smallest plant seed

The smallest of all the seeds

I recently listened to someone make a defence of a very high view of biblical inspiration. The claim was that every word in the Bible was written down by authors whose involvement in the process was little more than taking dictation from God. If that’s correct, the presenter explained, it would follow that there are no errors of any kind in the Bible.

After making his case the presenter moved on to dealing with “apparent errors” in the bible, starting with its “scientific claims”. Valiant attempts at explaining away biblical cosmology and human anatomy were made before he moved on to one of Jesus’ parables: the parable of the mustard seed. The version recorded in Matthew reads:

Mt 13:31–32 He put before them another parable: “The kingdom of heaven is like a mustard seed that someone took and sowed in his field; it is the smallest of all the seeds, but when it has grown it is the greatest of shrubs and becomes a tree, so that the birds of the air come and make nests in its branches.” 1

This parable contains a well known example of a claim that when taken at face value is absolutely false; that of the mustard seed (brassica nigra 2 ) being the smallest seed. Here’s the thing: the mustard seed is not the smallest seed – not by a long shot 3 . The claim is flat out wrong as there are many seeds which are much smaller. And because it’s Jesus making the claim this example of “scientific inaccuracy” is especially powerful – not only can it be said that “the Bible is wrong”, but Jesus is too. 4

What follows is a transcript of what the presenter said. He started off by explaining that “some” believe that,

“Jesus, perhaps because he was constrained by his understanding of the world around him, thought it may be the smallest seed.”

“I’d suggest to you that’s almost blasphemous; this is the son of God.”

Sadly, it’s all too common in conservative Christian circles for those who hold strong views on a topic to fling accusations of ‘blasphemy’ or ‘heresy’ in the direction of those who don’t share their views. But, such is life. The presenter continued:

“So how do we understand it? Maybe it was the smallest of the seeds that a sower would have sown. Qualify the word ‘all’ for us. We don’t know; Jesus was there; maybe there was a pile of seeds in front of him and he said “of all these seeds the mustard seed is the smallest one. We don’t know do we. And so I think we need to be careful before we start reading this stuff into the text.”

What a fantastic example of special pleading! Let’s take a look at what the passage actually claims.

The Parable of the Mustard Seed

This teaching of Jesus is found in the synoptic gospels. First, Matthew:

Mt 13:31–32 He put before them another parable: “The kingdom of heaven is like a mustard seed that someone took and sowed in his field; it is the smallest of all the seeds, but when it has grown it is the greatest of shrubs and becomes a tree, so that the birds of the air come and make nests in its branches.”

Mk 4:30–32 He also said, “With what can we compare the kingdom of God, or what parable will we use for it? It is like a mustard seed, which, when sown upon the ground, is the smallest of all the seeds on earth; yet when it is sown it grows up and becomes the greatest of all shrubs, and puts forth large branches, so that the birds of the air can make nests in its shade.”

Lk 13:18–19 He said therefore, “What is the kingdom of God like? And to what should I compare it? It is like a mustard seed that someone took and sowed in the garden; it grew and became a tree, and the birds of the air made nests in its branches.”

Only Matthew and Mark mention the seed’s size, describing it as being either the smallest of “all the seeds”, or of “all the seeds on earth”.

Note what the gospels don’t say:

  • They don’t say that there were piles of different varieties of seeds in front of Jesus
    • In Matthew (13:1) he’s sitting by the sea, an unlikely location for piles of different kinds of seeds to be lying around
    • In Mark (4:10) he’s alone with the disciples somewhere; there’s no reason to think that this quiet place alone would have had piles of different types of seed lying around
    • In Luke (13:10) he’s in a synagogue on a sabbath day, also an odd place to imagine there’d be piles of different seed varieties lying around
  • They don’t say “of all these seeds that are sown on the ground the mustard seed is the smallest one” as the presenter wished it said
  • They don’t qualify the word “all”

No further qualification is given – the gospels don’t say that the mustard seed was just a small seed, they don’t say that it was the smallest of the seeds sown in fields, and they don’t say it was the smallest seed known to mankind. They state that the mustard seed was the smallest seed.

