NUMBER 4 GRANT: PHLOX NOMENCLATURE 25

NOMENCLATURE OF THE MAIN SUBDIVISIONS OF PHLOX (POLEMONIACEAE)

Verne Grant Section of Integrative Biology and Plant Resources Center, The University of Texas, Austin, Texas 78712

Abstract: The task of finding the correct names for the main subdivisions of Phlox has been beset with difficulties in interpreting the intent of older authors, particularly Asa Gray. Gray divided Phlox into four main subgroups, some of which have been considered sections, but these are now seen to be only informal groups. Currently Phlox is subdivided into three sections: Phlox, Divaricatae Peter, and Occidentales A. Gray. The name Occidentales A. Gray was not validly published as a section; Gray used it only as part of a heading. The oldest valid name for what has been called sect. Occidentales is sect. Pulvinatae Peter. Recent papers have used the name sect. Annuae A. Gray in place of sect. Divaricatae, on grounds of priority. However, the name that Gray actually used was Annuae, Texenses, and it, like Occidentales, was not validly published. The sections of Phlox are being reconsidered at present in the light of new molecular evidence. Some changes will be needed, but old valid infra­ generic names will still have a role to play in new infrageneric classifications.

Keywords: Phlox, nomenclature, Asa Gray.

The genus Phlox has had a history of terms subgenus and section in the nine­ problems with the nomenclature of the teenth century. Some authors used the cat­ main infrageneric subgroups. Gray (1870, egory subgenus, others the category section, 1878, 1886) did not make it clear in his still others used both, or neither. Further­ treatments whether his main subdivisions more, some authors identified the type of were subgenera or sections. Grant (1959) category they were using, in the form Gilia concluded that they were sections, which sect. Ipomopsis (Bentham, 1833), while oth­ turns out to be wrong. Wherry (1955) set ers marked their subgroups with symbols up a good system of sections for that time, and numerals only, leaving it for the reader but picked invalid names for them. Grant to infer the intended rank as best he/she (1959) took up Gray's name Occidentales could. The double-S symbol ( §) was widely for one of Wherry's sections, but Gray's used to designate sections but was also used name is not valid. A similar problem has for primary subdivisions of other ranks. arisen recently with the introduction and We cannot be certain about the type of use of the name Phlox sect. Annuae by infrageneric category, whether section or Prather (1994) and Ferguson et al. (1999). subgenus, in the numerous cases where the In order to understand the problems, original author did not identify his intent we have to start with Gray's treatments by attaching a category name to the taxon (1870, 1878, 1886), and then follow the name. In such cases we have to be satisfied chain of later synonyms and substitutions. with a clear inference from the context, if This along with reference to the rules of possible, or otherwise treat the names as nomenclature will enable us to designate rankless if they are validly published (Greu­ the correct names for the main infrageneric ter, 2000, Art. 35). groups. In Gray's three treatments of the North SECTIONS OR SUBGENERA American Polemoniaceae (Gray, 1870, 1878, 1886), he recognized five genera. In Brizicky (1969) has documented the two of these, Collomia and Gilia, he set up lack of standardization in the use of the formal primary subgroups. Their taxonom-

