Fruits and Vegetables

1
Fruits and Vegetables
2
Outline

• This stuff is scattered in the book.
• Pp. 92-101
• pp. 44-47
• Tomato
• Apple
• Citrus
• Brassica
• Banana
• Carrot
• Onion
• Squash and Melon
• Tropical Fruits

3
Fruits Botanical and Popular

• Botanically, a fruit is the ripened ovary wall.
  The ovary is part of the carpel, the innermost
  whorl of a flower, the female reproductive
  structure. The ovary contains the ovules, the
  haploid equivalent to mammalian eggs.
• Some fruits also contain parts of the flower
  base.
• Botanical fruits can be classified as fleshy, dry
  dehiscent, and dry indehiscent. Most of what are
  popularly called fruits are fleshy fruits.
• The generally understood common definition of a
  fruit is sweet and aromatic fleshy plant products
  that are mainly eaten as dessert or a first
  course in a meal, and not as the main meal.
• Thus, many fleshy fruits (in a botanical sense),
  such as tomato and cucumber, are considered
  vegetables in popular culture.
• In botany, a vegetable is simply any plant or
  plant part.
• In the common definition, vegetables are plant
  products eaten with the main course. In taste,
  they are salty or sour or savory, but not sweet.
  Some vegetables are botanical fruits tomatoes
  and cucumbers for example. Others are plant
  stems, leaves, and roots.

4
Legal Fruits

• Botanically, a fruit is an ovary that has ripened
  after fertilization.
• However, in 1883 a 10 duty was placed on all
  vegetables being imported into the US.
• John Nix, an imported from New Jersey, argued
  that he shouldnt have to pay the duty on
  tomatoes, because botanists consider them fruits.
• The case went all the way to the Supreme Court
  (which means at least 3 separate courts examined
  the question). In 1893, the Court ruled that for
  legal purposes, tomatoes were a vegetable, not a
  fruit.
• Based on popular usage vegetables (including
  tomatoes) are eaten at dinner, while fruits are
  sweet and are eaten at dessert.
• Tomatoes are the state vegetable of New Jersey.
  Ohio considers tomatoes to be the state fruit. In
  Arkansas, tomatoes are both the state vegetable
  and the state fruit (indecisive).

5
Tomato Fight!

• In Spain, they have an annual tomato fight

6
Tomatoes

• The tomato is a New World crop, native to the
  west coast of South America and first
  domesticated in Mexico. It is in the Solanaceae
  (nightshade) family, as are potato, chile pepper,
  tobacco, and petunia.
• Species Solanum lycopersicum, but until
  recently Lycopersicon esculentum.
• Brought back to Europe and to Asia (initially to
  the Phillipines) by the Spanish. It grew well in
  the Mediterranean climate and quickly caught on
  there.
• Many varieties. A big distinction determinate
  vs. indeterminate.
• Determinate tomatoes flower and set fruit all at
  once, and have a sfixedsize. Bush tomatoes,
  favored by commercial growers.
• Indeterminate varieties are vine types, which
  contnue to flower and set fruit until killed by a
  frost. Favored by home growers.

7
Tomato Stories

• Lycopersicon means wolf peach, because it is
  related to deadly nightshade. Some thought it
  could be used to generate werewolves this was an
  old German legend about nightshade, which
  Linnaeus borrowed when he named the species.
• It was thought to be poisonous in Britain and
  America, despite being eaten in large quantities
  elsewhere.
• In 1820, Colonel Robert Gibbon Johnson stood on
  the steps of the Salem Massachusetts courthouse,
  in front of 2000 people, and ate an entire
  bushel of tomatoes to prove that they werent
  poisonous. He survived. The local band played
  a mournful dirge as he ate, because they were
  sure he would soon die.
• This story may not actually be true the first
  account appeared in print in 1906. It was
  dramatized in an early television series called
  You Are There, in 1949.
• First varieties to reach Europe were yellow, not
  red. In Italy they were called pomo doro
  (golden apple). This may have been mistranslated
  into French as pommes damour (love apple).
• Some thought they were aphrodisiacs (one of the
  eternal quests of humankind).