The whole point of the parable depends on the mustard seed being thought of as the smallest seed. Jesus was trying to get the message across that the kingdom of God begins as t_he very smallest thing_ and would end up huge, so he chose the mustard seed as his illustration. It was known as the smallest seed, and people knew that it grew into a sizeable plant (I’ve seen them in Israel a couple of meters high at least).

Elsewhere the mustard seed is used in exactly that sense. For example, having failed to cast a demon out of a boy the disciples ask Jesus,

Mt 17:19–20 “Why could we not cast it out?” He said to them, “Because of your little faith. For truly I tell you, if you have faith the size of a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move; and nothing will be impossible for you.”

So, to come back to our presenter, when he demands that the word ‘all’ is qualified for him, he’s demanding something of the gospels that they have no interest in doing. The gospels don’t qualify ‘all’. If the presenter wants to add to the text and qualify the unqualified, that’s his own business. It’s not a little ironic that the presenter’s final sentence was,

“I think we need to be careful before we start reading this stuff into the text.”

The point is that the mustard seed was proverbially small 5 – there was no other seed that was smaller. And that’s exactly what we find in Jewish writing.

Mustard seeds in contemporary thought

The view that the mustard seed was the smallest of all the seeds is assumed in Jewish thought from the time of Christ.

The Mishnah’s discussions on the purity and impurity of an amazing range of kitchen utensils makes for pretty dull reading. But, trawl through it for long enough and you’ll find the rules around just how infinitesimally small an amount of “joined up” egg-based dough was required to pollute a kneading-trough standing on an angle 6 :

…even if [the pieces of dough that made up the egg’s bulk] were small as a mustard seed—it is joined together. (m. Tohar. 8:8) 7

There we go. When they wanted to describe the very smallest amount of something, the illustration they used was the mustard seed.

Next up, the Babylonian Talmud. This time we find out just how little menstrual blood the Israelite women considered to be enough to make them ritually unclean:

“Israelite women imposed a strict rule on themselves. If they produce a drop of blood as small as a mustard seed, they refrain from having sexual relations on its account until seven clean days [on which no further blood appeared] have passed.” (b. Ber. 31A) 8

Once again the mustard seed is used to illustrate an infinitesimally small amount of something; in this case, blood.

Even in today’s Middle East the idea still lingers – the Theological Dictionary of the New Testament informs us of,

an Arab proverb: “No mustard-seed slips from the hands of the miser.” 9

More examples of the mustard seed being used proverbially as the smallest amount of anything could be given but I’ll spare you.


If you subscribe to the idea that every passage in the Bible should be taken literally by default, and you also believe that every claim in the Bible is scientifically accurate, then you’re going to get yourself into trouble.

Though seemingly pious, this literalist approach to biblical interpretation doesn’t make sense on any level. After all, the bible was written by, and to, people who lived thousands of years ago so if it contained modern science it wouldn’t have made any sense to those it was addressed to in the first instance.

So, coming back to that presentation defending a “high” view of inspiration… It turns out that because of the presenter’s presuppositions of inerrancy and scientific accuracy of scripture he felt the need to explain away what appeared to him to be a scientifically inaccurate claim in the text. Instead, he should have recognised that he was dealing with a colloquialism; a figure of speech. Had he done so he wouldn’t have completely missed the point of what Jesus was teaching. What he should have recognised is the passage’s proverbial use of the mustard seed’s small size, not a scientific claim about their comparative size.

The mustard seed being the smallest seed is not a question of science, it’s a question of culture.

So, if you’re reading something that looks like a scientific claim, first make sure that you’ve taken the cultural context into account before declaring the passage’s apparent scientific claim a hill to die on.


