bbc national geographic journey to forever Charles Darwin had no explanation, calling it an “abominable mystery”. But now scientists think they have solved the riddle of how flowers came to dominate the conifers and ferns that preceded them. The flowers’ secret, they say, was to exploit a change in soil fertility, and create a feedback loop that allowed new flowers to feed off dead ones. The relative explosion of flowering plants greatly worried Darwin. In a letter written on 8 March 1875 to palaeobotanist Oswald Heer, he said: “The sudden appearance of so many Dycotyledons in the Upper Chalk appears to me In a later letter to botanist Joseph Hooker, head of the Royal Botanic Gardens at Kew, Darwin described it as an “abominable mystery”. The great problem for Darwin and others at that time was that the Late Cretaceous was very rich in fossil angiosperm (flowering plant) species, while the Early Cretaceous was almost devoid of any early examples. This rapid bloom in flowering plant species did not fit Darwin’s belief that evolution was an extremely gradual process. Since then, many more fossils of flowering species have been discovered, showing that they emerged over a longer period. Today scientists believe that at the start of the Cretaceous Period, 125 million years ago, gymnosperms, the group of plants that contains cycads and conifers, dominated the globe. Just a few groups of angiosperms had evolved, and these were rather small fragile plants that probably grew in aquatic environments, or alongside streams.Some are also thought to have colonised extremely dry, possibly salty places, since they had quite thick leaves which would have helped conserve water. But then, between 125 and 65 million years ago, these flowering plants exploded into life. For example, around 105 million years ago between five and 20% of all plant species were angiosperms. By 65 million years ago, over 80% were flowering plants. “The change from a gymnosperm- and fern-dominated world to a world dominated by fast-growing angiosperms is one of the most important changes in the history of the biosphere of our Earth, with enormous consequences for the opportunities of mammals,” says Frank Berendse, an ecologist at Wageningen University in The Netherlands. “Although the change in diversity occurred much more gradually than thought at Darwin’s time, the change in abundance occurred very fast,” Berendse says. Berendse and Wageningen University colleague Marten Scheffer now think they can explain how it happened.They outline their idea in the journal Ecology Letters. Initially, gymnosperms flourished in poor soils. Such plants have longer-lived leaves which are capable of squeezing more nutrients out of the ground, but the litter they create tends not to decompose very fast. So while gymnosperms benefit from poor soils, they also do little to improve soil quality. But then came some subtle changes in soil fertility. Angiosperms started colonising more fertile soils, gaining a foothold. These early flowering plants then began changing the ecology of the soil. As they perished, they create a greater turnover in litter that replenished the soil, allowing yet more flowers to grow. “From that time a positive feedback developed, where an increase in angiosperm dominance led to an increase in soil fertility and an increase in soil fertility led to a further accelerated expansion of the angiosperms,” says Berendse. The idea that such sudden shifts in vegetation can occur is supported by evidence from the modern day. Over the past 30 years, heathlands in western Europe have gone from being dominated by dwarf shrubs to perennial grasses, the researchers say.Like gymnosperms, the shrubs have long-lived leaves and stems which minimise the loss of nutrients but prevent the plants growing fast. But once the grasses took hold, their faster growth rates created a feedback loop which added more nutrients to the soil, allowing yet more grass to grow. A similar shift has also taken place in raised bogs, in which peat mosses can quickly be out-competed by vascular plants, say the researchers. Berendse’s and Scheffer’s idea remains a hypothesis for now. But it is one that “could explain the very fast expansion of angiosperms around the globe,” says Berendse. They hope to test the idea further by examining the geological record for tell-tale signs that soil fertility did increase during the rise of the angiosperms, and that flowering plants initially came to dominate at lower latitudes, which should have had more nutrient-rich soils. a most perplexing phenomenon to all who believe in any form of evolution.” From the moment the first tulip was planted in Dutch soil, in 1593, the