Fresh, Green, and Wintry

When I was a child hiking in the woods with my mother, she snapped off a twig of a cherry (or black) birch (Betula lenta), put it in her mouth and said, “Hmm, wintergreen.” I don’t actually remember where or when this happened, or even whether it was actually my mother who did it (although it was the sort of thing she would have learned at camp), but nonetheless I learned it, and eventually learned that yellow birch (B. alleghaniensis) twigs have the same flavor.

Gaultheria procumbens
Gaultheria procumbens

I was probably not until I was in college that I actually saw true wintergreen (Gaultheria procumbens), a small plant of the forest floor. Gaultheria is a calcifuge, that is it dislikes alkaline settings and is found in acidic soils, often beneath oaks. It is only 3 to 5 inches tall and spreads locally via rhizomes. Individual plants spring up from the rhizomes to bear three shiny dark green leaves and creamy “urn-shaped” flowers. The latter show are common among the ericads (Ericaceae or heath family). The leaves are evergreen, which most certainly accounts for its common name. The fruits are bright red and stay attached to the plant through the winter.

The odor that has become known as “wintergreen” is caused by a chemical called methyl salicylate. It is related to acetyl salicylate, more commonly known as aspirin. Both chemicals have analgesic properties in small doses, but are fatal if taken in larger doses. While 10 g of aspirin can kill an adult, it takes only 7 grams of wintergreen to do so. Wintergreen’s medicinal uses are largely, as with acetyl salicylate, to do with pain relief. It is, for example, an ingredient in Bengay.

Clark's teaberry gum is wintergreen flavored
Clark’s teaberry gum is wintergreen flavored

But wintergreen is probably more popularly known as a flavoring. It is used in toothpastes and chewing gums, in ice creams and candies. When mixed with sugar and dried it can build up an electric charge, which is released in the form of a spark when it is crushed. It is not an urban myth that sparks are visible when wintergreen Lifesavers are crushed in the dark.

In the past wintergreen oil was commercially produced by steam distillation of macerated leaves of G. procumbens. When the ericad proved difficult to procure in large amounts, birch twigs were also used. Yet another group of plants, the meadowsweets (Spiraea spp.) also harbor methyl salicylate and have been used as a source. If you simply sniff G. procumbens leaves, they don’t have a strong wintergreen odor. The odor (caused by the aromatic ring in methyl salicylate) is released through enzymatic action on a chemical called gaultherin. The leaves are fermented before being distilled in order to maximize the amount of methyl salicylate in the oil; it is as much as 99 percent of the oil.

Modern manufacturing now creates wintergreen oil esterifying salicylic acid and methanol. But it is still produced from botanical sources for the essential oil market.

Chopped yellow birch twigs
Chopped yellow birch twigs

The birches are a more abundant source of wintergreen. B. lenta is not a large tree, but it is still a tree rather than a creeping herbaceous ground cover, and it is often a very common member of the mid canopy of the eastern deciduous forest. It is a smaller member of the northern hardwood community. B. alleghaniensis is a larger tree (and also part of the northern hardwood community) and generally not as common or widespread as B. lenta.

I learned to call B. lenta “cherry birch” first because of its resemblance to the Prunus species like black or choke cherry. When these trees are young their bark is smooth and dark, broken up by horizontal ellipses (lenticels). Their leaves are all oval and toothed. Other names for B. lenta include black birch, sweet birch, or spice birch. In addition to being the commercial source for wintergreen before the chemists took over, B. lenta also produces a sweet sap that can be cooked down like maple sap to produce a molasses-like syrup, although it takes three times as much sap compared to a maple.

The sap can also be distilled to make a birch oil, which is the flavoring for birch beer, a carbonated beverage that was once popular and can still be found in the rural areas of the northeastern U.S. and eastern Canada.

 

Small But Mighty Oak

Bald on Breakneck Mountain
Bald on Breakneck Mountain

The scrub or bear oak (Quercus ilicifolia) will forever be associated in my mind with the Hudson Highlands, specifically the peaks of the Hudson Highlands. These are small mountains, most of them 1,000 to 1,500 feet above sea level (although it must be said that because the Hudson River is at sea level, you see the entire mountain, as it were). Nonetheless, many of them are topped by “balds,” expanses of bare metamorphic rock that sometimes cover half an acre or more. The edges of these balds are inevitably ringed by thickets of scrub oak.

