7

PUTTING DOWN ROOTS: USEFUL PLANTS FOR THE STRANDED TIME TRAVELER

A taste for these plants is definitely worth . . . cultivating.

The following is a list of the plants that have been most useful to humanity, as well as the things you can do with them. Plants predate humanity and their natural evolution generally proceeds slowly, which means that in any time where you can find humans, you will also find plants that match or approximate the entries on this list. It is important to note, however, that the plants you encounter may be slightly different—or in some cases markedly different—from the kinds you are familiar with. For more information on why this is, and how you can recover the plants you’re familiar with from their weird ancestors you’re seeing, see Section 5.

Examine the following pages to find the most useful plants native to your region: plants are listed alphabetically, and each includes the area they first evolved in. If you don’t know what region of the planet you’re on, you can try to find some plants you recognize around you and then locate them in these pages. In the unlikely event you don’t know what any one of these plants look like, at the very least you’ll know what sorts of things you can expect out there, and while entire books have been written about each of these plants, a few sentences about each species is technically better than nothing. Depending on your time period, you may get lucky and find instances of these plants outside their native ranges.¹¹

7.1: APPLES

ORIGIN

Central Asia

USES

• The apple tree was among the first trees cultivated, and its fruit has been improved for thousands of years, so if you’re back before selective breeding was invented, expect some disappointing and tiny sour apples consisting mostly of seeds and a core. Enjoy!

• Apples picked in fall and stored in a cool place keep well over winter.

NOTES

• Apple cider can be made by leaving out apple juice and allowing natural yeast to ferment it. It might not be delicious, but it will be alcoholic!

7.2: BAMBOO

ORIGIN

Warm, moist tropical regions

USES

• For a long-lasting writing surface (especially useful before paper), scrape off the outer green skin, split them open on one side, and flatten them. Multiple shoots can be joined together!

• Great for flutes (also, blow guns), plus the shoots are edible.

• Can be used to construct arrows, baskets, scaffolding, furniture, walls, flooring, electric light filaments, water pipes, and as a reinforcing agent in concrete if steel is not invented yet, since bamboo has a tensile strength (the ability to withstand heavy loads without snapping or being pulled apart) that’s almost as good as steel.

• Attracts adorable giant pandas.

NOTES

• Bamboo is an incredibly versatile plant, and if you are stranded in an area of the planet where it grows, you will have a lot of what you need for a civilization from this one plant alone!

• Bamboo is one of the fastest-growing plants in the world, and that’s useful if you want plants, like, yesterday.

7.3: BARLEY

ORIGIN

Temperate regions worldwide

USES

• Humans eat it! Animals eat it too! This is an essential crop available over most of the world!

NOTES

• Barley beer is among the first alcoholic drinks ever made by humans!* To find out how to make your own beer, see Section 10.2.5.

• One of the oldest extant recipes is for a barley beer, and you know we’re going to give it to you (see sidebar on this page). Cheers!

7.4: BLACK PEPPER

ORIGIN

Southern Asia and Southeast Asia

USES

• Harvest the red fruits of the pepper vine and let them dry in the sun, and you’ll have black peppercorns that you can then grind into your food for that spicy, peppery flavor.

• A ubiquitous spice in the modern era, it remains the world’s most traded spice!

NOTES

• In Medieval Europe, pepper was worth ten times more than any other spice! People either love this stuff or hate bland food. Maybe both? Probably it’s both.

• Pepper was also thought to cure constipation, insomnia, sunburn, and toothaches, as well as other diseases. It doesn’t, so don’t waste your time.

7.5: CACAO PLANT

ORIGIN

Rain forests of Central and South America

USES

• Chocolate is delicious, and the cacao bean is where it comes from. Scoop the beans from the pods, let them ferment beneath banana leaves, then dry them in the sun, roast them, and remove the shell. Grind what’s left and you’ve got pure chocolate.

• Naturally bitter, for centuries chocolate was roasted, ground, and then added to stews or wine, but chocolate really took off in Europe when paired with sugar and made into a delicious beverage!

NOTES

• The pulp from the bean pods can also be eaten (or, like any sweet fruit, fermented), and it was the pulp—rather than the beans—for which the plant was originally cultivated!¹²

• Chocolate is one of the most sought-after flavors in the world, so get ready for your civilization to be pretty popular.

