Wednesday, November 26, 2008

Camellia japonica

Despite the fact that it is *far* too cold for late November, plants are still managing to bloom.

Here's a Camellia japonica at the BBG, blooming in the Japanese garden:

Thank goodness for winter-blooming plants! Happy Thanksgiving!

Tuesday, November 25, 2008

Nandina domestica

Nandina domestica, unfortunately, has gorgeous fall color this time of year:

I say it's unfortunate because in the past ten years or so it's become apparent that this plant is fairly invasive in the southeast US. I suppose it is not a total surprise, as this plant is in the Berberidaceae family, which also includes Berberis thunbergii, the Japanese barberry, which is also highly invasive.

When I teach students about invasive plants like barberry and nandina, I try to instill some sense of responsibility in them. While I personally am not outraged by the use of these plants in intensely urban conditions (where they will have a very hard time finding nearby woods to invade), one should seriously consider alternatives when they live in suburban or rural areas, as no doubt such species will misplace the native herbaceous and shrub layer of forests and meadows.

The plant above is growing in my parents place in Virginia. They have a wooded lot, so while we haven't removed it, we do check out the woods and remove any would-be conquerers.

Many feel that native plants should be exclusively used in order to prevent invasion of plants like nandina and barberry into nearby natural habitats. It's an ongoing debate. While I avoid using invasive plants, I don't eschew all exotic species, though some may consider it more politically correct.

I've begun reading the Robert Sullivan book, Rats: Observations on the History and Habitat of the City's Most Unwanted Inhabitants. Coincidentally enough, last night I read an interesting description of the native/non-native debate in a footnote I've copied below. It doesn't address the subtle, vital difference between non-native and invasive, but it did include some new information:
The term native when used in regards to plants and animals can be complicated. In an essay entitled "The Mania for Native Plants in Nazi Germany," published in a collection called Concrete Jungle, Joachim Wolschke-Bulmahn, the director of Studies in Landscape Architecture at Dumbarton Oaks, in Washington , D.C., says, "The missionary zeal with which so-called foreign plants are condemned as aggressive is significant. Such characterizations do not contribute to a rational discussion about the future development of our natural and cultural environment, but possibly promote xenophobia." Wolschke-Bulmahn points out that some plants that are considered "native" to the United States may have been carried over from Siberia by people migrating to American over a land bridge, and he writes of an early proponent of native plants, Jens Jensen, a landscape architect who lived in Wisconsin who advocated the destruction of "foreign" plants, especially "Latin" or "Oriental" plants. Jensen had close ties to Nazi landscape architects in Germany. In a journal, Jensen wrote: "The gardens I have created myself...shall express a spirit of American and therefore shall be free of foreign character as far as possible." In 1938, Rudolph Borchardt, a Jewish writer persecuted by the Nazis, wrote this of native plant advocates like Jensen: "If this kind of garden-owning barbarian became the rule, then neither a gillyflower nor a rosemary, neither a peach-tree nor a myrtle sapling nor a tea-rose would ever have crossed the Alps. Gardens connect people, time and latitudes...The garden of humanity is a huge democracy. It is not the only democracy which such clumsy advocates threaten to dehumanize."
The book, by the way, is a terrific read, not only full of fascinating, at times squeamish, information about rats but also about New York City history. It reads very easily, too.

Monday, November 24, 2008

Wollemia nobilis

A week ago yesterday, I was on the train coming from Brooklyn to Manhattan. A seasoned New Yorker, I can tune out my neighbors on the train with ease. But when one of the people to my left said "botany" I immediately began to pay attention. He was talking about the academic landscape of plant sciences to a man and a woman, who I later learned, were his daughter and grandson.

I had to interrupt. It turns out that the man speaking was a plant scientist, working at the herbarium of the University of Florida. He had taken his family to the Brooklyn Botanic Garden to see Wollemia nobilis, or the Wollemia pine, discovered for the first time in 1994.

was found in the Wollemi National Park, 200 km away from Sydney. That's just over 100 miles. 100 miles from a major city, and yet, this plant was growing unnamed, unidentified by all. That's kinda amazing these days. It was discovered by a park officer named David Noble (thus nobilis for a species name).

The specimen at the BBG was petite, to say the least. The largest ones found in the Wollemi Park reached 130 feet. The plant is unique in that the flattened leaves can grow off the stem in two ranks, as well as four ranks.

Wollemia is in the Araucariaceae family, and perhaps it's most recognizable relative in this climate would be the monkey puzzle tree, or Araucaria araucana, which is native to Chile and Argentina.