8
Tomato Pollination

• The wild plants are self-incompatible they must
  be outcrossed to produce seeds and fruit.
• To facilitate this, the female parts extend well
  beyond the flower, and the stamens stay enclosed
  within the petals.
• The native pollinator, a small bee, didnt move
  with the plants to the Old World.
• Selection for self-fertility was very useful.
  However, the anthers shed pollen very slowly, and
  is aided by the wind or the wing motion of
  bumblebees. In the greenhouse, a vibrator is
  used (the electric bee). This is called buzz
  pollination. The bumble bees want to eat the
  pollen tomato flowers produce very little
  nectar.

9
Growing Tomatoes

• Tomatoes are often picked green (unripe), because
  they are firm and survive mechanical harvesting
  and shipping better.
• Much plant breeding work went into producing
  fruit that could be harvested mechanically. One
  result was the square tomato.
• They can be ripened with ethylene gas.
• Ethylene is a plant hormone that stimulates
  flower opening, fruit ripening, and leaf shedding
  in many plants. It has been used since ancient
  Egyptian times to stimulate fruit ripening, by
  burning incense or by gashing figs in a closed
  room. A modern use it to put unripe fruit in a
  closed paper bag with a banana, which
  concentrates the ethylene the banana produces and
  speeds ripening. It is produced by almost all
  plants, both as part of the natural fruiting
  cycle and in response to wounding or other
  stresses.
• Conversely, florists use ethylene inhibitors to
  extend the shelf life of cut flowers.

10
Flavr-Savr Tomatoes

• The Flavr-Savr tomato was the first genetically
  engineered food product allowed on the US market,
  starting in 1994.
• It was more resistant to spoiling and rotting, it
  had a longer shelf life, than normal tomatoes.
• This was accomplished by blocking the enzyme
  polygalacturonidase, which degrades the cell
  walls and makes fruit more susceptible to fungal
  infection (which is what rotting is).
• Didnt catch on. A big problem was that the
  starting tomatoes were not from a high quality
  strain, so yield was less than half of what good
  commercial varieties produce, and many of the
  fruits were small. Also, the fruits were more
  delicate than regular tomatoes.
• Production ceased in 1997.

11
Apples

• Apple trees (Malus pumila) are native to central
  Asia. The capital city of Kazakhstan, Alma-Ata,
  means father of the apple. (The city is now
  named Almaty).
• Alexander the Great brought them back to Europe
  in 300 BC.
• Apples are members of the Rosaceae, the rose
  family. Many other fruits also come from three
  subdivisions of this family
• The apple subfamily also includes pears and
  quinces. The fruits are called pomes.
• The plum subfamily includes plums, cherries,
  apricots, and peaches stone fruit, also called
  drupes.
• The rose subfamily includes strawberry,
  raspberry, and blackberry. These are aggregate
  fruits several ovaries fused together.
• Apples account for 60 of the temperate regions
  fruit production. It is the worlds second
  largest fruit crop, after oranges.

12
Growing Apples

• Apples can be grown from seeds, that is, by
  sexual reproduction. However, apples are
  genetically diverse, and the process of meiosis
  ensures that every seed will be different from
  all others. This diversity is good for survival
  in nature, but it is bad for agriculture there
  is no easy way to maintain specific varieties if
  the plants are grown from seed.
• Genetic uniformity is achieved by growing them
  vegetatively, by grafting cuttings onto the base
  of other trees. The base tree, called the
  rootstock, is from a strain that is
  disease-resistant and grows well in the region,
  but doesnt produce high quality fruits. The
  scion (the grafted plant), produces good fruits
  of a specific variety.
• When new varieties are desired, the trees are
  grown from seed. Most new varieties appear
  spontaneously among the offspring of genetic
  crosses between different strains. Sometimes bud
  sports appear mutations that occurred in a bid,
  producing a branch on a tree that it noticeably
  different from the rest of the tree.

