Posts Tagged ‘Tree Buds’

I’ve met people who thought that buds appeared in spring just before the leaves came out but no, buds actually form in late summer, when trees begin storing reserves to help them get through winter. The period is called lignification and it happens when trees stop their active growth cycle. One of the ways to identify trees and shrubs in winter is by their buds. The size and placement of buds as well as the number of bud scales (cataphylls) can all help with identification. Bud scales are modified leaves that cover and protect the bud through winter. Some buds can have several, some have two, some just one scale called a cap, and some buds have none at all. Buds that have several scales are called imbricate and have scales that overlap like shingles. I’m starting this post with some unusual trees that aren’t often seen in this area, and the bud shown above is a sweet gum bud. It is a good example of an imbricate bud. It is also a good example of a rarity here.

Sweet gum trees (Liquidambar styraciflua) are easily identified by their unusual seed pods, above, and by the large size of their buds, which can be green, red or orange. I’ve read that Native Americans used the hardened resin from these trees for chewing gum. The resin was also used in a tea to calm the nerves and, when powdered and mixed with shavings from the tree, was used as incense by the Maya. The resin is said to look like liquid amber, and that’s where the first part of the scientific name, Liquidambar comes from.

Another tree you’ll have a hard time finding in this area is the European copper beech (Fagus sylvatica purpurea.) I’ve looked at its buds before in March and maybe they were swelling up to prepare for bud break, but they seemed bigger than those on our native trees. This year in January they really don’t look much different than our native beech buds. Long and pointed, they are a different shape than the sweet gum bud we saw but are still imbricate buds because of their shingle like, overlapping bud scales. They’ll open with maroon foliage, which over time will become a beautiful bronze / purple.

I love the bark on this old beech tree. It reminded me of an elephant’s skin. This tree lives on the grounds of the local college and there is another in Dublin, but otherwise I don’t know of any other European beeches in this area.

Tibetan cherry (Prunus serrula Tibetica) is another tree you might have a hard time finding but if you had studied your buds, you would recognize these big, shiny red buds as more imbricate buds. A gummy resin often fills any spaces between the scales and makes the bud waterproof. If water ever reached the bud and froze it could kill or damage it, so nature found a way to prevent that from happening. The shape of many imbricate buds also ensures that water will run off, rather than stay on the bud. Bud scales also help prevent moisture loss. These buds are very pretty, in my opinion.

The bark of a Tibetan cherry is very interesting. It is also called the paper bark cherry because of the way its bark peels as it ages, much like a birch. It is used as an ornamental tree as much for its bark as for its flowers, which are similar in shape and size to other ornamental cherries. The mahogany bark has very long, closely spaced lenticels that give it an unusual appearance. Lenticels are corky pores that allow gases like oxygen to reach the living cells of the bark. Without enough oxygen bark can die, so it “breathes.”

The most unusual tree bud to appear in this post is that of the ginkgo, which I find at the local grocery store, of all places. The short shoots bear terminal buds that are small at less than an eighth of an inch, with room for just two overlapping scales. A bud with only two overlapping scales is called two ranked. You can see how the terminal bud and many leaf scars are crowded together. Ginkgo is considered a “fossil tree” that has been on earth for millions of years. It is also considered the oldest living seed plant. It is said to be capable of living several hundred years, and there are trees in China that are thought to be at least 400 years old.

Buds with two scales that meet but do not overlap are called valvate buds, and a good example of a valvate bud can be found on nannyberry shrubs (Viburnum lentago). Though the scales in the photo do happen to overlap somewhat normally they would not, so they are still considered valvate. Nannyberry is one of our few native viburnums with edible fruit. They can get quite tall, almost the size of a small tree. According to the book The Origins of English Words “nannyberry” is also called sheep berry and that name comes from its fruit, which is said to resemble sheep droppings. The nanny part of the name comes from the nanny goat. Squirrels and birds are said to eat the fruit but I see huge numbers of them still on the bushes well into winter.

Cornelian cherry buds (Cornus mas) are also good examples of valvate buds. In the spring when the plant begins to take up water through its roots the buds swell and the two scales part to let the bud grow. What confuses me about this shrub is how the two outer scales never seem to be completely closed. It doesn’t seem to matter though because they always flower beautifully. Some bud scales like these are hairy and some are covered with sticky resin that further protects the bud. Cornelian cherry is an ornamental flowering shrub related to dogwoods. It blooms in early spring (in March) with clusters of blossoms that have small, bright yellow bracts.

One bud scale covering a bud is called a cap, and magnolia bud scales are good examples of that. Magnolia flower buds are described as “densely pubescent, single-scaled, terminal flower buds” and that’s what we see here. The hairy single scale will fall off when the bud inside has swollen to the point of blossoming. Once the plant flowers the ground under it will be littered with these hairy caps for a short time, so if you’d like to see one up close that’s the time to look.

