An Australian Government Initiative [logo]
Australian Lichens - Information about Australia's flora
ANBG logo
Home > Gardens | CANBR > Plant Information > Plant Groups > Lichen > Case Studies

Case Studies

Diyarbakir's heavenly bread and other manna of things

In May 1893 the Royal Academy of Belgium received a letter from Jules de Berlet, the Belgian Minister for the Interior, which reads as follows in translation:

My department has received, from the Belgian consul at Aleppo, the enclosed sample of a substance used as food by the Kurds of Mesopotamia and which they call "heavenly bread".

In early May of 1890 a violent storm raged across the vilayet of Diarbékir, in some places ravaging the fields, uprooting trees and leaving a trail of desolation, except near Djebel-el-Ooffet where abundant hail fell on the surrounding plain and, on melting, revealed a thick bed of the substance in question.

Based on information gathered in Diarbékir and Mardin, this material exists neither in the vilayet in question nor in the nearby area, so a whirlwind must have carried it from a distant region.

There are those who claim this is simply some vegetable material that the torrential rains had exposed.

Whatever the case, the material in question, when kneaded with a third of its weight in flour, is found edible and today constitutes a significant part of the food of the inhabitants of this province.

Although phenomena of this celestial type reported by our consular agent are not of great rarity, especially in the lands of south-east Asia Minor, I thought it useful to bring this to the attention of the Royal Academy of Belgium.

Diyarbakir (or Diarbékir in French writings) is a district in south-eastern Turkey. Leo Errera, professor of botany at the University of Brussels and a member of the Academy, examined the sample and published a paper about it. He began his report with the observation that it was easy to see...

...that this substance is nothing other than the lichen known by the name Lecanora esculenta...found first by Pallas in the arid, calcareous and gypsum mountains of the desert of Tartary. Ledebour and Eversmann found it abundant in the Kirghiz steppes, near the southern part of the river Jaïk at the foot of gypsum hills around the salt lakes. This lichen has also been reported from Persia by Parrot, where it is thought to fall from the sky. To summarise, it is common in Asia Minor and is found also in Palestine and in Algeria. In some parts of Asia Lecanora esculenta covers the soil to such a degree that, according to Parrot, it forms beds 15 to 20 centimetres thick.

Manna lichens

R.A. Donkin begins his book Manna: an Historical Geography with the words:

The description "manna" has no uniform or precise meaning.

The word has been used widely for several millennia to name foodstuffs, often sweet, unusual or unexpected (rather than everyday items) that are found in the arid areas of Eurasia and the etymological roots of manna are in the ancient languages of the Middle East, perhaps as early as Sumerian. In medieval times scholars from North Africa through to Central Asia recorded a variety of mannas, many of which can be identified with certainty as plant exudates, either direct or indirect via intermediary sap-sucking insects. On the other hand there are also various reports of manna in which the exact nature of the substance remains a puzzle. Later the word was used much more widely and applied to plant exudates in many parts of the world, including Australasia.

The edible lichens of arid areas are typically small and vagrant and the expression manna lichen has been coined as an informal collective term for the small, terrestrial VAGRANT LICHENS of the arid areas of Eurasia and North Africa, though not all have been recorded as being eaten. To many western people the word manna would be synonymous with the manna of the Bible. Were those biblical passages referring to a lichen? Probably not, but that's the subject of the final section on this page. For the present I'll give some more general information about the manna lichens.

According to Donkin various Islamic scholars wrote about what must have been vagrant lichens and...

The medico-botanists of the golden age of Islamic science did not confuse L[ecanora] esculenta with the saccharine substances known as "manna"...

Donkin gives some comments made by the 12th century Islamic scholar al-Idrisi, who noted that a substance called gawz gundum... something that grows in deserts which cross the centre of sterile mountains. It grows between stones, is yellowish in colour and does not rise above the soil higher than the size of a finger-nail. Al-Rāzī, al-Basrī and Is-hāq ibn 'Imran call it "dandruff of the stone" (bahaq al-hagar, lichen).The best kind is that imported from Khorāsān. It occurs also in our land, in the east of Andalusia, in the mountains around Saragossa, but it is not of the same quality as that which is imported from Khorāsān. Our people collect it when it is dry. It looks then a kind of granular earth like chickpeas and is of a greyish colour.

