(3008) Proposal to conserve the name Philodendron chanchamayense (Araceae) with that spelling

(3008) Philodendron chanchamayense Engl. in Bot. Jahrb. Syst. 37: 125. 19 Sep 1905 (‘chinchamayense’) [Angiosp.: Ar.], orth. cons. prop.

Typus: Peru, Dep. Junín, Prov. Tarma, La Merced im Chanchamayo-Thal, lichter Wald, 1000 m, Dec 1902, Weberbauer 1864 (B).

The binomial referenced in the title of this proposal has long been accepted for a species of Philodendron subg. Pteromischum (Schott) Mayo, widespread in the western portion of the Amazon basin in South America, and distinctive morphologically by virtue of its relatively short-petiolate and narrow leaves with conspicuous (at least in dried material) blackish resin canals. The correct spelling of its epithet, however, has been a bone of contention. The name Philodendron chinchamayense (with that spelling) was validated by Adolf Engler (in Bot. Jahrb. Syst. 37: 125. 1905) based on a single specimen collected three years previously by his countryman August Weberbauer “im Chanchamoyo-Tal” (as cited by Engler), Peru. Although Engler did not specify the etymology of his epithet in an explicit manner, he must certainly have based it on the type locality, orthography notwithstanding. Engler's usage of two different spellings is prima facie evidence of an orthographical (if not a typographical) error, because both cannot be correct. In fact, as it turns out, both versions are erroneous: the Peruvian place-name (referring to a river, a town, a district, and a province) on which the epithet of this species must have been based is correctly spelled “Chanchamayo”, and was so spelled even in Engler's time (“Chanchamayo-Thal” is handwritten quite legibly on the label of Weberbauer's type specimen). The Chanchamayo River valley has attained wide repute even outside Peru as a premier coffee-growing region. I have been unable to find any evidence that the spellings “Chinchamayo” or “Chanchamoyo” have ever been used by anyone other than Engler (although “Chanchamayu”, a historic Quechua spelling, persists on a minor scale).