Scrub oak is so called because it rarely reaches heights greater than 15 feet. Its other name “bear oak” reputed refers to the fact that only bears eat its bitter acorns. (This is not actually so, as deer and turkeys also feed on the acorns.) Finally, its trivial name ilicifolia means “holly-leaved.” Indeed, like all oak leaves Q. ilicifolia leaves have a waxy coating that makes them resemble hollies. In addition the general shape, only faintly lobate and with the ends of the lobes tipped with small bristles, it recalls Ilex as well.

Quercus ilicifolia
Quercus ilicifolia

The scrub oak is associated with areas that have been burnt. It is one of the first woody trees to colonize such places. I suspect that the balds on top of the Highlands were caused by fires. That is definitely the case on Mount Desert Island in Maine, where a famous fire of the late 1940s burnt thousands of acres, denuding the mountain tops, which were then quickly eroded down to bare rock. Scrub oak is found there too.

I have delightful memories of approaching the summits of various Highland mountains and knowing that we were near the top because we began to encounter the scrub oak, which is found nowhere else in the forest. On warm sunny days you would inevitably hear a lot of slithering, thumping, and thrashing of dry leaves as the myriad snakes that had been sunning themselves in the branches of the oaks dropped to the ground and headed for cover. If you moved quickly, you could see the last of them making for the undersides of the ledges. If you moved especially quietly you could also manage to come up on a few snakes still draped in the branches.

The scrub oak is gnarled in its habit, its branches twisted in spaces as if it had grown around something complex that had since disappeared. The bark is gray and eventually furrowed or platy like the larger oak species. The leaves are dark green above and light green below. In its cragginess and muted coloration it seems suited to the marginal habitats where it tends to be found.

Scrub oak
Scrub oak

In addition to mountain tops, it is also found on pine barrens, where fires are frequent, and scrublands along the coast and on coastal islands, where the stresses include wind and salt, as well as fire. Scrub oaks have very deep taproots, so they survive fire not be failing to burn (like sequoias), but through their ability to regenerate a new canopy from their roots.

In areas where fires are less frequent or conditions are less marginal, scrub oak is an early successional plant and is eventually overtopped by pines and taller oaks. But the trees growing at the tops of the Hudson Highlands have likely been there for decades; they are growing right at the edge of bare rock and it will take some time before enough soil builds up to allow anything else to take hold. The geological record of the Highlands is full of charcoal that denotes repeated fires, with peaks of oak pollen directly above them. Historically fires were started by lightning and by the tribal people.  And fires are still common in the areas today.

Food and Medicine That Tastes of Lemon

Anybody who likes Thai cuisine likes lemon grass, as it is present in half the menu items of most restaurants from the soups and appetizers straight through the entrées. Many vernacular names are misleading, but lemon grass actually is a grass and it does smell and taste like lemons.

Lemon grass
Lemon grass

The genus Cymbopogon is distributed from southern Asia and its adjacent islands over into Africa. The source of most culinary lemongrass is C. citratus, which is grown in Southeast and South Asia (but is native to southern India and Sri Lanka). It is hardy and evergreen in USDA Zones 10 and 11, but the roots may survive and re-sprout to Zone 8. It is a clump grass and grows to be between 2 and 4 feet tall.

As a kitchen item it can be purchased both fresh and in powdered form. The fresh plants resemble scallions and are used in much the same way. If the plants are fresh enough, you can even put them in a vase and get them to root and then start your own patch of lemongrass. It prefers full sun. It is not only useful for culinary purposes, but it also quite attractive as an ornamental planting.

Citral, an essential oil, gives lemon grass its lemony scent and taste. It is a mixture of two terpenoids (geranial and neral) and has strong antimicrobial qualities and pheromonal effects in insects (it seems to attract bees, but repel other insects). These qualities give not only culinary but also medicinal purposes.

Cymbopogon nardus or citronella grass is grown as a source for citronella oil, which is used in soaps, candles, and insect-repellent sprays. It is thought to be native to Indonesia, but is grown widely in tropical Asia. It is used as a companion plant to tomatoes and broccoli because it wards of insects. It spreads vegetatively by its roots though, and can take over a garden unless confined in some way.

