Taxonomic Reassessment of the British and Irish Tetraploid Marsh-Orchids

New Journal of Botany Journal of the Botanical Society of the British Isles

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Taxonomic reassessment of the British and Irish tetraploid marsh-orchids

R. M Bateman & I. Denholm

To cite this article: R. M Bateman & I. Denholm (2012) Taxonomic reassessment of the British and Irish tetraploid marsh-orchids, New Journal of Botany, 2:1, 37-55

To link to this article: http://dx.doi.org/10.1179/2042349712Y.0000000004

Published online: 12 Nov 2013.

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Download by: [Botanical Socitey of the British Isles] Date: 14 March 2016, At: 03:15 Taxonomic reassessment of the British and Irish tetraploid marsh-orchids

R. M. Bateman*1, I. Denholm2

1Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond, Surrey, TW9 3DS, UK, 2School of Life Sciences, University of Hertfordshire, Hatfield, Herts AL10 9AB, UK

Spasmodic progress in understanding the morphology of European allotetraploid marsh-orchids of the genus Dactylorhiza achieved in the second half of the twentieth century has in the twenty-first century been largely superseded by rapid progress in the molecular systematics of the group. However, a grand synthesis is still needed to integrate the re-circumscriptions of taxa achieved primarily through molecular data with improved identification ability derived from corresponding morphometric datasets. In anticipation of such a synthesis for the British Isles, we here summarise the taxonomic consequences of recent biosystematic research into the genus. These changes better accommodate infraspecific variation that reflects either local ecologically specialised races or especially regional contrasts in the frequency and degree of expression of anthocyanin pigments. We review recent nomenclatural changes, supporting such changes – and enacting further changes – only where they are clearly wholly unavoidable. Dactylorhiza traunsteinerioides (Pugsley) Landwehr ex R.M. Bateman & Denholm ssp. francis-drucei (Wilmott) R.M. Bateman & Denholm, comb. nov., encompasses all Scottish (and probably some northern Irish) populations of D. traunsteinerioides, including those formerly attributed to D. ‘lapponica’ p.p. and D. ‘ebudensis’; the latter becomes D. traunsteinerioides ssp. francis-drucei var. ebudensis (Wiefelspu¨tz ex R.M. Bateman & Denholm) R.M. Bateman & Denholm, comb. nov. Also, Dactylorhiza praetermissa (Druce) Soo´ ssp. schoenophila R.M. Bateman & Denholm, ssp. nov., is established to encompass populations located in southeast England, south of a line from the Severn to the Wash, that were formerly attributed to D. traunsteinerioides on the basis of their gross morphology and habitat preference but have genotypes characteristic of D. praetermissa; varietal level may eventually prove more appropriate. A relatively broad morphological circumscription is recommended for D. purpurella (T. & T.A. Steph.) Soo´ var. cambrensis (R.H. Roberts) R.M. Bateman & Denholm. The evolutionary histories and present conservation status of British and Irish tetraploid marsh-orchids are also summarised.

Keywords: allotetraploid, dactylorchid, Dactylorhiza majalis, DNA, ecotypes, infraspecific taxonomy, morphometrics, pigmentation

Introduction limited sampling of populations meant that we were Three decades ago, building on a ﬁne tradition of obliged to rely on a thorough literature review to morphometric analysis of the UK’s dactylorchid taxa describe, rank and, in cases where it appeared (e.g. Heslop-Harrison, 1954; Roberts, 1966), we began necessary, synonymise the remaining named infraspe-

Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 our morphometric monograph of the genus Dac- cific taxa previously reported from Britain and Ireland. tylorhiza in the British Isles (Bateman & Denholm, Our study was further limited by exclusive reliance on 1983 et seq.) by systematically revising the tetraploid phenotypic data; genotypic analyses based on DNA marsh-orchids, D. majalis (Rchb.)P.F.Hunt& sequencing were still in their infancy in the early 1980s. Summerh. sensu lato (2n580). Our analytical approach A few subsequent studies obtained detailed mor- was based on quantifying a large number (initially 51, phometric datasets from the tetraploid marsh-orchids later 52) of morphometric characters for ten plants of Scotland (e.g. McLeod, 1995), Belgium (e.g. each sampled from a modest number (15) of popula- Tyteca & Gathoye, 1989), and Scandinavia (e.g. tions that, nonetheless, encompassed all of the species Pedersen, 1998, 2004, 2007, 2010a, b). However, this and subspecies, and the majority of varieties and forms, period of investigation was notable primarily for then recognised (though the study did not include progressively added, contrasting genotypic datasets Scottish populations). Although much of our formal to supplement (or, in a disappointingly high propor- classification was based on quantitative analysis, tion of studies, to substitute for) phenotypic data. Allozymes (McLeod, 1995; Hedreń, 1996a, b) were Corresponding author, email: [email protected] succeeded by genome fragmentation techniques

ß Botanical Society of the British Isles 2012 DOI 10.1179/2042349712Y.0000000004 New Journal of Botany 2012 VOL.2 NO.1 37 Bateman and Denholm Tetraploid marsh-orchid systematics

(Hedreń et al., 2001; Devos et al., 2006), then nuclear all formally named taxa, however seemingly trivial, and plastid DNA sequencing (Bateman et al., 2003; though in practice we have not yet conducted our Pillon et al., 2007), then nuclear and plastid micro- morphological ‘grand synthesis’ using multivariate satellites (Nordstro¨m & Hedreń, 2009; Hedreń et al., morphometrics. In addition, we have consistently 2011a). The latest approaches were based on epige- been reluctant to make piecemeal taxonomic changes, netics (Paun et al., 2010) and gene expression (Paun because we believe strongly that formal taxonomic et al., 2011). treatments are better conducted as the final element In a recent review, Bateman (2011a) argued that of a research project – after multiple sources of data these recent technical innovations, combined with have been painstakingly gathered, thoroughly ana- improved geographical sampling, have greatly lysed, and their systematic implications carefully improved our understanding of the evolution – and considered (Bateman, 2009, 2011a). However, thereby of the systematic relationships and taxo- experience has taught us that some of our colleagues nomic circumscriptions – of the tetraploid marsh- reach taxonomic judgements far more hastily, in their orchids. However, he also observed that agreement understandable (if sometimes counter-productive) among scientists actively researching these issues has enthusiasm to achieve fuller and more detailed not led to similar agreement on optimal taxonomic taxonomic coverage (compare the highly contrasting status. Most notably, the ‘British School’ currently classifications of tetraploid marsh-orchids summarised views the four native tetraploid marsh-orchids (and in Table 1). Indeed, it is the multiple, Europe-wide also, importantly, the two native spotted-orchids) as monographic treatments that are currently in prepara- full species (e.g. Bateman, 2006a, 2011a, b; Stace, tion that have encouraged us to accelerate our plans to 2010). In contrast, the ‘Scandinavian School’ views review the taxonomy and nomenclature of the British the four tetraploid marsh-orchids as subspecies of an and Irish tetraploid marsh-orchids, in advance of exceptionally morphologically and ecologically vari- completing our own morphometric monograph. We able (and undoubtedly polyphyletic) ‘superspecies’, emphasise that our taxonomic decisions remain D. majalis sensu latissimo, and the two spotted- subject to future change as yet more data accumulate. orchids as subspecies of an exceptionally morphologically and ecologically variable (diploid-polyploid Rationale of the present taxonomic treatment aggregate) ‘superspecies’, D. maculata sensu latissimo Comparison of extensive morphometric and molecu- (e.g. Pedersen, 1998 et seq.; Hedreń, 2002; Hedreń lar data gathered from European dactylorchids et al., 2008; Nordstro¨m & Hedreń, 2009). demonstrates that the single most frequent category Thus far, attempts to summarise these biosyste- of taxonomic error has been to over-estimate the matic advances in order to better classify and systematic value of anthocyanin-based characters. conserve British and Irish dactylorchids have focused These pigmentation characters are both exceptionally on re-circumscription of species (as recognised by the visually striking and capable of being expressed British School: Bateman, 2006a, 2011a), acknowl- throughout the body of the plant, thereby influencing edging that the species constitutes the most mean- not only flower colour and markings but also both ingful of all taxonomic levels. However, this decision diffuse pigments and localised markings of all of the also implicitly recognised that operating below the above-ground vegetative organs of the plant. Thus, species level introduces into any such discussion an many of the most visually striking features of a intimidating plethora of taxa regarded as infraspecific dactylorchid tend to be positively correlated and Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 by both the British and Scandinavian schools. These are hypothesised to reflect contrasts in expression of taxa remain embedded in an even more extensive very few underlying genes. As there is inevitably a morass of prior names that seriously challenge temptation to separate such striking variation in attempts at circumscription, description and identifi- pigmentation into anthocyanin-poor and anthocya- cation, as well as often bringing the over-valued nin-rich morphs and to formally name them, this formal law of nomenclatural priority into conflict suite of characters has strongly influenced, arguably with the under valued informal law of nomenclatural dominated (Bateman, 2006a) the taxonomy of familiarity (cf. Pedersen et al., 2003; Kreutz, 2004; Dactylorhiza through the centuries. Bateman et al., 2010; Pedersen, 2011). Each of the four allotetraploid species found in the In order to address these issues, through the last British Isles encompasses at least one named antho- 30 years we have spasmodically increased to 52 the cyanin-poor morph (usually the nominate race) and number of tetraploid marsh-orchid populations at least one anthocyanin-rich morph. In the cases of analysed morphometrically by us; also, from 1996 at least two of the species, D. traunsteinerioides and onward we have stored dried tissue samples for DNA D. purpurella, the anthocyanin-rich morphs increase sequencing. In theory, we are now in a position to in frequency, relative to the conspecific anthocyanin- integrate phenotypic and genotypic data for almost poor morphs, toward the north and west. Moreover,

