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Posts Tagged ‘Tree Identification’

I don’t know why I get an itch to start looking at buds at this time of year but I always have. Maybe it makes me think of spring. Buds do give clues that the ground has thawed by taking up water and swelling, and if you watch a bud every other day or so in spring you can see it happen. I usually watch lilac buds, but nothing says spring like the sugar maple buds (Acer saccharum) in the above photo. Sugar maples have large, pointed, very scaly terminal buds flanked by smaller lateral buds on either side. The lateral buds are usually smaller than the terminal bud. Sugar maple twigs and buds are brown rather than red like silver or red maples and the buds have several scales. Buds with many scales that overlap like shingles are called imbricate buds. A gummy resin fills the spaces between the scales and makes the bud waterproof. This is especially important in cold climates because water freezing inside the bud scales would destroy the bud.

For those who can’t see or don’t want to look at small buds like those on sugar maples fortunately there are big buds on plants like rhododendron. It also has imbricate buds that are large enough to see without magnification. Bud scales are modified leaves that cover and protect the bud through winter. Some buds can have several, some have two, some have just one scale called a cap, and some buds are naked, with none at all.

You can see the gummy resin that glues some bud scales together on this gray birch (Betula populifolia) bud. Ruffed grouse will eat both the buds and catkins and pine siskins and black-capped chickadees eat the seeds of gray birch. Yellow-bellied sapsuckers feed on the sap and I’ve seen beavers take an entire clump of gray birch overnight, so they must be really tasty. Deer also browse on the twigs in winter.

Some of the smallest buds I know belong to hawthorns (Crataegus) and the cherry red hawthorn bud in the above photo could easily hide behind a pea. There are over 220 species of hawthorn in North America, with at least one native to every state and Canadian province. In New Hampshire we have 17 species, so the chances of my identifying this example are slim to none. The closest I can come is Gray’s hawthorn (Crataegus flabellata.) I know the tree in the photo well so I know that its blossoms will be white. Hawthorn berries are called haws and are said to have medicinal value. Native Americans mixed the dried haws and other fruits with dried venison and fat to make pemmican.  The dried flowers, leaves, and haws can be used to make a tea to soothe sore throats, and hawthorn also shows promise for treating heart disease.

If you can’t identify a hawthorn by its buds then its thorns will help. On this example they were about 2 inches long and just as sharp as they look. Native Americans made fences around their settlements with brambles and thorny branches like those from hawthorns. They also made very sharp awls and fish hooks from hawthorn thorns.

The lilac buds (Syringa vulgaris) in the above photo are another good example of imbricate buds. Lilac buds are very red and in spring once the plant begins taking up water again they can swell quickly enough to notice, if they’re regularly watched. I’ve watched lilac buds in spring since I was just a small boy and it has always been one of my favorite things to do in the spring. They aren’t swelling yet but it won’t be long before spring is here.

Highbush blueberry (Vaccinium corymbosum) buds are also imbricate buds, and also very red. It’s interesting that almost everything about the blueberry is red except for its berry. The new twigs are red, the bud scales are red, and the fall foliage is very red.

A bud I most look forward to seeing open is the beech (Fagus grandifolia.) There are beautiful silvery downy edges on the new laves that only last for a day or two, so I watch beech trees closely starting in May. Botanically beech buds are described as “narrow conical, highly imbricate, and sharply pointed.” In May they are one of the most beautiful things in the forest.

Buds with just two (sometimes three) scales are called valvate. The scales meet but do not overlap. This Cornelian cherry bud is a great example of a valvate bud. In the spring when the plant begins to take up water through its roots the buds swell and the scales part to let the bud grow. Some bud scales are hairy and some are covered with sticky resin that further protects the bud. Cornelian cherry (Cornus mas) 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. It has a long history with mankind; its sour red fruit has been eaten for over 7000 years, and the Persians and ancient Romans knew it well.

Magnolia flower buds in botanical terms are “densely pubescent, single-scaled, terminal flower buds.” The hairy single scale is called a cap and it will fall off only when the bud inside has swollen to the point of blossoming.

Sycamore bud scales (Platanus occidentalis) are also made of a single brown cap which will fall off to reveal the bud only when the weather warms. When buds are covered by a single bud scale they are encircled completely by a bud scale scar when the scale falls off.

The mountain ash bud (Sorbus americana) in this photo looks like it has a single cap like bud scale but it actually has several overlapping scales which are quite sticky. It looks like a squirrel might have been nibbling at this one.

Red maple flower buds (Acer rubrum) are small and round or oval with short stalks and 4 pairs of bud scales. The bud scales are often purple and / or tomato red. They have a fine fringe of pale hairs on their margins. Red maples can be tapped and syrup made from their sap but the sap gatherers have to watch the trees carefully, because the sap can become bitter when the tree flowers. Seeing the hillsides awash in a red haze from hundreds of thousands of red maple flowers is a treat that I always look forward to. Unfortunately I’ve found that it’s almost impossible to capture that beauty with a camera.

Box elder buds (Acer negundo) and young twigs are often a beautiful blue or purple color due to their being pruinose. Pruinose means a surface is covered in white, powdery, waxy granules that reflect light in ways that often make the surface they are on appear blue. Certain grapes, plums, and blueberries are pruinose fruits. Certain lichens like the beautiful smoky eye boulder lichen have fruiting bodies (Apothecia) that are often pruinose.

Staghorn sumacs (Rhus typhina) have no bud scales at all, so their naked buds are hairy and the hairs protect the bud. Another name for staghorn sumac is velvet tree, and that’s exactly what its branches feel like. Native Americans made a drink from this tree’s berries that tasted just like lemonade, and grinding the berries produces a purple colored, lemon flavored spice.

Hobblebush (Viburnum lantanoides) is another native shrub with naked buds. This photo shows that the flower bud in the center and the surrounding leaf buds are clothed more in wool than hair, but there are no scales for protection. Still, they come through the coldest winters and still bloom beautifully each spring.

Sometimes there is no flower bud at the end of a hobblebush branch so the leaf buds are able to clasp tightly together, and they always remind me of praying hands. I’m not sure what caused the dark spots on these examples. It’s something I’ve never seen before.

The chubby little green and purple buds of red elderberry (Sambucus racemosa) are some of my favorites, but I don’t see them often. I find that being able to identify trees and shrubs when they don’t have leaves adds another layer to the enjoyment of nature study, and I hope readers will try to learn a few. If you are interested in studying tree and shrub buds, start with one in your own yard that you are sure of like a maple tree, and then branch out to those you don’t know well. The following information might be helpful:

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.
Caplike bud: A bud with a single scale that comes off in the spring.
Naked bud: A bud with no scales.

Winter is on my head, but eternal spring is in my heart. ~Victor Hugo

Thanks for stopping in.

 

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