Lemon grass leaves and oil are both used as medicine for a variety of complaints, including anything to do with the digestive tract, aching joints, and headaches. None of these have been verified scientifically.

Lemon grass bulbs
Lemon grass bulbs

In addition to being used as a spice, lemon grass is also used to make tea in many cultures (Asian and in the tropical New World). While this tea is purported to be medicinal (e.g. reduces anxiety), that has not be verified.

But most people will be interested in growing it for use in the kitchen, and that is (if various websites can be believed) not that difficult. Not surprisingly, a plant that contains an oil that repels insects is not bothered by many pests, but it can succumb to spider mites when it is being kept indoors over the winter. The latter strategy is necessary in any area that experiences a frost. In a colder climate you can bring the plants indoors in the winter, trim them down to just a few inches tall, put them in small pots and stick them in a sunny window, keeping them barely moist to slow their growth.

Potted lemon grass
Potted lemon grass

In the warmer months you can put them in large (>12-inch diameter) pots or tubs. They can be harvested as soon as they get to be 12 inches tall. You can separate the plants you want from a clump, making sure to get the entire bulb at the bottom and even a few roots.

The heart of the bulb has the consistency of butter. This is the most flavorful part and is the best for cooking. (The leaves and the rest of the plant can be used to make teas and to flavor soups and stews.) You can mince or purée the inner part of the stalk base and freeze it, breaking off small pieces as needed.

Mary’s Gold

When I was a kid we planted a lot of marigolds in our vegetable garden. The smell of the plants was so strong that it was easy to believe that they would keep away insect pests and nematodes. The marigolds were acting as a companion plant to members of the Solanaceae—tomato, eggplant, potato—tobacco, and chile peppers. Something that I didn’t hear as a kid was that they should not be planted next to legumes, as their roots secrete thiophenes, which kills the nitrogen-fixing bacteria in the legume roots.

Calendula officinalis
Calendula officinalis

More recently I have been told that marigold is important in herbal medicine, mostly applied topically to reduce inflammation brought on by various causes, include radiation therapy for breast cancer. But this marigold is a different one from the one that is so useful in gardens. The important herbal marigold is Calendula, particularly C. officionalis, while the insect repeller is Tagetes, often T. patula (“French” marigolds) in our garden.

The name “marigold” is applied to many members of the Asteraceae—the genera Calendula and Tagetes are both members of this family—but it is also applied as a vernacular name to plants like the marsh marigold, which is a member of the Ranunculaceae (buttercup) family (but has flowers that resemble those of T. tenufolia). This vernacular name is an elision of “Mary’s gold,” with Mary of course referring to the Virgin Mary. The original connection to the mother of God is not recorded, but the name appears to date from the 12th century, when it was applied to Calendula, which is native to the Mediterranean region of Europe.

Tagetes patula "Bonanza Yellow"
Tagetes patula “Bonanza Yellow”

Both Calendula and Tagetes, many species of which are native to Central and South America, are annuals. At least the most frequently cultivated and hybridized species are annuals; perennial species exist and are gaining popularity of late in horticultural circles. While perennials tend to bloom during a short period of time each year, annuals tend to have a much longer flowering period. In the climate of western Europe Calendula flowers almost year round and therefore manages to be in bloom for nearly every festival to the Virgin Mary from the Feast of the Annunciation in February, when the last blossoms of the previous year cling to old plants in southern Europe, to the Immaculate Conception in December. This is also has the genus got its Latin name; it is in flower on nearly every calends (first day of the month) through the year.

C. officinalis is a typical looking aster with small disc flowers at the center of the blossom and prominent oval ray flowers radiating out from the central disc. This arrangement and the golden color of the petals evoked the common depiction of the Virgin Mary, with golden rays of light streaming out from her head.

It is perhaps not coincidental that this was a plant already prominent in herb lore because of its ability to speed the healing of wounds and reduce skin inflammations. This would appear to be part of a wider phenomenon of pagan culture being incorporated into the Christian tradition as the latter displaced the former in peasant culture throughout Europe during the Middle Ages.

Tagetes essential oil from T. minuta
Tagetes essential oil from T. minuta

The marigold flowers are pulverized and suspended in oils and made into a tincture and applied directly to the skin to treat wounds and rashes. This application is somewhat accepted by Western medicine, but taking C. officinalis internally to easy stomach cramps and constipation is greeted less enthusiastically but not entirely dismissed. The important ingredient would appear to be flavonoids, which are present in high concentration in Calendula. These anti-oxidants are known to protect the body from unstable molecules (free radicals), viruses, and bacteria.