38 New Journal of Botany 2012 VOL.2 NO.1 Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016

Table 1 Comparison of the present classiﬁcation of the tetraploid marsh-orchids with ten other classiﬁcations, most proposed since 1996. Taxa are grouped according to the four species recognised here, rather than groups proposed by the original authors

Bateman and Denholm (1983) Soo´ (1980)1 Sell and Murrell (1996) Stace (1997)2 Ettlinger (1997, 1998)

D. majalis ssp. praetermissa D. majalis ssp. praetermissa D. praetermissa D. praetermissa D. majalis ssp. praetermissa – var. junialis D. majalis s.s. (5 junialis) ––f.junialis – var. junialis – – var. junialis D. majalis ssp. occidentalis D. majalis ssp. occidentalis D. comosa ssp. occidentalis D. majalis ssp. occidentalis D. majalis ssp. occidentalis – var. kerryensis – (incl. scotica) ––f.kerryensis – (incl. ebudensis) – – var. kerryensis – var. scotica – (incl. cambrensis) – ssp. scotica – ssp. cambrensis – ssp. ebudensis – var. cambrensis – ssp. cambrensis – ssp. cambrensis D. majalis ssp. purpurella D. majalis ssp. purpurella D. purpurella ssp. purpurella D. purpurella D. majalis ssp. purpurella – ssp. majaliformis – – var. majaliformis D. majalis ssp. traunsteinerioides5 D. traunsteineri ssp. traunsteineri D. traunsteineri ssp. traunsteineri D. traunsteineri D. majalis ssp. traunsteineri – var. francis-drucei – ssp. lapponica* – ssp. lapponica D. lapponica – ssp. lapponica

Lang (2004) Kreutz (2004)1 Govaerts (2005)1 [World Checklist] Delforge (2006)1,3 Bateman (2006a),4 Stace (2010) Present study

D. praetermissa D. praetermissa ssp. praet. D. praetermissa D. praetermissa D. praetermissa D. praetermissa ssp. praet. – ssp. junialis/pardalina – ssp. junialis – var. junialis – var. junialis – junialis – – var. junialis – ssp. schoenophila D. majalis s.s.6 D. majalis ssp. occidentalis D. majalis ssp. occidentalis D. occidentalis D. kerryensis8 D. kerryensis – ssp. scotica – ssp. kerryensis – var. kerryensis D. kerryensis D. ebudensis – – var. occidentalis – ssp. cambrensis – ssp. ebudensis D. ebudensis – ssp. cambrensis D. purpurella D. purpurella D. purpurella D. purpurella D. purpurella D. purpurella – ssp. majaliformis – ssp. majaliformis – var. cambrensis D. cambrensis7 – cambrensis – – var. cambrensis aea n Denholm and Bateman

e ora fBotany of Journal New D. traunsteineri D. traunsteinerioides D. traunsteineri D. traunsteinerioides D. traunsteinerioides D. traunsteinerioides ssp. traun. D. lapponica D. lapponica* D. lapponica* D. lapponica – ‘lapponica’ – ssp. francis-drucei – – var. ebudensis

Note: 1Information abstracted from Europe-wide classifications. 2Followed by Preston et al. (2002). 3Original author’s grouping of taxa contrasts strongly: traunsteinerioides 5 traunsteineri group, occidentalis z ebudensis z lapponica 5 majalis group, rest 5 praetermissa group. 4Followed by Foley & Clarke (2005) and Harrap & Harrap (2005). 5Var. eborensis was also listed. 6 Considered occidentalis synonymous with majalis s.s. systematics marsh-orchid Tetraploid 7 2012 Includes majaliformis. 8Named occidentalis by Bateman (2006a). *Unclear whether the author believed that this taxon is present in the British Isles. VOL .2 NO .1 39 Bateman and Denholm Tetraploid marsh-orchid systematics

the distribution of the relatively anthocyanin-rich D. taxa under comparison. Here, the descriptions are kerryensis/occidentalis is also predominantly westerly restricted to characters thought to provide statisti- within Ireland (Bateman, 2006a, 2011a, b; Hedreń cally significant distinctions between the two taxa. et al., 2011a). However, it is uncommon for popula- Adjectives describing the frequency of that character tions of any of these three species to be composed state in that particular taxon represent the following wholly of either anthocyanin-rich or anthocyanin- frequencies: rarely(20%, occasionally520–50%, often5 poor individuals. These facts cause serious problems 51–80%, usually>80%. The most convincingly diag- of identification: Should the field botanist apply nostic characters are italicised. names to individuals or to populations? How much variation in pigmentation was permitted in the Dactylorhiza traunsteinerioides original description (protologue) of the named taxon? A recent historical review of the systematics of the And should subsequent botanists feel empowered to narrow-leaved marsh-orchids (Bateman, 2011a) delib- expand the original circumscription in order to better erately focused on the species level, emphasising in accommodate such variation, or is it preferable to particular the recent molecular evidence that argues coin yet another formal epithet to circumscribe the strongly for reassignment to D. praetermissa (q.v.) of relevant phenotype (noting in passing that epithets all populations that were previously attributed to D. are by no means in short supply in the byzantine traunsteineri(oides) but occur south of a line extending realm of dactylorchid taxonomy)? from the Severn to the Wash (Hedreń et al., 2011a). From our earliest work (Bateman & Denholm, Formal infraspecific taxonomy was deliberately evaded 1983) onwards, we have viewed all taxonomic ranks by both Bateman and Hedreń et al. but forma as being applicable primarily to popula- The earlier decision of Bateman & Denholm (1983) tions rather than individuals. We have also preferred to recognise D. traunsteinerioides as a species dis- to expand previous diagnoses, and where necessary to tinguishable from the Alpine D. traunsteineri was implement new combinations, rather than coin new explicitly tentative, being based primarily on per- epithets (cf. Bateman, 2009). Here, for the first time, ceived subtle morphological differences between we have broken this self-imposed constraint, feeling morphometric data on British and Irish populations obliged to coin one new name in order to finally lay versus traditional descriptions published in the classi- to rest long-standing controversies surrounding the cal taxonomic literature. Other authors remained circumscriptions of infraspecific taxa that have convinced of the conspecificity of British and Alpine been widely regarded as belonging to that most narrow-leaved marsh-orchids (e.g. Roberts, 1988; problematic of allotetraploid dactylorchids, D. traun- Foley, 1990, 1994). Nonetheless, several molecular steineri(oides). Much-debated taxonomic problems datasets acquired more recently (Pillon et al., 2007; surrounding D. ‘lapponica’ and D. ‘ebudensis’ are Nordstro¨m & Hedreń, 2008; Paun et al., 2010; remedied via new combinations, and several purely Hedreń et al., 2011a) have encouraged us to continue nomenclatural issues are also addressed, though to distinguish at species level between narrow-leaved not all are satisfactorily resolved. It will be evident allotetraploid marsh-orchid taxa found in three from Table 1 that these taxonomic decisions diverge disjunct regions: the Alps (D. traunsteineri [Sauter] moderately from the circumscriptions and classifica- Soo´), Scandinavia (D. lapponica [Laest. ex Hartman] tion given in edition 3 of the New Flora of the British Soo´), and the British Isles (D. traunsteinerioides Isles (Stace, 2010) and substantially from those in [Pugsley] Landwehr ex R.M. Bateman & Denholm). Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 edition 2 (Stace, 1997), which formed the framework Although the morphometric distinctions between for the national plant atlas (Preston et al., 2002). Our these taxa remain subtle, the cumulative molecular classification has remarkably little in common with evidence supports arguments that they had indepen- the treatment, rich in infraspecific taxa, which was dent evolutionary origins in their three respective laid out in the Flora of Great Britain and Ireland (Sell geographical enclaves (Bateman, 2006a, 2011a; Pillon & Murrell, 1996). et al., 2007; Nordstro¨m & Hedreń, 2008, 2009; Paun We have organised the following taxonomic et al., 2010; Hedreń et al., 2011a). account under the four main epithets that were The name D. traunsteinerioides is based on ‘Orchis treated first as subspecies of D. majalis by Bateman & majalis ssp. traunsteinerioides’ Pugsley (1935, p. 124), Denholm (1983) and later as species by Bateman the holotype originating from a population near (2006a, 2011a; contra Hedreń et al., 2011a). Formal Wicklow in EC Ireland that is believed to no longer diagnoses also follow the style laid down by Bateman be extant. Several permutations of the epithet were & Denholm (1983): taxa are compared via a chosen subsequently devised, reviewed by Bateman & Den- threshold value for each character; this approximates holm (1983), but only recently did Clive Stace inform a trough that separates two peaks corresponding to us that the combination Dactylorhiza traunsteiner- the modal values among individuals of the pair of ioides (Pugsley) Landwehr was illegitimate because the