Unless otherwise noted all scripture quotations from The Holy Bible: New Revised Standard Version (Nashville: Thomas Nelson Publishers, 1989) ↩

R. T. France, The Gospel of Matthew (The New International Commentary on the New Testament; Grand Rapids, MI: Wm. B. Eerdmans Publication Co., 2007), 527. ↩

See Moles, Angela T., David D. Ackerly, Campbell O. Webb, John C. Tweddle, John B. Dickie, and Mark Westoby. “A Brief History of Seed Size.” Science 307, no. 5709 (January 28, 2005): 576-580. ↩

Let’s be clear – the issue here isn’t lazy atheist arguments against the Bible, but fundamentalist Christians who burden the Bible with claims it doesn’t make for itself. ↩

Ulrich Luz, Matthew: A Commentary (ed. Helmut Koester; Hermeneia—a Critical and Historical Commentary on the Bible; Minneapolis, MN: Augsburg, 2001), 261. ↩

Jacob Neusner, The Mishnah : A New Translation (New Haven, CT: Yale University Press, 1988), 1054. ↩

Jacob Neusner, The Babylonian Talmud: A Translation and Commentary (vol. 1; Peabody, MA: Hendrickson Publishers, 2011), 205. See also b. Meg. 4:4, I.7.L. ↩

Claus-Hunno Hunzinger, “Σίναπι,” ed. Gerhard Kittel, Geoffrey W. Bromiley, and Gerhard Friedrich, Theological Dictionary of the New Testament (Grand Rapids, MI: Eerdmans, 1964–), 288. ↩

Updated: May 21, 2018

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Orchid seeds: Nature’s tiny treasures

Orchids have the smallest seeds in the world and they produce millions of them, but why? Kew’s seed morphologist Wolfgang Stuppy explains the clever survival plan that lies behind this seemingly wasteful strategy.

By Wolfgang Stuppy

Seeds come in all shapes and sizes. Famed for both its volume and suggestive shape, the seed (actually a single-seeded stone) of the Seychelles nut or double coconut (Lodoicea maldivica, Arecaceae) holds the unbeaten record for the world’s largest seed. It can weigh up to 18 kg and resembles something that, while bobbing in the waves of the Indian Ocean, gave sailors in the Middle Ages all kinds of, well, “seedy” ideas.

Seeds like dust

At the other extreme of the spectrum we find the seeds of orchids. Famed for their beautiful and fascinating flowers, with over 26,000 species worldwide, orchids are the largest of all flowering plant families. What’s more, they also hold the world record for having the smallest seeds of all flowering plants. A typical orchid seed is merely the size of a speck of dust.

To give an impression of the dimensions involved: a single capsule of the tropical American orchid Cycnoches chlorochilon produces almost four million seeds, and one gram of seeds of the southeast Asian species Aerides odorata contains 3.4 million seeds. At around 0.2 mm in length, Aerides odorata has the smallest seeds I have ever come across at Kew’s Millennium Seed Bank. According to the literature [Arditti, J. & Abdul Karim Abdul Ghani (2000) Numerical and physical properties of orchid seeds and their biological implications (Tansley Review No. 110). New Phytologist 145: 367-421], there are orchids with even smaller seeds. Those of the New Caledonian species Anoectochilus imitans are said to be the smallest of all, measuring just 0.05 mm in length. At a ‘gigantic’ 6 mm, the seeds of the lopsided star orchid (Epidendrum secundum) are allegedly the longest of any orchid.

The reduction in seed size and weight is mainly achieved at the expense of embryo and endosperm, the latter failing to develop in orchids. At the time of dispersal, orchid seeds consist of a spindle-shaped, wafer-thin seed coat that encloses an extremely small and simplified embryo in the shape of a spherical cluster of cells. Just one single cell layer thick, the seed coat (also called testa) forms a balloon around the embryo, a clear adaptation to wind dispersal.

With a little help from their friends

Because orchid seeds lack a food reserve in the form of an endosperm or a large embryo, most of them, especially terrestrial ones, are generally unable to germinate on their own. They first have to engage in a mycorrhizal relationship with a fungus that helps to feed the emerging seedling. Some orchids are able to join up with many different species of fungi whilst others only accept a very specific fungus to enter their lives (or rather roots). Few orchids don’t need any fungus at all for their germination, such as certain species of Disa from South Africa, a remarkable exception among terrestrial orchids.