Tagetes have oil glands in the leaves and the plants have a strong odor. The main components of this oil are limonene, ocimene, tagetone, and valeric acid. In addition to its use as a companion plant, Tagetes species are also used in herbal medicine as as an antibiotic, antimicrobial, anti-parasitic, antiseptic, anti-spasmodic, disinfectant, insecticide, and sedative substance. All parts of the plant are steam distilled to yield an essential oil called “tagetes oil.”

Not a Rose and by Another Name

For some reason I don’t like the shrub that we call the “rose of Sharon.” It is planted widely because it flowers now, when most other flowering shrubs are finished blooming, and it is also quite hardy and requires little care. It also flowers abundantly for several weeks. When you look more closely at a bush in bloom you can easily spot the numerous buds in various stages of opening.

Hibiscus blossom (Photo: Eric Kounce)
Hibiscus blossom (Photo: Eric Kounce)

There is something dumpy and middle-aged looking about a rose of Sharon shrub. The leaves are coarsely toothed and their surfaces are often disfigured by infestations. The bark is gray and rumpled looking. The flowers have papery petals that are ridged like a crinoline dressed. The sexual organs of the plant are prominent, protruding well beyond the rim of the tubular corolla with the stamens protruding along the final eighth of the organ and the pistils clustered at the distal end.

Having declared my mild dislike of the plant, I would say that this means I wouldn’t plant one in my yard. However, as I find myself moving into a house with a seven-foot specimen in the side yard, my first impulse was to help it recover some dignity. It seems to have been simply let to grow without any pruning to speak of. This is, of course, fine if what want is a shrub that is there to fill some space and brighten up your side yard in mid summer.

Usual full habit of rose of Sharon
Usual full habit of rose of Sharon

But the very bushiness of this specimen gives it a sort of dowager appearance that I think a few carefully selected limb removals might improve. I would like to give the bush some shape. This is to some extent aesthetic, but also is a practical matter: it is right in front of you went you open the gate to get into the back yard. It has gotten large enough so that you essentially make a trip around the shrub to get into yard. I find this irritating.

After consulting some sites online I found that they advise you to prune a rose of Sharon in the late winter or early spring because it flowers on the current year’s growth, so you want to get to it before it starts growing. But because this is a shaping operation and not an attempt to get more flowers out of it, I think I will have at it sometime in August.

We had one on our property when I was growing up and it was in full sun, which is what all references say they prefer. In fact, they are prone to disease if they are grown in too shaded a location. My childhood rose of Sharon was multi-trunks and its stems grew almost straight up, radiating slightly with height, giving the overall appearance a stiff vase like appearance.

The one in my new yard is not in full sun and has a more compact appearance and the stems are more meandering and gnarled. I confess that I prefer it to the more usual habit. I may get to like this particular specimen, which is one of the white flowered variety with a red band at the proximal end of each petal, making a red ring at the base of the corolla.

This would appear to be the wild type, which originally comes from Korea and China, in spite of the name Linnaeus gave it: Hibiscus syriaca. Many cultivars exist, most of them in shades of red, pink, and purple, but some pure white.

Pancratium maritimum, a candidate for the Biblical "rose of Sharon" (Photo: Zvika-Eigenes Werk)
Pancratium maritimum, a candidate for the Biblical “rose of Sharon” (Photo: Zvika-Eigenes Werk)

Botanically, it is unrelated to the Rose of Sharon of the Bible, which has not been identified with certainty, but was apparently some sort of crocus, tulip or lily (something that came up from a bulb) and grew on the Plain of Sharon along the Mediterranean coast of Israel.

H. syriaca is only called rose of Sharon in the United States. In the United Kingdom it is referred to as the rose mallow. It is all very vague as to why Jesus is identified with the rose of Sharon mentioned in the Song of Solomon. The reference in the song is to a bride and Jesus is often referred to as the bridegroom of the Church.

How H. syriaca, came to connected to this particular rose is unknown. That a hibiscus would be called a rose is less odd. Any attractive flower is often called a rose, as for some reason they are regarded as the perfect flower.