LUNDELLIA 4:25-29. 2001 26 LUNDELLIA DECEMBER, 2001

ic names were preceded by the symbol §, a nostic phrases as were the secondary and numeral, and a substantive name in capital tertiary subdivisions. To be sure, Gray used letters, e.g., § 1. DACTYLOPHYLLUM, in the the § symbol for the main subgroups of genus Gilia. Gray did not attach the term Phlox, but he used this symbol for the pri­ section or subgenus to the taxonomic mary subdivisions in all genera whether name. However, he referred to the sub­ they had formal subgenera ( Collomia, Gilia) groups as "sections" in the text (Gray, 1878, or not (Polemonium). p. 137; 1886, p. 137), and he called the sym­ The names Occidentales and Annuae, bol § the "sectional mark" (Gray, 1878, Texenses used by Gray (1870) in Phlox, and preface; 1886, preface). taken up by later authors, are not validly On this basis I concluded that Gray's published according to the rules of botani­ main formal subgroups were sections and cal nomenclature (Greuter, 2000). The listed them as such (Grant, 1959). Brizicky names are used only as headings for sets of (1969), however, found a statement in included species (Greuter, 2000, Art. 34.1). Gray's prefaces that I missed. "The char­ Furthermore Gray himself did not accept acters of sections of genera, when of com­ the epithets in question as shown by the paratively high rank, are designated by the fact that he replaced them with English sectional mark ( §) and printed in the larger phrases in later editions (Gray, 1878, 1886). type; and those of first importance, such as The Latin names of 1870 are so-called "pro­ may be termed subgenera, are distinguished visional names" and these are invalid by having a substantive name." (Gray, (Greuter, 2000, Art. 34.1). An additional 1878, preface; 1886, preface.) Thus, follow­ problem with the name Annuae, Texenses is ing Brizicky (1969) Gray's main formal in­ that it is a descriptive phrase. and is not in frageneric groups with substantive names the right word form for a sectional (or sub­ should be regarded as subgenera, not sec­ generic) name (Greuter, 2000, Art. 21.2). tions. LATER WORKS GRAY'S TREATMENT OF PHLOX Peter (1897a) subdivided Phlox into six Gray used a certain typography and main groups: Drummondianae, Reptantes, style for formal subgenera, e.g., § 1. Eu­ Paniculatae, Divaricatae, Subulatae, and COLLOMIA. However, he adopted a differ­ Pulvinatae. The names of the first five stand ent typography and style for his four main for representative species. The sixth is subdivisions of Phlox. named for the cushion-like growth habit of In the 1870 treatment, the first subdi­ a group of suffruticose western montane vision reads: "§ 1. Latifoliae, Perennes, species. A key gives the distinguishing char­ Americae Boreali-Orientales, uniovulatae." acters of these groups. The second is labelled "Subulatae, Suffruti­ The groups are marked with the§ sym­ culoso-perennantes ...". The third is "Oc­ bol which Peter used consistently for sec­ cidentales (transmontanae et montanae), tions. Space considerations in the key ... "~ The fourth subdivision set up for the would favor the use of a symbol rather than Phlox drummondii Hook. group is: "An­ a word for the category. Elsewhere, how­ nuae, Texenses, laxe, ramosae, ...". In the ever, Peter (1897b, p. 59) connects the sym­ 1878 and 1886 editions these phrases are bol § with the rank of section, as in "Gat­ given in English, e.g., "Annuals, all Texan, tungssection: Phacelia § Cosmanthoides 1 more or less pubescent." (Hydrophyllaceae; Fred Barrie, pers. Thus Gray did not recognize formally comm.). He used the term Untergattung for named sections in Phlox. His primary sub­ subgenus in both the Polemoniaceae and divisions in Phlox were labeled with diag- Hydrophyllaceae (Peter, 1897a, 1897b). Pe- NUMBER4 GRANT: PHLOX NOMENCLATURE 27

TABLE 1. The current sectional classification of Phlox (Wherry, 1955; Grant, 1959). 1 Sect. Phlox. Perennial herbs with soft deciduous leaves and long styles. P. glaberrima L., P. pan­ iculata L., P. subulata L., and other species. 2 Sect. Divaricatae. Perennial or annual herbs with soft deciduous leaves and short styles. P. divar­ icata L., P. drummondii Hook., P. nivalis Lodd., P. pilosa L., and others. 3 Sect. Occidentales. Cespitose or cushion-like subshrubs with stiff evergreen leaves and short styles. P. caespitosa Nutt., P. hoodii Richardson, P. sibirica L., and others.