40 New Journal of Botany 2012 VOL.2 NO.1 Bateman and Denholm Tetraploid marsh-orchid systematics

basionym was specified incorrectly by Landwehr remains virtually unchanged today (Bateman, 2006b), (1975, p. 80). We therefore corrected this legalistic but unfortunately, the only plant from the locality error at Clive’s behest (Bateman & Denholm in Stace, analysed by us thus far is suspected to be a hybrid 2006, p. 20). with D. fuchsii. Narrow-leaved marsh-orchid popula- Given the clear importance of geography in dic- tions from several nearby localities fit well within D. tating the species-level taxonomy of the D. traun- traunsteinerioides (Bateman, 2011a). steineri group as a whole (Bateman, 2011a), this is the Equally petite plants from Wester Ross, Scotland obvious principle from which to begin examining were first described as a full species, ‘Orchis’ francis- D. traunsteinerioides in order to determine whether drucei, by Wilmott (1936: Fig. 1), but the epithet was infraspecific subdivision is merited. The species has subsequently largely ignored until it was downgraded four centres of distribution in the British Isles: to a subspecies of D. traunsteineri by Soo´ (1962). Ireland, North Wales, northeast England and western Although the probable type locality of francis-drucei Scotland (Carey & Dines, 2002). As noted by at Loch Maree was recently refound, most of the Bateman & Denholm (1983), at least some popula- scientific work conducted on this taxon has utilised a tions of D. traunsteinerioides have been given sepa- similar population located 8 km to the north, at Loch rate epithets in three of these four areas; only those Kernsary (Bateman, 2011a). Admittedly, these extant of North Wales have remained steadfastly classified populations contain a majority of leaf-marked plants, under D. traunsteineri(oides) alone, from Lacey whereas Wilmott’s (1936) original description, photo- (1955) onward. Populations across its full range graph, and line drawing of francis-drucei specified share an affinity for neutral and alkaline flushes unmarked leaves, as well as an unusually pale (often tufaceous and surrounded by more acidic soils) background colour to the labellum. that are dominated by Schoenus nigricans. Populations in these four areas show remarkable Ssp. francis-drucei (< ‘lapponica’) consistency in all molecular datasets (Pillon et al., Perhaps the greatest taxonomic controversy that post- 2007; Hedreń et al., 2011a; Bateman et al., unpub- dated Bateman & Denholm (1983) was the assignment lished). Plastid haplotypes suggest modest introgres- to D. lapponica by Kenneth et al. (1988) of at least nine sion with other dactylorchids in the Anglesey allotetraploid dactylorchid populations known from populations, but the only substantial genetic devia- the western seaboard of Scotland (though not at that tion detected affected the Loch na Bron population, time known from the headquarters of francis-drucei near Mullagh Mhor, Co. Clare, western Ireland, in Wester Ross). Dactylorhiza lapponica (Laest. ex where both plastid and nuclear microsatellites indi- Hartman) Soo´ is a boreal taxon that has its head- cate possible introgression with D. kerryensis/occi- quarters in Scandinavia – the source of the holotype – dentalis (cf. Hedreń et al., 2011a). Thus far, we have but has also been reported from the Alps (e.g. detected no genetic markers within D. traunsteiner- Reinhard, 1985; Nordstro¨m & Hedreń, 2008). ioides to correspond with the clear north- and Kenneth et al. (1988) aggregated data for 20 characters westward decreases in the average sizes of all organs from seven Scottish populations in order to demon- and, nearing the coast, increase in the proportion of strate their similarity to aggregated data for 31 bona plants exhibiting comparatively dense spotting on the fide D. lapponica populations previously measured in leaves (Bateman, 2006a, 2011a). both Scandinavia and the Alps by Reinhard (1985). Although the type locality for traunsteineroides s.s. The archetypal Scottish population assigned to D. Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 resides in Co. Wicklow, east-central Ireland (Pugsley, lapponica, first found in 1963, is located at Knapdale, 1936, 1940; see also Vermeulen, 1947), at least some Kintyre (Kenneth et al., 1988). Although it has since Irish populations were distinguished from D. traun- been analysed for morphometrics and allozymes steinerioides as D. traunsteineri ssp. hibernica,with (McLeod, 1995; Bateman et al., unpublished), earlier sparing justification, by Landwehr (1975). ‘Sub- studies of the population were of necessity confined to species hibernica’ has as its type locality Scraugh traditional morphological comparisons. The popula- Bog in Co. Westmeath but also encompasses our tion was first ascribed to D. traunsteineri (Cunningham study site at Pollardstown Fen, Co. Kildare (cf. & Kenneth, 1979), then to D. kerryensis/occidentalis Landwehr, 1977; Bateman & Denholm, 1983). We are (Tennant & Kenneth, 1983), then back to D. traun- confident that Ireland does not support bona fide D. steineri (Lowe et al., 1986) before taking up longer- traunsteineri in addition to D. traunsteinerioides. term residence in D. lapponica (R.H. Roberts, pers. Yorkshire plants found near Rievaulx Abbey were comm., 1987; Kenneth et al., 1988; Allan et al., 1993; given the epithet eborensis by Godfery (1933) and Stace, 1997; Carey & Dines, 2002). These rapid transferred to a variety of traunsteinerioides by taxonomic shifts graphically reflect the subtleties of Pugsley (1939); see also Roberts & Gilbert (1963) the morphological distinctions among taxa and com- and Tennant (1979). The probable type population plexity of the related nomenclature.

New Journal of Botany 2012 VOL.2 NO.1 41 Bateman and Denholm Tetraploid marsh-orchid systematics Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016

Figure 1 Holotype (arrowed) and two isotypes of Dactylorhiza traunsteinerioides ssp. francis-drucei (BM).

42 New Journal of Botany 2012 VOL.2 NO.1 Bateman and Denholm Tetraploid marsh-orchid systematics

Figure 2 Holotype (arrowed) and two isotypes of D. praetermissa ssp. schoenophila, ssp. nov., from Cothill Fen, Oxfordshire (K). Note the much smaller scale of the main image relative to that in Fig. 1. Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016

Carey & Dines (2002) illustrated D. ‘lapponica’ as some Scottish populations of D. traunsteinerioides are occurring in 18 decads in Scotland north of the predominantly leaf-marked (e.g. Dun Caan on Midland Valley, distributed fairly evenly along the Raasay) and others are predominantly unmarked west coast. A steady ﬂow of subsequent records has (e.g. Applecross in Wester Ross), the majority are included outliers further east. Particularly striking is strongly polymorphic for this character (Fig. 2c–f of the fact that, of 11 decads recorded for D. ‘traun- Bateman, 2011a). steineri’ in Scotland, eight coincide with those for D. A further debate has concerned the possible ‘lapponica’, most of these combined records referring occurrence of ‘lapponica’ along the Antrim coast of to the same populations. We suspect that leaf mark- Ulster, which was rejected by Foley & Clarke (2005, p. ing was often used as the main ‘diagnostic’ charac- 246) and, through the implication of their distribution ter to separate ‘traunsteineri’ (unmarked to lightly maps, by Carey & Dines (2002) and Lang (2004). Also, marked) from ‘lapponica’ (lightly to heavily marked) ‘lapponica’ was not distinguished from ‘traunsteiner- – a distinction shown to be relatively trivial via both ioides’ in either of the recent monographs of Irish morphometric and molecular analyses (Bateman, orchids (Curtis & Thompson, 2009; Sayers & Sex, 2001, 2006a, 2011a; Hedre´n et al., 2011b). Although 2009). In contrast, lapponica was reported from