13
Apple Flower and Fruit

• To produce fruits, apple flowers must be
  pollinated, usually by honeybees.
• The apple fruit consists of an ovary with 5
  carpels fused together, surrounded by accessory
  tissue. The accessory tissue develops from the
  receptacle, the place where the flower is
  inserted into the plant stem.
• The swollen ovary containing the seeds is the
  core, and it is separated from the accessory
  tissue by a thin brown line.
• Most apples are picked by hand, either directly
  by the consumers or by low paid migrant workers.
• Mechanical harvesters are often used for cider
  apples still not well developed.

14
A Few Apple Legends

• Adam and Eve, the first man and woman in the
  Bible. The Devil tempted Eve to eat the fruit of
  the Tree of Knowledge of Good and Evil, which God
  had forbidden. She then convinced Adam to eat it
  also. For this action, God tossed them out of
  the Garden of Eden and forced them and all their
  descendants to work for a living. But, this
  fruit may have actually been an apricot it is
  not clear that apples grew anywhere near the
  Middle East when the Bible was written.
• William Tell, the Swiss hero and crossbow expert,
  refused to bow to the hat of the Austrian
  overlord (Gessler), which had been set on a pole
  in the town square. For this crime, he was
  forced to shoot an apple off his sons head. When
  Gessler asked why he had taken out two crossbow
  bolts, Tell replied that if he had missed with
  the first one, the second arrow was meant for
  Gessler himself. This sparked a rebellion that
  led to Switzerland becoming free of the Austrian
  Empire in 1315.
• Isaac Newton supposedly discovered gravity, or
  at least had the insight that gravity attracted
  the Moon towards the Earth in the same way that
  it attracted the apple toward the Earth, when an
  apple fell on his head.
• And New York City is the Big Apple, the
  Beatles record company Apple Corps, and the
  Apple computer company.

15
Johnny Appleseed

• Johnny Appleseed. John Chapman (1774-1845). He
  spread apples to western Pennsylvania, Indiana
  and Ohio.
• He wore old ragged clothes, a pot on his head,
  and went barefoot most of the time. He was a
  vegetarian who was uncomfortable with romance,
  and he never settled down. Well-liked by all, a
  strong believer in the Swedenborg version of
  Christianity.
• At that time, this area was part of the Old
  Northwest Territory, land west of the Appalachian
  Mountains, only lightly settled by Europeans.
• It had been French territory, but was ceded to
  Britain in 1763.
• The British forbade European settlement west of
  the Appalachians.
• After the American Revolution, settlement began,
  despite armed resistance from the Native
  Americans. Resistance east of the Mississippi
  River ended in 1832, with the Blackhawk War in
  this part of Illinois. Abraham Lincoln
  participated.
• Johnny Appleseed had a business he planted apple
  nurseries from seeds, then left a local resident
  in charge. After the trees grew, they were sold
  to the settlers.
• Apples were not well adapted to life in America,
  so using seeds instead of grafts aided in finding
  workable varieties.

16
Cider

• The apples planted by Johnny Appleseed were
  mostly used to make cider. We call this stuff
  hard cider today.
• Cider is made by grinding ripe apples, then
  pressing out the juice. The juice is allowed to
  ferment for up to 3 months.
• During this time period, cider was a common
  beverage, since water was generally contaminated.
  
• Fermentation stops when the alcohol content
  reaches about 10 this kills the yeast.
• The alcohol in cider can be concentrated to make
  applejack. The pioneer method is
  freeze-distillation. The cider was simply left
  out in winter weather. Some of the water would
  freeze, as pure water ice, leaving the alcohol
  still liquid. The colder the weather, the
  stronger the cider.
• During Prohibition (1930s), alcohol as illegal,
  and cider got re-defined as unfermented ,
  unclarified apple juice . Sometimes called soft
  cider.

