A Buckeye which has just leafed out.
We have two species of dwarf buckeyes growing in our woods. The photographs in this post are all of the Painted Buckeye (Aesculus sylvatica), but for convenience I will just refer to this species as Buckeye. Buckeyes are the among the first plants to leaf out in the spring. The new leaves and flowers appear to grow very rapidly. This photograph shows the leaves and flower buds which have reached this stage in only a couple of days.
A Buckeye bud.
We need to investigate the Buckeye bud to look for an explanation for this seemingly very rapid growth of the new leaves and flowers. Pictured above is a Buckeye bud that has just started to expand prior to the appearance of new leaves and flowers.
A Buckeye bud with some bud scales removed.
If we remove some of the bud scales (modified leaves that protect the bud over the winter) we see that inside the bud a number of structures are already present. These can be recognized as leaves in miniature.
A Buckeye bud just beginning to open.
When the bud begins to open in the spring, these leaf precursors begin to expand and protrude from the bud. They also begin to change to a dark bronze tone.
Leaf and flower primordia from inside a Buckeye bud.
If the bud scales are removed at the stage shown in the previous photograph, the primordial leaves can be clearly seen. Buckeye has palmately compound leaves, and each leaf has five petals. The flower primordia appear as small spherical structures at the bottom of the structure.
Flower primordia in a Buckeye bud.
This photograph shows a closeup of the small spherical structures inside the bud that will develop into the flowers. The next step merely consists of expansion of the structures that were already present in the bud. In fact all the structures inside the bud were formed last summer as the bud developed. The leaves and flower buds are secure over the winter inside the bud. When spring arrives, the bud takes in water, expands, and forms the first set of leaves and flower buds. So what appears to be rapid growth is merely the expansion of preexisting structures in the bud.
Newly leafed out Buckeye with flowers.
In a very short time after the buds open, fully leafed out plants with open flowers are present.
Buckeyes in our woods..
Here are some fully developed flowers that developed from the small spherical structures seen inside the bud.
Buckeyes in our woods.
The woods understory is full of Buckeyes enjoying the sun before the other deciduous trees form leaves. They are able to do this thanks to the preformed leaves and flower primordia stored in the buds.