New Journal of Botany 2012 VOL.2 NO.1 43 Bateman and Denholm Tetraploid marsh-orchid systematics

Antrim by Ettlinger (1997) and Harrap & Harrap morphological separation from ssp. traunsteinerioides (2005), suggested tentatively by Carey & Dines (2002) is evident in multivariate ordinations (McLeod, 1995). in the text accompanying their distribution maps, and This distinction, based largely on the vegetative stated with confidence and in greater detail by Ennis compactness of the plants and their relatively broad, (2003, 2007); see also Bateman (2011a). We have not often notched labella, could in theory reflect either yet analysed these northern Irish populations, but genetic or epigenetic responses to its unusual dune- images and specimens both strongly suggest that they slack habitat (Paun et al., 2010, 2011); comparison are consistent with classic populations of ssp. francis- with the well-known, substantial population of ssp. drucei such as Knapdale, just 70 km NNE on Kintyre, francis-drucei on the nearby island of Harris (Heslop- Scotland. Harrison et al., 1941; Kenneth et al., 1988) could prove informative in this context. Although we here margin- Var. ebudensis (‘scotica’) ally prefer the rank of variety for ebudensis,asin Recent reviews have summarised the biology Bateman & Denholm (1983, 1995), this choice of rank (Bateman, 2011b), ecology and distribution (Lowe, should still be viewed as provisional. Bateman & 2003; Horsman, 2011) of this intriguing taxon, which Denholm (1983) argued that raising the plant to the effectively forms a single large population in the status of subspecies would require use of the synon- Outer Hebrides in northern North Uist and southern ymous epithet scotica. Nonetheless, Lowe (2003, p. 81) Berneray. Var. ebudensis was repeatedly formally opted to describe the population as D. majalis ssp. described in the 1970s (Nelson, 1976; Wiefelspu¨tz, ebudensis (Wiefelspu¨tz ex R.M. Bateman & Denholm) 1976; Landwehr, 1977) but was probably first M.R. Lowe. reported from Uist in the 1930s (Campbell, 1937). The complex (and rather unsatisfactory) nomencla- Dactylorhiza traunsteinerioides (Pugsley) Landwehr tural and taxonomic history of ebudensis/scotica – and ex R.M. Bateman & Denholm the even more ambiguous evolutionary relationships Basionym: Orchis majalis Rchb. ssp. traunsteiner- and taxonomic status pertaining at the time – were ioides Pugsley, Proc. Linn. Soc. Lond. 148: 124 detailed by Bateman & Denholm (1995) and Lowe (1936). (2003). Like most previous and subsequent observers, Synonyms (selected): Dactylorhiza majalis (Rchb.) these authors assumed on traditional morphological P.F. Hunt & Summerh. ssp. traunsteineroides (Pugsley) evidence that ebudensis had a close relationship with R.M. Bateman & Denholm, Watsonia 14: 372 (1983); D. kerryensis/occidentalis/majalis s.s. However, later D. traunsteinerioides (Pugsley) Landwehr, Orchideee¨n analysis of nuclear ITS and especially plastid se- 37: 79 (1975). quences revealed substantial differences between the Ssp. traunsteinerioides two taxa; the results suggested that ebudensis more Stem often exceeds 20 cm, usually exceeds 3 mm in likely originated relatively recently, through a se- diameter. Sheathing leaves often 3 or more, usually parate allopolyploid event, that was presumed to exceed 8 cm, occasionally attached within 5 cm of the have occurred in its current coastal location (Pillon stem base; leaf markings occasionally present, exclu- et al., 2007). sively adaxial. Inflorescence often exceeds 4 cm. Basal This evolutionary interpretation was considered bracts often exceed 20 mm, floral bracts often exceed sufficient evidence by Bateman (2006a) to support 14 mm, unmarked. Labellum length to apex of Delforge’s (2000) decision to elevate ebudensis to

Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 central lobe usually exceeds 7.5 mm, length to apex species level, a step rapidly followed by Stace (2010). of lateral lobes usually exceeds 6.5 mm; width usually Unfortunately, Pillon et al. (2007) analysed only a exceeds 9.5 mm. Spur length usually exceeds 8 mm, single individual from the population, and despite the width midway along length usually exceeds 3 mm. fact that it exhibited a typical ebudensis phenotype Lateral outer perianth segments rarely possess (McLeod, 1995), it now appears more likely that the annular markings. Occasional in western and east- plant in question had acquired ‘foreign’ plastids central Ireland, north Wales, north-east England; through introgression with abundant co-occurring fens and calcareous flushes. diploid plants of D. incarnata coccinea (Bateman, 2011a, b). The larger samples of 13 individuals of Ssp. francis-drucei (Wilmott) R.M. Bateman & var. ebudensis analysed by Hedreń et al. (2011a) Denholm, comb. nov. yielded one further plant that contained an incar- Basionym: Orchis francis-drucei Wilmott, Proc. nata haplotype. The remaining plants proved to Linn. Soc. Lond. 148: 128 (1936). closely resemble ssp. traunsteinerioides in allozymes Synonyms: Dactylorhiza traunsteineri (Sauter) Soo´ (Bateman et al., unpublished), ITS sequences, ssp. francis-drucei (Wilmott) Soo´, Nom. Nov. Gen. nuclear microsatellites, and plastid haplotypes Dactylorhiza: 6 (1962); Dactylorhiza francis-drucei (Hedreń et al., 2011a), but nonetheless partial (Wilmott) Averyanov, Bot. Zhurn. 69: 875 (1984).

44 New Journal of Botany 2012 VOL.2 NO.1 Bateman and Denholm Tetraploid marsh-orchid systematics

Stem rarely exceeds 20 cm, occasionally exceeds Lingay Strand and Newton Ferry, N. Uist’ by J.W. 3 mm in diameter. Sheathing leaves occasionally 3 or Campbell (10 & 18 June 1936) and A.J. Wilmott more, rarely exceed 8 cm, usually attached within 5 cm (accessioned 1937). of the stem base; leaf markings usually present, rarely abaxial. Inflorescence rarely exceeds 4 cm. Basal Dactylorhiza praetermissa bracts occasionally exceed 20 mm, floral bracts occa- The precise circumscription and evolutionary rela- sionally exceed 14 mm, rarely marked. Labellum tionships of D. praetermissa continue to challenge length to apex of central lobe often exceeds 7.5 mm, systematists. Ample evidence has gradually accumu- length to apex of lateral lobes rarely exceeds 6.5 mm; lated that, like the other three British and Irish width occasionally exceeds 9.5 mm. Spur length occa- tetraploid marsh-orchids, D. praetermissa originated sionally exceeds 8 mm, width midway along length through allopolyploidy between the broad diploid occasionally exceeds 3 mm. Lateral outer perianth lineages epitomised by D. fuchsii (including D. segments occasionally possess annular markings. saccifera)andD. incarnata (Hedreń, 1996a, b; Occasional in western Scotland and the Hebrides, Hedreń et al., 2001; Devos et al., 2006; Pillon et al., probably also in Antrim; calcareous flushes. 2007). However, unlike the remaining allopolyploids, TYPE: ‘West Ross; slopes above Loch Maree, 23 D. praetermissa is inferred to have originated prior to June 1935, coll. A.J. Wilmott’ (Wilmott, 1936, p. 128) the most recent glaciation and hence may not have (holotype BM: Fig. 1). done so within the British Isles but rather further south (Pillon et al., 2007; Hedreń et al., 2011a). Var. francis-drucei The location of the southern and eastern distribu- Stem often exceeds 10 cm. Bract peripheral cells tional margins of D. praetermissa, and its relationship usually exceed 75 mm, occasionally barrel-shaped. with the often co-occurring D. majalis s.s., have been Sheathing leaves usually attached at least 1 cm above much discussed and remain controversial. Although the stem base; leaf markings occasionally exceed still in need of a detailed morphometric comparison, 3 mm in mean diameter. Labellum width occasionally these two species are rarely difficult to distinguish exceeds 9.5 mm (exceeds length by an average of 1– from each other in the field on morphological 2mm); lateral lobes rarely indented.Distributed grounds. Rather, it is in the molecular realm that throughout the range of the subspecies. the taxonomic distinction appears relatively weak. Var. ebudensis (Wiefelspu¨tz ex R.M. Bateman & Interestingly, D. majalis shows only a small subset of Denholm) R.M. Bateman & Denholm, comb. nov. the ITS alleles found in D. praetermissa, whereas the Basionym: Dactylorhiza majalis (Rchb.f.) Soo´ ssp. converse is true of plastid haplotypes (Pillon et al., occidentalis (Pugsley) Soo´ var. ebudensis Wiefelspu¨tz 2007; Nordstro¨m & Hedreń, 2009). Thus, we cannot ex R.M. Bateman & Denholm, Edinb. J. Bot. 52: 57 reject the possibility that one of these taxa was (1995). derived from the other, rather than through separate Original diagnosis: W. Wiefelspu¨tz in J. Landwehr, allopolyploidy events. Nonetheless, on present evi- Wilde Orchideee¨n van Europa: 557 (1977). dence, we prefer to maintain D. praetermissa separate Synonyms (selected): D. majalis ssp. ebudensis from D. majalis. (Wiefelspu¨tz ex R.M. Bateman & Denholm) M.R. The law of nomenclatural priority continues to Lowe, Eurorchis 15: 81 (2003); D. ebudensis (Wiefel- bring unwelcome complexity to attempts to make spu¨tz ex R.M. Bateman & Denholm) P. Delforge, meaningful sense of the tetraploid marsh-orchids. As Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 Nat. Belges 81: 397 (2000). we approach the centenary of Druce’s (1914) ‘Orchis Stem rarely exceeds 10 cm. Bract peripheral cells praetermissa’, a threat to the familiarity of this epithet rarely exceed 75 mm, usually barrel-shaped. Sheath- recently (re-)emerged in the form of Pedersen’s (2009, ing leaves rarely attached at least 1 cm above the 2010, 2011) arguments that the epithet integrata stem base; leaf markings often exceed 3 mm in mean (based on ‘Orchis incarnata’ L. var. integrata E.G. diameter. Labellum width usually exceeds 9.5 mm Camus [in Fourcy, 1891], with a holotype from (exceeds length by an average of 3 mm); lateral lobes Chateau-Landon, south of Paris) refers to the same often indented. Apparently confined to one large taxon as praetermissa and pre-dates the epithet by population and a few small outliers near the northern 22 years. We remain suspicious of this suggested tip of North Uist, Outer Hebrides; calcareous dune synonymy, desiring stronger evidence that the holo- slacks. type of integrata, which was obtained from the TYPE: Scotland, North Uist, Lingay Strand, ambiguous Continental margin of the distribution in dunes near Newton Hotel, 4 June 1974, W. currently attributed to D. praetermissa (e.g. Tyteca Wiefelspu¨tz, DM 37 (lectotype HEID). The herbar- & Gathoye, 1993), is indeed conspecific. Fortu- ium of the London Natural History Museum (BM) nately, integrata was not used at species level un- contains no less than 52 specimens collected ‘between til 1984 (D. integrata [E.G. Camus ex Fourcy]

