Theophrastus’s Enquiry into Plants or Historia Plantarum (Greek: Peri phyton historia) was, along with his mentor Aristotle’s History of Animals, Pliny the Elder’s Natural History and Dioscorides’s De materia medica, one of the most important books of natural history written in ancient times, and like them, it was influential in the Renaissance.
Theophrastus looks at plant structure, reproduction, and growth; the varieties of the plant around the world; wood; wild and cultivated plants; and their uses. Book 9 in particular, on the medicinal uses of plants, is one of the first herbals, describing juices, gums, and resins extracted from plants, and how to gather them.
Historia Plantarum was written sometime between c. 350 BC and c. 287 BC in ten volumes, of which nine survive.
In the book, Theophrastus described plants by their uses and attempted a biological classification based on how plants reproduced, a first in the history of botany.
He continually revised the manuscript, and it remained in an unfinished state on his death. The condensed style of the text, with its many lists of examples, indicate that Theophrastus used the manuscript as the working notes for lectures to his students, rather than intending it to be read as a book.
Historia Plantarum was first translated into Latin by Theodorus Gaza; the translation was published in 1483. Johannes Bodaeus published a frequently cited folio edition in Amsterdam in 1644, complete with commentaries and woodcut illustrations. The first English translation was made by Sir Arthur Hort and published in 1916.
The books describe the natural history of plants as follows:
Book 1: Plant anatomy
Theophrastus tours plant anatomy, including leaves (phylla), flowers, catkins, fruits (karpoi), seeds, roots (rhizai), and wood.
Plants are classified as trees, shrubs, herbaceous perennials, and annual herbs; these divisions are acknowledged to be rough and ready, as is the division into wild or cultivated, whereas the aquatic/terrestrial division appeared to be natural.
Theophrastus notes that some plants are irregular, while the silver fir has branches always opposite each other and other plants have branches equally spaced or in rows. Figs have the longest roots, while the banyan sends roots down from the shoots, forming a circle of roots at a distance all around the trunk.
Book 2: Tree and plant propagation
Theophrastus writes that plants can grow spontaneously, from seed, or from vegetative parts of the plant. Plants with bulbs grow from those. Soil and climate influence growth.
Some plants change into others unless care is taken, so bergamot turns into mint, and wheat turns into darnel. He reports that if celery is trodden after sowing, it will become curly and that figs are the easiest trees to propagate, whereas date palms have to be grown from several seeds together, and they like irrigation, dung, salt (at the age of one year) and being transplanted.
Other kinds of palm have different habits and fruits. He notes that gall insects come out of wild figs and make the cultivated figs swell, which helps to prevent premature shedding of the fruit. The male spathe of the date palm is cut off and brought to the female, and its dust is shaken over the female tree to make it fruit.
Book 3: Wild trees
Theophrastus asserts that all wild trees grow from seed or from roots. He mentions that the philosophers spoke of spontaneous generation, as when Anaxagoras claims the air contains the seeds of every plant, whereas Diogenes believed plants arose when water mixed with earth.
In places like Crete, Theophrastus writes that native plants spring up if the ground is simply disturbed, and that wild trees are generally more vigorous than cultivated ones, give fruit later, and like cold and hilly terrain. He asserts that trees that can grow both on hill and plain grow better and taller when grown on the plain.
The book offers numerous examples of Theophrastus’s note-like style, with lists of species interspersed among the general explanations. For example:
“Now among wild trees, those are evergreen which was mentioned before, silver-fir fir ‘wild pine’ box andrachne yew Phoenician cedar terebinth alaternus hybrid arbutus bay holm-oak holly cotoneaster kermes-oak tamarisk; but all the others shed their leaves …”
Book 4: Trees and shrubs from abroad
Theophrastus describes trees and shrubs from different places and habitats, as for instance a sheltered part of the Arcadia region near Krane in a deep valley where the sun never reaches, and the silver-fir trees are exceptionally tall.
He looks into the plants of Egypt, Libya, Asia, northern regions, and then aquatic plants from the Mediterranean, wetlands, especially in Egypt, reeds, and rushes. He also considers factors that limit the life of plants including diseases and weather damage.