Netherlands has been in extravagant bloom and the Dutch have been in thrall to flowers, inventing a whole horticultural industry and turning their lowland fields into a blanket of blooms. The flowers reach their climax, of course, in April and May, when Holland offers Europe’s quintessential spring drive. For anyone who wants to see nature in all its glory and smell the roses—or in this case the tulips, hyacinths, narcissi, and daffodils—western Holland is the prime place to be. And the Dutch, as practical as they are aesthetic, have made certain that visitors won’t miss a single bloom. Starting in Haarlem, the northernmost point of the Bollenstreek Route—also known as the Bloemen Route (Flower Route)—and running approximately 25 miles south to Leiden, this drive takes in the densest concentration of flower fields, with alternating strips of flowers shooting in thick ribbons of primary colors to the flat Dutch horizon. The show starts as early as late January, when the first crocuses come up. These are followed by daffodils, narcissi, and hyacinths. Irises and tulips emerge through early May, followed by gladioli, dahlias, and fragrant lilies. The queen of this nonstop flower extravaganza is the tulip, bursting out in every candy color. Flower sellers set up stalls along the road and sell garlands to adorn your car. But it isn’t just the beds of blooms that make this drive eye-popping. What you’ll also pass along the route is the sturdy billion-dollar industry that those seemingly wispy flowers support: the auction houses that sell the flowers; the public gardens that showcase the flowers; the museums and private gardens that celebrate the horticultural tradition; a series of gabled, Vermeer-worthy villages that grew rich on the flower industry; and two elegant cities, Haarlem and Leiden, that offer as much history and canal-side beauty per square block as Amsterdam itself. All this makes for a short drive dense in attractions and rich enough to command three days of sightseeing. Arrive at your starting point, Haarlem, a day early so you will have time in the city before striking out. (The trains from Amsterdam’s Centraal Station to Haarlem leave at least twice an hour and make the 12-mile trip west in 20 minutes). Haarlem’s historic center is seamed with canals and punctuated by the landmarks that hometown artists painted. There’s a reason why the classic Dutch painters mastered the art of depicting flowers, and it wasn’t just because they had florid imaginations. What the country’s Golden Age artists were really painting was a national still life, the view just outside their windows. The best way to get in the mood for your blooming drive is to stop by the Frans Hals Museum (Groot Heiligland 62; www.franshalsmuseum.com), one of Holland’s top small galleries. Check out Jan van Goyen’s fine landscapes, which manage to pack in all the signature Dutch scenery you’ll be passing: pearly rivers, sailing boats, and villages with church spires. Tellingly, van Goyen himself became notorious in the 17th century for swapping two of his ultimately timeless, priceless paintings for a handful of short-lived tulip bulbs. From Haarlem, head south on highway N208 to Lisse. This town makes a quaint pit stop in its own right, but its real claim to fame is the Bloemen Route’s showstopper: the Keukenhof Garden (Stationsweg 166a, Lisse), which started as the small kitchen garden of a 15th-century countess and now bills itself as nothing less than the most beautiful spring garden in the world, designed to showcase the art of Dutch bulb growers. Spilling across 70 acres of wooded parkland and attracting more than 700,000 visitors annually, the garden has nine miles of walking paths that wind around ponds, a windmill, greenhouse pavilions holding indoor displays, and more than seven million bulbs planted three layers deep to ensure a blaze of color from the end of March to mid-May. For a taste of Golden Age Dutch grandeur, stop by the tower-ringed Castle Keukenhof (www.kasteelkeukenhof.nl), which sits directly across from the entrance to the garden. Built by a former commander of the Dutch East India Company, which helped make 17th-century Holland very rich, the castle features the kitchen where aristocratic feasts of yore were prepared. Continue south, taking N208 to the larger highway A44, and you’ll come to the town of Leiden, a calmer, crucial Bloemen landmark. The small, historic town is home to Holland’s oldest university as well as the Botanical Garden, which looks miniature after Keukenhof but may seem more beautiful in its understatement, and which claims more of a historical pedigree. “The Botanical Garden was planted in 1594,” says curator