#fig trees

By Andy Corbley-Jul 9, 2025

Some species of fig trees store calcium carbonate in their trunks—essentially turning themselves (partially) into stone.

This ‘auto-petrification’ may offer a strange new way to reduce human carbon emissions, as the mineral created by the trees has a much longer lifespan than organic carbon absorbed and deposited in its root system.

An international team of scientists found that three species of Ficus that grow in Kenya were able to draw carbon dioxide (CO2) from the atmosphere and store it as calcium carbonate ‘rocks’ in the surrounding soil.

The figs are one of the first fruiting trees shown to have this ability, known as the oxalate carbonate pathway. One species in particular, Ficus wakefieldii, was especially prolific.

All trees use photosynthesis to turn CO2 into organic carbon, which forms their trunk, branches, roots and leaves, but certain trees also use CO2 to create calcium oxalate crystals.

When parts of the tree decay, these calcium oxalate crystals are converted by specialized bacteria or fungi into calcium carbonate—the same mineral as limestone or chalk. This increases the soil pH around the tree, while also increasing the availability of certain nutrients.

The inorganic carbon in calcium carbonate typically has a much longer lifetime in the soil than organic carbon, making it a more effective method of CO2 sequestration.

“We’ve known about the oxalate carbonate pathway for some time, but its potential for sequestering carbon hasn’t been fully considered. If we’re planting trees for agroforestry and their ability to store CO2 as organic carbon while producing food, we could choose trees that provide an additional benefit by sequestering inorganic carbon also, in the form of calcium carbonate,” said Dr. Mike Rowley, a senior lecturer at the University of Zurich (UZH) who presented his study on the subject at the Goldschmidt Conference in Prague.

Rowley and his team identified how far from the tree the calcium carbonate was being formed and identified the microbial communities involved in the process.

“As the calcium carbonate is formed, the soil around the tree becomes more alkaline,” Dr. Rowley said. “The calcium carbonate is formed both on the surface of the tree and within the wood structures, likely as microorganisms decompose crystals on the surface and also, penetrate deeper into the tree. It shows that inorganic carbon is being sequestered more deeply within the wood than we previously realized.”

They are now planning to assess F. wakefieldii’s suitability for agroforestry by quantifying its water requirements and fruit yields and by doing a more detailed analysis of how much CO2 can be sequestered under different conditions.

Most of the research into the oxalate-carbonate pathway has been in tropical habitats and focused on trees that do not produce food. The first tree to be identified as having an active oxalate-carbonate pathway was the Iroko (Milicia excelsa). It can sequester one ton of calcium carbonate in the soil over its lifetime.

Calcium oxalate is one of the most abundant biominerals and the crystals are produced by many plants. The microorganisms that convert calcium oxalate to calcium carbonate are also widespread.

“It’s easier to identify calcium carbonate in drier environments,” explained Dr. Rowley.

“While the vine with its clusters was the most characteristic manifestation of Dionysus, he was also a god of trees in general. Thus we are told that almost all the Greeks sacrificed to ‘Dionysus of the tree.’ In Boeotia one of his titles was ‘Dionysus in the tree.’ His image was often merely an upright post, without arms, but draped in a mantle, with a bearded mask to represent the head, and with leafy boughs projecting from the head or body to shew the nature of the deity….

Dionysus in Boeotia, from Daremberg & Saglio’s Dictionnaire des antiquités grecques et romaines, vol. I, pt. 1 (1873, p. 626).

(Source: Charles Daremberg & Edmond Saglio, Public Domain, Internet Archive)

“At Magnesia on the Maeander an image of Dionysus is said to have been found in a plane-tree, which had been broken by the wind. He was the patron of cultivated trees; prayers were offered to him that he would make the trees grow; and he was especially honoured by husbandmen, chiefly fruit-growers, who set up an image of him, in the shape of a natural tree-stump, in their orchards. He was said to have discovered all tree-fruits, amongst which apples and figs are particularly mentioned; and he was referred to as ‘well-fruited,’ ‘he of the green fruit,’ and ‘making the fruit to grow.’ One of his titles was ‘teeming’ or ‘bursting’ (as of sap or blossoms); and there was a Flowery Dionysus in Attica and at Patrae in Achaia. The Athenians sacrificed to him for the prosperity of the fruits of the land. Amongst the trees particularly sacred to him, in addition to the vine, was the pine-tree. The Delphic oracle commanded the Corinthians to worship a particular pine-tree ‘equally with the god,’ so they made two images of Dionysus out of it, with red faces and gilt bodies. In art a wand, tipped with a pine-cone, is commonly carried by the god or his worshippers. 

A thyrsus-wielding maenad dangles temptation before a satyr (while trodding on his snake) in the Roman-era Mosaic of the Seasons from Palermo (now found in the Museo archeologico regionale di Palermo). 

(Source: Giovanni Dall'Orto, Attribution, via Wikimedia Commons)

“Again, the ivy and the fig-tree were especially associated with him. In the Attic township of Acharnae there was a Dionysus Ivy; at Lacedaemon there was a Fig Dionysus; and in Naxos, where figs were called meilicha, there was a Dionysus Meilichios, the face of whose image was made of fig-wood.”