This reads like a good description of a vagrant lichen and there is good evidence that terms such as "fat of the earth", "honey earth" and "pigeon dung" were also used to designate vagrant lichens in various areas. The last appears to have been in common use in the Euphrates area.

The first mention of a manna lichen in a European publication may have been in 1739 by Johann Amman, who described a small lichen found near Orenburg on the Jaïk (or Ural) River. In translation his long Latin name for it reads: coral-like lichen, bushy, growing on the ground, small, becoming yellow, densely branched. There is certainly no doubting Peter Simon Pallas' sighting of a manna lichen in the 1770s. He described a species he named as Lichen esculentus (the epithet esculentus alluding to its use as food) and gave two illustrations. Curiously enough, his two illustrations are now thought to illustrate two distinct manna lichen species and this leads to the subject of the taxonomy of the group. In 1831 Pallas' Lichen esculentus had a name change to Lecanora esculenta and that name was used for many decades to designate almost any small, vagrant lichen found from the western end of the Mediterranean through to what is now the Xinjiang region of western China. By the late 19th century it had become clear that more than one species was involved and that the genus Lecanora, as then constituted, was a very unnatural mix of species. Consequently the manna lichens are now placed in the genus Aspicilia and the following are recognized as manna lichens: Aspicilia alpicola, Aspicilia aschabadensis, Aspicilia cerebroides, Aspicilia emiliae, Aspicilia esculenta, Aspicilia fruticulosa, Aspicilia fruticulosofoliacea, Aspicilia hispida, Aspicilia jussuffi, Aspicilia lacunosa, Aspicilia tominii and Aspicilia vagans. I have listed just the manna lichens of the genus Aspicilia. The bulk of the species in this genus are crustose and non-vagrant.

Aspicilia fruticulosa (click to enlarge)

Falls of manna lichens

The substance sent by the Belgian consul in Aleppo had been reported as having fallen from the sky and similar falls of manna lichens have been reported from a number of places, mostly near the headwaters of the Tigris and Euphrates rivers. The first published record of such a fall appears to have been made in 1828 by Louis Jacques Thénard, the celebrated French chemist. He presented a note at the meeting of Parisian Academy of Science on 4 August 1828:

The Minister for Foreign Affairs recently received a small packet from Russia, bearing the words: Grains that fell from the sky in Persia.

The Russian lieutenant general, Count Soklen, who had served in Persia, recently received a small quantity of these grains, which covered the soil to a depth of six inches in some places. This astonishing rain fell in the province of Romoè, not far from Mount Ararat. It appears that this was not the first time, for the inhabitants spoke of having seen the same wonder in 1824. This unexpected collection was made at the beginning of April but, unfortunately, it is not known in which direction the wind was blowing at the time. Sheep were the first to eat the grain and later people took it and made a very passable bread from it.

M. le comte de La Ferronnays forwarded this material to M. Thénard for analysis and M. Thénard first consulted M. Desfontaines about the nature of the substance. The latter immediately recognized it as a lichen, closely resembling (and perhaps identical with) the genus Lecidea. The chemical analysis also showed the Persian material to be a lichen.

It is easy to understand how these lichens could form beds six inches thick in various places. Lifted by the winds and carried across the plains, the lichens would accumulate here and there, depending on the obstacles created by the terrain.

The accompanying map shows where manna lichens are reported to have fallen between 1824 and1890. The map is based on information recorded in European publications and the published reports are usually brief or vague. The dot to the northwest indicates an area near Smarhon (or Smorgon) in modern Belarus and the eastern-most dot indicates Herat in Afghanistan. There are no similar reports of manna lichen falls from North Africa.

It is worth noting that falls of non-lichen mannas have also been recorded. So if you come across a reference to a rain of manna don't immediately assume that lichens are being referred to.

Other observations

Manna lichens could give rise to great optimism. In the mid 1800s the Algerian-based French army doctor Adolphe Armand noted that, according to a comrade of his... could conclude, with complete surety, that expeditionary columns travelling in the south would find sufficient nourishment from this cryptogam, should their supplies fall short.

