 

 

On the underside of each is the perfect round hole which the aphid made and through which it burrowed in spring into the leaf to feed on sap.

As the leaf grew, the aphid injected it with a substance to grow the gall around her. 

 

 

Gall opening on the leaf’s underside surrounded by the detritus pushed out by the mother aphid and the juvenile aphids

 

 

 

 

The aphid fills the gall with approximately 60 female offspring, developed without sexual intervention (parthenogenically).

 

 

 

These disperse when they  mature – all at the same time – and are winged.   

They begin to lay eggs of a third generation.  These are both male and female.

This third generation reproduces sexually.  Each females lays up to 10 eggs on the bark of a witch hazel. 

These eggs survive the winter to start the cycle again the following spring. 

 

The H. hamamelidis aphid is closely related to a second species of aphid, H. cornu which has seven generations each year and a relationship with both the common witch hazel and the river birch tree.  

The two species interbreed but progeny are thought to be sterile.

 

 

Last year’s fruit on a tree in late July 2025.

  The fruit persists and matures at the same time as the flowers of the succeeding year appear. Here flower buds have not yet appeared for flowers which will blossom in September of this year.

 

 

The presence of these H. hamamelidis aphids are thought to protect witch-hazels from consumption by animals.

They are not thought to be harmful to the witch-hazel unless the galls are so numerous that they interfere with the plant’s photosynthesis. 

 

The life-cycle of this aphid’s close cousin, H. cornu,  with its seven generations each year and all the to-ing and fro-ing, however, is detrimental to river birch trees.

 

 

The common witch-hazel blossoms in September, persisting into December. Their flowers are fragrant and roll up in freezing temperatures. Their autumn foliage is yellow.

The tree is dazzling to us who are preparing for imminent winter.

 

 

Photos from the site of Mt. Cuba Center, Hockessin, DE

 

 

In very early Spring, Japanese and Chinese varieties of witch-hazels blossom in yellows, oranges and reds. 

Aphids are also reported for these Asian plants growing in North America.