17
Citrus

• The citrus family (Rutaceae) contains many edible
  fruits orange, grapefruit, tangerine, lemon,
  lime, and several other less well known species.
• Not really clear how many species there are lots
  of hybrids, both ancient and modern. And, some
  "species" are clonally propagated and not
  sexually reproducing.
• The family is native to tropical southeast Asia.
  Most varieties are very sensitive to frost and
  can only be grown where it never freezes.
• Citrus flowers each have several carpels, and the
  fruits have a thick rind that surrounds a set of
  segments, each derived from a single carpel. The
  segments are filled with pulp.

18
Citrus History

• The citron was widely grown in the Mediterranean
  region in Greek and Roman times.
• Sour oranges, lemons, and limes were introduced
  by Arab traders in the Middle Ages.
• The sweet orange, today the worlds leading fruit
  crop, was brought to Europe by Portuguese traders
  in the 1500s.
• Citrus came to the New World with the Spanish.
• Florida oranges are mostly grown for orange
  juice.
• Navel oranges came from Brazil, but all US navel
  oranges are probably descended from two trees
  planted in Riverside California in 1873.

19
Citrus Fruit

• Orange trees take 3 years to mature, and then
  bear fruit for about 20 years.
• Citrus fruits have a thick rind that contains oil
  glands. The glands secrete a fragrant essential
  oil, which attracts animals.
• The fruits have several fused carpels each
  orange slice is derived from a single carpel.
• The fruits only ripen while on the tree, so they
  have to be picked when ripe, but not over-ripe.
• Oranges on the tree are a mottled yellow and
  green color. The orange color is due to
  carotene, which is masked by chlorophyll in the
  fruit. Ethylene gas can be used to speed up the
  degradation of the chlorophyll, leading to the
  orange color.
• Citrus fruits are high in vitamin C, which
  prevents scurvy.

20
Scurvy

• Scurvy is a disease caused by a vitamin C
  deficiency. Vitamin C is needed to help
  synthesize collagen, the main protein in our skin
  and connective tissue.
• A person with scurvy becomes weak and listless,
  spots form on the skin, and the mucus membranes
  bleed. In bad cases, old wounds open up and the
  teeth fall out. If not treated, it is lethal.
• Scurvy used to be very common on long sea
  voyages. Vitamin C is found in fruits,
  vegetables, and fresh meat, but all of these were
  lacking. Sailors ate salted meat and hard
  biscuits.
• Most animals, but not primates (or guinea pigs)
  can synthesize their own vitamin C.
• James Lind, a surgeon in the British navy,
  described how citrus fruits could prevent and
  cure scurvy in 1753. His ideas weren't
  consistently followed until the early 1900's.
• British sailors are called "limey" because they
  were forced to eat limes to prevent scurvy.
• Work with guinea pigs starting in 1907 led to the
  understanding that a specific nutrient was
  lacking, and eventually to the isolation of
  vitamin C and an understanding of how it works.

21
Orange Juice

• Most Florida oranges are converted into juice.
• Most fruit is hand picked. But mechanical
  harvesters are improving. One method is to shake
  the tree hard enough to knock all the fruit off.
• The ripe oranges are squeezed to extract the
  juice. Then, pulp and seeds are filtered out
  most of this ends up as animal feed. The juice
  is then concentrated by evaporation, then frozen.
  It is now "frozen concentrated orange juice".
  It gets shipped to packaging plants around the
  country, often dairies, since the packaging
  process is the same as for milk. It gets
  reconstituted by adding water, then sold to the
  consumer.
• Some pulp is added back to produce the pulpy
  varieties favored by some consumers.
• Frozen concentrated orange juice is a commodity
  whose futures (bets on future costs) are traded
  publicly.

22
Brassica

• The Brassica genus is part of the mustard family.
  A wide variety of vegetable crops come from
  Brassica they are called cole crops. The
  condiment mustard also comes from members of this
  genus.
• Members of Brassica oleracea include cabbage,
  collard greens, kale, Brussels sprouts, kohlrabi,
  broccoli, and cauliflower. The different strains
  have been bred for different traits.
• Also, B. chinensis is bok-choi, B. campestris is
  turnip, and rutabaga is B. rapa.
• Also, B. napus is rapeseed or canola, B. nigra is
  black mustard, B. alba is white mustard, and B.
  juncea is brown mustard.
• The yellow color of prepared mustard (called
  American mustard in other countries) is due to
  tumeric added to the ground mustard seed.
• The hot taste of mustard is due to an enzyme
  reaction, which produces a volatile oil when the
  ground seeds are mixed with water.