In 1867 the botanist Roberto de Visiani published a paper about manna lichens and included some observations attributed to General Jussuf of the French army in Algeria. The general let the horses eat what they wished and one of them happily ate a barley-lichen mix for three weeks with no ill-effects. The general also had two breads made, one from pure lichen and the other in which the lichen was mixed with 10% flour. The former had a very weak texture and crumbled easily whereas the latter looked very much like the soldiers' bread and had much the same flavour.

However Armand offered a less than optimistic view. In his opinion bread made from a lichen-flour mix had a detestable flavour. Another objection was that he'd seen horses, when offered the lichen alone, refuse to eat it. If a handful were mixed with a nosebag full of barley, the horses ate the barley but left the lichen, just as they left other foreign objects in their feed. Finally, the same horses, when presented with an equal mix of barley and lichen refused to touch the mix at all. From native inhabitants Armand heard that the lichen was not edible, was thought to be poisonous to certain animals (such as sheep) and that it was called ousseck el trab (or "excrement of the earth").

The bryologist Howard Crum visited Libya during the 1980-81 winter, saw manna lichens in situ and sought out information about their use. Here are some extracts from his published report:

I encountered no one in Libya who had actually eaten the lichen, although one person told me that his father had depended on it as food during internment by the Italians early in the Second World War

Libyan sheep herders normally take their flocks to lichen feeding grounds only in times of severe drought. Where it grows in abundance the lichen is conspicuous even from a motor car travelling at relatively high speeds, but leading a flock to it requires a landmark visible from afar. In eastern Libya, at least, shepherds erect cairns so that good pasturage can be relocated.

There have been no reports of lichen rains in North Africa, and no one that I talked to in Libya knew of lichen rains even during the violent wind storms of July and August.

A range manager who had observed the lichen in the Wadi al Masus area of eastern Libya for the past 16 years told me that the area occupied by the lichen had not expanded and that a fairly continuous cover had been maintained throughout that time, regardless of the season...In the Wadi al Masus region the lichen is abundant over an area 70km long and 30km wide.

Clearly there are some contradictions between the different reports and various explanations are possible. Informants may have been mistaken, perhaps different species are involved, perhaps there is variation in composition, perhaps the effect of manna lichens depends on what else is being eaten or drunk. With regard to the last point, Crum noted that... was said that sheep need carotene, or vitamin A, from other plants in order to digest the lichen well and that the lichen causes "stomach trouble" unless given with a food supplement such as mash.

Chemical analysis has shown the major component of manna lichens to be calcium oxalate (typically 60% or more) with starch levels up to 23%. In humans ingestion of calcium oxalate can cause breathing difficulties, problems with digestion, liver or kidney damage or death. Many humans are painfully aware of another aspect of calcium oxalate since most kidney stones are composed of it.

Incidentally, Crum noted that it was easy to see when sheep had been eating lichen rather than plant matter. The dung of animals eating only lichen was fine textured whereas sheep with a significant amount of plant matter in their diet produced fibrous dung.

Lichens as biblical manna? Far from proven!

Leo Errera had noted that one could not fail to think of Lecanora esculenta as the biblical manna. Here is a translation of his concluding pair of paragraphs:

We know that other substances have also been designated as manna, in particular sugary exudates from various trees. That of the ash tree currently has pharmaceutical uses; that which bears the name Sinai manna is produced from Tamarix mannifera, via the insect Coccus manniparus.

As far as it is possible to base a botanical determination on those vague Biblical texts, it appears that two sorts of manna, a lichen and an exudate, are confused in Scripture. Along with O'Rorke and Planchon, I think that the description in Exodus (chapter 16) agrees well with a Tamarix exudate, whereas the passage in Numbers (chapter 11) agrees more with our lichen.

