In Holland between 1634 and 1637, tulip bulbs that produced flowers with irregular stripes, streaks, and feathery patterns cost thousands of dollars. But those who bought the tulip bulbs in this era of tulipomania were regularly disappointed. They discovered that the seeds of the bulbs didn’t produce tulips that were “broken,” as these bi-colored flowers were described. Moreover, each season, the bulbs’ flowers were fewer and weaker. Although the little bulbs that grew off the parent bulb (called offsets) produced broken flowers, the next-gen bulbs were always less productive than their parent.
It turned out that the source of the spectacular patterns was one of the dozen tulip viruses. Unfortunately, the virus weakened the plant, and ultimately the genetic line of a bulb would die out.
In the early 1980s, the Dutch government outlawed the sale of virus-infected tulips. But the flowers pictured here are not illegals. Today’s tulip breeders have manipulated the genetics of tulips to produce patterns, so you can buy bulbs that produce flowers that recall the seventeenth-century beauties, but will bloom exuberantly for many years.
My book group read Rebecca by Daphne du Maurier this month, and we were all surprised by the descriptions of deeply fragrant azaleas at Manderlay in Cornwall. Around Washington, DC, the azaleas we know, while beautiful, are unscented. Why?
Azaleas are members of the rhododendron genus, and are closely related to the woodland rhododendrons. Most azaleas with scent are deciduous, so they lose their leaves in the fall. Most unscented azaleas are evergreen. Around Washington, DC, azaleas are often used as foundation-hiding plantings, so the evergreen (and therefore unscented) varieties are more popular.
About 1900––a few decades before du Maurier wrote Rebecca––Lionel de Rothschild fell in love with deciduous azaleas and bred his own cultivars at his Exbury estate in Hampshire (not far from Cornwall.) Some of the “Exburys” are particularly fragrant, so the second Mrs. de Winter may well have been entranced by Exburys.
This year, we lost a number of backyard shrubs to a particularly cold winter. I’m looking at deciduous azaleas as replacements. Not only do they provide fragrance, their leaves turn shades of bright orange, yellow, and gold in the fall.
In my yard in suburban Maryland, hellebores are the first of the spring flowers. This year, despite the unusually cold weather, they were up as early as ever. Even so, I know they’ll be in bloom for weeks and even months. What makes them such persistent bloomers?
For one, their petals are not really petals. They’re colored sepals, the leaves that cover and protect a developing flower bud. Because sepals are tougher than petals, they last longer. After the flower has been fertilized, the sepals’ pigments decay and the green pigment, chlorophyll, becomes evident. The longer the green sepals persist, the bigger the plant’s seeds. That’s probably because the sepals are photosynthesizing, enabling the plant to gather more solar energy and make more carbohydrates.
So, where are the hellebore’s petals? They have evolved into the little green leaves you can see at the base of the many stamens. (There can be up to 150 per flower.) The little leaves are known as “honey leaves,” and are actually nectaries that lure insect pollinators. No same old, same old about hellebores.
One of the most interesting and easy plants for cold climate gardeners is the Coffea arabica. I’ve had a potted one for years. It lives in a shady spot in the backyard in summer. In the colder months, I move it indoors to an east-facing window. Last May, per usual, my tree (about five-feet tall because I prune it regularly) produced a crop of small, white flowers. Nine months later, I have very ripe coffee cherries. (You can see the remains of the flowers at the tips of the cherries.) Inside each cherry are two coffee beans, which are the seeds of the coffee plant.
I’ve never tried to roast the beans (too much trouble and a home oven isn’t great for roasting coffee), but yesterday I tested a cherry. There’s not much pulp on it, but what there is, is deliciously sweet. In countries where coffee is grown, sometimes the pulp is dried and used as a tea. The tea, called cascara, is rich in antioxidants. Now, a Hawaiian company called Kona Red is producing a coffee berry juice. Last week, Walmart began offering the juice in 2,100 of its stores. I may have a new use for my next crop!
Stems come in all shapes and sizes, and some of them are eminently edible. Take the potato, (which I can do only if I add lots of butter.) The potato is actually a “stem tuber,” a stem that stores energy in the form of carbohydrates.
Potatoes differ from “root tubers” such as carrots, radishes, and sweet potatoes. The “stem-ness” of the potato is evident when you look into its eyes. The eyes are actually axillary buds, just like you find on the nodes of above-ground stems. When the eyes grow out, they form shoots, which then branch and sprout leaves. Cut up a potato and plant pieces that have eyes, and each one can grow into a new potato plant. Root tubers, on the other hand, are for storing energy, and have no buds.