Araucaria araucana in the Jardin du Plantes, Paris.

Scientists have compared the pollen of Wollemia to fossils of pollen, and Wollemia's pollen more closely resembles the fossil pollen than any living genus in this plant family. Wollemia has other characteristics that make it closely resemble plants from the Cretaceous era, meaning this species has most likely survived for over 90 million years.

I think this whole story is incredible. On the one hand, you have a plant growing in a fairly well-tread area and yet it wasn't discovered until 1994. On the other, you have an individual who saw this tree and knew his plants well enough to realize this was something different. The comprehensive knowledge one must have to spot a new species is impressive. Finally, it's simply exciting to know that we haven't seen it all yet. Not nearly, one hopes.

Wednesday, November 19, 2008

Student Post, English Oak

This post is by Ngoc Ngo, who is also an accomplished photographer:

The English countryside is full of magnificent trees, and the English Oak , Quercus robur, is among the most majestic. Known to grow from the Urals and the Caucasus, from Mount Taurus and Mount Atlas, almost to the Arctic Circle, it is a tree full of historical and mythological associations. In ancient times, massive oak forests covered most of central Europe, and oak was the favorite timber of the Greeks and Romans. Being particularly prone to lightning strikes, the oak tree was associated with the supreme gods in many ancient cultures, including Zeus, Jupiter, and Thor. Ancient kings wore crowns of oak leaves to symbolize their roles as representatives of gods on earth. In ancient Rome, it was also the custom for commanders to wear crowns of oak leaves during their victory parades.

Historically, the English valued the oak for its strength and durability, which made excellent timber for building ships and churches. Much of Tudor architecture was built with oak. Because of their size and longevity, oak trees were often planted as boundary markers. Prominent oak trees were also used as the locations for the reading of the Gospel during ceremonies, leading to their being known as Gospel Oaks. The high tannin content of the oak bark was found to be useful for tanning leather during the Industrial Revolution. Other common uses for the bark included making brown ink and a tonic for treating harness sores on horses.

The cultural significance of oak trees in England is summed up by the historian Simon Schama; “Ancient Britons were thought to have worshipped them; righteous outlaws are sheltered by them; kings on the run hide in them; hearts of oak go to sea and win empires.” The oak is a symbol of strength, refuge, longevity and resilience. Robin Hood was reputed to hide in the hollow of an oak tree. King Charles the Second also found refuge in another hollow ancient oak tree near Boscobel on September 6, 1651 before successfully reclaiming his crown. The accommodating tree became known as the Royal Oak, and today there are countless pubs in England with the same name.

Botanically, Quercus robur is in the Fagaceae family. Its common name is English Oak, or Pedunculate Oak. Its size can reach 75 to 100 feet in height and width. Its leaves are alternate, simple, obovate to obovate-oblong, 2 to 5” long, with rounded lobes, rounded apex and auriculate to rounded base. The earlobe-like (auriculate) leaf base is a distinguishing feature from the otherwise similarly shaped Q. alba leaf. There are 3 to 7 pairs of veins on the leaf, which is dark green above and pale blue-green underneath. The bark is deeply furrowed and grayish black in color. Q. robur is monoecious, and the flowers appear 7-14 days after the leaves burst. Fertilized flowers develop into acorns of about 1” long, narrow elongated conical, enclosed by a cap. The acorns ripen in the autumn and fall on the ground before the leaves drop.

The Greek botanical writer Theophrastus, writing around 300 BC noted: “The oak bears more things beside its fruit than any other tree.” The complex ecosystem of an oak tree provides the habitat for at least 350 varieties of insect, more organisms than any other trees. The insects in turn attract birds. Caterpillars and moths also feed on oak leaves. In southern England, the oak trees also host colonies of the rare Purple Emperor Butterfly in the summer months. In the autumn, the acorns that fall to the ground provide an important food source for wood pigeons, rooks, squirrels, and mice, all of which in turn attract birds of prey, such as sparrow hawks and owls.

The life expectancy of an oak averages from 200 to 400 years; however, there are specimens aged over 800 years. The oldest oak in England is thought to be the Bowthorpe Oak in Bourne, which is estimated to be over 1,000 years old. My favorite is this beautiful specimen in the countryside of Sussex, south of London. The tree stands alone in an open field dissected by a public footpath. I have spent many wonderful hours walking along this footpath, and I am always happy to see the sight of this magnificent tree, a symbol of strength and a source of so much life.