New Journal of Botany 2012 VOL.2 NO.1 45 Bateman and Denholm Tetraploid marsh-orchid systematics

Averyanov), and even then it was employed by of ‘typical’ D. praetermissa – the five populations Averyanov (1984) without taxonomic justification. from southeast England quantified by Bateman & Our preference for continued recognition of praeter- Denholm (1983), plus that subsequently measured missa at species level protects us from feeling obliged from Chippenham Fen, Cambridgeshire – and five to spend valuable time compiling yet another formal narrow-leaved populations from southern England (and most likely unsuccessful) case for conserving an that had previously been assigned to D. traunsteineri epithet that is familiar, and represents a well-under- (oides) – Beeston Bog and Foulden Common in stood biological entity, against an epithet that is Norfolk, Market Weston Fen in Suffolk, Maple- unfamiliar and biologically ambiguous. Presumably, durwell Fen in North Hampshire, and Cothill Fen in integrata will now gradually replace praetermissa in Oxfordshire (Fig. 2). the taxonomic literature at subspecies (and varietal) Unsurprisingly, this comparison suggests that ssp. levels, as D. majalis (Rchb.) P.F. Hunt & Summerh. schoenophila is morphologically intermediate between ssp. integrata (E.G. Camus ex Fourcy) H.A. Pedersen ssp. praetermissa and D. traunsteinerioides. Compared (2009, 2011). with ssp. praetermissa, its vegetative organs are on average smaller and, in the case of leaves, fewer; in Ssp. schoenophila addition, the lateral lobes of its labellum tend to be Although Harrap & Harrap (2009) primarily used more strongly reflexed. Also, flowering typically peaks East Anglian plants to characterise D. traunsteiner- slightly earlier than in co-occurring plants of ssp. ioides, they also presciently noted that it is ‘often praetermissa. Nonetheless, we acknowledge that a case hybridised out’ by D. praetermissa in these localities could be made for recognising schoenophila as a (29 hectads were reported to support D. traunsteiner- variety rather than a subspecies (M. Hedreń, pers. ioides in the region by Carey & Dines, 2002). comm., 2012). Populations that are at least super- Dactylorhiza praetermissa (Druce) Soo´ is typically ficially similar in morphology to ssp. schoenophila dominated by ITS allele III, whereas D. traunsteiner- occur sporadically in the Low Countries (cf. Devillers ioides is dominated by allele V (both alleles being & Devillers-Terschuren, 1986; Kreutz & Dekker, 2000; derived from the D. fuchsii group: Pillon et al., 2007), Delforge & Mast de Maeght, 2003; Bourne´rias & Prat, often co-occurring with the D. incarnata-derived 2005). allele X. In fact, the modest number of populations Recent images of D. praetermissa ssp. osiliensis from southern and eastern England that were pre- (Pikner) Kreutz (2006a, p. 99) (e.g. http://www. viously consistently included within D. traunsteiner- guenther-blaich.de/artlen.php) suggest a close mor- ioides (or D. traunsteineri) on morphological grounds phological similarity to the southern English D. actually possess DNA profiles that accord with D. praetermissa ssp. schoenophila. Based on D. osiliensis praetermissa (Hedreń et al., 2011a). This observation Pikner (Pikner & Delforge, 2005, p. 77), this putative led Bateman (2011a) to argue strongly in favour of endemic of the Baltic island of Saarema, offshore reassigning the East Anglian populations of D. Estonia, merits future morphometric comparison ‘traunsteinerioides’ to D. praetermissa, as a new in- with ssp. schoenophila. However, the ca 1500 km fraspecific taxon that specialises in occupying fens that separate ssp. osiliensis from ssp. schoenophila dominated by Schoenus nigricans – a taxon estab- argue against a shared genetic history – an inference lished here as ssp. schoenophila (Fig. 2). reinforced by ‘in press’ analyses of ITS ribotypes, We emphasise that the following descriptions of D. nuclear microsatellites and plastid haplotypes in Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 praetermissa ssp. praetermissa and ssp. schoenophila, osiliensis (M. Hedreń, pers. comm., 2011). In and our use of subspecific rather than varietal rank, particular, ribotypes are more typical of the D. are provisional. The descriptions are not (yet) the traunsteineri(oides) group and contrast with the result of a taxonomically comprehensive multivariate near-fixation of allele III demonstrated by Hedreń re-analysis of the morphology of British and Irish et al. (2011a) in D. praetermissa sspp. praetermissa, dactylorchid populations – one that would, for and schoenophila. example, allow the controversial populations in Another epithet that could in theory claim priority south-central and eastern England formerly attribu- over schoenophila is ‘D. majalis ssp. traunsteineri var. ted to D. traunsteinerioides to be compared with that bowmanii Jenkinson’, which has its type locality species. Instead, we have unequivocally accepted the at Exbury, South Hampshire (Jenkinson, 1995b) various categories of molecular data that indicate an but has also been reported from a few additional affinity of these populations with D. praetermissa localities in southern Hampshire (Jenkinson, 1995a) rather than with D. traunsteinerioides (Hedreń et al., and east Dorset (Jenkinson, 1991). Roberts & Foley 2011a). This precept allowed us to make a straight- (1997) used a morphometric summary to argue that forward comparison of raw morphometric data ga- the Exbury plants were in fact depauperate plants of thered by us between six populations representative D. praetermissa. However, subsequent nuclear ITS