She’s As Sweet as Basswood Honey …

I think of them as “basswoods” if they are the American species and “lindens” if they are the European, but they are actually called “lime trees” more often in the United Kingdom, although they are quite unrelated to the citrus tree. They are in the genus Tilia and they were grouped into the Tiliaceae by Cronquist, the taxonomy I learned in grad school. But apparently molecular data has shown that they are in the Malvaceae or mallows, which includes cotton, okra and hibiscus, which are not exactly towering deciduous trees like the basswoods/lindens/limes.

Basswood leaves with bracts and fruit
Basswood leaves with bracts and fruit

Given all these different names for the same trees, always wondered about the etymology and finally decided to look it up. The “bass” in the American name is a corruption of bast, which sturdy fibers that run through the phloem cells along the inner bark of these trees. It was traditionally used as a fiber for weaving by various North American tribes as well as for thread to sew canoes together. You have to soak the bark for a month in an alkaline solution to get the bast to separate from the phloem and xylem. Linen, derived from flax plants, is another type of bast fibre.

Linden and lime turn out to be derived from a common root in the Old English linde, which means pliable, and also gives rise to the word lithe. Linden was originally an adjective form, like oaken, which is to say it described something that was made from the wood of the tree. (The citrus tree is native to the Middle East and the name was originally lim in Arabic.)

Teilhard de Chardin
Teilhard de Chardin

The name of the genus is simply the Latin name for the tree. In some old Protestant Bibles the species is referred to a teil or til tree, but this was largely abandoned in favor the the Anglo-Saxon-derived linde. Although not perhaps before it gave rise to the name “Teilhard.” Historically one of the uses of linden wood was to make shields, so this is perhaps an example of synecdoche producing a given name. A warrior could have been called “hard shield” (Teilhard) or “good helmet” (Wilhelm) because that was their attribute that contributed most significantly to the common good.

These trees are common in the forests of northern Europe and eastern United States, so they have been long harvested and put to a variety of uses. The wood is very light-colored—in some species it is almost white—and appears to almost lack grain. This attribute, along with the fact that it is relatively easily worked, made a block of it a common starting point for sculpture. It is not particularly strong, so when it is milled, it is often then put to use for temporary purposes, like crates and other packaging.

Basswood honey
Basswood honey

It has a significant use while it is still standing and producing flowers: it is a preferred source of monofloral honey. The flowers themselves are showy, either white or creamy and hanging in loose cymes from a flat finger-shaped bract. The flowers are perfect (contain both male and female organs) and in T. americana they appear a couple of weeks after leaf-out, which works out to be early June here in central New York.  T. chordata (small-leaved linden), a European species, is widely planted as a street tree in the United States. There are four of them in front of the building where I worked. They were flowering as recently as last week. The dried petals are still there, but small berries are forming all over the trees.

The honey is noted for its pale color and strong flavor. This is a distinct departure from the usual correlation of darker color with strong flavor in honey varieties (i.e. buckwheat honey). The aroma is said to recall balsam, camphor, or menthol and the flavor as a bite to it.

Really, Really Old

In my other blog (flowertropes.com) I just wrote about the tallest tree (coast redwood) and the largest tree (giant sequoia), both of which live on the west-facing slopes of the California Coast Range and the Sierra Nevada, respectively. The oldest living trees live on the east side of the Sierra Nevada and in subalpine environments scattered across the Great Basin of Nevada into Utah and down into Arizona and New Mexico.

Great Basin bristlecone pines
Great Basin bristlecone pines

The bristlecone pine is the common name applied to three species of coniferPinus longaevaP. aristata, and P. balfouriana. They aren’t particularly common, but their timberline populations seem to be growing in response to warmer conditions there, where they are sometimes the only tree species present because of the challenges presented by the environment. In other altitudes and other parts of their range, their inherently low reproduction rate has caused a steady erosion of their numbers.

P. longaeva (Great Basin bristlecone) shows a distinct preference for carbonate soils, derived from limestone, marble, but especially dolomite. The latter are rich in calcium and magnesium, but poor in phosphorus. This limits the growth of many plants, which reduces competition for the pines, allowing them to form groves. When these groves are just below the treeline additional challenges are presented, including low temperatures, low rainfall, and high winds. Consequently the trees grow very, very slowly in these conditions.