Carla Teune, “and the first director of the garden was Carolus Clusius, one of the greatest botanists of his time. When he came to Leiden, he brought the tulip bulbs to this new garden.” Though he didn’t plant the first bulbs in Holland, Clusius did nurture a dizzying variety of tulip species, and helped spawn the Dutch tulip craze. Teune recommends some other attractions in Leiden, a town well worth an overnight stay. Among her favorite stops: the De Valk Windmill Museum (Binnenvestgracht 1), where you can climb through an 18th-century windmill to gain a panoramic view of the city; and the Leiden American Pilgrim Museum (Beschuitsteeg 9), which offers an overview of the Pilgrims’ life in Holland. Now it’s time to dive back into the fields. The nice thing about the Bloemen Route is that it allows for a variety of highlights, and one of the best lies about 30 minutes south of Leiden (take A4 south and then turn west on N222) at Naaldwijk, where you can see what a muscular commercial force all those flowers have become, and how important they are to the Dutch economy. “The biggest Dutch flower auctions generate an annual turnover of nearly $5 billion,” says Piet Kralt, senior communications advisor to the FloraHolland company, which runs some of the country’s largest auctions. The village of Naaldwijk sits in the middle of the Westland, the world’s largest greenhouse area, and the Naaldwijk flower auction house (Middel Broekweg 29) offers tours. Though you can’t actually participate in the auction yourself, a recorded guide to the proceedings offers an explanation of the process, from the moment the growers bring in their flowers to when the wholesalers, retailers, and exporters start bidding on the harvest. It’s a reminder of the besotted 17th-century Dutch collectors who were willing to swap tracts of land, bags of gold, carriages, and canal houses for a the precious treat of a few rare tulip bulbs. This drive should be done around mid-April for the best flower-viewing opportunities, and is calmest on weekdays, when there is less traffic; it is also a very popular bicycling route. IN 2,500 SQUARE FEET, a family of four can grow each year enough sunflower seed to produce three gallons of homemade vegetable oil suitable for salads or cooking and 20 pounds of nutritious, dehulled seed — with enough broken seeds left over to feed a winter’s worth of birds. The problem, heretofore, with sunflower seeds was the difficulty of dehulling them at home, and the lack of a device for expressing oil from the seeds. About six months ago, we decided to change all that. The job was to find out who makes a sunflower seed dehuller or to devise one if none were manufactured. And to either locate a home-scale oilseed press or devise one. No mean task. Our researches took us from North Dakota — hub of commercial sunflower activity in the nation — to a search of the files in the U.S. Patent Office, with stops in between. We turned up a lot of big machinery, discovered how difficult it is to buy really pure, unrefined vegetable oils, but found no small-scale equipment to dehull sunflowers or press out their oil. The key to success, however, was on our desk the whole time. In spring 1977, August Kormier had submitted a free-lance article describing how he used a Corona grain mill to dehull his sunflower seeds, and his vacuum cleaner exhaust hose to blow the hulls off the kernels. A second separation floated off the remaining hulls, leaving a clean product. We’d tried it, but because some kernels were cracked and the process involved drying, we hadn’t been satisfied. Now we felt the best approach was to begin again with what we learned from Mr. Kormier and refine it. Staff Editor Diana Branch and Home Workplace Editor Jim Eldon worked with a number of hand- and electric-powered grain mills. While the Corona did a passable job, they got the best results with the C.S. Bell #60 hand mill and the Marathon Uni Mill, which is motor-driven. “I couldn’t believe my eyes the first time I tried the Marathon,” Diana says. “I opened the stones to 1/8th inch, and out came a bin full of whole kernels and hulls split right at the seams. What a thrill that was!” She found that by starting at the widest setting,and gradually narrowing the opening, almost every seed was dehulled. The stones crack the hulls open, then rub them to encourage the seed away from the fibrous lining. The Bell hand mill worked almost as well. “As long as the stones open at least as wide as the widest unhulled seed, any mill will work,” she says. Because the seed slips through the mill on its flat side, grading is an important step to take before dehulling. We made three sizing boxes. The first is 