46 New Journal of Botany 2012 VOL.2 NO.1 Bateman and Denholm Tetraploid marsh-orchid systematics

sequencing tentatively identified the Exbury plants by at best a minority of the individuals in the as representing introgression between surrounding relevant populations (and so are best identified as plants of D. praetermissa ssp. praetermissa and the individuals rather than populations), and are sus- widespread diploid D. fuchsii (data in Bateman et al., pected to represent very few genetic differences from 2003; Pillon et al., 2007). Such hybridisation was thenominateraces,arebesttreatedasformae described at the site even in the original description of (Bateman & Rudall, 2011). However, plants of var. ‘bowmanii’ (Jenkinson, 1995a), and would readily junialis appear to constitute the majority of plants explain the unusually deeply three-lobed labella of in some Continental populations (e.g. Kreutz & these enigmatic plants. Also, at its locus classicus, Dekker, 2000), suggesting that the epithet can be ‘var. bowmanii’ inhabits clay soils that are neutral and applicable to populations as well as occasional only periodically waterlogged (Jenkinson, 1995a), individuals. Moreover, Pedersen (2010a) reported rather than the calcareous ever-wet Schoenus fens surprising allozymic evidence of at least some restric- that characterise ssp. schoenophila. Ironically, at least tion of gene-flow between spotted and unspotted some other populations in Hampshire and Dorset individuals of D. praetermissa at a population near attributed to ‘bowmanii’ by Jenkinson (1991, 1995a, North Warnborough, North Hampshire. Given the b) do genuinely represent ssp. schoenophila. None- present (albeit still equivocal) evidence, varietal status theless, we are confident that the epithet ‘bowmanii’ is appears more appropriate for junialis. not an appropriate biosystematic basis for a variety Dactylorhiza praetermissa (Druce) Soo´, Nom. Nov. of D. praetermissa, despite occasional recent sugges- Gen. Dactylorhiza: 5 (1962) tions to the contrary (e.g. Harrap & Harrap, 2009; L. Basionym: Orchis praetermissa Druce, Rep. Bot. Lewis, pers. comm., 2011). Exch. Club Brit. Isles 3: 340 (1914). Var. junialis Synonyms (selected): Dactylorhiza majalis (Rchb.) As with the other tetraploid marsh-orchid species, the P.F. Hunt & Summerh. ssp. praetermissa (Druce) presence of leaf-marked individuals in some popula- D.M. Moore & Soo´ in Amaral Franco & Moore, Bot. tions of the predominantly unmarked D. praetermissa J. Linn. Soc. 76: 367 (1978); ?D. majalis ssp. integrata has long caused considerable taxonomic controver- (E.G. Camus ex Fourcy) Soo´, Nom. Nov. Gen. sy (Bateman & Denholm, 1983): these ‘Leopard Dactylorhiza: 5 (1962). Marsh-orchids’ have variously been treated as a full Ssp. praetermissa species, when the English-based epithet pardalina Stem often exceeds 30 cm tall, often exceeds 5 mm in (Pugsley, 1935) takes priority, or as an infraspecific diameter. Sheathing leaves often 4 or more, occasionally taxon, when the Netherlands-based epithet junialis moderately hooded; longest leaf often exceeds 12 cm (Vermeulen, 1933) takes priority. Affinities with in length, usually exceeds 2 cm in width, usually placed either D. majalis or D. praetermissa have been sug- above widest leaf; non-sheathing leaves often 2 or gested for both epithets, some authors attributing one more; basal leaf/sheath usually present. Inflorescence of the epithets to one species and the other epithet often exceeds 18 flowers. Bracts often contain diffuse to the other species. Bateman & Denholm (1983) anthocyanins; cells along bract margin rarely exceed confidently synonymised the two names as var. 80 mm in length. Labellum usually more-or-less flat, junialis. lateral lobes rarely indented; lateral sepals occasion- Recent molecular and morphometric analyses from

Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 ally near-vertical, often marked with solid spots. England (Bateman et al., 2003; Pillon et al., 2007; Flowers late May to late June. Widespread and Hedreń et al., in press), Denmark (Pedersen & locally frequent throughout Wales and England Hedreń, 2010) and the Netherlands – or, in one case, northward to North Lancashire and North all three regions (Pedersen, 2010a) – strongly suggest Yorkshire; often forms extensive populations. that the British and Continental populations do indeed belong to the same infraspecific taxon and Ssp. schoenophila R.M. Bateman & Denholm, ssp. confirm the attribution of at least the majority of nov. these spotted-leaved plants to D. praetermissa. Given Stem rarely exceeds 30 cm tall, rarely exceeds 5 mm that such plants constitute a small minority of most in diameter. Sheathing leaves rarely 4 or more, usually populations in the UK, we were tempted to down- moderately hooded; longest leaf occasionally exceeds grade their taxonomic status from variety (correctly 12 cm in length, rarely exceeds 2 cm in width, D. praetermissa var. junialis [Vermeulen] Senghas occasionally placed above widest leaf (longest often5 [1968]; see the detailed nomenclatural discussion in widest); non-sheathing leaves occasionally 2 or more; Pedersen [2011]) to forma (correctly D. praetermissa f. basal leaf/sheath occasionally present. Inflorescence junialis [Vermeulen] P.D. Sell [in Sell & Murrell, occasionally exceeds 18 flowers (comparatively spar- 1996]). Infraspecific taxa that are routinely represented se). Bracts usually contain diffuse anthocyanins; cells

New Journal of Botany 2012 VOL.2 NO.1 47 Bateman and Denholm Tetraploid marsh-orchid systematics

along bract margin occasionally exceed 80 mmin large spots, rings or blotches’ (Stephenson & length. Labellum rarely more-or-less flat (lateral lobes Stephenson, 1920, p. 164). As with D. praetermissa, typically moderately to strongly recurved), lateral the dominantly unspotted nature of the leaves of D. lobes occasionally indented; lateral sepals often near- purpurella has often led to plants that possess leaf vertical, occasionally marked with solid spots. markings – especially dense leaf markings – being Flowers mid-May to mid-June. Occasional in East viewed with suspicion as more likely belonging to Anglia, very local in southern England and possibly other species of tetraploid marsh-orchid. However, also the Low Countries; usually forms small the particularly distinctive genotype of D. purpurella, populations. evident in data for allozymes (e.g. Hedreń, 1996a, b), TYPE: British Isles, Oxfordshire [previously nuclear (Bateman et al., 2003; Pillon et al., 2007; Berkshire], Cothill Fen. 18 June 1945, H.W. Pugsley Hedreń et al., 2011a) and plastid sequences and (holotype BM 001074167). Fig. 2. This locality was microsatellites (Hedreń et al., 2011a), makes it chosen by us as the locus classicus because it has a abundantly clear that most tetraploid marsh-orchid long and relatively well-documented history (cf. populations located toward the north and west of the Heslop-Harrison, 1953), enjoys a high conservation British Isles that are dominated by leaf-marked status as a National Nature Reserve and Site of individuals are, like unmarked populations, attribu- Special Scientific Interest, and maintains a smaller table to D. purpurella (Bateman, 2006a; Pedersen, surrounding population of ssp. praetermissa than do 2007; Hedreń et al., 2011a). There appears to be a most populations of ssp. schoenophila (we are not geographical cline between anthocyanin-low and aware of any population of ssp. schoenophila that anthocyanin-high modes that complicates attempts does not also have ssp. praetermissa in the vicinity). to partition this variation into cohesive infraspecific However, the plants occupying the Schoenus fen are taxa. Hence, the degree of divergence in morphology less morphologically distinct from ssp. praetermissa in general, and in pigmentation characters in than in some East Anglian populations. In total, 21 particular, required to distinguish the anthocyanin- specimens from Cothill are held in the London rich var. cambrensis from the less anthocyanin-rich Natural History Museum (BM): the 16 plants that var. purpurella is debatable. were collected by A.R. Clapham (26 June 1943) and If treated as a subspecies rather than a variety, ‘H.W.P. & M.M.’ (4 & 18 June 1945) all spent time in cambrensis would correctly be named D. purpurella ssp. the herbarium of dactylorchid specialist H.W. majaliformis E. Nelson ex Løjtnant. Both of these Pugsley, and a further five were collected later by epithets were adversely affected by an unfortunate D.P. Young (2 June 1953). However, even the BM’s series of nomenclatural errors (issues to which our impressive total was exceeded by C.E. Hubbard’s attention was first drawn in 1997 by the late Derek overly enthusiastic collecting of 26 plants (most with Turner Ettlinger). Specifically, D. majalis ssp. cambren- attached tubers) for the Kew herbarium from ‘near sis was first described by R.H. Roberts under Cothill in Juncus–Schoenus–Carex swamp, near Dactylorchis (1961; see also Roberts, 1962) and later Hurst’s Swamp’ (9 June 1943), all labelled with transferred to Dactylorhiza (Roberts, 1966) but eight speculative identifications claiming various hybrid years elapsed before it was correctly typified at that origins that were later amended as ‘Orchis traun- rank with page details of the basionym (Roberts, 1969). steineri Sauter’ in a calligraphy resembling that of Similarly, D. purpurella ssp. majaliformis was described orchidologist V.S. Summerhayes. in detail by Nelson (1976) in his benchmark mono- Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 Etymology. Derived from the Latin schoenus (rush) graph, but the name was not typified for a further three and Greek philia (affection, fondness), reflecting the years (Nelson, 1979), when the taxon was also given a reliable association with Schoenus nigricans that D. more detailed description by Løjtnant (1979). praetermissa ssp. schoenophila shares with bona fide Thus, the epithets cambrensis, which has a Welsh D. traunsteinerioides. holotype (Roberts, 1961), and majaliformis, which has a Scottish holotype (Nelson, 1976; Løjtnant, Dactylorhiza purpurella 1979), existed in parallel for a brief period before we Following on from the above species, ongoing synonymised the latter into the former at varietal taxonomic and nomenclatural problems in D. purpur- level, as D. majalis ssp. occidentalis var. cambrensis ella (T. & T.A. Steph.) Soo´ also largely surround the (R.H. Roberts) R.M. Bateman & Denholm (1983). anthocyanin-rich forms that deviate from the major- As this decision was based on the inclusion in our ity of plants, which are unmarked. One fact that has analysis of just a single population of cambrensis been largely forgotten in these various discussions is from Portmadoc, Merioneth, it is perhaps unsurpris- that the protologue specified leaves ‘with small, often ing that many authors continued to recognise cam- very small, solid spots, regularly distributed or only brensis and majaliformis as separate taxa; most at the tips of the ls., easily overlooked, never with observers viewed majaliformis as an infraspecific