The wood of these pines is very resinous and their slow growth makes it very dense. This combination makes the wood resistant to insects, fungi, and other pathogens, as well as the physical elements.

Edmund Schulman
Edmund Schulman

The above factors conspire to cause the bristlecone pine to live for thousands of years. The oldest known living specimen is over 5,000 years old, which makes it as old as the pyramids at Giza. This tree is growing in the White Mountains of California and its location is kept secret. It was discovered in the 1950s by Edmund Schulman, a pioneer in the study of these trees, but its age was not determined until 2012, when it was found to be 5,060 years old.

This is not the “Methuselah” tree that was the oldest known living bristlecone until 2012. That tree was also discovered by Schulman and was dated 4,789 years old in the late 1950s. It is now 4,847 years old and reportedly quite healthy and still growing.

A tree in Wheeler Peak, Nevada was cut down in order to determine its age. This story is found in numerous places on the Internet. There is a lengthy version of it here. In 1964 a geography student doing research on the glacial history of the Great Basin. He and a partner were coring bristlecone pines on Wheeler Peak to determine their ages and found that several were over 4,000 years old. Toward the end of their field season, their coring tool broke and they asked the U.S. Forest Service for permission to cut down a tree in order to count the rings.

Through the 1950s a group of conservationists had been attempting establish a Great Basin national park in order to protect the trees. Various other land-use interests conspired against the establishment of the park, but in the process of traveling regularly to Wheeler Peak, the conservationists had given names to individual trees. The one that was cut down was called “Prometheus,” and it had proved to be 4,862 years old. It became a cause celebre and helped bring further protection to the trees. The national park was eventually established in 1986.

Bristlecone pine cones; note bristles at the tips of the scales.
Bristlecone pine cones; note bristles at the tips of the scales.

Because of its dense resinous nature and the aridity of its habitat, the wood of the bristlecone pine doesn’t decompose when it dies and falls to the ground. Dead trees can also remain standing for centuries. Dendrochronologists, scientists who determine the age of trees, decades ago noticed that tree rings include patterns of thinner and thicker bands that correspond with variations in the regional climate. (Bristlecone pines seems to respond to variations in temperature more than rainfall.) Using statistical analysis these shared patterns can be matched from tree to tree.

The overlaps between tree-ring patterns of living and dead bristlecone pines have been found and then overlaps have been found in the tree-ring patterns of older dead pines. In this way a composite record has been extended back nearly 9,000 years.

Geochemists have sampled the carbon in these rings (which can be dated to an exact year simply by counting) to determine their carbon-14 content. In this way it has been found that the ratio of carbon-14 to carbon-12 has fluctuated over the millennia. The carbon-14 record in the composite tree-ring record has allowed geochronologists to “correct” the radiometric age dates determined from carbon-14, making the method more accurate.

The Primitive Flower

My grandfather—my father’s father—was a mechanical engineer and he would have very much liked one of his grandsons to have followed in his footsteps (as neither of us sons had), so he tended to give my brother and me books on science. Time Life had a Nature series and a Science series. We got the complete Science series from our grandfather in a custom-made wooden case. The Nature series on the other hand, we got, I think, from our mother’s mother, and I don’t think we ever had the complete set. Both my brother and I, however, spent a lot more time going through the Nature books than the Science books, and neither of us became engineers.

Rudolph Zallinger's mural. Note the magnolia at left.
Rudolph Zallinger’s mural. Note the magnolia at left.

They reproduced images of dinosaurs in one of the Time Life nature volumes. Like most kids, my brother and I were crazy about dinosaurs, memorizing their names, drawing them, playing with plastic ones, and arguing over which dinosaur could beat up which. The images in the Time Life book were taken from Rudolph Zallingers “Age of Reptiles” mural, which is still on display at the Yale Peabody Museum of Natural History. One startling detail has stuck with me through all these years: the appearance of a magnolia tree right next to the Tyrannosaurus rex in the Cretaceous Period portion of the mural. All the other plants were (at the time) unfamiliar to me, but there were plenty of magnolias on Long Island.

The "cone-like" fruit of the magnolia.
The “cone-like” fruit of the magnolia.

