Scott Bauer, USDA
Scott Bauer, USDA

Know Your Citrus

Scott Bauer, USDA
Scott Bauer, USDA

As winter approaches, you might notice that peaches and plums are disappearing from the produce aisle, and berry prices are going through the roof. But look! The new citrus fruit is here to give us a taste of the tropics in time for the winter holidays. Citrus fruits all belong to the genus Citrus, and can be hybridized with each other. The citrus fruits we know were developed from just a few that occur in the wild, including citron, pomelo, and mandarin. The variety of citrus fruits we encounter at the grocery store in the winter months are mostly hybridized from those species and their descendants.


Photograph by Johann Werfring.

Citron (Citrus medica) is the citrus fruit that gave “citrus” its name. Records of the fruit go back thousands of years in Mesopotamia, although its origin may be India or Southeast Asia. Citron is more temperature-sensitive than other commercial citrus grown in the U.S. but flourishes in South America and the coastal areas of the Mediterranean. Americans are mostly familiar with citron as a candied ingredient in fruitcake, made from the fruit’s peel.


Photograph by Forest & Kim Starr.

The pomelo (Citrus grandis) is the largest of all citrus fruits. They can grow up to nine inches in diameter and weigh over four pounds! Pomelos are native to Southeast Asia, but are gaining popularity worldwide. They appear green or yellow when ripe, and the flesh is white or shades of pink. The taste is like a sweet grapefruit, and in fact, grapefruit is sometimes called pomelo and the pomelo is sometimes called Chinese grapefruit, although they are different fruits.


Photograph by Flickr user Lotte Grønkjær.

The mandarin (Citrus reticulata), or mandarin orange, is one of the oldest citrus fruits, and the ancestor of many other fruits we know. It is a small, sweet-tasting orange originating in Southeast Asia. Mandarins are also distinct from oranges in that they are easy to peel. It has some close relatives that are sometimes hard to distinguish. Tangerines (Citrus tangerina) are closely related to mandarin oranges, although the name is usually reserved for the more reddish fruit. They are named after the city of Tangier, Morocco, from where they were exported to Europe. Clementines (Citrus ×clementina) are hybrids developed from crossing a Mandarin orange and a sweet orange. They are sweeter than tangerines, but just as easy to peel. Clementines are usually seedless, and are sometimes referred to as “seedless mandarins.”


Photograph by Morlawmina.

Oranges (Citrus sinensis) are the citrus fruit we are most familiar with. They do not exist in the wild, but were cultivated in Asia since ancient times. It is thought that the first oranges were hybrids of the pomelo and the mandarin. Oranges were brought to the Middle East in the 9th century, and into Italy by 11th-century Crusaders. By the 15th century, they had been introduced to Europe, and soon after, trees were being grown in the Caribbean Islands and in Florida. However, orange trees are temperature sensitive and the fruit was difficult to transport over long distances, so the fruit was rather expensive for most people. They were considered a real treat for the holidays, which explains their association with Christmas. Your parents or grandparents will likely remember how special it was to see an orange in the toe of their Christmas stocking.

That changed in the 1920s, when canned orange juice began to be marketed as a health drink. Vitamins were pushed as the new miracle cure, and the National Fruit Growers Exchange took advantage of the craze to promote orange juice. But orange juice didn’t really take off until frozen orange juice concentrate was developed in 1948. Frozen concentrate could be shipped all over at a fraction of the price of whole oranges, without spoiling. Plus, the growers’ orange crops could be preserved year-round. Orange juice was pushed as a natural and healthy breakfast drink, a campaign which worked wondrously. However, in the past decade, sales of orange juice are down in comparison with other juices and fresh fruit.


Image by א (Aleph).

Grapefruit (Citrus x paradisi) is a hybrid derived from pomelos and sweet oranges. It is believed to have been an accidental hybrid arising in Barbados and Jamaica in the 18th century. The name came from the tendency of the fruits to grow in clusters resembling huge grapes. The grapefruit was a novelty fruit outside of Florida until the 1930s, when the Grapefruit Diet was introduced. The diet recommended that a half a grapefruit be eaten before each meal. Those on the diet lost weight, but it wasn’t because grapefruit enzymes burned fat, as was often said. It was more likely because the low-calorie grapefruit filled the dieter’s stomach, causing them to eat less of other foods.


Photograph by Gareth Bogdanoff.