23
Brassica Plants

• Brassica oleracea is native to the Atlantic coast
  of Europe, and was domesticated in ancient
  Greece. It is a cool weather crop.
• Mustard flowers are yellow or white, and they
  have 4 petals.
• The plants grow as a rosette of leaves that stays
  low to the ground. When it is mature, the plant
  "bolts". It shoots up a tall stem with the
  flowers on it.
• Most of the Brassica vegetable crops are
  harvested before bolting. The expression "gone
  to seed", meaning decreased in quality because of
  age and neglect, comes from this phenomenon.
• Although most Brassica vegetables are eaten
  fresh, cabbage can be converted to sauerkraut by
  shredding it and allowing it to ferment in salt
  water. Sauerkraut can be stored for a long time,
  and it retains vitamin C.

24
Brassica Breeding

• The different varieties come from breeding for
  different traits.
• Cabbage has lateral branches and meristems
  suppressed, so all growth goes into leaves
  produced by the terminal meristem.
• Brussels sprouts are similar to cabbage, except
  each lateral meristem develops into a little
  head.
• Kohlrabi is swollen stem bases.
• Broccoli heads are immature flower buds
• Cauliflower is a mass of stem tips, harvested
  before the flowers develop. The white color is
  due to a mutation that inhibits chlorophyll.

25
Triangle of U

• Brassica species easily hybridize, and there is a
  set of tetraploid species derived from
  hybridization of diploids followed by doubling
  the chromosomes.
• Chromosome numbers reflect the ancestral species.
• First noticed by Woo Jang-choon, a Korean working
  in Japan, in 1934. By the time his name had gone
  from Korean to Japanese to English, it came out
  Nagaharu U.

26
Jack-o'-Lantern

• Carving faces in turnips is (allegedly) an old
  tradition in the British Isles. Pumpkin carving
  is more recent (pumpkins are a New World crop).
• An Irish legend, with many variants explains the
  origin Jack was a farmer who met up with the
  Devil one day. Jack managed to trap Satan in his
  wallet by putting a cross in there (the Devil
  lost his powers when faced with a cross). He let
  Old Scratch out only when he promised to never
  take Jack's soul. One day Jack died, and Heaven
  refused him he hadn't been a very good person.
  And, due to his bargain, Hell also refused him.
  Jack was forced to wander for eternity in the
  darkness. But, the Devil, having a sense of
  humor, tossed him an ember from Hell, which never
  goes out. Jack hollowed out a turnip, his
  favorite vegetable, and put the ember in there to
  use as a lantern. He then wandered the Earth
  endlessly, and he became know as Jack of the
  Lantern, or Jack-o'-lantern.

27
Banana

• Genus Musa, several species. All edible bananas
  are lumped together as Musa x paradisiaca, which
  reflects their hybrid origin.
• Two forms are popular the sweet banana we eat as
  a fruit, and the starchy plantain, which is
  cooked and eaten as a vegetable in many tropical
  countries.
• In Asia, they are also used for beer making, and
  in general are used about like we use potatoes.
  Also, fiber for cloth and paper can be extracted.
  
• Native to Southeast Asia and northern Australia.
  The wild banana was very important in
  pre-agricultural days. Probably first
  domesticated in New Guinea
• Spread to India by 600 BC, and throughout the
  Pacific Ocean region by the Polynesians. Arab
  traders brought it to Africa about 2000 years
  ago. It flourished and spread throughout the Old
  World tropics.
• Brought to the New World by the Portuguese in the
  1500s. Did well here too.

