Greetings guys, gals, and non-binary pals!
Welcome back to Botany After Dark!
My name is Kate, and I will be your host for this journey.
Before we begin this episode, I would like to say thank you for all the support the podcast
has gotten since it launched last week.
Your feedback is appreciated and noted.
Today, we venture into the world, of Tomatoes.
*cue intro music*
Let us (Lettuce) begin with a brief history.
Tomatoes are native to the Americas.
From ethnographic accounts and the archaeological record, it is possible to conclude that the
fruit we know as “tomato” has been part of the human diet for thousands of years.
While exact dates are not known, records indicate that by at least 500 BCE, some species of
tomatoes were being actively cultivated in what is present-day southern Mexico.
Some researchers say the tomato’s origin is the region of central Mexico that would
become the Aztec Empire, though others point to the wild species still
growing in the Andes as evidence that they were first domesticated in Peru.
There are other theories that suggest simultaneous domestication and species presence, though
it is most likely that while having Peruvian origins, initial
domestication occurred in central America.
Until we find distinctive archaeo-botanical evidence,
it seems that ultimately, both the time and place of domestication for the tomato are
unknown.
We do, however, know that It was not until the 1500s that European explorers encountered
this fruit and subsequently returned to their homelands with it.
According to accounts, the tomato was widely enjoyed in southern Europe, becoming a component
in many regional dishes, especially in Italy and Spain, where it first arrived.
However, as the fruit moved north, through trade and travel, people began to be wary
of it.
In Britain, for example, the tomato was admired for its beauty but was thought to be highly
poisonous.
“Why” you ask?
Tomatoes had been regularly consumed for most likely thousands of years prior to European
awareness.
What could possibly be the reason?
The berries of this vine, which produces such often flavorful and fragrant fruits, have
a highly acidic nature.
While this is not often problematic unless an individual has a sensitivity to such acids
or a specific allergy to the plant, it bears noting in this instance.
Most often those falling ill directly after consuming this “new food” were from the
upper classes, with their fancy pewter plates and cutlery.
The common folk were fine, in this instance at least, but that is for another day.
That highly acidic juice tomatoes are known for began eating away at the pewter, releasing
the toxic lead contained therein.
It is this that ultimately *lead* to their demise.
While a relatively stable compound for creating goods, it is also highly toxic.
According to the World Health Organization, lead poisoning causes abdominal pain, constipation,
headaches, irritability, memory problems, sterility, and peripheral neuropathy.
In severe cases, these potential symptoms extend to, anemia, seizures, coma, or death.
It is no wonder, therefore, why the culprit was seen as this new and fascinating import,
rather than the utensils the aristocracy had used for centuries.
While lead compounds were inherently present in everything from city pipes and makeup,
to the very air people breathed, in some instances, the general
public had not encountered a substance that was factually edible, yet
also corrosive enough to directly release the lead contained in the pewter flatware.
Until then.
People fell ill and likely died from exposure to these toxins, thus beginning the tomato’s
200 years of uncertainty.
Naming associations likewise played a strong role in furthering this assumption.
Though it was not officially, scientifically identified as Solanum lycopersicum until Carl
Linneas’ 1753 text “Species Plantarum” many had previously
observed the physiological similarities between the tomato and other native European species
of the same genus.
The tomato bore a rather striking resemblance to the fruit of the deadly nightshade.
I will come back to that in a moment.
This is not surprising, as both are part of the Solanaceae family, along with the potato
and other such plants.
In the literature, it is also uncertain as to which species
observers were referring, as the deadly nightshade (Atropa belladonna), woody nightshade (Solanum
dulcamara), and black nightshade (Solanum nigrum) are similar,
but rather different plants.
I will go into depth on their particular characteristics at a later date, but for now, suffice to say
that while the former two are potentially toxic, if ingested, the
latter is more or less benign.
If the berries are consumed ripe.
If they are unripe, generally appearing green rather than black or dark purple, the berries
contain solanine.
In that instance, a person might experience severe stomach upset, nausea, abdominal pain,
diarrhea, and burning at the back of their throat, rather
like someone might experience from eating green potatoes.
This is not, however, a characteristic of ripe tomatoes.
Though by the late 1500s, roughly 100 years after the fruit’s introduction, most of
France, Spain, and Italy were actively consuming them, creating complex
national dishes with these new additions, John Gerard, an English
barber-surgeon, still believed them to be poisonous.
Oddly, he was one of the first to cultivate them in England.
In his highly plagiarized herbal compendium, published in 1597, Gerard characterized the
tomato through the poisonous nature of its leaves and stems,
which contain glycoalkaloids, among which is the previously mentioned
solanine.
As is readily evident, however, the ripened fruit poses no problems to most humans, if
consumed in a sensible manner.
Returning to the naming structure, and the tomato’s resemblance to other European nightshades,
it bears noting that the colloquial name for the fruit
of the nightshade in several regions was the Wolf peach.