• The most universally agreed-upon-to-be-delicious chocolate form is milk chocolate, which you can produce by adding milk, sugar, and fats to your chocolate over heat, and then allowing it to cool. Milk chocolate keeps well and is high in calories, making it a useful food on long voyages (see Section 10.12.5: Boats).

7.6: CHILI PEPPER

ORIGIN

Central and South America

USES

• Good for making food spicier and, therefore, more delicious. Also: extremely useful in making chili.

• The active component is called “capsaicin” and can be used in very light concentrations for temporary pain relief: it works by overloading pain receptors.

NOTES

• Capsaicin is the second-most widely consumed condiment, after salt. People love this stuff!

7.7: CINCHONA

ORIGIN

Bolivia, Peru

USES

• The bark of this tree contains quinine, and guess what? Quinine is a treatment for malaria!

NOTES

• To fight malaria, strip the bark from the tree, dry it, powder it, and gobble it. Side effects include headaches, trouble seeing, ringing in the ears or deafness, and an irregular heartbeat, so don’t eat quinine unless you need it!

7.8: COCONUT

ORIGIN

Indo-Pacific regions

USES

• An extremely versatile plant: its fronds can be used for fuel, baskets and mats can be woven from its leaves, its stalks can form brooms, the hair from the coconut shell can be woven into rope, and of course coconut flesh is extremely delicious!

NOTES

• Coconuts are airtight, which means the water they contain is actually germ- and bacteria-free. They’re a great source of safe and clean drinking water, and one that doesn’t require any technology to produce! You might even say they’re “coco-nuts,” but you won’t, because you’re too busy being stranded in the past to make puns right now.

7.9: COFFEE

ORIGIN

Africa

USES

• Dry the beans, grind them up, and run water through them to produce a black liquid that a lot of people like to drink for some reason.

• Unrelatedly, coffee is high in caffeine, which is the world’s most-consumed psychoactive drug!

NOTES

• Caffeine prevents the symptoms of drowsiness and stimulates parts of the central nervous system.

• You can overdose and die from consuming too much caffeine, so maybe take it easy with the coffee there, champ.

7.10: CORN

ORIGIN

The Americas

USES

• A staple crop of American civilizations, corn is a convenient and efficient way to feed both humans and animals. Everyone loves corn! Or at least, everyone will eat it when there are no other options.

• An extremely versatile vegetable, corn can be boiled, baked, steamed, eaten raw, crushed into corn powder, heated to make popcorn, baked into bread, or brewed into beer.

NOTES

• Domesticated corn (available after around 7000 BCE) does not naturally reproduce: to produce more corn, you must conserve kernels until next spring, then bury them in the ground. It’s been so thoroughly domesticated that it can no longer survive without human aid and interference. Thanks for the trust, corn!

7.11: COTTON

ORIGIN

The Americas, Africa, India

USES

• Even in the modern era, it’s one of the most important non-food crops in the world.

• Cotton can be used to make soft, breathable clothing and textiles, along with sails and fishing nets for boats, paper, coffee filters, tents, and even fire hoses.

• Cotton fiber is very high in cellulose, which makes it great for papermaking: see Section 10.11.1.

NOTES

• To make cotton yarn—which can then be woven in fabric—first pick the fluffy balls off the tops of cotton flowers. Pull them across a rough board to separate the seeds from the lint. The lint can then be combed to straighten out its fibers and spun into yarn. See Section 10.8.4 for more.

7.12: EUCALYPTUS

ORIGIN

Australia

USES

• Bark resins can be used to produce mouthwash.

• The flowers attract honeybees that make delicious honey.

• The leaves produce oil that’s actually surprisingly useful in medicine (allow your eyes to drift over to the notes section for details).

• Also, eucalyptus oil can be used to make food taste deliciously spicy and can be added to soaps as a perfume.

NOTES

Eucalyptus oil . . .

• applied topically is antiseptic and anti-inflammatory. Apply it to wounds to help prevent infection!

• swallowed helps relieve cold and flu symptoms such as sore throat.

• inhaled as a vapor is a decongestant and treatment for bronchitis.

• applied to skin also works as an insect repellant! Thanks, eucalyptus oil, you’re super useful.