A tangelo (Citrus X tangelo) is a hybrid derived from crossing a mandarin and a grapefruit. Tangelos are juicy, brightly-colored, and have a loose peel that’s easy to remove. They also have a distinctive “neck” that protrudes from the sphere. Ugli fruit is a variety of tangelo with a not-quite spherical shape, believed to have been an accidental hybrid of grapefruit and mandarin that occurred in Jamaica around 1917.


Photograph by Flickr user Choo Yut Shing.

Kumquats (Citrus japonica) are tiny, oval-shaped citrus fruits. Sometimes the fruit is placed in the genus Fortunella instead of citrus. Kumquat trees are hardier than other citrus plants and can be grown at more northern latitudes. The fruit can be eaten whole, peel and all, except for the seeds. They are also pickled, candied, and used to flavor tea.


Photogaph by Flickr user Susy Morris.

Lemons (Citrus × limon) possibly originated in India, and are thought to be a hybrid of the citron and the bitter orange. Lemons are so acidic that they are used as flavoring and as an acidic preservative rather than a fruit. As Peter, Paul, & Mary put it: 

Lemon tree, very pretty, and the lemon flower is sweet
But the fruit of the lemon is impossible to eat.


Photograph by Steve Hopson.

The name lime encompasses about a dozen species of citrus fruit that are generally green and lemon-shaped. They are almost as acidic as lemon but have their own distinct flavor. Like lemons, they are mainly used as a flavoring agent. In 1747, British Royal Navy surgeon Dr. James Lind discovered that citrus fruits could prevent scurvy, a disease which particularly afflicted sailors who spent months at sea. In 1795, the navy began carrying lemons to provide sailors with vitamin C. However, limes were easier to get in the Caribbean islands ruled by the British, so they switched to limes. It was only later found that lemons have two to four times the vitamin C of limes, depending on the variety.

Kerry Hayes, Warner Bros. Entertainment Inc. and Legendary Pictures
10 Monster Facts About Pacific Rim
Kerry Hayes, Warner Bros. Entertainment Inc. and Legendary Pictures
Kerry Hayes, Warner Bros. Entertainment Inc. and Legendary Pictures

Legendary Pictures took a gamble on Pacific Rim, Guillermo del Toro’s 2013 monster/robot slugfest. Since it wasn’t based on a preexisting franchise, it lacked a built-in fanbase. That can be a serious drawback in our current age of blockbuster remakes and reboots. The movie underperformed domestically; in America, it grossed just over $100 million against its $180 million budget. Yet Pacific Rim was a huge hit overseas and acquired enough fans to earn itself a sequel, Pacific Rim Uprising, which arrives in theaters this week. Here are 10 things you might not have known about the movie that started it all.


Idris Elba in 'Pacific Rim' (2013)
Warner Bros.

One foggy day in 2007, Beacham—who’d recently moved to California—was walking along Santa Monica Beach. As he looked out at the Ferris wheel on the city’s eponymous pier, he pictured a looming sea monster. Then he imagined an equally large robot gearing up to fight the beast. “They just sort of materialized out of the fog, these vast godlike things,” Beacham said. He decided to pursue the concept further after coming up with the idea of human co-pilots who’d need to operate their robot as a team, which added a new thematic dimension.

“I didn’t know I had something I wanted to write until I realized these robots are driven by two pilots, and what happens when one of those people dies? What happens to the leftovers? Then it became a story about loss, moving on after loss, and dealing with survivor’s guilt," Beacham said. "That made the monsters scarier because now you care about the people who are in these robots.”


Pacific Rim was picked up by Legendary Pictures and handed over to director Guillermo del Toro. A huge fan of monster cinema, del Toro enthusiastically co-wrote the final screenplay with Beacham. Sixteen concept artists were hired to sketch original robot and creature designs for the film. “We would get together every day like kids and draw all day,” del Toro told the New York Daily News. “We designed about a hundred Kaijus and about a hundred Jaegers and every week we would do an American Idol and we would vote [some of] them out.”


In “Charlie Kelly: King of the Rats,” the tenth episode of It's Always Sunny in Philadelphia's sixth season, Charlie Day’s character gives us a darkly comedic monologue about rodent extermination. Little did the actor know that the performance would open a big opportunity for him. Impressed by the rat speech, del Toro offered Day the part of Dr. Newton Geizler, Pacific Rim’s socially-inept kaiju expert. “He said to himself, ‘That’s my guy. That guy should be in my next movie because if he killed rats, he can kill the monster,’” Day recalled during an appearance on Late Night with Jimmy Fallon. On the movie set, del Toro often joked about how much he enjoys It’s Always Sunny. As a way of repaying his director, Day helped get del Toro a minor role in the series.