When I took plant systematics as a graduate student we learned the structure of flowers in great detail, as they are vital to classifying plants. Magnolias have very primitive flowers, with parts that are less differentiated from the leaves they evolved from than one finds in more derived flowers. What appear to be petals on a magnolia are in fact “tepals“; they have not differentiated into petals and sepals. In addition, the cone-shaped fruit develops from a receptacle at the center of the flower marked by a spiral arrangement of stamens and carpels. The flowers are also perfect; they retain male and female organs. According to Cronquist’s Evolution and Classification of Flowering Plants (1988), the textbook that I used in grad school, the Magnoliidae subclass includes the most primitive living families: the water-lily family (Nymphaeaceae), buttercup family (Ranunculaceae) and magnolia family (Magnoliaceae).

Hence Zallinger’s inclusion of the magnolia tree in his dinosaur mural. The basal position of magnolias among the flowering plants, i.e. the angiosperms, was originally due to the arrangement of the carpels into a cone-like structure that resembled gymnosperm cones (i.e. pines). But it has since been shown that they are not actually homologous structures.

Magnolia grandiflora of the southeastern U.S.
Magnolia grandiflora of the southeastern U.S.

The ancient pedigree of the magnolia is also attested to by the fact that it is beetle-pollinated, rather than bee-pollinated, presumably because bees evolved after magnolias did. As bees gather pollen from flowers, the latter must have evolved before the former. Early flowering plants, then, had to be pollinated by either the wind or animals other than bees.

The genus Magnolia has only been found in fossil form back to 20 million years ago, the Miocene Epoch, well after the dinosaurs went extinct. But fossils of extinct members of the Magnoliaceae family has been found in rocks 95 million years old, or the early part of the Late Cretaceous Period. While fossils have been found in North America, Europe, and Asia, there are no modern magnolia species in Europe or the western part of Asia. Today native species are found only in southern China and in the southeast United States.

Spruce Down, Fir Up

A lot of people refer to all evergreens as “pine trees,” but as you go further north this is less and less likely to be so. In North America pines (Pinus) dominate the evergreen forests of southeastern United States on the Piedmont and in the coastal lowlands. In the mountains and further north the spruces (Picea) and the firs (Abies) are much more common with the boreal forests (taiga) consisting largely of these two genera, especially in the eastern half of North America. (All three genera are part of the pine family Pinaceae.)

Norway spruce
Norway spruce

Spruces and firs are readily distinguished from each other when they have cones, as spruce cones (like those of pines) hang below the branches, while fir cones stand erect above the branches like candles. Whereas pine and spruce cone scales open to release their seeds at maturity, fir cones disintegrate to release seeds. Trees may not produce cones for the first 15 or 20 years of their lives, sometimes longer.

In eastern North America there are only two species of fir: balsam fir (A. balsami) and Fraser fir (A. fraseri). The latter is present only in disjunct populations at high altitude in the southern Appalachians. In the same region there are three species of spruces: red (P. rubens), black (P. mariana), and white (P. glauca). The red spruce is the most widespread in the east (ranging furthest south), while the black spruce ranges further north. The white spruce is more widely distributed in the West compared to the other two species.

Balsam fir
Balsam fir

These taxa are all monoecious: they have both male and female cones on the same trees. The male cones release pollen in the late spring and it is borne on the wind to female cones. After fertilization the cones mature through the summer and are ready to release seed in late September or October.

All these firs and spruces (except the black spruce) are grown for use as Christmas trees and their boughs are also cut for making Christmas wreaths and other holiday decorations.

You can tell the difference between spruces and first by rolling the needles in your hand. Spruce needles are round and fir needles are flattened. They are arranged differently on the branches too. Picea needles are attached to branches in a spiral pattern all the way around, while Abies needles are attached similarly, but the needles themselves twist at the bases to produce two double-ranked rows of needles on either side of a branch. Furthermore, while spruce needles appear attached to small pegs emerging from the branches, the point of attachment for fir needles is flattened or even depressed.

The ecology of these trees is similar: they require shorter, relatively cool summers and cold winters. As a result they often grow together to create a boreal forest. Of the five, P. mariana can tolerate the wettest habitat and is often found in and near bogs, where the soil is saturated and low in free oxygen. P. rubens and A. balsami are the next most tolerant of moisture, growing right down to sea level in Maine and the Canadian Maritime provinces, where their branches can be hung with bearded moss (Usnea spp.), a form of lichen.