I was lucky to find a seed pod on the magnolia that I looked at but unfortunately it was quite dry. I’d like to find a fresh one because I’ve read that they’re full of bright red seeds. I’ll look for one this spring to show you.

Big, black and pointed mountain ash buds (Sorbus americana) fooled me into thinking they had a single cap like bud scale at first, but they actually have several overlapping scales which are quite sticky. I finally got a photo that shows this. You have to look closely at buds to see what is really going on, so it helps to have a loupe or a macro lens.

The terminal buds on a Colorado blue spruce (Picea pungens) are oval shaped and imbricate with many bud scales. Sometimes the scales pull back from the bud (reflex) as these did, creating what look like tiny green flowers. In a way they remind me of the male flowers on a haircap moss, but of course they’re much bigger.

Here is a look at the side of the bud in the previous photo. Evergreen buds can be very sticky, but I’ve noticed that much more sap or resin flow occurs on warm days. On a cold day in January these buds were hardly sticky at all. You can also see the rows of whiteish breathing pores (stomata) on some of the needles in this shot. Carbon dioxide, oxygen, and water vapor enter and exit the tree through these tiny openings. There are many millions of them on a single tree.

If you see that some of the branches on your Colorado blue spruce are a bit deformed like those seen in the above photo your tree has the Eastern spruce gall adelgid living on it. They cause crab claw like galls but don’t do any real harm to the tree. I’ve had them on a tree in my yard for years now and it is still as healthy as the day I planted it. By the way, a blue spruce can be green.

If I had to choose a favorite tree bud the flower buds of the red maple (Acer rubrum) would have to be at the top of the list. They’re very beautiful but more than that, they are one of my first signals that spring has finally come. It doesn’t matter what the calendar says, when I see red maple flowers, I know winter is over. Of course sometimes they get a little over anxious and will get frost bitten, but more often than not they’re a reliable indicator. Each small flower bud has four pairs of bud scales.

Sugar maple terminal buds (Acer saccharum) appear on the end or terminus of a branch. The larger, pointed, very scaly bud is flanked by lateral buds on either side. The lateral buds are usually smaller than the terminal bud and the twigs and buds are brown rather than red like silver or red maples. These buds have imbricate bud scales and they show the whitish, sticky resin that “glues” one scale to another.

Norway maple (Acer platanoides) buds are also imbricate but instead of sticky resin on the edges of its bud scales they have a fringe of fine hairs which help shed water. These buds are relatively large and easy to study using a hand lens, so they’re perfect for children in the field.

Buds that have no bud scales but are very hairy like those seen on witch hazel (Hamamelis virginiana,) are called naked buds. The hairs take the place of bud scales when it comes to protecting the bud and it works well. Other naked buds are found on staghorn sumacs (Rhus typhina) and the native viburnum called hobblebush (Viburnum lantanoides).

Witch hazel flower buds are also very hairy, but rounder than its leaf buds. It won’t be long before the yellow or orange strap like flower petals appear on the spring witch hazels. It’s something I’m impatiently looking forward to.

I know that not everyone gets as excited over buds as I do but I also know that there are children who read these posts so I often have them in mind when I do a post like this one. I hope something like a post on buds might help jump start a child’s interest in nature. They aren’t that complicated and hopefully bud scale terminology won’t seem too intimidating.

If you are interested in learning about tree and shrub buds, start with one in your own yard that you are sure of, like a maple tree or even your rhododendron, and then branch out to those you don’t know well. The following information might help to get you started:

A bud scale is made up of modified leaves or stipules that cover and protect the bud in winter. Usually the number of bud scales surrounding a bud will help identify a tree or shrub.

Imbricate bud: A bud with numerous scales that overlap each other like shingles.

Valvate bud: A bud with two or three scales that do not overlap.

Two Ranked Bud: A bud with two scales that do overlap.

Caplike bud: A bud with a single scale that comes off in the spring.

Naked bud: A bud with no scales.

If you find that you have the itch to learn even more about buds and trees, this little book is for you. I’ve had my copy since I was a teen but it’s still in print. It is very helpful and easy to understand.

Must we always teach our children with books? Let them look at the stars and the mountains above. Let them look at the waters and the trees and flowers on Earth. Then they will begin to think, and to think is the beginning of a real education.  ~David Polis

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1. Horse Chestnut Bud Break

Leaf and flower buds can look very different when they first open compared to when they’re fully grown. The colors alone can make them quite beautiful but sometimes there are other surprises. For instance, when the leaves on this horse chestnut (Aesculus hippocastanum) unfurled they revealed the flower bud that they had been protecting. It was as big as my thumb.

2. Beech Buds Breaking

Bud break is defined as “when the green tip of a leaf can be seen emerging from the bud,” but there is often far more to it than that. These beech buds turned a beautiful orangey color and the tension brought on by some cells growing faster than others caused them to curl. Any time now the leaves will begin to unfurl completely and they will look like downy, silvery angel wings for just a very short time.