• is also extremely flammable, so much so that burning eucalyptus trees sometimes explode, so be careful with it.

• can be toxic if too much is consumed: a lethal dose is in the range of 0.05 mL to 0.5 mL per kg of body mass.

7.13: GRAPES

ORIGIN

Western Asia

USES

• The fruit can be eaten raw, sun dried to produce raisins (which keep for longer), or fermented to produce wine, which humans, historically, have enjoyed getting pretty buzzed on.

• While grapes will ferment on their own, the art of the wine maker is to stabilize the drink after fermentation stops, preserving it at the right moment to produce a more delicious beverage.

NOTES

• If you’re around when steam travel is beginning between Europe and America, be aware that the unprecedented speed of these ships will allow pale yellow American “phylloxera” insects—all of whom used to perish on the previous, longer oceanic crossings—to survive the voyage. When these insects arrive in Europe, they will become an epidemic, destroying vineyards there for generations. The eventual solution will be to graft European grape plants onto the rootstock of phylloxera-resistant American grape species: the sooner you come up with this, the more you will alter the history of the world (at least the wine-drinking parts of it).

7.14: OAK TREES

ORIGIN

Northern hemisphere

USES

• Oak is a very dense, strong, but flexible hard wood, resistant to insects and fungus.

• Everything from boats to buildings can be made from oak!

• Oak bark also contains tannins: chemicals that let you turn gross animal skin into flexible, wearable leather. See Section 10.8.3 for instructions.

NOTES

• Oak trees can live for more than 1,500 years, and it takes about 150 years for an oak tree to grow to the point where it can be harvested for wood, so oak farming is a situation in which you’ll want to plan ahead.

7.15: OPIUM POPPY

ORIGIN

Eastern Mediterranean

USES

• A pretty plant that also happens to produce a sap from its seed head that contains opium: the source of morphine (a painkiller), codeine (another painkiller, also used to treat coughs and diarrhea), and heroin (a highly addictive narcotic).

• If you’re not interested in drugs, poppy seeds can also be used as a tasty spice!

NOTES

• Harvest opium by scouring the surface of a ripening poppy head in the evening, collecting the sap that oozes out in the morning. Let it dry in the sun and you’ve got raw opium.

• Morphine can be extracted from poppies by cutting up the dried plants and boiling them in three times their weight of hot water until a paste forms at the bottom. Add lime (see Appendix C.3), repeat the process, and then add ammonium chloride (Appendix C.6) to precipitate out morphine, which is then purified by hydrochloric acid (Appendix C.13).

7.16: PAPYRUS

ORIGIN

Egypt, tropical Africa

USES

• A great thing to write on before you’ve either invented paper or discovered that if you dry and stretch animal skins you can make parchment to write on instead.

NOTES

• Make papyrus paper by peeling away the outer layer of papyrus stalks, then cutting them into long strips. Let them soak in water for a few days. Align them side by side, edges slightly overlapping, then put another layer on top, perpendicular to the first. Press them flat for a few days, and ta-da!: you have produced a single sheet of papyrus paper!

7.17: POTATO

ORIGIN

The Andes in South America

USES

• Potatoes are one of the few plants that contain all the nutrition humans need! You can live entirely off potatoes (but shouldn’t, because then you’re extremely vulnerable to crop failure).

• All parts of the potato are poisonous until cooked, so don’t eat raw potatoes. Their poison gives you a slight advantage: humans are the only animals that cook their food,* so animals that also find potatoes toxic won’t steal them from your fields.

• Boil them, mash them, stick them in a stew, even cook them in oil to make delicious fries and potato chips (which are not healthy, but which are extremely delicious, and listen, sometimes a civilization just wants a bunch of chips for dinner, okay?). Potato chips don’t normally get invented until the 1800s CE, but they’re so easy to make that you might as well enjoy them now.

NOTES

• Potatoes can be grown almost anywhere except in the tropics, and they produce more calories per square kilometer than any cereal crop!

• Historically there was European resistance to the potato: Protestants thought they were an evil thing from the “New World” that multiplied underground and whose curvaceous shape was “suggestive.” Yes: if you can trace your ancestry back to the early days of the United States, there’s a fair chance your ancestors were turned on by potatoes. This resistance was overcome in many ways, most notably in France, where potatoes were planted on the grounds of the Palace of Versailles, where “guards” were placed to protect this new and mysterious royal vegetable. At night the guards would retire, and citizens, curious about this new crop, would raid the fields, soon growing potatoes themselves.