As noted by Errera himself, his was not the first word on biblical manna and nor was it the last. There are many publications (from before Errera's time and up to the present) and web pages in which the identification of a biblical manna with a lichen is presented as fact. What can be said for sure is that the biblical descriptions are so vague as to make the case for a lichen very unreliable. Certainly these lichens seem to appear miraculously at times, so it is understandable to see why the equation Biblical manna=lichen was made but Howard Crum refers to the idea as simply "...a pious conceit of Victorian times". The seemingly miraculous manna falls were reported widely in the popular press during the 1800s so the phenomenon was rarely out of the public mind for too long. You can read more in the MANNA LICHENS IN THE POPULAR PRESS CASE STUDY. Interestingly, though manna is mentioned also in the Koran, a lichen appears never to have been thought a candidate for Koranic manna.


Amman, J. (1739). Stirpium Rariorum in Imperio Rutheno Sponte Provenientium Icones et Descriptiones. Petropoli. [Ruthenia consisted of parts of the modern day eastern Europe-Ukraine area. The lichen is described on page 176, where it is given the long phrase-name: Lichen coralloides, fruticosus, terrestris, parvus, flavescens, densissime ramificatus.]

Armand, A. (1854). L'Algérie Médicale. Victor Masson, Paris. [Pages 26-29 discuss the Manne du désert.]

Crum, H. (1993). A lichenologist's view of lichen manna. Contributions from the University of Michigan Herbarium, 19, 293-306.

Donkin, RA. (1980). Manna: an Historical Geography. Junk, The Hague. (= Biogeographica 17). [The author presents a detailed review of the literature pertaining to manna and discusses lichens on pages 43-54. The map of manna falls on this web page is based on Map 7 in Donkin's book. There is much overlap between Donkin's 1980 and 1981 publications.]

Donkin, RA. (1981). The "Manna Lichen" : Lecanora esculenta. Anthropos, 76, 562-576. [There is much overlap between Donkin's 1980 and 1981 publications.]

Errera, L. (1908). Sur le <<Pain du ciel>> provenant du Diarbékir. Recueil de l'Institut Botanique (Université de Bruxelles) , 3, 187-193. [The first publication of this paper had been in the Bulletin de l'Académié royale de Belgique, 3e série, 26, 1893, 83-94 - but I have seen only the 1908 version.]

Harrison, SG. (1950). Manna and its sources. Kew Bulletin, 5, 407-417.

Pallas, PS. (1778). Reise durch verschiedene Provinzen des russischen Reichs, Dritter Theil. Frankfurt und Leipzig. [The description of Lichen esculentus is on page 80 of the Anhang and the two illustrations are in Figure 4 of Plate 1. According to various bibliographic sources an edition of this work had been published in St. Petersburg in 1776, under the same German language title.]

Sohrabi, M & Ahti, T. (2010). Nomenclatural synopsis of the Old World's "manna" lichens (Aspicilia, Megasporaceae). Taxon, 59, 628-636. [The authors point out that the two illustrations given in Pallas' Figure 4 most likely represent two different species - known today as Aspicilia esculenta and Aspicilia vagans.]

Thénard, LJ. (1828). Sur une matière tombée de l'atmosphère dans la province de Romoè, en Perse. Annales de Chimie et de Physique, 39, 422-423. [A footnote at the end of this short article asserts: "Note communicated to the Academy by M. Thénard". I don't know if this is all of Thénard's presentation to the Academy. Amongst the Academy's own publications I have found only a brief mention in Volume 9 of the Procès-verbaux des Séances de l'Académie, published in 1921. Volume 9 contains the records of meetings held from 1828 to 1831 and simply notes that on 4 August 1828 Thénard gave an account of his study of "a substance said to have fallen from the sky in Persia, and which was found to be a lichen".]

Visiani, R. (1867). Prof. De Visiani's Bericht über einen Regen einer vegetabilischen Nahrungs-Substanz, welcher im März 1864 in Mesopotamien niedergefallen ist. Flora, 50, 197-205, 213-220, 225-230. [General Jussuf is mentioned on pages 204-205. This paper is a German translation of Visiani's "Relazioni di una nuova specie di Manna caduta in Mesopotamia nel marzo passato", which appeared in 1865 in Atti del Reale Istituto Veneto di Scienza, Lettere ed Arti, ser. 3, 10, 284-306. I have not seen the Italian original.]