The Promised Land

A land of wheat and barley, of vines and fig trees and pomegranates, A land of olive trees and honey — Deuteronomy 8:8 | New Revised Standard Version (NRSV) New Revised Standard Version Bible, copyright © 1989 the Division of Christian Education of the National Council of the Churches of Christ in the United States of America. All rights reserved. Cross References: Genesis 49:11; Deuteronomy 8:7; Deuteronomy 8:9; Deuteronomy 32:13

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Legends and myths about trees

Trees in Buddhism (1)

Fig trees (Ficus) - Trees that bear fruit without flowering

“Enter the fig forest and seek the flowers, but get none. In the world of the three realms (Trailokya: Ref), you seek the unwavering and you do not get one. The practitioner who knows this, forsakes this and that together...like a snake shedding its old skin.” - Buddha

Above is an extract from a verse of the Buddha in the Sutta Nipata No.5.

A common feature of the fig genus (ficus) is the peculiar inflorescence. They appears as if it suddenly bears fruit without flowering. They are hermaphrodites or dioecious, collectively known as fig trees or figs. These belonging to the family Moraceae have about 850 species and are native throughout the tropics, with a few species also found in semi-temperate zones.

Hermaphrodites are generally those that have male and female reproductive organs in one individual. Those that do not are referred to as gonochoric. In the case of plants, they are referred to as monoicous and dioicous, respectively.

The fig fruit develops as a hollow, fleshy structure called the syconium that is lined internally with numerous unisexual flowers. The tiny flowers bloom inside this cup-like structure. The small fig flowers and later small single-seeded (true) fruits line its interior surface. At maturity, these 'seeds' (actually single-seeded fruits) line the inside of each fig.

The fruit of most species are also edible though they are usually of only local economic importance or eaten as bushfood. However, they are extremely important food resources for wildlife. Figs are also of considerable cultural importance throughout the tropics, both as objects of worship and for their many practical uses.

The Bodhi tree is well known for Siddhartha Gautama (Ref2) sat under the tree, meditated and finally attained enlightenment becoming the Buddha, also known as "sacred fig tree", belongs to this fig family.

木にまつわる伝説・神話

仏教の樹木 (1)

イチジク(無花果) 〜花を咲かせずに実のなる木

“無花果の林の中に入りて、花を求めて得ることなし。三界世間（参照）の中にありて揺るがざるものを求めて得られず。かく知っている修行者は、これをもあれをも、ともに捨てる。蛇が旧き皮を脱ぎ捨てるがごとく。“ーブッダ

上記は、経集 (スッタニ･パータ 5) にあるブッタの詩篇の抜粋である。

イチジク属に共通する特徴は、花序が特殊であることだ。イチジクが無花果と言われるように、この仲間は、花が咲かずに唐突に果実を生じるように見える。雌雄同体あるいは雌雄異株で、高木になるものから低木、またはつる性の木本になる種もある。モクセイ科に属するこの植物は、約850種あり、熱帯地方全域に自生し、数種は半温帯にも分布している。

雌雄同体 (しゆうどうたい) とは、一般に、雄の生殖器官と雌の生殖器官を一個体に持っているものを言う。そうでないものは雌雄異体 (しゆういたい) という。植物の場合にはそれぞれ、雌雄同株 (しゆうどうしゅ)、雌雄異株 (しゆういしゅ) という。

イチジクの果実は、中が空洞で肉厚の「サイコウニアム (隠頭花序)」と呼ばれる構造で、その内部には多数の雌雄同体の花が並んでいる。小さな花は、このカップ状の構造物の中で咲く。その内面には、小さなイチジクの花と、後に小さな一粒の種の真果が並ぶ。成熟すると、この「種子」(実際は1粒の果実) がイチジクの内側に並ぶ。

果実はほとんどの種で食用になるが、通常は地域経済的に重要であるか、山菜・野生の果物として食されるに過ぎない。しかし、野生動物にとっては非常に重要な食糧資源である。イチジクは、熱帯地方において、崇拝の対象として、また多くの実用的な用途として、文化的に非常に重要なものである。

My obsession with accuracy, it seems, has led me again to this post. I feel it must be changed to better match how it is I write now. Maybe in two years time, I shall rewrite it once more. Regardless. Welcome or welcome back to the story of my tragic namesake: Syceus.

So, it begins: Syceus was a child of Gaia as well as a Gigante, who were simply men of great strength— despite being oftentimes referred to as ‘giants’— that were notoriously troublesome. These very same Gigantes were quick to take up arms against the Olympians when persuaded by Gaia.

Politics, having been complicated so far back as ancient Greece, would have it so war breaks out between the Gigantes and Olympus.

In short, the Gigantes proved to be a threat to the rule of Zeus, whose victory was not assured until Hercules joined the war. When the odds were favourable to Zeus, Syceus fled to Cilicia to escape his wrath. Wishing to prevent her son from dying at the mercy of Zeus, Gaia hid Syceus in her bosom, turning him into a fig tree.

While this is heavily summarised, being drawn from my entirely unnecessary and excessively sesquipedalian presentation on everyone who got turned into a plant in Greek Mythology, the story is one I have always found to be beautiful. Accentuated, perhaps as I quite like figs.

Not only is the fruit rich in taste and dynamic in appearance, but fig trees have incredible historical significance, being associated with triumph and wisdom for thousands of years. In ancient Greece, fig trees were considered an honour to bestow upon winners of competitions and were seen to shield humans from evil spirits. Odysseus, as it were, was even spared from the lethal whirlpool formed by the sea monster Charybdis by the branches of a single fig tree.

Any opportunity to speak about an arbitrary interest of mine I will take. Mythology, unsurprisingly, is a long withstanding one. Enough that, despite the many changes in my life, my username remains ‘syceusfig’ based on this very story. Will I find myself still unsatisfied with how I have rewritten this? Perhaps. But time will tell, I suppose.