7.18: RICE

ORIGIN

Asia and Africa

USES

• Rice has been continuously cultivated for tens of thousands of years, so billions of humans have found it both convenient and tasty.

• Try it with a curry on top: delicious.

• A staple crop for Asian civilizations.

NOTES

• More than 1/5 of the calories consumed worldwide by humans come from rice, more than any other plant!

• Rice grows best in wet soils, so areas with high rainfall work great, but it can be cultivated to grow almost anywhere as long as you water it.

• Rice can be grown in a flooded field, which has the benefit of both deterring vermin and preventing weeds that can’t survive flooding from growing.

7.19: RUBBER PLANT

ORIGIN

Different species of rubber trees are native to South America

USES

The sap from rubber trees is a flexible, sticky, and waterproof latex that has many uses:

• making erasers (from which we get the term “rubber,” for rubbing out mistakes)

• pressing into sheets to make waterproof clothing

• as an adhesive or cement

• as an insulator when dealing with electrical currents (Section 10.6.1)

NOTES

• Natural rubber decays, but it can be transformed into a less sticky, more flexible, and longer-lasting material through chemistry! This process is called “vulcanization” (and while you can of course call it whatever you want, “vulcanization” already sounds pretty sweet).

• The easiest way to vulcanize rubber is to add sulfur to it while it’s being heated. If you don’t have pure sulfur lying around, great news! The South American rubber plant is typically found with another plant climbing on it: a vine with large, fragrant night-blooming white flowers. The juices from these “moonflower” plants contain sulfur. You’ve got all the ingredients you need to make vulcanized rubber side by side!

7.20: SOYBEAN

ORIGIN

East Asia

USES

• Soybean plants produce two times as much protein per square kilometer as other vegetables, five to ten times more than land used for grazing animals to make milk, and fifteen times more than land set aside for meat production. You like protein? You came to the right place.

• Soybeans are also a great source of many essential nutrients.

NOTES

• Like yams, soybeans are toxic to humans (and all other animals with just one stomach) when raw, and need to be cooked before being eaten. Listen: you should be cooking a lot of the mysterious food you find anyway. Plenty of foods have toxins that get destroyed by cooking, and no foods become toxic when cooked. Cooking: it’s great!

7.21: SUGARCANE

ORIGIN

New Guinea

USES

• The juice pressed from sugarcane plants can be boiled down to a density at which table sugar crystallizes out! While not necessary for civilization, sugar does make life sweeter (and also contributes to diabetes and obesity and makes it harder for your body to process fiber, so maybe go easy on the sugar).

• If you’re not in the tropics where sugarcane grows, you may be in temperate climates where sugar beets are found! Shred the plant and then boil it for hours to extract the sugars. The resulting liquid can then itself be boiled down to produce a thick molasses.

NOTES

• The dried pulp left over from sugarcane sugar extraction can be used to make paper.

• Sugarcane is one of the most efficient photosynthesizing plants: it converts more sunlight into biomass than just about any other plant! This means if you want to use plants as a fuel source, you’ll get the best and most productive use of your land by growing sugarcane, drying it out, and then burning it to boil water (which can be used in your steam engine, see Section 10.5.4). You can even burn the dried pulp left over from producing sugar, making sugarcane even more efficient.

7.22: SWEET ORANGE

ORIGIN

China and Southeast Asia

USES

• Contains tons of vitamin C and comes conveniently wrapped for transit!

NOTES

• Humans require vitamin C but cannot produce it on their own, so eat an orange if you don’t want scurvy (or if you already have it, because it’s a cure).

• Most fresh foods contain vitamin C, but the vitamin breaks down when exposed to light, heat, and air, so most preserved foods don’t contain any at all! Section 9: Basic Nutrition shows how knowing this simple fact will save thousands if not millions of lives.

• The sweet orange was not bred until the 1400s CE, so before then expect some very bitter oranges.

7.23: TEA

ORIGIN

China, Japan, India, Russia

USES

• Put the dried leaves in hot water and it’s delicious.