1/4-inch hardware cloth [wire screen]. The second is two layers of 1/4-inch cloth, moved slightly apart to narrow the opening in one direction, and the third is two layers of screen adjusted to make a still-smaller opening. Since the smallest unhulled seeds are about the size of the largest hulled kernels, the grading step prevents these undersized seeds from passing through unhulled. Processed together at a closer setting, the smallest seeds hulled out.Jim Eldon’s workshop is littered with strange-looking pieces of apparatus. They represent initial attempts to build a workable winnowing box, using Kormier’s vacuum exhaust idea for a source of air. Jim, Fred Matlack and Diana finally made a box with a Plexiglas front, through which they could observe what was happening. They cut a hole in the back of the box with a sliding cover to regulate the air pressure, and fiddled with various arrangements of baffles. The result was a stream of hulls exiting through one hole while the kernels fell to the bottom of the box. Now they were ready to try a five-pound sample of unhulled sunflower seeds to see how much they could recover. The five pounds were graded and dehulled, then winnowed. We got about one hull for every ten kernels in the final, winnowed product. These are easily picked out. They usually contain kernels still held behind the fibrous strings of the hull. Their weight prevents them from blowing out with the empty hulls. We found that bug-eaten seeds do blow away with the chaff, which was a bonus for cleanliness of the final product. Toss the hulls to the birds, who will find broken seeds among them. Starting with 80 ounces of unhulled seed, we ended up with 41-1/4 ounces of edible whole seeds, 1.8 ounces of damaged seeds suitable for animal feed, and 36.6 ounces of hulls. It took us about an hour. Not bad. Sunflower seeds store perfectly in the hulls, but they deteriorate more rapidly when shelled out. The grain mill dehuller and winnowing box give the gardener a way to have the freshest possible seeds for eating at all times of the year. With the construction of one more piece of equipment — the oil press — he can have absolutely fresh, unrefined, polyunsaturated sunflower oil for salads, mayonnaise and cooking.Most light, refined vegetable oils have been extracted using hexane, a form of naphtha. The oil is then heated to boil off the hexane. Lye is dumped into it. It’s washed with steam, then heated to remove odors and taste before being laced with preservatives and stabilizers. It may feel oily in the mouth, but you might as well taste air. No so with fresh-made sunflower oil — it’s deliciously yet subtly nutty in flavor, adding unsurpassed flavor to salads. There’s good reason to believe that sunflower oil may become the #1 vegetable oil in the U.S. in a few years. It’s already #1 in health-conscious Europe. Corn oil has already caught on here for health reasons, and sunflower oil is so much better. Sunflower oil’s 70 percent polyunsaturate is just under safflower, with corn oil bringing up the rear with 55 percent. And sunflowers yield 40 percent oil, soybeans only 20 percent. Our oil press is relatively simple, but it must be welded together. Check the construction directions for details. The press consists of a welded tubular frame which accepts a three-ton hydraulic jack. You may already have one. If not, it can be purchased at most auto and hardware stores for about $16. A metal canister with holes drilled in its sides and one end welded shut holds the mashed sunflower seeds. A piston is inserted in the canister and then inverted and slipped over a pedestal on the frame. The jack is set in place, and the pressure gradually increased over half an hour. The oil drips from the sides of the canister into a tray — the bottom of a plastic jug slipped over the pedestal works fine — which empties the oil into a cup. You can filter the oil with a coffee filter to remove pieces of seed and other fine particles that would burn if the oil were used for cooking. If it’s for salads or mayonnaise, there’s no need to filter it. We first tried using “confectionary” sunflower seeds for oil. These are the regular eating kernels we’re used to seeing. They give less than half as much oil as the oilseed types of sunflower. Although you can use confectionary types such as MAMMOTH RUS- SIAN for oil, don’t expect to get more than an ounce and a half from a pound of seed. Oilseed produces three or more ounces of oil from a pound of seed and is well worth planting along with confectionary-type seeds. Oilseed has another big advantage — to prepare it, you can put the whole, unhulled seed into a blender and whiz it until it forms a fine