Fir needle attachment
Fir needle attachment

As lumber pine, spruce, and fir are often treated indistinguishably as SPF. None of them tolerate moisture or insect infestation well, so they can only be used for indoor purposes. Balsam fir is regarded as the least advisable to use as lumber, and it is most often used to make pulp and as the layering for plywood. The “fir” that is regarded as superior to spruce or pine for decking is Douglas fir (Pseudotsuga), which grows in western forests and is one of the more important lumber-producing trees in North America.

In contrast to fir (Abies), spruce is a valuable timber tree. In addition to being used for framing lumber and pulp wood, sruce is often used for instrument making, particularly the sounding boards of stringed instruments. When it is used for this purpose it must be from very old, slow-growing trees (very tight grained) and it is referred to as “tonewood.”

The Winter Bloomer

If you live down south, the camellias flower through the winter. The American Camellia Society has nine acres of plantings at Massee Lane Gardens in Fort Valley, Georgia (south of Macon). The society was founded in 1945 and is “dedicated to fostering appreciation for and knowledge of plants of the genus Camellia.” The genus is a member of the family Theaceae, which rather gives away the inclusion of the plant from which we make tea, Camellia sinensis. But more people likely know the genus as a source of thousands of cultivars grown as ornamental plants.

Camellia japonica, Pink Perfection variety
Camellia japonica, Pink Perfection variety

In the United States the camellia is most popular in the South because most varieties are only hardy north to USDA Zone 7, which extends north into Virginia, although a few can tolerate Zone 6 (southern Pennsylvania). They can be planted as far south as Zone 10. Most cultivated varieties come from the wild species C. japonica and C. sasanqua, but others, like C. reticulata and C. higo, have also been used as starting points.

There are perhaps 250 wild species in a range extending from the Himalayas east to Japan and Indonesia. But camellias are so strongly associated with the American South that it is the state flower of Alabama. They were, however, brought to this country in 1797 and grown in greenhouses in New England.

As an ornamental shrub it is apparently relatively easy to grow. Most varieties are between 6 and 15 tall with either a rounded or pyramidal shape (or resembling a small tree). The evergreen leaves are usually a glossy, making the plant attractive even without blossoms on it. The flowers look like roses, and like roses the wild types have a single ring of petals, but the cultivated types are often doubled. Many species and varieties have prominent yellow stamens.

Yellow camellia
Yellow camellia

The color of most varieties—again like roses—ranges from white through a spectrum of pinks into red. Yellow-flowered camellias grow in south China and Vietnam and this color has been added to some cultivars. Some varieties have “variegated” petals, meaning they are streaked with more than one color.

The plants grow about a foot every year, which is regarded as slow-growing. For this reason, many of them are potted.

The cultivars derived from C. japonica bloom in the winter and the early spring, while those derived from C. sasanqua flower in the fall. The sasanqua varieties—which have darker leaves and smaller blooms—are hardier and tolerate drought and full sun more than the japonica varieties. Gardeners like to plant shrubs derived from both species in order to get a long period of bloom in their gardens. All camellias like well-drained, acidic (pH 6.0 to 6.5) soils.

<span styThey are shallow rooted, so although they prefer dappled light and can be planted under trees, they shouldn’t be placed under shallow-rooted trees like maples and birches

Camellia sasanqua hedge
Camellia sasanqua hedge

They don’t need a lot of pruning. C. japonica varieties should be pruned after they bloom in the spring, and C. sasanqua need to be pruned very early in the spring before the flower buds form. Removing some of the buds will encourage the remaining ones to produce larger, showier flowers.

C. japonica cultivars are most often used as specimen plants, while C. sasanqua varieties can be turned into hedges or topiaries and espaliated. The sasanqua types can tolerate pruning from a young age, but other varieties should be allowed to reach the height and shape that is desired or maturity (which ever comes first) before being pruned.

Very few diseases affect camellias, but they are host plants to many plant pathogens, so they are often grown separated from other species in nurseries.

When the flowers finish blooming, the calyx (the ring of sepals) falls with the corolla (petals), which is unusual. The Chinese have decided that the corolla symbolizes the spirit of a woman and the calyx that of a man (protecting the petals by surrounding them at the base). The fact that they fall together is considered a symbol of undying love.