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.

Johannes Bodaeus published a frequently cited folio edition in Amsterdam in 1644, complete with commentaries and woodcut illustrations.

The Enquiry into Plants is in Hort's parallel text a book of some 400 pages of original Greek, consisting of about 100,000 words.

[4] Plants described include poppy (mēkōn), hemlock (kōnion), wild lettuce (thridakinē), and mandrake (mandragoras).

It was published simultaneously by William Heinemann in London and G. P. Putnam's Sons in New York, as a two-volume book Theophrastus Enquiry into Plants and minor works on odours and weather signs in 1916.

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.

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.

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 were 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 ..."[12] 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.

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.

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.

Theophrastus classifies undershrubs as spiny, such as thistle, eryngo and safflower, and spineless, such as marjoram, savory, sage, horehound, and balm.

Theophrastus reports that cabbage, radish and turnip are sown in July after the summer solstice, along with beet, lettuce, mustard and coriander.

Theophrastus reports that these plants grow differently according to the region, so for instance crops in Salamis appear earlier than those elsewhere in Attica.

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.

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 a 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.

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.

[3] 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.

[14] 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 mediaeval pharmacology, which was based on unthinking acceptance of the Natural History of Pliny the Elder and the De Materia Medica of Dioscorides.

[17] The Italian scholar Julius Caesar Scaliger's accurate and detailed commentaries on the Historia Plantarum were published in Leyden in 1584, after his death.

[18] 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.