• Also, it’s a source of caffeine, which can be valuable if you haven’t been to Africa yet to discover coffee.

NOTES

• Tea is the second-most widely consumed drink in the world (only water is more popular), so yeah, it’s pretty tasty.

• Tea can be made from other plants too, but these are usually called “herbal teas.” Proper tea comes from the tea plant, and you should accept no substitutes.

• Try it with milk and sugar, or iced with lemon!

7.24: TOBACCO

ORIGIN

Central America

USES

• Contains nicotine, a stimulant.

• You can smoke it if you want to become addicted to a plant!

NOTES

• In the twentieth century CE tobacco was the leading cause of preventable death, and 1 in every 10 people who died worldwide died because of tobacco use.

• Even secondhand exposure can be fatal, so don’t smoke it or be around people who do.

• Avoid introducing tobacco to your civilization, and you will save yourself billions of dollars and millions of lives and prevent the invention of vaping.

7.25: WHEAT

ORIGIN

Middle East (Fertile Crescent)

USES

• This is a staple crop for European civilizations. Ground wheat (which is what it sounds like: wheat pulverized into powder by grinding it between two rocks: see Section 10.5.1), mixed with water and given a little heat, produces flatbread and biscuits that will last quite a while before rotting. You can use wheat to make ale too: see Section 10.2.5.

• Dried wheat stores well and will still grow wheat plants next spring.

• To separate the grain from the plants, just lay cut plants on the ground and hit them with sticks: this causes the grain to separate. Next, to separate the wheat from the chaff (i.e., the grains from the empty husks), just throw your grains into the wind: the chaff and straw will be carried away while the denser wheat falls down.

• Pre-domesticated wild wheat had an important feature that was soon bred away: the seed heads would open to scatter their seeds on the ground or in the wind. Humans naturally preferred to collect wheat with closed pods—since then the seeds weren’t lost—and this quickly led to domesticated wheat, which keeps its seed heads closed. These closed seed heads mean that domesticated wheat is now unable to survive without humans to plant it.

NOTES

• Wheat is grown on more land than any other food and is the most popular vegetable source of protein.

• Bread is a staple food that’s both simple and nutritious and has been consumed for tens of thousands of years, so it’s no surprise it’s inspired several sayings: depriving someone by taking the bread out of their mouth, being savvy and knowing which side your bread is buttered on, the idea that we can’t live on bread alone, and things being the greatest thing since sliced bread.

• Sliced bread, incidentally, was first commercially available on July 7, 1928 CE. Before then you had to slice bread yourself, all the while whispering “the greatest thing ever would be to not have to do this anymore.”

• You can invent fans if you don’t want to rely on windy days when separating wheat from chaff: combine an electric motor (Section 10.6.2) with a propeller (Section 10.12.6).

• Domestication of wheat can be achieved in as little as twenty years!¹³

7.26: WHITE MULBERRY

ORIGIN

China

USES

• This plant is the preferred food for silkworms (see Section 8.15), which produce silk.

NOTES

• For more than a thousand years the Chinese traded silk while also keeping the knowledge of how it was produced completely secret from the rest of the world, ensuring they’d have a monopoly on this extremely lucrative product. (The fact that anyone who exported silkworms or their eggs was condemned to death probably helped.)

• Theories of where silk came from included the petals of a rare flower, the leaves of a special tree, or even an insect that would eat until it exploded, sending silk everywhere.

• These theories were sadly incorrect: silk comes from the cocoons of silkworms and can be harvested by simply taking the cocoons off a white mulberry tree, but if you want to produce it on a larger scale you’ll want to farm the silkworms yourself. Section 10.8.4 has complete instructions.

7.27: WHITE WILLOW

ORIGIN

Europe and Asia

USES

• The leaves and bark contain salicin, which metabolizes into salicylic acid in the body when eaten. Salicylic acid is the primary ingredient in aspirin, which is one of the most commonly used drugs in the world, and one you’ll want to have access to.

• You can use willow to make baskets, fishing nets, fences, and walls. Humans have been using willow to make things for a really long time: willow nets date back to 8300 BCE!

NOTES

• Aspirin can treat the symptoms of fever, reduce inflammation, and provide temporary pain relief.

• Like sugarcane, willow is a good source of biomass for fuel.