meal, while confectionary seeds must be dehulled first. The entire sequence of grading, dehulling and winnowing is avoided with oilseed. Oil types produce about a tenth of a pound of seed per head in commercial production. Gardeners, with their better soil and care, invariably do better than that. Our conservative estimate is that 1,280 plants will be enough for three gallons of oil. Spaced one foot apart in rows two feet apart, 1,280 oilseed plants will take a space 40-by-56 feet, or 80-by-28 if you want a more rectangular patch to face south. We worked in pound batches, since the canister just holds one pound of mash. After blending, we heated it to 170 degrees F. (77 deg C) by placing it in a 300-degree F. (149 deg C) oven and stirring it every five minutes for 20 minutes. Heating gets the oil flowing and doubles the yield of oil. In case you’re wondering, “cold-pressed” oils sold commercially are also heated, and some are subjected to the entire chemical process. The term has no firm meaning within the industry, according to the literature we’ve surveyed. Heating does not change the structure of fats. It will not turn polyunsaturated fats into saturated fats. In fact, Dr. Donald R. Germann in his book, “The Anti-Cancer Diet”, says that “… an unsaturated fat must be heated to high temperatures — above 425 degrees F. or 200 degrees C. — at least 8 or 10 times before any shift toward saturation occurs…” Dean C. Fletcher, Ph.D., of the American Medical Association Department of Foods and Nutrition in Chicago, says, “It’s true that either high temperature or repeated heating does change the nature of some of the unsaturated oil molecules. (But) the flavor of the oil changes as these chemical changes occur, spoiling its taste. This effect is probably more profound than any of the physiological changes the altered oil might produce within the body.” From 500 gm. of heated mash, we pressed 89 gm. of oil, 89 percent of the entire amount available and twice as much as we could press from unheated oil! The decision is up to you whether or not to heat the mash, but that extra 50 percent seems like an awful lot, especially when the whole technique is so labor intensive. The oil should be stored in the refrigerator, and it’s probably best to use it within a month, since it has no preservatives. Mayonnaise made with such fresh oils should be kept refrigerated and used within two weeks. The leftover cake, still containing 50 percent of its oil, is a nutritious addition to your dishes, and makes excellent feed for animals or winter birds. Store the pressed cake in the freezer Sun-loving flowers make an excellent choice for butterfly gardens as butterflies require the heat of the sun to warm their bodies and boost energy. Although there are many bright flowers available that thrive in full sun, some attract more butterflies than others. Try these hardy plants to brighten your yard and provide sweet nectar for hungry butterflies.
Purple Coneflower
Purple coneflower creates a striking display of color in a butterfly garden. This hardy perennial returns every year creating a burst of color from early summer until frost. Dramatic purple blooms atop tall slender stems feature petals that fold backward exposing the dark center. Grown in full sun, these flowers provide nectar for butterflies for months.
Shasta Daisy
Brilliant white Shasta daisies make a striking contrast with other more colorful flowers and are natural attractors for butterflies. They return each year in bigger and hardier clumps and produce large snow-white blooms. Blooming begins in early summer and continues until frost. Add Shasta daisy for contrast in your butterfly garden.
Asters
Asters produce clusters of blooms in late summer and early fall. Wild varieties range from blue to deep purple, but cultivated varieties are available in a wider range of colors. These hardy plants thrive in full sun making them ideal for butterfly gardens.
Zinnias
Fiery zinnias create a dazzling blaze of color throughout the summer. Available in dwarf 8 inch varieties to towering giants of 4 feet or more, these delightful flowers are easy to care for and thrive in full sun. Plant varieties in yellow, yellow-orange and fiery reds to attract butterflies to your garden.
Gloriosa Daisy
Add Gloriosa daisy near purple coneflower and Shasta daisies for contrast to brighten the garden and create depth. Grown as annuals in northern climates these delightful flowers often self seed and return with vigor the following year adding a splash of color that is sure to attract butterflies to you garden. Flowers bloom atop slender stalks and feature petals in shades of yellow, gold and mahogany surrounding a dark center.