48 New Journal of Botany 2012 VOL.2 NO.1 Bateman and Denholm Tetraploid marsh-orchid systematics

taxon of D. purpurella occurring in western and other words, Pedersen’s (2007) population of ‘var. northern Scotland but cambrensis as an infraspecific maculosa’ appears to represent a better match with taxon of D. majalis (or, more specifically, D. Robert’s concept of cambrensis than do the Danish kerryensis/occidentalis) occurring as an outlier in dactylorchid populations attributed to cambrensis by western Wales (Sell & Murrell, 1996; Stace, 1997; Pedersen. Certainly, the plant illustrated by Pedersen Ettlinger, 1997, 1998; Kreutz, 2004; Lang, 2004). (2007) as being typical of the Ynyslas population of However, in our opinion, broader sampling of D. purpurella would have been assigned by us to var. populations and detailed molecular analysis greatly cambrensis, suggesting that our circumscription of increased empirical support for the decision of var. cambensis is appreciably broader than Pedersen’s Bateman & Denholm (1983) to unite majaliformis and is thus synonymous with ‘var. maculosa’. This with cambrensis as a single infraspecific taxon, albeit distinction is of more than academic relevance, as it of D. purpurella rather than D. kerryensis/occidentalis dictates whether recent contentious records that (Bateman, 2006a, 2011a; Pillon et al., 2007; Hedreń expand the British and Irish range of var. cambrensis et al., 2011a). Consequently, in 2005, we formalised into northwest England (A. Gendle, pers. comm., the name D. purpurella var.cambrensisR.M. 2005; Habron & Habron, 2007) and southern Ireland Bateman & Denholm comb. et stat. nov. in Foley (Ennis, 2011) should be accepted. Certainly, Nelson’s and Clarke (2005, p. 373; note that the combination (1976) original description of D. purpurella ‘ssp. D. purpurella var. majaliformis [E. Nelson] Kreutz majaliformis’ encompassed plants with both lightly (2006b) was published the following year. spotted and unspotted leaves. However, our confidence in taking this position Like Pedersen (2007), we find little taxonomic value was slightly eroded by Pedersen (2007), who com- in D. purpurella ‘var. pulchella’. First ascribed to pared 16 Danish and two Welsh populations of D. ‘Orchis’ praetermissa by Druce (1920) and later purpurella s.l.:nine(oneofthemWelsh)were transferred to ‘Orchis’ purpurella by Pugsley (1935), its attributed to var. purpurella, eight to var. cambrensis, only credible diagnostic character is dot-and-dash and one Welsh population (Ynyslas, near Abery- labellum markings that are actually more typical of stwyth, east-central Wales: an exceptionally complex D. praetermissa (Bateman & Denholm, 1983). We are population, according to our data) to the more therefore somewhat perturbed by Pedersen’s (2011) taxonomically obscure var. maculosa – a taxon based conclusion that, in listing the basionym of D. majalis on ‘Orchis’ purpurella var. maculosa T. Stephenson ssp. purpurella var. pulchella (Druce) Soo´ (a variety that (1937) and later recombined as D. majalis ssp. we listed for completeness but had not analysed purpurella (T. & T.A. Stephenson) D.M. Moore & scientifically and so did not explicitly endorse in Soo´ var. maculosa (T. Stephenson) R.M. Bateman & Bateman & Denholm, 1983), we inadvertently gener- Denholm (1983) (the combination D. purpurella var. ated a combination that should henceforth take maculosa has not yet been made). Pedersen (2007) precedence over the nominate variety (i.e. replaces lectotypified this variety using an existing specimen D. majalis ssp. purpurella var. purpurella). This from east-central Scotland. In his quantitative would not be a sensible nomenclatural innovation. analysis he recorded 23 morphometric characters, Returning from nomenclature to biology, we 18 of which contributed to a principal components remain suspicious of sporadic reports of outlying analysis whose first axis served only to separate the populations of D. purpurella from the Southampton single population of var. maculosa from the remain- area of South Hampshire and from Oxfordshire (e.g. Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 ing populations on the basis of its larger flowers and Summerhayes, 1968; Jenkinson, 1995a; Carey & greater vegetative robustness. The much weaker Dines, 2002). We predicted that these few plants second axis largely separated populations and indi- would yield genetic profiles characteristic of D. viduals of var. purpurella from those of var. cam- praetermissa rather than D. purpurella. Sadly, we brensis on the basis of the paler flowers and especially failed in our attempts to extract DNA, either from the heavier spotting on the leaves and inflorescences one of the earliest-described herbarium specimens of of the latter. D. ‘purpurella’ collected from Hampshire or from Pedersen’s (2007) attribution of the Ynyslas labella mounted by us in 1983. population to var. maculosa is of particular interest Lastly, the decision of Curtis & Thompson (2009) as, along with Newborough Warren on Anglesey, this to refer Irish populations of D. purpurella to a far locality provided the plants that were used to erect more obscure taxon, D. majalis (Rchb.) P.F. Hunt & var. cambrensis by Roberts (1961, 1966). And among Summerh. var. brevifolia (Rchb.) Kreutz (2004), is the characters used by Roberts to delimit cambrensis perhaps best described as individualistic. Kreutz were the relatively large flowers and vegetative (2004) himself recognised D. purpurella as a full species robustness that caused him to compare cambrensis distinct from D. majalis. Also, Reichenbach (1851, p. not with D. purpurella but rather with D. majalis.In 58) based the epithet brevifolia on a questionably

