Interesting question, Peter.

Linnaeus started this practice when he set final parts of plant names in Italics. In Philosophia botanica he advised (canon 307) that varietal names should be set in Italics to make a variety distinct from a species. When he invented binomials, he set nomina trivialia in Italics (in Species plantarum, and also in its precursors as noted by Stearn in the preface to Ray Society's Species plantarum), and placed them aside on book margins in order to make them distinguishable and easy to catch by an eye.

Other authors followed this practice, like Miller in Gardeners Dictionary did. Generic names were in capital letters or in expanded font, specific epithets in Italics. Then Italics were set to binomials as a whole, apparently for uniformity. Names at higher ranks were sometimes (or in some countries) italicized but most commonly not because they were not considered of such importance.

So I assume that the sole purpose of this practice was to make plant species names distinguishable from the other text, so that they can be easily captured. Linnaeus cared so much about ease and speed of book use and writing, and this practice seems to be one of his inventions on the way to make plant inventories more practical.

Interesting question, Peter.

Linnaeus started this practice when he set final parts of plant names in Italics. In Philosophia botanica he advised (canon 307) that varietal names should be set in Italics to make a variety distinct from a species. When he invented binomials, he set nomina trivialia in Italics (in Species plantarum, and also in its precursors as noted by Stearn in the preface to Ray Society's Species plantarum), and placed them aside on book margins in order to make them distinguishable and easy to catch by an eye.

Other authors followed this practice, like Miller in Gardeners Dictionary did. Generic names were in capital letters or in expanded font, specific epithets in Italics. Then Italics were set to binomials as a whole, apparently for uniformity. Names at higher ranks were sometimes (or in some countries) italicized but most commonly not because they were not considered of such importance.

So I assume that the sole purpose of this practice was to make plant species names distinguishable from the other text, so that they can be easily captured. Linnaeus cared so much about ease and speed of book use and writing, and this practice seems to be one of his inventions on the way to make plant inventories more practical.

Hi Peter:

You must have seen that there is a clear instruction in the Melbourne Code in this regard and there has been no change in the Shenzhen Code.

"As in all recent editions, scientific names under the jurisdiction of the Code, irrespective of rank, are consistently printed in italic type. The Code sets no binding standard in this respect, as typography is a matter of editorial style and tradition, not of nomenclature. Nevertheless, editors and authors, in the interest of international uniformity, may wish to consider adhering to the practice exemplified by the Code, which has been well received in general and is followed in a number of botanical and mycological journals. To set off scientific names even better, the abandonment in the Code of italics for technical terms and other words in Latin, traditional but inconsistent in early editions, has been maintained."

Alexander Sennikov - thank you for your excellent answer. It confirms what I and my colleagues suspected that this is not a requirement by the ICN but a long standing convention (one I agree with by the way).

Subir Bandyopadhyay - thank you as well - as I had stated, I had only a quick look at the code - and in that perusal I was looking for specific recommendations, rules etc - because in part the question I was asked was does the ICN require Italics be used for 'species' names, and if not then why do we do it? So I had missed the section you noted. Both Alexander and your answers serve me nicely to demonstrate the origins and why we do what we do. As the question was set to me, the clear inference taken was that if the code does not require it, then people should not do it (I don't agree with this), or failing that, the code should specifically require it (I also don't agree with this). I feel it would be a sad day when every single aspect of what we do has to be governed by an article or rule - but it may yet come to that.

Thank you both for looking into this matter and offering your opinion. I will make sure to update my lectures on this matter.

Thanks Peter.

Kia ora Sergei - thank you very much for your reply. The late Dr David Galloway always insisted on italicizing suprageneric names as well. But despite his plea that New Zealand people follow suite they never have.

I have answered your other very welcome email just now.

Ciao Peter

Interesting information from the book entitled 'Botanical Latin' by WILLIAM T. STEARN (pp. 52-53)

At first the Latin alphabet existed only in the form of capitals

(majuscules), admirable indeed for monumental inscriptions on stone

such as the Column of Trajan but much less so for rapid script on

papyrus and vellum. By the eighth century A.D. alternative small

letters (minuscules, ' lower-case' letters) had developed; those known

as Caroline minuscules, which are ancestral to those of modern printing,

became firmly and widely established in western Europe during the

reign of Charlemagne (c. 742-814). The modern use of capital and

lower-case letters together, as in generic names, has no classical precedent.The sloping letters known as italic, in which botanical names

are usually printed, derive from the hand-writing of fifteenth-century

Italian scholars and were made popular by the editions of the classics

printed in them by Aldus Manutius (1450-1515) and his sons.

Fascinating indeed. Thanks again.

Hi.

It's true, as pointed out by Sergei, that not always scientists use italics for taxonomic levels like class, family or order, but there is a wide agreement to use it with genus, species and subspecies, and even in the case of form and variety (in the taxonomy of plants). In fact, many journals publish in italics only genera, species and subspecies. This implies that not all the people and publications use italics in the entire taxonomic sequence of a certain taxon. I consider this an interesting and important question, and probably we need a rule to be followed by everyone working with biodiversity.

Best regards.

In my opinion writing the family name in roman / italics is a matter of editorial discretion.

So far as I remember in the Shenzhen IBC there was a proposal on the style of writing of the abbreviated author names (of plant names) but that was not accepted.

Hi Peter,

Very interesting question and answers! I am very much following and learning. Thanks so much!

I was thinking about this issue, and I found this paper (Article In defense of the use of italic for Latin binomial plant names

• The scientific names of genus- or species-group taxa should be printed in a type-face (font) different from that used in the text; such names are usually printed in italics, which should not be used for names of higher taxa. Species group names always begin with a lower-case letter, and when cited should always be preceded by a generic name (or an abbreviation of one); names of all supraspecific taxa begin with an upper-case (capital) letter.

Anyway, in my opinion, this topic is fascinating to involve students in the study of codes.