• Willow, like ash, is a tree that really wants to grow: so much so, in fact, that it’s possible to cut down a willow and not kill it. This is done through “coppicing”: a process in which you cut down the tree in winter—when it’s dormant—but leave the stump. In spring, the tree will use the same root system to regrow, and it can be re-harvested by undergoing coppicing again, in two to five years. Regularly coppiced trees remain at their juvenile stage, and therefore don’t die of old age, which makes them a renewable source of wood fuel! Other trees can be coppiced too, but willows are particularly well suited due to their growth speed.

7.28: WILD CABBAGE

ORIGIN

Mediterranean and Adriatic coasts

USES

• Can be selectively bred into kale, Brussels sprouts, broccoli, cauliflower, and more. All are descended from the same ancestor, making this plant very versatile for selective breeding!

NOTES

• Cabbages grow readily in most climates and soil types, so they are an easy source of calories.

7.29: YAM

ORIGIN

Africa, Asia

USES

• A starchy vegetable rich in minerals, carbohydrates, and vitamins, though lacking in protein.

NOTES

• This is distinct from the sweet potato found in America, also called “yams,” because humans just love being confusing.

• Many yams, especially those that haven’t been domesticated, are toxic. The toxins are destroyed by boiling, baking, or roasting the yams, so be sure not to eat these raw! Plus they’re better when they’re roasted; you’ve got to try them.

Sidebar: It’s Time for Some Beer

One of the oldest naturally extant recipes (i.e., one that reached the present via ancient Sumerian clay tablets from around 1800 BCE, rather than being brought here by time travelers) is a recipe for barley beer. Well, technically it’s a hymn proclaiming the charms of one of the Sumerian gods, Ninkasi, but it actually spends most of its time describing how to make beer instead. It’s as if the Christian Lord’s Prayer read:

Our Father, who art in heaven, hallowed be thy name. Thy kingdom come, thy will be done, on Earth as it is in heaven. Give us this day our daily bread, including pizza, which is a flatbread topped with cheese, if thy pizza be plain, and with vegetables for thy vegetarians, or with meat, if thou hath put meat lovers amongst us, all of which can be prepared in thy name as follows . . .

If you were in a religious society and wanted information to be preserved and shared for as long as possible, wrapping it in the cloak of a prayer or hymn could easily do the trick.* Here’s an excerpt of that hymn to Ninkasi, translated from ancient Sumerian, that contains this ancient beer recipe:¹⁴

Your father is Enki, Lord Nidimmud,

Your mother is Ninti, the queen of the sacred lake.

Ninkasi, your father is Enki, Lord Nidimmud,

Your mother is Ninti, the queen of the sacred lake.

You are the one who handles the dough and with a big shovel,

Mixing in a pit, the bappir [a Sumerian unleavened barley bread] with sweet aromatics,

Ninkasi, you are the one who handles the dough and with a big shovel,

Mixing in a pit, the bappir with date-honey,

You are the one who bakes the bappir in the big oven,

Puts in order the piles of hulled grains,

Ninkasi, you are the one who bakes the bappir in the big oven,

Puts in order the piles of hulled grains,

You are the one who waters the malt set on the ground,

The noble dogs keep away even the potentates [autocratic rulers like queens or kings],

Ninkasi, you are the one who waters the malt set on the ground,

The noble dogs keep away even the potentates,

You are the one who soaks the malt in a jar,

The waves rise, the waves fall.

Ninkasi, you are the one who soaks the malt in a jar,

The waves rise, the waves fall.

You are the one who spreads the cooked mash on large reed mats,

Coolness overcomes,

Ninkasi, you are the one who spreads the cooked mash on large reed mats,

Coolness overcomes,

You are the one who holds with both hands the great sweet wort,

Brewing it with honey and wine.

Ninkasi, you are the one who holds with both hands the sweet wort to the vessel

Brewing it with honey and wine.

The filtering vat, which makes a pleasant sound,

You place appropriately on a large collector vat.

Ninkasi, the filtering vat, which makes a pleasant sound,

You place appropriately on a large collector vat.

When you pour out the filtered beer of the collector vat,

It is like the onrush of Tigris and Euphrates.

Ninkasi, you are the one who pours out the filtered beer of the collector vat,

It is like the onrush of Tigris and Euphrates.