Tuesday, November 18, 2008

Student Post, Cherrylaurel

We are just past the peak of autumn and most of the trees are bare. While there's no shortage of material to post about, this seems to be a good time to post some more blog entries from my students. First off, the cherrylaurel, by Pat Miller:

In Washington, DC it is de rigor for visitors to swoon over the famous Yoshino Cherries with their magnificent scent and flowers. Oh how they remind us of the chiffon dresses popular in the 1960’s. But on this trip, I was distracted by a plant I’d never seen before. Its leaves, a perfect shade of dark green, appear to stand smartly at attention guarding Jefferson’s Memorial while making a hedged path that frames the monument. The hedge is perfectly formal, yet surprisingly natural. And it perfectly complements the magnificent cherries.

Speaking of perfection, I found out the Landscape Designer’s name. It is Arthur Edwin Bye and he was my new hero, but the green-leafed beauty remained a mystery. Some 12 years after this journey to Washington, I am working at a nursery in Connecticut surrounded by trucks and workmen. It is early May and the men start to unload various shrubs from Hines Nursery. And there they were again; still green, still dazzling and standing at attention. B&B in all their glory with hundreds of fluffy white flowers. The plant looked fabulous to me and I couldn’t wait to bring one home.

Now my love can be properly identified: Prunus Lauroserasus, and this particular cultivar is ”Otto Luyken”. From that day forward I never stopped planting “Cherry Laurels’ in my clients’ gardens even though (it seems it was a lot colder back then) I was told they were not really “Winter Hardy” in Fairfield County.

Fast forward to Jen’s first class meeting at Bryant Park. It’s Fashion Week in the City and, wait, isn’t that Lindsey Lohan walking right through he Park!

Speaking of celebs, our first plant of the day is a “Cherry Laurel” all perky and bright resting underneath the canopy of a Dogwood. I toned down my excitement in front of my classmates but I could hardly control myself. There were some “Shot Holes “ in the leaves, which I’ll get to later, but they were nearly perfect specimens in a really low-light environment.

The great thing about “Laurels” besides the great leaves, great color and great habit is they can be planted in the sun or the shade, at least that’s been my experience. I now have 31 plants on my property and have planted dozens on others so I think I know what I’m talking about. In the US, the shrub is referred to as a “Cherry Laurel”, “Skip Laurel” or sometimes “English Laurel.” But in England, not surprisingly, they refer to it as Cherry Laurels.

Prunus laurocerasus , Rosaceae family.

“Otto Luykens” (Cherry Laurel) is named after the director of the “Hesse Tree Nurseries” (Baumschulen Hesse) in Weener (a town in Lower Saxony, Germany close to the Netherlands. His nursery bred the cherry laurel variety beginning in 1940 and introduced it to the trade in 1953. Royal Horticultural Society Award of Merit in 1968, Award of Garden Merit in 1984.

“Schipkaensis” (Skip Laurel) Selected in 1889 from Schipka Pass at 4,000’ near Kasanlik, Bulgaria by Spath of Berlin. Royal Horticultural Society Award of Merit in 1959.
They are indigenous to South Eastern Europe and Asia Minor. For more than 400 years they have been grown as hedges and ornamental garden shrubs in Europe.

“Otto Luyken “ has a compact habit and matures to 4’ high by 6’ wide but can be easily maintained and pruned to 3’ high by 4’ wide. The 4” long and 1” wide leaves are a very shiny dark green (holly –like in color). The plants are covered with fuzzy-feathery billowy fragrant creamy white flowers that appear heaviest during May on upright 2” to 5” spikes (racemes). A “raceme” is an inflorescence with stalked flowers, which radiate off a single unbranched stem. The individual flowers are cup shaped with 5 petals and are almost a half-inch across. The fruits are 1/2 in (1.3 cm) cherry like drupes (stone fruits) that ripen to dark purple. (Floridata) Some people like the fragrance and others find it offensive. It is a matter of opinion whether or not the flowers have a powerful fragrance or a rather offensive odor. Many people feel it smells sweetly of honey and Dirr calls it “sickeningly fragrant” To be honest; I’ve never even noticed a smell one way or another.

