Quercus coccolobifolia: How a Name Was Lost

I was recently in Mexico and had the opportunity of seeing a remarkable oak, now known as Q. jonesii. It has striking round leaves and I found it growing on rock, in populations where no other plant seemed to be able to grow. It was an impressive sight.

The experience led me to look up the name of the oak, and I found that for many years it had been referred to by the much more attractive and sonorous name of Q. coccolobifolia. But this name had now been banished from the realm of acceptance, guilty of the sin of synonymy. Why? Here is the story.

The name Quercus coccolobaefolia (original spelling) was first used by Aimée Bonpland when he wrote it on the label of a specimen he had collected in Santa Rosa, Guanajuato (the same locality where I saw it), in 1803, currently at the Muséum nationale d'Histoire naturelle (MNHN) in Paris. The epithet indicates a resemblance to the leaves of Coccoloba, a neotropical plant commonly known as sea grape. Coccoloba was first called other names by early botanists and Linnaeus assigned the plant to Polygonum uvifera in the first edition of his Species plantarum (1753). Then in 1756 Patrick Browne, in The Civil and Natural History of Jamaica, came up with the name Coccolobis, and Linnaeus used this name in his second edition of Species Plantarum (1762), changing the classification to Coccoloba uvifera. Browne’s name is derived from the Ancient Greek κόκκος (kókkos, “seed, berry”) + λοβός (lobós, “capsule or seed of leguminous plants”). The name refers to the grape-like fruits of the plant.

However, the specimen Bonpland’s label is attached to does not look like the leaves of Coccoloba at all. It is in fact what he later called Q. reticulata, a synonym of Q. rugosa. But another specimen collected by Bonpland in the same location is of the oak that interests us, and the resemblance to the round, stiff leaves of Coccoloba is quite clear. So it appears that Bonpland somehow got his labels in a twist and he applied the new name Q. coccolobaefolia to the wrong specimen.

In 1913 Trelease examined Bonpland’s specimens in the Paris herbarium and saw the problem. On the specimen with the round, Coccoloba-like leaves he wrote: “Quercus Sycomora”, a name which he later abandoned, and on the specimen that bore Bonpland´s label “Quercus coccolobaefolia sp. n.” he wrote: “Possibly the label of this Sta. Rosa plant (reticulata) and of that which I call Sycomora (no. 4269) have been crossed.”

In The American Oaks, published in 1924, Trelease reinstated Bonpland’s name for this oak, but as he could not determine with any certainty what Bonpland’s intentions were, he published Quercus coccolobaefolia as a new species, and designated as the type Bonpland’s specimen No. 4269. “A specimen of Q. reticulata,” he wrote, “bearing the descriptive name here adopted for this black oak [i.e., Q. cocolobaefolia], occurs in the herbarium of the Muséum d’Histoire Naturelle, at Paris, noted as new and coming from the same locality as reticulata, while the present plant is without name. The probability is that its collectors intended the name to be used as is here done, but the possible crossing of labels makes this so uncertain that the name can hardly be attributed in its present use to Humboldt and Bonpland.”

So Trelease had rescued the name from oblivion. Well, not quite, it turns out. On the same page of The American Oaks, Trelease also described a very similar species, which he distinguished from Q. coccolobifolia because the leaves were puberulent beneath, not glabrescent, and because it grew in the Western Sierra Madre region of Mexico, while Q. coccolobifolia was found in the Eastern Sierra Madre. To the western species he assigned the name Q. Jonesi (later corrected to jonesii), in honor of Marcus Eugene Jones (1852–1934), who collected the type specimen in Jalisco. Though both these names, Q. coccolobaefoila (coccolobifolia) and Q. Jonesi (jonesii), were published by Trelease in 1924, Trelease clearly acknowledged that Q. coccolobifolia was first coined by Bonpland over a century earlier. He grouped both species in a series he named Coccolobaefoliae, suggesting that he if had considered the two taxa to be the same thing, he would have chosen Q. coccolibaefolia as the name for it.