ter's infrageneric names in Phlox thus meet THE MONTANE SUFFRUTICOSE the requirements of the code (Greuter, PHLOXES 2000, Art. 35.5) for valid publication as sec­ tion names. One of Gray's (1870, 1878, 1886) four Brand (1907) divided Phlox into two main subgroups of Phlox was the suffruti­ subgenera: subgen. Microphlox for the suf­ cose species of the western mountains. In fruticose western montane species, and su­ his 1870 treatment he referred to them as "Occidentales (transmontanae et montan­ bgen. Macrophlox for other species of both ae) ..." In the 1878 and 1886 treatments he eastern and western North America which retains the subdivision, but drops the term are mainly erect and herbaceous. Brand's Occidentales, and presents the distinguish­ complex systetn of categories below the ing characters in English. subgenus level does not concern us here. As noted earlier, Wherry (1955) took Wherry's (1955) monograph of Phlox up Brand's name Microphlox for this sec­ was a milestone, based as it was on exten­ tion, and I (Grant, 1959) took up Occiden­ sive knowledge of the plants in field, gar­ tales A. Gray. I did not delve sufficiently den, and herbarium. Wherry divided Phlox into the documents at the time, but the into three sections. For some reason he problem with this choice is now obvious. chose to assign new or modified names to The name Occidentales was part of a de­ these sections that did not conform to the scriptive heading in a synoptical treatment, rules of nomenclature. His names were: not the name of a true formal subgroup, sect. Protophlox Wherry, sect. alpha-Phlox and furthermore, Gray did not reuse this Wherry, and sect. Microphlox (Brand) name in his later (1878, 1886) treatments. Wherry. The name is not validly published. In my family-wide treatment (Grant, The oldest valid name in the rank of 1959) I naturally followed Wherry (1955) as section for the montane suffruticose phlox­ to the circumscription and composition of es is sect. Pulvinatae Peter (1897: 46). Peter the sections but it was necessary to find the cited the following species under sect. Pul­ legitimate names for them. I rounded up all vinatae: P. muscoides Nutt., P. bryoides the infrageneric names in Phlox that I could Nutt., P. hoodii Richardson, P. caespitosa find, legitimate or otherwise, grouped them Nutt., and P. douglasii Hook. The designat­ by Wherry's system of sections, listed them ed type species of sect. Pulvinatae is P. hoo­ chronologically, and then identified the old­ dii Richardson (Grant 1959: 119). The in­ est legitimate names in what I then consid­ formal subgroup name Occidentales A. ered to be sections. These were: sect. Di­ Gray, nomen nudum, is reduced to synon­ varicatae Peter (for Protophlox), sect. Phlox ymy under Phlox sect. Pulvinatae Peter. (for alpha-Phlox), and sect. Occidentales A. THE PROPOSED SECTION NAME Gray (for Microphlox). Wherry (1966) kind­ ANNUAE ly accepted these substitutions (Table 1). It should be noted that Wherry and I were in Phlox § Annuae, Texenses of Gray frequent contact during those years. (1870) was duly included in the list of in- 28 LUNDELLIA DECEMBER, 2001

frageneric names (in Grant, 1959, as a sec­ et al. (1999). These form a subclade in the• tion). I passed over it because it was a two­ ITS cladogram. More extensive work on the word phrase and a heading, not a proper Pulvinatae is in progress (Ferguson et al., section name, and I took up sect. Divari­ unpubl.). catae of Peter (1897a) instead. However, There have been some reasons for skep­ Prather (1994) recently reversed this deci­ ticism about the naturalness of the ·two sion, on the grounds that "Gray's name mainly herbaceous sections, Divaricatae and clearly has priority" over Peter's name. But Phlox. Wherry (1955) based these sections the priority rule does not apply to invalid largely on the length of style and stigma, names, and, as pointed out earlier, Gray's raising the specter of single-character clas­ name was not validly published. sification. Prather (1994) cited the name as "sec­ The problem comes into focus in the tion Annuae A. Gray." This represents a group containing Phlox subulata L., P. ni­ change to a form of the name that Gray valis Lodd., and P. bifida Beck. These plants never used. Ferguson et al. (1999) then took have slightly woody, trailing or decumbent up Prather's (1994) section Annuae in their stems that form mats, and mostly persistent paper on the molecular (ITS) systematics of leaves. Older authors grouped the first two eastern North American phloxes. The name species together (Gray, 1870, 1886; Brand, Annuae can be treated nomenclaturally as 1907) or all three together (Wherry, 1934; follows: Phlox sect. Annuae L.A. Prather Fernald, 1950; Smith and Levin, 1967). (non A. Gray), nomen nudum, (Prather, However, P. subulata and P. bifida have 1994: 64). It should be reduced to synony­ long styles~ and P. nivalis a short style in­ my under Phlox sect. Divaricatae Peter in cluded in the corolla tube. On this basis the present three-section classification, or Wherry (1955) placed them in separate sec­ under Phlox sect. Drummondianae Peter if tions, the long-styled species in sect. Phlox, that section is recognized. and the short-styled species in sect. Divar­ icatae. DISCUSSION The molecular (ITS) evidence of Fer­ guson et al. (1999) shows that the above This paper deals with the correct nam­ three species together with a fourth one, P. ing of the primary subgroups or sections of oklahomensis Wherry, form a monophyletic Phlox. Nothing has been said so far about subgroup. The latter, P. oklahomensis, is the biologically more important problem of slightly woody and spreading, and has a the correct, that is, naturcil or monophylet­ short style; it is currently in sect. Divarica­ ic, circumscription of the subgmups them­ tae. Growth habit appears to be a better in­ selves. In recent decades we have operated dicator of relationship than style length in within the framework of Wherry's (1955) this case. three-section system, with sections Divari­ If it is deemed desirable to segregate the catae (Annuae), Phlox, and Pulvinatae (Oc­ P. subulata group as a -section, the name cidentales). How good are these sections? At Phlox sect. Subulatae (Bentham, 1845) is present molecular evidence is being brought available (cf. Grant, 1959, p. 117). to bear on this question (Fe)"guson et al., Another case is the wide-ranging poly­ 1999, and unpubl.). typic species, P. pilosa L., placed in sect. Di­ The western montane siiffruticose varicatae by Wherry (1955). In the ITS phloxes (Pulvinatae) have seemed to be a cladogram of Ferguson et al. (1999) some ·natural group on the basis of morphology subspecies of P. pilosa fall in a predomi­ and ecology. Two or three species of Pul­ nantly Divaricatae clade, while other sub­ vinatae (two in Wherry's system or three in species group with species of sect. Phlox in other systems) were sampled by Ferguson another clade. NUMBER4 GRANT: PHLOX NOMENCLATURE 29