The Code (Art. 60.1; Turland & al. in Regnum Veg. 159. 2018) allows for “the correction of typographical or orthographical errors”, one or the other of which Philodendron chinchamayense is a clear example. According to Art. 60.3, “The liberty of correcting a name is to be used with reserve, especially if the change affects the first syllable and, above all, the first letter of the name”; nevertheless, several conflicting examples are condoned, e.g., those of Agaricus rhacodes Vittad. (Art. 60 Ex. 2), Globba trachycarpa Baker (Ex. 3), and Gluta renghas L. (Ex. 6). As far as I have been able to establish, the first author to correct Engler's P. chinchamayense to P. chanchamayense was Weberbauer himself (in Engler & Drude, Veg. Erde 12: 282. 1911), who did so without comment in an enumeration of plant species from the “Chanchamayo-Tal”. Shortly thereafter, however, Engler's original misspellings of both the species epithet and type locality were inexplicably perpetuated (also without comment) by his disciple Kurt Krause (in Engler, Pflanzenr. IV. 23Db (Heft 60): 13–14. 1913), in what still stands as the most recent comprehensive revision of the genus Philodendron. James Macbride (in Publ. Field Mus. Nat. Hist., Bot. Ser. 13(1): 470. 1936), in his influential Flora of Peru Araceae treatment, became perhaps the first author to address the issue pointedly, correcting Engler's epithet to chanchamayense while observing that, “Through an error, the specific name appeared originally as chinchamayense.” Macbride's correction has been adopted in several important floristic works, mostly dealing with Peru, e.g., Brako & Croat (in Monogr. Syst. Bot. Missouri Bot. Gard. 45: 77. 1993), Londoño-Vega & Alvarez-Dávila (in Caldasia 19: 454–455. 1997), and Vásquez Martínez (in Monogr. Syst. Bot. Missouri Bot. Gard. 63: 750. 1997). Why, then, should the present proposal even be necessary? Article 60 Ex. 7 states that “The original spelling of the generic name ‘Nilsonia’ Brongn. […] is an orthographical error correctable under Art. 60.1 to Nilssonia, the conservation of which is not therefore required.” That same logic might have served equally well for P. chinchamayense ca. 1997; however, since that time the pendulum has swung steadfastly in the opposite direction, resulting in uncertainty and nomenclatural instability. I may have unwittingly fueled the about-face myself by using “Philodendron chinchamayense Engler” to head a species entry (Grayum in Syst. Bot. Monogr. 47: 218. 1996) in a partial revision of P. subg. Pteromischum, noting only that “Engler's original spelling was altered by Macbride (1936) to the orthographically preferable ‘chanchamayense’”; however, I dealt with the name tangentially, in an appendix, with no intention of addressing (let alone resolving) the orthographical controversy at that point in time. Despite my intent, the tide has turned during the past 25 years, with most relevant publications opting to retain Engler's original spelling: e.g., Kessler & Croat (in Selbyana 20: 232. 1999), Govaerts & Frodin (World Checkl. Bibliogr. Araceae: 381. 2002), de la Torre & al. (Encicl. Pl. Útiles Ecuador: 187. 2008), Croat & Acebey (in Monogr. Syst. Bot. Missouri Bot. Gard. 127: 263. 2014), and Galeano & al. (in Bernal & al., Cat. Pl. Líquenes Colombia 1: 731. 2016). The spelling “chanchamayense” has lingered to a minor extent, e.g., in some theses (Barbosa, Divers. Fl Est. Acre [Ph.D. thesis, Univ. Fed. Sta. Catarina]: 36, 110. 2003, https://core.ac.uk/download/pdf/30366076.pdf; Lingan Chavez, Araceae S.E. Peru [M.S. thesis, Texas Christian Univ.]: 47, 58, 65, 67, 69. 2008, https://repository.tcu.edu/bitstream/handle/116099117/4079/lingan.pdf), but several major online databases (IPNI, JSTOR Global Plants, Tropicos) currently accept only P. chinchamayense and return no results for P. chanchamayense. And if that were not enough, Google searches (undertaken 26 Oct 2023) returned about 3900 hits for P. chinchamayense, compared to just 9 for P. chanchamayense! In view of these facts, the question posed previously might be turned on its heels: why is the present proposal even justified?

Had I given the orthography of this epithet the same consideration in 1996 that I have devoted to the issue in recent weeks, I would certainly have opted for Macbride's corrected spelling, which held the high ground up to that time. But the situation has changed dramatically in the past quarter century, during which time Engler's original spelling has become re-entrenched. Accordingly, automatic correction of Engler's mistake can no longer be entertained, and formal conservation of the orthographically correct spelling chanchamayense becomes the only viable option, hence the present proposal. One way or the other, this is mainly a database issue; a survey of specimens in the MO herbarium reveals that the physical annotations themselves are divided more or less equally between Philodendron chanchamayense and P. chinchamayense (considering only those specimens correctly determined to species rank), sometimes with the third letter crossed out manually and “corrected” one way or the other. As a general rule, Peruvian collections favor the former spelling, and Bolivian collections the latter (the species also occurs in Ecuador, Colombia, and western Brazil, where different names have often been used). Should this proposal be approved, wholesale re-annotations of herbarium specimens would be unnecessary (though minor manual corrections, along the lines indicated above, would be optional); only simple and straightforward tweaks to some major databases would be required. Rejection of this proposal would obviate those database tweaks (though not the manual corrections to specimen annotations), but would maintain forever the original erroneous spelling of the species epithet, which must be especially hard to swallow for Peruvian biologists. The species in question may be much collected and well marked (by the standards of P. subg. Pteromischum), but is not grown commercially for any purpose and has no economic value in world commerce (see, e.g., Plowman in Econ. Bot. 23: 97–122. 1969), though it has been used ritually by some indigenous groups in Ecuador (de la Torre & al., l.c.).