“Schipkaensis” is the more upright cultivar and has the same basic characteristics as the “Otto Luyken”. This shrub can reach 10’ high and 4’ to 5’ wide. I have seen it planted as an individual plant but it ‘s much more suitable as a hedge for screening. It’s a really nice alternative to arborvitae in many landscapes. Both cultivars are fast growing. The USDA hardiness zones vary from source to source but for the most part it averages between Zones 5-8, Skip is said to be the hardiest variety and is said to grow as far north as Chicago. I have experienced some winter sunburn (leaves turn brown) particularly when I have planted them on a north/west side of a house and an unprotected area. If I have any doubts about the location I usually spray them with an anti-desiccant (wilt-pruf) for the first year or two and then after they are established I leave them alone. I have even planted them near the coast and they seem to tolerate the salt sprays and all the wind that goes along with living by the sea.

Many sources list these shrubs for deer damage but my own personal experience (and I Bambi’s extended family was tripping through my yard for years) shows that they don’t bother with it because they can be toxic. Along with their great use as a hedge plant, I like to use them to cover a foundation Otto is an expellant plant for shady borders and mass plantings. Makes a great plant near homes, walkways and roads, as the roots will not damage foundations.
Laurels are susceptible to something called” Shot-hole” (as if someone shot a hole at the leaf). It is usually caused by the bacterium Pseudomonas syringae pv. mors-prunorum, which also causes bacterial canker. The disease is usually worst at the garden centers and nurseries due to the watering practices-overheard sprinklers. Once they are planted they usually do much better. Most of the sources say to avoid overhead irrigation and make sure you remove and distroy the fallen leaves. If you want to be really smart about it buy clean plants to begin with. I have seen plants covered with Shot hole after a long wet summer and it usually goes away, especially after a dry, cold winter. Identical symptoms can be caused by a minor fungal pathogen known as Stigmina carpophila. In general, they can deal with difficult growing conditions. They need to have moisture but do develop problems when they are in a wet environment (Dirr says they are prone to root rot in places with inadequate drainage) and I have found them to be drought tolerant once they are established in the garden.

It appears that the deer stay away for good reason. …….Water distilled from the leaves is used as almond flavoring and in perfumery. All parts of the plant contain hydrogen cyanide, a poison that gives almonds their characteristic flavor. This toxin is found mainly in the leaves and seed and is readily detected by its bitter taste. It is usually present in too small a quantity to do any harm but any very bitter seed or fruit should not be eaten. In small quantities it can stimulate respiration and improve digestion. I read that Cherry Laurel water has been used in Paris fraudulently to imitate the cordial, Kirsch. I bet that gets your heart racing
Unfortunately, there are those people who don’t share my opinion of the Laurel.
They refer to this wonderful shrub as “unsexy” and say it doesn’t scream, “buy me” at the nursery but I just shrug and comfort myself in the thought that if it was good enough for a guy with the stature of AE Bye it’s good enough for me.

The images accompanying this post came from plantings in my own yard and my favorite nursery where I bought and planted them successfully for twenty years.

Monday, November 17, 2008

Edible Plants

A few weeks ago, I went on an 'edible plants' tour of the west side of Central Park, led by an ethnobotanist. I was familiar with some of the edibles, but these two were very pleasant surprises:

Chenopodium album, or lamb's quarters, or fat hen. This is a common weed and you can encounter it not just in the park, but growing out of tree pits on the sidewalk (not that I'd recommend you sample that particular specimen). The leaves were mildly bitter, like a mellow arugula. Really tasty.

Below is the flower bud of Commelina communis, or day-flower. The buds tasted very much like sugar-snap peas, though they were much smaller. This weed is also quite common and is easy to recognize due when you realize it's related to Tradescantia, a genus that includes the perennial spiderwort (T. virginiana) and the houseplant commonly referred to as wandering Jew (Tradescantia zebrina).

Like those other plants, Commelina will grow in sprawling heaps, the weight of the foliage too heavy to be supported by the fleshy stems. When the plant sends out a new branch, it looks distinctly like an elbow, with a knobby leaf indicating the point where the stem sends out new growth.

Thursday, November 13, 2008

An "other stuff" item

This is just so weird. So crazy, I had to post it.

It's funny, in an alternate-reality kinda way. I would pay good money to meet someone who even remotely takes the content of this magazine spread seriously.

Of course, I am a little embarrassed that once again, Lindsay Lohan is featured on this blog!

Tuesday, November 11, 2008

Daylength & Fall Color

I am a little bit fascinated by the circadian rhythms of plants, so I can't help but share a photo of these dreaded Bradford pears growing in southern New Jersey.

Check it out:

So, on one side you have a row of trees that are still fairly green. On the other side of the street, the trees are at their fall color peak. If you think about it, it makes perfect sense: The trees that are further along in their procession to dormancy (the red ones) are on the south side of the street. They sit just north of the adjacent townhome, which reduces the amount of daylight they receive. The trees on the left have slightly more day-length and thus won't turn color at the same time as their neighbors.