It was later determined, however, that these two species were not distinct enough to be considered separate species. So they were synonymized, but for a time there was confusion as to which should be adopted as the correct name. Rogers McVaugh, in his Flora Nova-Galiciana published in 1974, used Q. coccolobifolia, citing as synonyms Q. jonesii and Q. endlichiana, another name published by Trelease in 1924. Susana Valencia Ávalos, in her list of oak species native to Mexico published in 2004 (“Diversidad del género Quercus (Fagaceae) en México”), also used Q. coccolobifolia as the correct name, citing the same synonyms. Thierry Lamant and Antoine Le Hardÿ de Beaulieu in their Guide illustré des chênes (2010, second edition) did the same, though they noted: “Il fut décrit en 1924, tout comme l’un de ses synonymes (Q. jonesii Trel.) et de ce fait, on trouve indifféremment ces 2 noms dans les ouvrages et articles mexicains.” (“It was described in 1924, as was one of its synonyms (Q. jonesii Trel.) and, as a result, these two names are found interchangeably in Mexican works and articles.”) This was indeed the case, but in order to know which name of the two should be accepted as correct, it had to be determined who had been the first author to synonymize them and their choice should be followed. This is stated in Article 11.5 of the Code:

When, for any taxon at the rank of family or below, a choice is possible between legitimate names of equal priority at the corresponding rank … the first such choice to be effectively published … establishes the priority of the chosen name.

It turns out that the first author to make the choice was Maximino Martínez in 1966. In Los Encinos de México XIV he wrote, after explaining why he found the species to be indistinguishable: “Estas observaciones me inducen a concluir que no hay diferencias específicas entre los dos Quercus mencionados y que, por lo tanto, se pueden reducir a una sola especie que será Q. Jonesi que es el que tiene prioridad, quedando el Q. coccolobaefolia como sinónimo.” (“These observations lead me to conclude that there are no specific differences between the two oaks mentioned and that, therefore, they can be reduced to one species, which will be Q. Jonesi, the one that has priority, while Q. coccolobaefolia will remain a synonym.”). It is not clear, however, why Martínez states that Q. Jonesi has priority. It does not: the names have equal priority, being published in the same work. It would seem that Martínez mistakenly believed (and in that he is not alone) that names that appear earlier within a work have priority over those that appear on a later page or plate. Immediately after the statement quoted above, we find:

Quercus Jonesi Trel. loc. cit. pl. 257
=Q. coccolobaefolia Trel. loc. cit. pl. 258

Could it be that Martínez understood that Q. Jonesi had priority because it appeared on a plate 257, while Q. coccolobaefolia appeared on pl. 258? In fact the names are published on p.136 of The American Oaks, where Q. Jonesi appears above Q. coccolobaefolia. Interestingly, in the key for Series Coccolobaefoliae on p.135, Trelease lists Q. coccolobaefolia above Q. Jonesi:

In any case, Martínez’s decision sealed the fate of Q. coccolobifolia. The final nail in its coffin was driven home by Bartholomew and Almeda, who in their “Nomenclator botanicus of Fagaceae in Latin America” (2023) stated: “Martínez (1966) was the first person to synonymize Q. coccolobifolia under Q. jonesii.”

Martínez’s choice is, in my view, contrary to what I understand as Trelease’s preference, and also belies the origin of Q. coccolobifolia as a name coined by Bonpland more than a century before Trelease published Q. jonesii. But there is not much we can do about it. Save lament the loss of a beautiful and sonorous name (or keep using it among friends, as Michael Heathcoat Amory apparently did!)

Acknoweldgment

I am grateful to Allen Coombes for reviewing a draft of this note and suggesting improvements.

Unless mentioned otherwise, photos are of Q. jonesii at Presa Peralillo, Santa Rosa, Guanajuato, Mexico © Roderick Cameron