Most of the film’s special effects were computer-generated, but not everything was digital. For the robot cockpit scenes, del Toro had his team build the interior of a full-scale Jaeger head. The finished product stood four stories tall and weighed 20 tons. And like a Tilt-A-Whirl from hell, it was designed to rock around violently on its platform via a network of hydraulics. Once inside, the actors were forced to don 40-pound suits of armor. Then the crew strapped their feet into an apparatus that Charlie Hunnam has compared to a high-resistance elliptical machine.

Certain shots also required del Toro to dump gallons of water all over his exhausted, physically-strained stars. So yeah, the experience wasn’t much fun. “We saw every one of the actors break down on that set except for the female lead actress Rinko Kikuchi," del Toro said. "She’s the only actor that didn’t snap."


Del Toro wanted Gipsy Danger, his ‘bot, to have the self-confident air of a wild west gunslinger. To that end, he and concept artist Oscar Chichoni developed a swaggering gait that was based on John Wayne’s signature hip movements. The Jaeger’s Art Deco-like design was influenced by the Chrysler and Empire State Buildings.


Hailed as the “fortieth greatest guitarist of all time” by Rolling Stone, Rage Against the Machine's Tom Morello rocked the MTV generation with hits like “Bulls on Parade” and “Killing in the Name.” Pacific Rim bears his mark as well. The film’s lead composer was Ramin Djawadi, whose other works include the Game of Thrones theme. Wanting to add a “rock element” to the Pacific Rim soundtrack, he and del Toro reached out to Morello. The guitarist didn’t need much persuading.

“When they asked me to put some giant robot riffs and screaming underwater monster licks on the film score, I was all in,” Morello said. Djwadi was pleased with the rocker's contributions to the project. As he told the press: “Tom’s unique style and sounds really defined our robots.”


A definite highlight of this movie is Gipsy Danger’s duel with the winged kaiju Otachi in downtown Hong Kong. Both characters were computer-generated, as were the majority of the streets, cars, and towers in this epic sequence. However, there is one moment which was at least partly realized with practical effects. Gipsy punches through the wall of an office building early in the fight. We see her fist rip through a series of cubicles and gradually decelerate until it lightly taps a chair with just enough force to set off a Newton’s Cradle desktop toy. For that shot, effects artists at 32Ten Studios constructed a miniature office building interior featuring 1/4-scale desks, cubicles, and padded chairs. The level of detail here was amazing: 32Ten’s staff adorned each individual workspace with lamps, computers, wastebaskets, and teeny, tiny Post-it notes.


Rinko Kikuchi in 'Pacific Rim' (2013)
Kerry Hayes, Warner Bros. Entertainment Inc. and Legendary Pictures

Audiences reacted strongly to Kikuchi’s character Mako Mori, who inspired an alternative to the famous Bechdel test. Some critics praised the culmination of her relationship with Raleigh Beckett (Hunnam). Although it’s common practice for the male and female leads in an action flick to end their movie with a smooch, Mori and Beckett share a platonic hug as Pacific Rim draws to a close. Del Toro revealed that he shot three different versions of that final scene. “We did one version where they kiss and it almost felt weird. They’re good friends, they’re pals, good colleagues,” del Toro said.


At the end of the credits, there’s a tribute that reads: “This film is dedicated to the memories of monster masters Ray Harryhausen and Ishiro Honda.” Harryhausen passed away on May 7, 2013—two months before Pacific Rim’s release. A great stop-motion animator, he breathed life into such creatures as the towering Rhedosaurus in 1953’s The Beast From 20,000 Fathoms.

Ishiro Honda was another giant of the kaiju genre, having directed Rodan, War of the Gargantuas, and numerous Godzilla films. Del Toro has great respect for both men. When Harryhausen died, the director said, “I lost a member of my family today, a man who was as present in my childhood as any of my relatives.” He also adores the Japanese monster classics and says he’d love to see a Pacific Rim-Godzilla crossover someday. Maybe it’ll happen.


If you’re not familiar with the practice of “Sweding,” let us fill you in: The 2008 comedy Be Kind, Rewind is about two co-workers at a VHS rental store who accidentally erase every tape in stock. Hoping to save their skins, they create ultra low-budget remakes of all the films they’ve destroyed using cardboard sets and cheap costumes. It’s a process these guys call “Sweding” as a ploy to convince everyone that their (unintentionally hilarious) knockoffs were produced in Sweden. Since Be Kind, Rewind was released, Sweding has become a legitimate art form.