28
Bananas as Plants

• The banana is a monocot, and the trunk of the
  banana tree is really tightly packed leaf bases
  arising from an underground corm.
• The plant takes about a year to mature, starting
  from a cutting. It then flowers and sets fruit.
  The plant then dies, but the corm send out new
  stems (called suckers).
• Fruits are picked green (unripe). Ripening is
  induced are they have been shipped to market, by
  treating them with ethylene gas.
• Most varieties are sterile triploids, which are
  propagated vegetatively. They are seedless for
  this reason.
• Also leaves them vulnerable to pathogens bananas
  are genetically identical, so a pathogen that
  kills one will probably be able to kill all of
  them. The banana industry is periodically
  devastated by such diseases, and much breeding
  work goes into developing resistant varieties.

29
Seedless Fruit

• Banana fruits develop without fertilization.
  This is called parthenocarpy, and it is a common
  way of getting seedless fruit. It is due to a
  spontaneous genetic mutation, and it is found
  naturally in many plants.
• When a plant is moved from its ancestral home to
  another part of the world, the pollinating insect
  (or bird, etc.) often doesnt came along or cant
  survive.
• A variation on parthenocarpy some fruits need
  fertilization to develop, even though the embryos
  abort. Thus the seeds are tiny or non-existent.
• In some species, spraying with plant hormones
  like auxin can induce parthenocarpy. This is
  commonly done with garden tomatoes.
• This can also be done with genetic engineering.
• Triploids are naturally sterile and seedless.
  Triploids can be propagated vegetatively, or
  triploid seeds can be produced by crossing a
  diploid with a tetraploid.

30
Banana Republics

• Bananas rot quickly after harvest. Before steam
  ships, they were almost unknown in temperate
  climates.
• Around 1900, refrigerated steam ships were able
  to bring them to market in America and Europe.
  This led to a vast increase in their popularity.
  At one point, bananas were cheaper than
  local-grown apples!
• The United Fruit Company owned much of the land
  and infrastructure in several Central American
  countries, including Nicaragua, Honduras,
  Guatemala, Panama, and El Salvador.
• The people who had formerly farmed the land were
  then hired at extremely low wages to work the
  plantations.
• Several violent coups were engineered by United
  Fruit to remove popular governments that wanted
  to interfere. Vastly unequal distribution of
  wealth and political problems remain as a legacy
  in Central America to the present time.

31
Carrots

• Daucus carota. Domesticated form of Queen Anne's
  Lace, a common roadside flower in late summer.
• Umbel-shaped flower.
• Contains carotene, the orange pigment which the
  body converts to vitamin A (retinol), the visual
  pigment.
• The idea that eating a lot of carrots will
  improve your night vision started in England in
  World War 2, when British gunners were able to
  accurately shoot down German airplanes in the
  dark of night. This was actually because the
  British had invented radar, but they didn't want
  the Germans to know that, so the British
  government propaganda ministry started the rumor
  about carrots.
• biennial grow as a low rosette of leaves one
  year, store food in underground taproot (which we
  eat), then send up a flower stalk the next year
  using that food.
• We harvest it after the first growing season.
• Diploid, grown from seed. Commercial seed is
  inbred enough to give uniform growth, but not so
  inbred as to produce inbreeding depression.

32
Carrots

• Native to Afghanistan (it's the center of
  diversity). And other temperate parts of western
  Asia and eastern Europe.
• In the wild, carrot roots are branched and woody
  we have selected for a single unbranched taproot.
• When first domesticated, carrots were purple.
• Caused by a pigment called anthocyanin, which is
  used in many flowers for red, pink, and purple
  shades. It's water soluble, producing
  purple-brown stews
• Spontaneous mutants removed this pigment same
  taste, but no ugly color in the stew.