Book 5: Wood
Theophrastus describes the wood of different trees, the effects of climate on wood, of knots, and ‘coiling‘ in timber and other differences in quality.
He discusses which woods to use for specific purposes such as for carpentry, shipbuilding, and for building houses, and the making of charcoal.
The most useful trees are said to be silver-fir and fir, and they have the best wood in the largest sizes; the silver-fir is softer than the fir, and its wood has layers like an onion and is made entirely of these layers. The strongest and most attractive wood is smooth, without knots.
In Syria, terebinth wood is dark and close-grained, Theophrastus reports and used both for the handles of daggers and, turned on the lathe, for making cups. He claims that the hardest timber is of oak and holm oak, while elm warps the least, so it is used for the pivots and sockets of doors, which must be straight.
The wood of palms is light and soft like cork-oak but is tougher and less brittle, so it is good for carving images. Timber from the cedar, ebony, box, olive, oak, and sweet chestnut keeps well and resists decay. He asserts that Tamarisk wood from Greece is weak, but from the Arabian island of Tylos it is as strong as kermes-oak.
The wood of oak and the knotted parts of fir and silver-fir are described as the hardest to work. Ships are generally made of silver-fir, fir, and Syrian cedar; in Cyprus, they use Aleppo pine which is better than the fir that grows there.
Theophrastus records that in the lowlands of Italy (the country of the Latins) they grow bay, myrtle, and excellent beech trees long enough for the whole length of a ship.
Book 6: Undershrubs, with thorns or without
Theophrastus classifies undershrubs as spiny, such as thistle, eryngo, and safflower, and spineless, such as marjoram, savory, sage, horehound, and balm. He notes that some have a hollow stem, such as deadly nightshade and hemlock.
Roses, he writes, vary in a number of petals, the roughness of the bark, color, and scent; they have five, twelve, twenty, or more petals, and those with the sweetest scent come from Cyrene and are used for making perfume. The times of flowering of different species are listed.
Book 7: Pot-herbs
Theophrastus reports that cabbage, radish, and turnip are sown in July after the summer solstice, along with beet, lettuce, mustard, and coriander.
Leeks, celery, onion, and orache are sown in January. Cucumber, gourds, basil, purslane, and savory, in contrast, he writes, are sown in April. Ripe seeds do not germinate at once but wait for the right time. He asserts that all the herbs can be grown from seed, while rue, marjoram, and basil can be raised from cuttings, and garlic, onion, and other bulbs are grown from their roots.
All the flowers of a herb appear at one time, except for basil which puts out a series of flowers starting low on the plant. Cumin has the most fruits, but it is said you have to curse and insult the plant to get a good crop.
Theophrastus describes varieties of some herbs, for instance, that the white lettuce is sweetest and tenderest, while there are many kinds of onion, with Sardian, Cnidian, Samothracian, and Ascalonian varieties from those regions. Garlic is said to be planted close to the solstice; the Cyprian variety is largest and is used in salads.
All herbs except rue are said to like dung. Of the wild herbs, Theophrastus reports that some such as the cat’s ear are edible, whereas others like dandelion are too bitter to be worth eating.
Book 8: Cereals and legumes
Theophrastus groups together the cereals and the legumes (peas and beans), and includes millet and other many-seeded plants like sesame also. These can only be grown from seed. They can be sown early, as with wheat, barley, and beans, or in spring after the equinox, for plants like lentils, tares, and peas.
Vetch and chickpeas can, he reports, be sown at either season. When sprouting, beans form a shape like a penis, from which the root grows down, and the leafy stem upwards. Wheat and barley flower for four or five days, whereas the legumes flower for much longer.
Theophrastus reports that these plants grow differently according to the region, so for instance crops in Salamis appear earlier than those elsewhere in Attica. Wheat varieties are recorded as being named for their localities; they differ in color, size, growth habit, and food value.
In a place near Bactra in Asia, the wheat grains are said to grow as big as the stone of an olive, whereas pulses do not in Theophrastus’s view vary to the same extent.