Their dependence on certain fungal partners is most probably the reason why orchids produce vast numbers of tiny seeds. With their small size, low weight and balloon-testa, orchid seeds are perfectly adapted to wind-dispersal. However, their strategy is not to travel long distances. Scattering large numbers of seeds with the wind merely heightens the chances that at least some end up in a place where they are lucky enough to meet their specific fungal partner without which they cannot germinate.

Long-distance dispersal would mean that the same amount of seed is distributed over a larger area which could actually lower the odds of encountering a compatible host in a suitable location. The fact that many orchid species are endemics with very limited distributions supports this theory. This does not mean, however, that their seeds are not able to cover long distances. Orchids managed to reach isolated islands far away from the mainland. As famously documented, they were among the first pioneers to resettle on the islets of Krakatoa after the catastrophic volcanic eruption of 27 August 1883.

Why so small?

Shedding millions of seeds most of which go to waste, seems very wasteful. However, evolution shows no mercy with wasters and given the orchids’ success, their seed dispersal strategy must pay off. In fact, producing lots of very small seeds with literally no food reserve (apart from some oil droplets and starch grains in the embryo) is energetically inexpensive and doesn’t take up that much of a plant’s energy at all.

The survival benefits of producing millions of tiny seeds clearly outweigh the costs of producing them. Not only orchids prove this point. Other families, like the Orobanchaceae (broomrape family), pursue the same strategy. As parasites, they have a similar problem to orchids: they need to get their seeds to meet the right host partner in order to grow into a new plant.

Vanilla ice cream and seed morphology

Since we are talking orchids here and most of us love ice cream, here’s a seed morphological nugget for you. Next time you treat yourself to some good quality vanilla ice cream you can discover that the tiny black spots in it are actually real vanilla seeds (in cheap ice cream they might be fake!). Vanilla is made from the fermented fruits (‘pods’) of the vanilla orchid (Vanilla planifolia). That’s how all those seeds end up in your ice cream. Sadly, though, the seeds of vanilla are nowhere near as exciting as those of other orchids. They are just very simple, unexciting looking, tiny black discs. Lacking the transparent balloon-like seed coat so typical of other orchids, their seeds are obviously not wind-dispersed.

In fact, the seed dispersal strategies of vanilla orchids are still enigmatic. The fruits of many Vanilla species, including the ones of V. planifolia, open when ripe to expose their tiny seeds covered in an extremely sticky layer of oil. The oil might serve as an adhesive to attach the seeds to visiting animals, which could either be insects or vertebrates. For example, it has been observed that euglossine bees are attracted by the fragrance of vanilla fruits and act as seed collectors and potential dispersers.

Orchid seed research at the Millennium Seed Bank

At this point I asked my colleague, Tim Marks, to tell us something about the research into orchid seeds he is involved in at the Millennium Seed Bank and he writes:

‘Being wind-dispersed, orchid seeds are naturally dry at release and appear to be desiccation tolerant. The latter is essential for us to be able to preserve them under very dry and very cold (freezing!) conditions, as we do with other seeds in the Millennium Seed Bank.

‘Unfortunately, orchid seeds have the reputation to be short-lived under seed banking conditions. Our research is engaged in finding out why this is and how we can extend their survival.

‘A basic concept in understanding their specific requirements for storage is to test the relationship between temperature and moisture content upon viability and germination. By running long-term storage experiments with temperatures between -196°C (liquid nitrogen) and +20° (ambient), and a variety of moisture contents, it is possible to identify species-specific requirements.

‘Some orchid species prove tolerant to a range of conditions, while others store better in liquid nitrogen. However, to prevent repeating this on all species, we are looking at a number of seed characteristics that could affect this response. One of these is lipid content of the seed, the physical properties of which could affect seed physiology as they go through the freeze and thaw cycles that stored seeds are subjected to. It is possible to produce thermal fingerprints describing the phase transitions between liquid and solid states that these go through, with the intention of developing a predictive model that will describe the observed responses to storage and during germination.’

Orchids have the smallest seeds in the world and they produce millions of them, but why? Kew's seed morphologist Wolfgang Stuppy explains the clever survival plan that lies behind this seemingly wasteful strategy.