33
Other Carrot Family Crops

• Carrots are members of the Apiaceae (also called
  Umbelliferaceae) family.
• Aromatic plants with hollow stems, feathery
  leaves, and flowers like umbrellas.
• The flowers attract parasitic wasps, which kill
  garden insects. This makes carrots good
  companions for other garden plants.
• We also eat parsnips, which look a lot like white
  carrots. And celery is also a member of this
  family.
• Many aromatic herbs parsley, dill, coriander,
  cilantro, cumin, fennel, caraway (seeds in rye
  bread), anise (licorice flavor).
• Coriander is the seeds and cilantro the leaves of
  the same plant.
• Some are quite poisonous. For example, hemlock,
  which Socrates was forced to drink for his
  execution for corrupting the morals of the young.
  Hemlock grows wild here in Illinois
• Silphium, a giant member of this family, was used
  for birth control in ancient Roman Empire. It is
  now extinct. Grew only in a small region of the
  Mediterranean coast in Libya, and it was
  over-used.

34
Onions

• Allium cepa.
• Onions are in the Lily family, which is a
  monocot.
• Onion is really a biennial or perennial the bulb
  grows in one year, then it sends up a flower
  stalk in the next year. We harvest them after
  the first season.
• We eat the bulb underground stem base surrounded
  by fleshy leaves
• In former times it was used as medicine for a
  large number of ailments.
• Smell due to release of smelly sulfur compound
• Tears when cutting come from release of sulfuric
  acid and related compounds.
• Can be grown from seed or from seed sets, which
  are small onions grown from seed using a seed
  set gives them a head start so they get bigger
  during the growing season.

35
Onions

• Wild onions are edible it was probably harvested
  from the wild long before it was cultivated.
• Cultivated from early times in both Egypt and
  China by 3000 BC. It stores well.
• Wild relatives in Central Asia, so that's
  probably where it was first domesticated, but no
  direct proof of this.
• We tend to use onion as a food flavoring, but it
  can also be eaten as a vegetable
• unattributed odd "fact" the people who built in
  Pyramids in Egypt may have lived on radishes and
  onions. Wikipedia links to a food/garden site
  that just says it out of the blue.
• Onion (as Allium) is a garden flower blue
  puffball heads. It's a perennial.
• Other relatives garlic, leek, shallot, chives.
• Garlic usage has greatly increased in the US in
  recent years people like spicier food.

36
Squashes and Melons

• Both are members of the Curcurbitaceae, the
  cucumber family. Squashes domesticated in New
  World, melons in Old World Africa and South East
  Asia independently. Very early domestication.
• All are creeping vines with separate male and
  female flowers on the same plant. We eat the
  fruits, which have multiple seeds surrounded by a
  fleshy fruit that has a hard rind.
• Originally grown for the seeds wild relatives
  can be eaten but the flesh is bitter. Seeds high
  in sulfur-containing amino acids. Pumpkin seeds
  are still widely eaten.
• Hard rind makes them easy to store, and soft
  flesh works well as a water source in the desert.

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Squash

• Squash four cultivated species in the genus
  Curcurbita, with lots of variation in form within
  each species, and overlapping between species.
  E.g., "winter squash" and "pumpkin" can be any
  one of the four.
• Types pumpkins, zucchini, butternut, turban,
  acorn, summer, plus others.
• Squash was gown along with maize and beans in
  ancient Mexico. The vine provides a ground cover
  that suppresses weeds, the beans fertilize the
  soil by fixing nitrogen, and the maize provides a
  living pole for the beans to grow on. This is
  called the three sisters method.
• Giant pumpkins are Curcurbita maxima. Current
  record (2010) 1810.5 pounds. Its been going up
  by 50 pounds a year or so.

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Melons

• Watermelon are from west Africa. Eaten in
  ancient Egypt by 2000 BC. King Tutankhamen's
  tomb contained many watermelon seeds. Grown in
  China by 1000 AD.
• Cantaloupe and honeydew melons are from central
  Asia. Also cucumbers same species.
• Cucumbers can be turned into pickles by soaking
  them in salt water (brine) at low pH (acid).
  Sometimes vinegar is added, along with spices
  such as dill and garlic. A bacterial fermentation
  process turns them sour. Originally used for
  food preservation, now mostly for flavor. Other
  vegetables can be pickled.
• Playwright Neil Simon once said, Words with a k
  in it are funny. Alka-Seltzer is funny. Chicken
  is funny. Pickle is funny....
• Loofah is a species of curcurbit whose fruit is
  allowed to partially rot, leaving a network of
  fibrous tissue. This is used for scrubbing your
  body the loofah sponge. The fruit can also be
  eaten as a vegetable before it matures.