Book 9: Medicinal uses of plants
This book is one of the first herbals, admittedly much simpler than those of Nicander, Dioscorides or Galen. Theophrastus covers juices, gums, and resins, the uses of some hundreds of plants as medicines, and how to gather them.
Resin is gathered by tapping trees including silver-fir and Aleppo pine; the best resin is from the terebinth. On Mount Ida in Crete, the people gather pitch from Corsican pine and Aleppo pine. Gums such as frankincense, myrrh, and balsam of Mecca are gathered either by cutting the plant or naturally. Frankincense and myrrh are gathered into the closely guarded temple of the Sabaeans. Cassia and cinnamon also come from the Arabian peninsula.
Drug collectors have certain traditions that may be accurate or may be exaggerated. Precautions are rightly taken when gathering hellebore, and men cannot dig it up for long; whereas the story that the peony must be dug up at night for fear that a woodpecker will watch and cause the man a rectal prolapse is mere superstition.
Similarly, the idea that you must mark three circles around a mandrake plant with a sword, and speak of the mysteries of love while cutting it, is just far-fetched.
Apart from Greece itself, medicinal plants are produced in Italy in Tyrrhenia, as Aeschylus records, and Latium; and in Egypt, which as Homer mentions is the source of the drug nepenthes that makes men forget sorrow and passion.
The best hemlock comes from Susa, while dittany, useful in childbirth, comes only from Crete. Wolfsbane comes from Crete and Zakynthos; it can be made into a poison that causes death a year or more after taking it, and there is no antidote.
Hemlock is a poison which brings a painless death; pepper and frankincense are antidotes for it. Strykhnos causes madness, but oleander root in wine makes people gentle and cheerful. Birthwort has many uses including for bruises on the head, snakebite, and prolapse of the uterus.
Pliny the Elder made frequent use of Theophrastus, including his books on plants, in his Natural History; the only authors he cited more often were Democritus and Varro.
John Scarborough comments that:
“The list of herbals assembled in Historia Plantarum IX became the direct ancestor of all later drug treatises in antiquity, and many traces of Theophrastus’s (and Diocles’s) original observations survive in the Materia Medica of Dioscorides. The analysis of the various plants and plant derivatives shows that the Greek rhizotomy and drug-vendors had collected much valuable information on the medical employment of plants, and Theophrastus invented a format for this type of information that would be followed after his own time.”
Mediaeval and Renaissance
Theophrastus was barely known to western Europe in the Middle Ages; his writings were popularized there only in the 15th century, when Greek manuscripts in the Vatican, possibly, like many other ancient Vatican Greek manuscripts, brought from the Byzantine Empire during its fall to the Ottomans in the 15th century, were translated into Latin by the Byzantine Greek refugee Theodorus Gaza at the request of Pope Nicholas V.
The effect was to stimulate Renaissance scholars to restart the exploration of plant taxonomy. The science of botany was founded as these scholars engaged with the accounts of plants, and especially of their medicinal uses, together with a newly critical reaction to medieval pharmacology, which was based on unthinking acceptance of the Historia Plantarum of Theophrastus, the Natural History of Pliny the Elder and the De Materia Medica of Dioscorides.
By the same token, however, Theophrastus (and Aristotle) fell abruptly out of use around 1550, as classical botany and zoology were effectively assimilated into Renaissance thought in the form of illustrated encyclopedias—which were still heavily based on classical writings.
Andrea Cesalpino made use of Theophrastus in his philosophical book on plants, De Plantis (1583). The Italian scholar Julius Caesar Scaliger’s accurate and detailed commentaries on the Historia Plantarum were published in Leyden in 1584, after his death.
The Chicago Botanic Garden describes Historia Plantarum as the “first great botanical work” of Theophrastus, “the first real botanist“; it states of the 1483 edition printed by Bartolomeo Confalonieri in Treviso that “all taxonomy of plants starts with this modest book“, centuries before the modern taxonomy of Linnaeus.
Anna Pavord observes in her 2005 book The Naming of Names that Theophrastus made the first-ever classification of plants, and Pliny the Elder, now much better known, used much of his material.