When Pacific Rim’s first trailer debuted in 2013, YouTubers Brian Harley and Brodie Mash created a shot-for-shot, Sweded duplicate of the preview. Instead of state-of-the-art CG effects, their version used toy helicopters, duct-tape monster masks, and an ocean of packing peanuts—and del Toro loved it. At WonderCon 2013, he praised the video, saying that it inspired the editing used in Pacific Rim’s third trailer. Harley and Mash happened to be at the same gathering. When del Toro met the comedic duo, he exclaimed “I loved it! My daughters loved it, we watched it a bunch of times!” Then he invited the Sweding duo to attend Pacific Rim’s premiere in Hollywood.

Composite by Mental Floss. Illustrations, iStock.
The DEA Crackdown on Thomas Jefferson's Poppy Plants
Composite by Mental Floss. Illustrations, iStock.
Composite by Mental Floss. Illustrations, iStock.

The bloom has come off Papaver somniferum in recent years, as the innocuous-looking plant has come under new scrutiny for its role as a building block in many pain-blunting opiates—and, by association, the opioid epidemic. That this 3-foot-tall plant harbors a pod that can be crushed and mixed with water to produce a euphoric high has resulted in a stigma regarding its growth. Not even gardens honoring our nation's Founding Fathers are exempt, which is how the estate of Thomas Jefferson once found itself in a bizarre dialogue with the Drug Enforcement Administration (DEA) over its poppy plants and whether the gift shop clerks were becoming inadvertent drug dealers.

Jefferson, the nation's third president, was an avowed horticulturist. He spent years tending to vegetable and flower gardens, recording the fates of more than 300 varieties of 90 different plants in meticulous detail. At Monticello, his Charlottesville, Virginia plantation, Jefferson devoted much of his free time to his sprawling soil. Among the vast selection of plants were several poppies, including the much-maligned Papaver somniferum.

The front view of Thomas Jefferson's Monticello estate
Thomas Jefferson's Monticello estate.

"He was growing them for ornamental purposes,” Peggy Cornett, Monticello’s historic gardener and curator of plants, tells Mental Floss. “It was very common in early American gardens, early Colonial gardens. Poppies are annuals and come up easily.”

Following Jefferson’s death in 1826, the flower garden at Monticello was largely abandoned, and his estate was sold off to help repay the debts he had left behind. Around 115 years later, the Garden Club of Virginia began to restore the plot with the help of Jefferson’s own sketches of his flower borders and some highly resilient bulbs.

In 1987, Monticello’s caretakers opened the Thomas Jefferson Center for Historic Plants, complete with a greenhouse, garden, and retail store. The aim was to educate period-accurate gardeners and sell rare seeds to help populate their efforts. Papaver somniferum was among the offerings.

This didn’t appear to be of concern to anyone until 1991, when local reporters began to obsess over narcotics tips following a drug bust at the University of Virginia. Suddenly, the Center for Historic Plants was fielding queries about the “opium poppies” in residence at Monticello.

The Center had never tried to hide it. “We had labels on all the plants,” says Cornett, who has worked at Monticello since 1983 and remembers the ensuing political scuffle. “We didn’t grow them at the Center. We just collected and sold the seeds that came from Monticello.”

At the time, the legality of growing the poppy was frustratingly vague for the Center’s governing board, who tried repeatedly to get clarification on whether they were breaking the law. A representative for the U.S. Department of Agriculture saw no issue with it, but couldn’t cite a specific law exempting the Center. The Office of the Attorney General in Virginia had no answer. It seemed as though no authority wanted to commit to a decision.

Eventually, the board called the DEA and insisted on instructions. Despite the ubiquity of the seeds—they can spring up anywhere, anytime—the DEA felt the Jefferson estate was playing with fire. Though they were not a clandestine opium den, they elected to take action in June of 1991.

“We pulled up the plants," Cornett says. “And we stopped selling the seeds, too.”

Today, Papaver somniferum is no longer in residence at Monticello, and its legal status is still murky at best. (While seeds can be sold and planting them should not typically land gardeners in trouble, opium poppy is a Schedule II drug and growing it is actually illegal—whether or not it's for the express purpose of making heroin or other drugs.) The Center does grow other plants in the Papaver genus, all of which have varying and usually low levels of opium.

As for Jefferson himself: While he may not have crushed his poppies personally, he did benefit from the plant’s medicinal effects. His personal physician, Robley Dunglison, prescribed laudanum, a tincture of opium, for recurring gastric issues. Jefferson took it until the day prior to his death, when he rejected another dose and told Dunglison, “No, doctor, nothing more.”


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