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Calabash

• The calabash, or bottle gourd, is another
  curcurbit of note. It was one of the first
  domesticated plants.
• It is grown for use as a container, not for food.
  When dried out, the woody rind in strong and
  waterproof.
• Also used as a body for musical instruments,
  stringed, rattles and drums
• and often highly decorated.
• It also has been used for smoking pipe bowls
  Sherlock Holmes (a fictional character) smoked a
  calabash pipe.

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Calabash Origins

• The calabash originated in the dry warm areas of
  southern Africa, where there a wild relatives.
• The wild species have thin rinds the cultivated
  varieties have clearly been selected for thick
  waterproof rinds.
• However, the calabash reached Asia very early it
  has been found at archeological sites that are
  8000 years old.
• Today Asian and African varieties are relatively
  distinct.
• The calabash was also grown in the New World 8000
  years ago, long before Columbus. This leads to.
  another ancient contact story how did it get to
  the Americas?
• The main theory for the past 150 years it
  rafted across the Atlantic Ocean from Africa in a
  mass of vegetation without human assistance. The
  rind is quite waterproof and the seeds are
  capable of germinating after a long dormancy
  period.
• Alternative a boatload of African fishermen
  blown off course and landing in South America.
• Much less likely by boat across the Pacific
  Ocean. Polynesia was settled much later between
  3000 and 1000 years ago.

41
More Calabash Origins

• Recent genetic and archeological study shows that
  the pre-Columbian calabash in America came from
  Asia. (D.L. Erickson et al., 2005, Proc. Nat.
  Acad. Sci USA 10218315-18320)
• This suggests it came over the Bering Land Bridge
  around 12,000 years ago with the original
  inhabitants of the New World, the Paleoindians.
  Sea level was much lower at that time, due to the
  Ice Age glaciers locking up much water.
• They were hunter-gatherers settled agriculture
  hadnt been invented yet. They also brought the
  dog to the New World.
• Dates from carbon-14 decay. It gets into plants
  from carbon dioxide in the atmosphere. When the
  plant dies, no new C-14 is added, and it slowly
  decays into nitrogen. So, the amount of C-14
  left is proportional to how long ago the plant
  died.
• Calibrated by counting tree rings. In some
  places, tree ring chronologies go back 10,000
  years.

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Genetic Evidence

• The scientists involved here wanted to compare
  DNA from New World archeological specimens to
  plants grown today in Africa and Asia.
• They collected calabashes from traditional
  farmers in both Africa and Asia, to avoid getting
  seeds form modern cultivars.
• Also needed very careful treatment of
  archeological material to avoid contaminating
  ancient DNA with modern DNA.
• Looking for differences in the DNA that would
  reliably distinguish between Asian and African
  varieties. There are a few regions in the genome
  that are easy to analyze and known to be quite
  variable. Mostly, the Asian and African varieties
  proved to be very similar in their DNA.
• Found three good differences in the chloroplast
  DNA. All modern Asian varieties had one allele
  and all modern African varieties had the other
  allele.
• Results of the 12 archeological samples, only 10
  produced any data. Of these, the nine that had
  pre-Columbian dates all had the Asian DNA
  markers.
• The one with a post-Columbian date had the
  African markers Columbus brought the African
  variety to the New World, and it has mostly
  replaced the Asian variety.
• So, there is strong evidence that the
  pre-Columbian calabash came from Asia. How it
  got there is not proven the Bering Land Bridge
  theory fits well with other knowledge of how the
  New World was settled.

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Calabash Data
44
Tropical Fruits

• Pineapple, date, figs, coconut, avocado,
  pomegranate, mango, papaya.
• Plus lots of others that are very tasty but don't
  ship well, so are only eaten locally.
• Not to mention nuts, which we haven't even
  touched on.
• The mind boggles