This was in reference to the erroneous belief that witches used these berries to turn either
themselves or others into werewolves.
Additionally, prior to the introduction of the tomato, poisons were sometimes coated
in a palatable sweet confection and left out for wolves.
It is supposedly this that French botanist, Tournefort, initially named the plant after,
providing the Latin botanical name, Lycopersicon esculentum.
It translates to "wolf-peach," which was also the name Galen gave to those poisonous lures
in the 3rd century, CE.
Though that designation was later changed, the inference remained, along with subsequent
correlations to the nightshade family.
In its native habitat, the tomato was known for being nutrient-rich, and its seeds revered
for both aphrodisiac and divinatory properties.
It is unknown whether this was shared during initial contact with the Spaniards, though
later the seeds were touted as aphrodisiacs in France.
In the Aztec Nahuatl [ˈnaːwatɬ] dialect, the tomato was called tomatl [ˈtomat͡ɬ],
which the Spanish then altered to tomate.
Today, the tomato is cultivated in over 140 different countries, and still has species
growing wild in its native range.
Plants can be either determinate (which have a set height and produce all their flowers,
and subsequently all their fruit, at once) or indeterminate (continuing
to grow and produce fruit throughout the growing season, sometimes
getting rather large).
The stems and leaves of these plants tend to be covered in short, spiky hairs and often
illicit a contact dermatitis response, when in direct contact with skin.
It is these hairs that facilitate the vining process, allowing the plant to better grip
onto its support structure.
These plants can generally grow 1 to 3 meters, or 3 to 10 feet in height when properly supported
on a frame or other structure.
Their leaves can be either compound, or simple, depending on the species and variety, though
cultivars have a higher tendency toward simple leaves.
It is the flowers’ appearance that are most indicative of other Solanaceae species, having
fused anthers, surrounding the pistil’s style.
This allows the plant to be self-fertilizing.
Interestingly, though most Solanaceae species share the distinctive downward-facing
flowers, often either dark blue-purple or white, just
under half are not able to self-fertilize.
This is an adaptive trait designed to ensure the genetic diversity of the species.
Though it is often classed as a vegetable, the tomato is a true fruit, or more specifically
a berry.
The tomato itself is formed from the ovary of a flower, each containing at least two
cavities for seeds, though sometimes many more, as in the case of beefsteak
tomatoes and the like.
In the event that you would like to grow your own plants from seed, it is important to note
that the seeds must come from a mature fruit and be dried and/or
fermented prior to germination.
Also, though tomato plants tend to be more heat or drought tolerant than some garden
species, simply by being native to hotter climates, they still need certain particular
care.
When the soil is dry, for example, they need water, just as many plants do.
However, often people over-water their plants, trying to make up for a short drought.
Especially in the case of the tomato, this tends to wash away calcium present in the
soil.
As such, sometimes tomatoes begin to rot on the vine.
Though there can be other causes, calcium deficiency is the most prevalent and the most
easily treatable.
There will be links below, as there are for all my sources, but the most common cause
of what is called “blossom end rot” is either a dilution of calcium,
in the case of too much water, or a lack of calcium, in the case of too little water.
This is because calcium is, by nature, a water-soluble mineral.
At present, the only known ways to combat this condition is to remove any affected fruit
from the plant, and side-dress the plant with bone meal, to
replace the absent calcium.
There are likewise organic calcium foliage sprays you can purchase to apply to the leaves
every week or so.
This does not salvage already rotten tomatoes, though it does potentially stop the situation
from happening to future harvests.
One way to mitigate this is to mix crushed eggshells into the soil, especially around
where the root ball of a newly transplanted tomato plant will grow.
Again, calcium is water-soluble and is much-needed for the plant’s and subsequent fruit’s
development.
Err on the side of caution and add too much, rather than not enough.
The tomato is a fascinating plant and part of culturally-significant dishes world-wide.
It has a long and storied past, filled with falsehoods, intrigue, and uncertainty.
Though today, one of the most widespread and well-known food crops, it likely started as
an invasive weed, spreading from its Peruvian homeland, northward into
what is today southern Mexico, where it was cultivated into more prominent, robust variants
of its wild ancestors.
Remember though, that the plant’s foliage is both toxic to ingest and can sometimes
incite a severe rash, if it comes into contact with skin.
In instances such as this, while you may have identified the plant correctly, as present-day
tomatoes are rather distinctive, and the fruit may well be edible,
that that does not extend to the whole plant.
Only certain creatures are able to eat the foliage and not experience significant detrimental
effects.
Just because it is natural, does not mean it is consumable.
If you look in the episode description, there are links to my blog and YouTube channel,
where I talk more about plants, as well as my Patreon and relevant social media links.
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To all my listeners at home, work, or somewhere in between, thank you for tuning in.
I’ll talk to you next week about Poison Oak.
Should be an interesting show.
Have a good one.
This is Kate, signing off.