3. Horsetail

Technically not a bud break but interesting nonetheless, the fertile spore bearing stem of a common horsetail (Equisetum arvense) ends in a light brown, cone shaped structure called a strobilus. Since it doesn’t photosynthesize at this point in its development the plant has no need for chlorophyll, so most of it is a pale, whitish color. When it’s ready to release its spores the cone opens to reveal tiny, mushroom shaped sporangiophores. The whitish “ruffles” at the base of each brown sporangiophore are the spore producing sporangia. When the horsetail looks like the one in the photo it has released its spores and will soon die and be replaced by an infertile stem. Nature can seem very complicated at times but it always comes down to one simple thing: continuation of the species.

4. Bitternut Hickory Buds aka Carya cordiformis

I was walking along an old rail bed and spotted an unbelievable shade of yellow. The strange color belonged to the buds of a bitternut hickory tree (Carya cordiformis), which is something I’ve never seen before. When I see something like this I wonder what the tree gains from having buds this color. It’s possible that it has something to do with keeping animals from browsing on the new shoots, but I don’t know that for sure.  It is said that the nuts from this tree are so bitter that even squirrels won’t eat them, so maybe the buds are too.

5. Box Elder Bud Break

The female flowers of box elder (Acer negundo) have bright green, hairy pistils with sticky stigmas that split in two. The winged seeds that appear after the flowers hang in clusters and will stay on the tree throughout winter, sometimes into spring. Some trees flower before growing leaves and some grow their leaves first and then flower. Box elders fall somewhere in between, with both flowers and leaves on the tree at the same time.

6. Japanese Knotweed

Japanese knotweed (Fallopia japonica) is a hated plant because of its invasive qualities but in spring it can be very beautiful as it unravels itself from the bud. I’ve heard that these new shoots taste much like rhubarb. Maybe if we stopped fighting it and started eating it we could lick the problem of its being so invasive. Last spring we had a hard, late frost and Japanese knotweed shoots were killed to the ground, but within 3 weeks they had come right back and grew as if it had never happened.

7. New Ginger Leaves

Our native wild ginger (Asarum canadense) takes its time opening its new leaves. I’ve been watching these plants for close to three weeks now, since they first came up, and this photo shows the progress they’ve made in that time. I wonder if the small brown flowers will take as long to appear as the leaves take to unfold.

8. White Baneberry Buds

The opening buds of baneberry always remind me of a hand and it isn’t hard to imagine webbed fingers clawing their way out of the soil. Here they grasp the flower bud which will soon become a globular mass of tiny white flowers. The plant shown here is white baneberry (Actaea pachypoda), also called doll’s eyes, and by the end of summer its flowers will have become porcelain white berries with single black dots on their ends. These berries are beautiful and especially attractive to children, but are also very toxic. Fortunately their bitter taste keeps most children from being poisoned by them.

9. Sweetfern Catkins

Sweetfern (Comptonia peregrina) sometimes hangs onto its old leaves even as it is making mew ones. In this photo last year’s leaves wrap around this year’s male catkins. I always run my hands over the leaves to release the fragrance that it is named for. Some compare it to soap, others to spices or fresh mown hay. It is a very unusual scent that smells clean and a bit spicy to me. Though its leaves resemble fern leaves it is really a deciduous shrub. Crushing a few leaves and rubbing them over your skin will keep mosquitoes and other bugs away.

10. Sweet Fern Female Flower

Further down the stem of the sweet fern not only are new leaves breaking, but the tiny scarlet female flower is waiting for the wind to bring pollen from male catkins. You can just make it out on the left, beside where the new leaves are forming. I think it is even smaller than the female flower of American hazelnut (Corylus Americana,) which means that it’s too small for these aging eyes to see. Getting a photo of it was simple luck.

11. Skunk Cabbage

Some of the biggest buds I know of are those of skunk cabbage (Symplocarpus foetidus.) As the leaves begin to unfurl they do look a bit like cabbage leaves but if you tried cooking them their odor would soon let you know that you weren’t dealing with cabbage! In this photo not only can you see the new leaves but the spathe and even the flower covered spadix in the broken spathe to the right of center. It’s the first time I’ve been able to get all of the different parts of a skunk cabbage plant in one photo.

 12. Sugar Maple Leaf Bud aka Acer saccharum

The late afternoon sun was doing some strange things to the veins on this emerging sugar maple leaf (Acer saccharum). I don’t think I’ve ever seen a new leave’s veins stand out from the body of the leaf in this way. I thought it was a beautiful sight but was surprised that a deer hadn’t eaten it.

When man gives his whole heart to Nature and has no cares outside, it is surprising how observant he becomes, and how curious he is to know the cause of things. ~William Davies

Happy mother’s day tomorrow to all of the moms out there. Thanks for coming by.





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