This was such a great illustration of how day-length influences fall color that I had to use it, even if it was the lousy pear tree.

Friday, November 7, 2008

Ginkgo biloba

This woman has hit the motherload as far as harvesting Ginkgo biloba fruit goes. These large specimens were indeed female and had a substantial, smelly bounty.

New Yorkers may not know this tree, nor know that there are female and male specimens, but they have probably smelled the ginkgo before. The smell is most aptly described as similar to vomit or dog waste, or a mix of the both. That doesn't prevent people like the woman in the photo - protected with latex gloves - from collecting the fruit. Ginkgo biloba is traditionally used by Asian cultures for tea and, of course, is a popular herbal remedy (promoting brain power) at the drugstore.

Now is as good a time as any to note that calling this a fruit is in fact a misnomer - ginkgoes are gymnosperms, which means that they are not flowering plants. Despite the fact they are broadleaved deciduous plants, they have more in common with a pine or a spruce than an oak or maple. Technically the woman in the first photo is collecting 'naked seeds.' Gymnosperms are more primitive plants than angiosperms (flowering plants) and the ginkgo's evolutionary history dates back over 150 million years. It is a living fossil.

Despite its homeopathic applications, female ginkgo trees are not commonly planted - 'never plant a female ginkgo' could be considered the horticultural equivalent of 'don't spit in the wind' - and they are on the Parks Department's list of noxious plants. Instead, the male plants are used, as the tree is nonetheless beautiful and, for the same reason that it has survived for so many millions of years, is very tolerant to urban conditions like pollution, compaction and drought.

Thursday, November 6, 2008

Mystery Aesculus

I was in Central Park last weekend when I stumbled along this species of Aesculus. I was quite taken with it -- the golden foliage was brilliant and it had a regular, columnar form.

It's not a horsechestnut (Aesculus hippocastanum) and certainly not A. parviflora or A. pavia. From anything I read about A. flava and A. x carnea, it seems the bark is too smooth. I am completely baffled. It could perhaps be A. chinensis or A. indica, though they both seem to be fairly rare, and the description doesn't seem to quite fit. This tree was like a buckeye on the trunk of a tuliptree...

Does anyone know what this is? Please, please tell me!

If not, I suppose I will have to wait until spring and see if the flowers give us any better clues!

Wednesday, November 5, 2008

Witch Hazel Fall Color

This fall color was too pretty to ignore -- it's Hamamelis x intermedia, or witch hazel. I've posted photos of this plant blooming in the gray winter, but the oranges and yellows that you can get in autumn is an equally good reason to use this plant. Our native witch hazel, Hamamelis vernalis is also a popular plant, but it has a more consistently yellow fall color.

The word Hamamelis is Greek and is a reference to a plant that flowers and fruits at the same time. -Melis is derivative of the Greek word for apple (similar to Malus, the actual genus for apple and melon). The common name is due to the fact that divining rods were historically made from this plant.

Tuesday, November 4, 2008

Black Tupelo

Like any single woman in Manhattan, I have been looking for a great specimen of black tupelo, or Blackgum, or Nyssa sylvatica for years and years.

Finally, last Saturday, I stumbled across it in Central Park's Ramble.

Black Tupelo is identifiable by its simple leaves with entire margins. The branches protrude from the trunk at 90 degree angles when the tree is young, but as it gets older, it has a pendulous and sprawling habit.

Another way to spot it -- if you aren't sure you're looking at blackgum, is to check out the telltale three dots above the bud scar.

Black Tupelo is a favorite tree of mine -- and I am not alone in my unconditional adoration. Dirr raves about this tree and its ability to exhibit the most brilliant and consistent fall color.

Really: what a beauty, eh?

Nyssa is rarely seen in parks or sidewalks as it's not the most low-maintenance tree. It has a tap root so it doesn't like to be transplanted at larger sizes and prefers well-drained soils. And more so, I think it would be all wrong in such a location -- its allure is partly due to the way it can stop you in your tracks in a natural location. And it certainly needs some room so it can stretch out enough to really show off.

Nyssa sylvatica literally means 'water nymph of the forest.' Nyssa is Greek for 'water nymph'; sylvatica means 'of the forest.' The word 'tupelo' is derivative of the native American term, ito opilwa, which means 'swamp tree.'

Now then: go out and vote!!