The two predominantly herbaceous Ferguson, C.J., F. Kramer, and R.K. Jansen. 1999. sections of Phlox do not hold up in their Relationships of eastern North American Phlox (Polemoniaceae) based on ITS sequence data. present circumscription (Ferguson et al., Syst. Bot. 24: 616-631. 1999). It will be interesting to see how the Fernald, M.L. 1950. Gray's Manual of Botany. 8th ed. herbaceous species can be grouped more New York: Van Nostrand. naturally when more evidence is obtained. Grant, V. 1959. Natural History of the Phlox Family. The Hague: Martinus Nijhoff. ACKNOWLEDGMENTS Gray, A. 1870. Revision of the North American Po­ lemoniaceae. Proc. Amer. Acad. Arts. 8: 247-282. ---. 1878. Polemoniaceae. Synoptical Flora of I discussed the problem with Alan North America, 1st ed. 2 (1) 128-151. New York: Prather, Carolyn Ferguson, and Tom Ivison, Blakeman, and Taylor. Wendt. The manuscript was read by these ---. 1886. Polemoniaceae. Synoptical Flora of individuals and by Fred Barrie, Beryl Simp­ North America, 2nd ed. 2 (1) 128-151. New York: son, and Karen A. Grant. Dr. Ferguson Ivison, Blakeman, and Taylor. Greuter, W. (ed.). 2000. International Code of Botan­ called my attention to the paper by G. Bri­ ical Nomenclature, 16th ed. Konigstein: Koeltz zicky. Dr. Barrie provided information Scientific Books. about Peter's usage of the§ symbol for sec­ Peter, A. 1897a. Polemoniaceae. Die natiirlichen tions in Die nattirlichen Pflanzenfamilien. Pflanzenfamilien. 4, 3a: 40-54. Leipzig: Wilhelm Nancy Elder, Librarian, obtained some old Engelmann. ---. 1897b. Hydrophyllaceae. Die natiirlichen library materials for me. The help of these Pflanzenfamilien. 4, 3a: 54-71. Leipzig: Wilhelm individuals is gratefully acknowledged. Engelmann. Prather, L.A. 1994. A new species of Phlox (Pole­ LITERATURE CITED moniaceae) from northern Mexico with an ex­ panded circumscription of subsection Divaricatae. Bentham, G. 1833. Collomia coccinea. Bot. Reg. 19: Pl. Syst. Evol. 192: 61-66. t. 1622. Smith, D.M., and D.A. Levin. 1967. Karyotypes of ---. 1845. Polemoniaceae. A. de Candolle, Pro­ eastern North American Phlox. Amer. J. Bot. 54: domus systematis naturalis regni vegetabilis, 9: 324-334. 302-322. Wherry, E.T. 1934. Supplementary notes on the east­ Brand, A. 1907. Polemoniaceae. Das Pflanzenreich, 4, ern phloxes. Bartonia 16: 38-44. 250: 1-203. Leipzig: Wilhelm Engelmann. ---. 1955. The Genus Phlox. Philadelphia: Morris Brizicky, G.K. 1969. Subgeneric and sectional names: Arboretum Monographs. their starting points and early sources. Taxon 18: ---. 1966. The genus Phlox, ten years after. Bar­ 643-660. tonia 35: 13-16.