A potato plant also produces flowers that range from white to pink and red to blue and purple. Some varieties produce green fruits about an inch in diameter. The fruits are poisonous, which is not too surprising since the potato is a member of the Solanaceae family, which includes deadly nightshade, henbane, mandrake, and other toxic “witches’ weeds.”
Charles Darwin, stung by criticisms after he published On the Origin of Species in 1859 that he hadn’t provided sufficient evidence of his theory of evolution, turned to orchids for additional support. He accumulated dozens of species, some from from the countryside near his home southeast of London, others from wealthy friends who had hired collectors to find tropical ones. He demonstrated that every ridge and fold of the flowers, all their colors and scents, had been shaped by natural selection to lure a particular insect and get it to pick up pollen and drop it off in the next flower.
One friend gave him specimens of the star orchid of Madagascar, which has six-inch, white flowers, a spicy fragrance, and, at their base, a “green, whip-like nectary of astonishing length.” What insect, Darwin wondered, could reach down a curving, 12-inch nectary to sip the nectar? He predicted the pollinator would be a moth because moths forage at night, drawn by scent and not by color. And he predicted it would have a foot-long tongue. Rubbish, said entomologists of the time: The idea of such a moth was ridiculous.
But in 1903, twenty years after Darwin’s death, a Madagascan hawk moth with a 12-inch tongue was discovered. Its tongue is usually curled up in a tight coil, but when it finds its particular flower, liquid streams into the tongue’s interior, unwinding it like a party horn. The moth was named Xanthophan morganii praedicta.
Eva-Maria Ruhl created this beautiful painting of the moth and orchid for the jacket of A Garden of Marvels.
At the house we rented in Tortola in the Caribbean, there was a cashew tree in bloom and fruiting (see the photo). The tree made me wonder why, when I shop for nuts, I never see cashews in their shells. Peanuts, pistachios, walnuts, and almonds, yes. But cashews are always shelled.
What you see in the photo is a ripening cashew fruit. The larger structure on the bottom is the “drupe,” which contains a single seed––the cashew––surrounded by a double shell. The smaller structure on top is the cashew “apple.” The apple––which will develop to be much larger than the drupe––is pulpy and juicy, and in Latin America is made into a sweet/tart drink. The reason we never see cashews in shells is that the shells are toxic. The toxin is related to urushiol, the toxin in poison ivy.
I just returned from Tortola in the British Virgin Islands where this Norfolk Island Pine loomed over the house my family rented last week. The Norfolk Island Pine––its Latin name is Auracaria heterophylla–– isn’t actually a pine, but it is definitely a conifer. It seemed out of place among the yellow hibiscus, red bougainvillea, and purple jacaranda that blossomed nearby. In my experience, conifers live in northern latitudes. So what’s it doing there?
In fact, conifers evolved in the tropics about 248 million years ago, long before any beautiful bloomers lived. This means that dinosaurs plodded through warm forests of conifers. A few inconspicuous flowering plants evolved just before the dinosaurs disappeared around 65 million years ago. Once those first flowering plants (that is, angiosperms) gained a foothold, they rapidly diversified and multiplied, and out-competed the conifers. Their winning strategy? They had broad, sunlight-capturing leaves instead of narrow needles, and therefore grew faster than conifers, shading them out. In general, conifers survived only where angiosperms didn’t do well, in regions that are freeeze-prone and have poor soil. The Norfolk Island Pine and other Araucaria, like the monkey-puzzle tree, are survivors in a world they once dominated.
Garden centers and Big-Box stores are now filled with red, white, pink, salmon, burgundy, and even purple poinsettias. Whatever color you choose, you want your plant to last as long as possible. So how should you choose an individual specimen?
What look like the petals of a poinsettia flower are actually modified leaves called “bracts.” The real flowers are at the center of the bracts. They’re bright yellow, but so small most people don’t notice them. Choose a plant whose flowers are closed or show the least amount of yellow pollen. Here’s why: The poinsettia will drop its bracts soon after it sheds its pollen.
Another tip: Don’t let the plant sit in water. The foil wrapping around the pot may be pretty, but when you water the plant, excess water will pool in the foil. I take the foil off and put my poinsettia on a plastic saucer with a ridged bottom.
Tomorow, December 12, is National Poinsettia Day. It marks the death of Joel Roberts Poinsett in 1851. Poinsett, a physician, diplomat, and amateur botanist, was appointed the first ambassador to Mexico in 1825. While there, he came to admire Euphorbia pulcherrima (that is, “most beautiful Euphorbia”), a common, vine-like shrub that grows ten feet tall or more in the Mexican climate. He sent samples home, and the plant became known as the poinsettia. Not until Paul Ecke, a California grower, figured out in the 20th century how to make seedlings branch and flower prolifically did it become popular. Ecke Ranch still produces over half the poinsettias sold in the world.