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sourced holotype, making a close relationship with the level in the third edition of his Flora (cf. Stace, 2006, boreal species D. purpurella less probable. p. 19), ultimately adopted D. kerryensis instead (Stace, 2010). Dactylorhiza kerryensis (5occidentalis) Encouraged by the successful bid of Pedersen et al. Recent molecular research has brought much greater (2003) to conserve D. majalis (Rchb.) P.F. Hunt & understanding of D. kerryensis (Wilmott) P.F. Hunt Summerh. over three prior epithets, an ensuing article & Summerh. (5 D. occidentalis [Pugsley] P. Delforge) co-authored by most of the systematists currently and demonstrated that it is genuinely endemic to actively researching Dactylorhiza (Bateman et al., Ireland. It possesses nuclear and especially plastid 2010) reviewed in greater detail the complex nomen- haplotypes that are distinct, but nonetheless are most clatural history of these two Irish taxa, eventually similar to D. purpurella (Hedreń et al., 2011a). proposing conservation of occidentalis over kerryensis Dactylorhiza kerryensis also yields almost entirely at species level. The case for conservation noted in ITS allele I, which is virtually absent from all other particular the much greater familiarity of the (also allotetraploids and was probably derived via an more geographically accurate) epithet occidentalis, allopolyploidy event that involved D. maculata and the fact that it has priority over kerryensis at (Bateman et al., 2003; Pillon et al., 2007; Hedreń sspecies level – the rank most commonly used for et al., 2011a). Despite some superficial morphological occidentalis during the last century – as well as at the similarities, D. kerryensis bears little genetic resem- ranks of varietas and forma. Unfortunately, the blance to bona fide D. majalis, which has proved ICBN Nomenclature Committee for Vascular Plants to be absent from the British Isles. However, the roundly rejected the proposal of Bateman et al. relationship between D. kerryensis and the exclusively (2010), optimistically arguing that, in the wake of the Continental D. sphagnicola still merits more detailed use of kerryensis at the species level by Stace (2010), study (M. Hedreń, pers. comm., 2012). ‘the botanical public should be now fully aware of Nonetheless, D. kerryensis does still present the same which name is correct’ (Brummitt, 2011, p. 1207). taxonomic challenge as the other three British and Irish We have therefore, with considerable regret, grud- tetraploid marsh-orchid species in terms of adequately gingly accepted priority to the epithet kerryensis at treating the considerable variation in anthocyanin species level, while recognising that many Conti- content among plants. In the case of D. ‘occidentalis’ nental workers are likely to continue to refer to this (but in contrast with the other three tetraploid species), taxon as a subspecies of D. majalis – a rank at which this widely recognised nominate race has long been it is unambiguously validated as ssp. occidentalis.We viewed as the anthocyanin-rich mode (Pugsley, 1935), view as anathema the currently legislated validity whereas the less frequent, anthocyanin-low populations of multiple valid epithets to represent the same that are characterised by unspotted leaves and paler, biological entity at different hierarchical levels. less heavily marked flowers have traditionally been Irrespective of relatively trivial legalistic arguments assigned to var. kerryensis (Wilmott, 1936). Delforge regarding its nomenclature, current research by Bren- (2006) recognised both taxa at species level, bravely dan Sayers and colleagues is likely to provide greater attributing D. occidentalis to the D. majalis group but insights into the nature and origin of this genuinely D. kerryensis to the contrasting D. praetermissa group. endemic species. Recent evidence suggests to us that However, both morphometric and molecular data the distributions given by several authors (e.g. Preston demonstrate that the anthocyanin-low var. kerryensis et al., 2002; Curtis & Thompson, 2009; Sayers & Sex, Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 is simply a less frequent, and more geographically 2009) for D. kerryensis in Ireland are far too wide- localised, variant of the species that is dominantly var. spread; the species may be confined to west-central and occidentalis. Unfortunately, Wilmott (1936) immedi- south-west Ireland, other records being attributable to ately recognised kerryensis at species level, whereas the D. purpurella or, less often, D. traunsteinerioides. earlier described occidentalis was treated first as a variety and then rapidly raised to a subspecies by Synthesis Pugsley (1935, 1936) before being raised again to full Taxonomic principles species by Wilmott (in Campbell, 1937). Thus, at The intensive application of morphometric and species level, kerryensis has nomenclatural priority, molecular techniques to the tetraploid marsh-orchids albeit by just one year, over the much more widely used has greatly increased our understanding of the group. epithet occidentalis – a fact recognised 47 years ago by Most importantly, the fact that the four species found Hunt & Summerhayes (1965) and reiterated by Jebb in the British Isles are only subtly distinct in both (2009), who therefore created the novel binomial D. morphology and genetics is readily explained by kerryensis (Wilmott) P.F. Hunt & Summerh. var. the insight that they represent independent origins occidentalis (Pugsley) Jebb. Thus, Clive Stace, who through allopolyploidy from the same two diploid had originally intended to use D. occidentalis at species lineages, D. fuchsii and D. incarnata. We have chosen

50 New Journal of Botany 2012 VOL.2 NO.1 Bateman and Denholm Tetraploid marsh-orchid systematics

to emphasise the independent evolutionary origins Much of the taxonomic disagreement surrounding (and thus monophyly) of the tetraploid marsh- Dactylorhiza emanates from contrasting definitions orchids by recognising the four taxa as full species of taxonomic ranks (or, more often, failure to apply (e.g. Bateman, 2006a, 2011a; Pillon et al., 2007; Paun any explicit definitions of taxonomic ranks). In our et al., 2011), in contrast with our earlier, wholly view, taxa ranked as species, subspecies, and varieties morphometric conclusions that treated the four spec- are all typically identified as populations rather than ies as subspecies of a ubiquitous D. majalis (Bateman as individual plants; in other words, they are assessed & Denholm, 1983). However, as is evident from at a demographic level where the concept of re- Table 1, other dactylorchid systematists prefer to productive isolation (arguably also monophyly) can emphasise the similarity of their diploid parental be applied to distinguish among taxa. The ranks of lineages by continuing to treat each tetraploid as a subspecies and variety differ mainly in degree of subspecies of D. majalis (e.g. Pedersen, 1998, 2007, morphological overlap, though degree of habitat 2010; Hedreń, 2002; Nordstro¨m & Hedreń, 2009; specialisation and/or abundance may also be con- Pedersen & Hedreń, 2010; Hedreń et al., 2011a). sidered. In contrast, the rank of forma is most useful Three of the four species are concentrated to the for treating polymorphism within populations; that north of the Weichselian glacial maximum in the is, for distinguishing individual plants that typically British Isles (Bateman, 2011a) and are presumably deviate from the remainder of the individuals of the younger in origin than the single, more typically ‘host’ populations in a small number of morpholo- Continental species (D. praetermissa) that occurs to gical characters that are presumably conferred by the south (Pillon et al., 2007). This seemingly mutations or epimutations that are likely to occur parapatric pattern of speciation offers at least a repeatedly across the range of the species. Hypo- regional challenge to the argument of Pillon et al. chromic (albino) and hyperchromic individuals con- (2006) that there is a mismatch between taxonomic stitute typical examples of formae, though some other and molecular diversity in the genus, the former being workers have preferred to treat them as varieties (e.g. concentrated in the north and the latter in the Ettlinger, 1991). Mediterranean region. From the viewpoint of deli- miting species, the degree of molecular divergence Taxonomic outcomes between them is arguably irrelevant once reproduc- Returning briefly to Table 1, remarkably little con- tive isolation has been achieved, and is reflected in the sensus is evident among specialists regarding the sequence data sufficiently well to allow molecular classification of the tetraploid marsh-orchids. For identification (Bateman et al., 2011). example, only recently have classifications been Intrinsic criteria of importance when attempting to published that do not recognise D. majalis as native circumscribe species and infraspecific taxa are genetic to the British Isles. Several authors attributed all of similarity, morphological similarity, and evolutionary the British taxa to D. majalis, whereas most of the cohesion, expressed through monophyly and/or re- remainder assigned to this species only kerryensis/ productive isolation (Bateman et al., 2011; Bateman occidentalis (in a unique treatment, D. traunsteineri & Rudall, 2011). Until hand-held DNA sequencing alone was segregated from D. majalis by Soo´, 1980). technology becomes available (and most likely well Among recent classifications, those of Lang (2004) beyond this point, in the unusually troublesome and Govaerts (2005) appear particularly anachronis- case of the tetraploid marsh-orchids), morphology tic. That of Delforge (2006) is unique in two ways; Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 will of necessity remain the mainstay of field iden- firstly in treating most named taxa as full species, and tification. When re-circumscribing the four species, secondly in placing those putative species in informal we have consistently sought positive correlations groups that bear little resemblance to the entities between genetic and morphological characters but circumscribed using molecular evidence – for exam- have ultimately prioritised genetic over morpho- ple, Delforge’s ‘praetermissa group’ contains taxa logical data. This decision reflects our belief that from within three of the four species, encompassing genetic data are the stronger indicator of degrees of purpurella s.l. and kerryensis (but not occidentalis s.s.) reproductive isolation, and thus offer greater pre- in addition to bona fide praetermissa. Below this dictivity regarding the biological properties of the level, it is primarily the anthocyanin-rich taxa that resultant taxa (Bateman, 2011a, c). These intrinsic have been treated as taxonomic (and nomenclatural) properties interact with the orchid’s environment to ‘footballs’, frequently changing allegiance between dictate extrinsic properties, such as habitat pre- successive classifications. ference and interspecific ecological partnerships In the case of the taxa discussed in this paper, we with pollinators and mycorrhizae, which in turn believe that by far the most important taxonomic goal combine with dispersability to determine its geo- – the optimal re-circumscription of the four tetraploid graphic distribution. species – has finally been achieved, generating entities

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that have biological, ecological, and geographical co- tempting to apply this name exclusively to heavily hesion and hence can at last be adequately mapped marked individuals and hence be obliged to down- (cf. Carey & Dines, 2002; Bateman, 2006a). How- grade it to a forma, but the more morphologically ever, taxonomic subdivision of those species into extreme populations also show some differences from infraspecific taxa remains more problematic. Setting var. purpurella in non-pigmentation characters. We aside the fact that it is a nomenclatural nightmare see little value in attempting to perpetuate Pedersen’s (confusion to which we, and many others, have (2007) distinction between var. cambrensis and var. contributed), it is also biologically problematic, as maculosa. The relationship between D. kerryensis var. current taxonomic practices oblige us to rely largely on kerryensis and the more frequent, anthocyanin-rich morphology. Compared with most other taxonomic var. occidentalis is broadly similar in nature to that treatments, we have downgraded the importance documented between D. purpurella var. purpurella attributed to discrete anthocyanin markings, particu- and var. cambrensis. In contrast, D. praetermissa var. larly those expressed on vegetative organs. Such junialis does appear to deviate from the nominate characters are often polymorphic within populations race only in markings; moreover, it occurs in few and show broadly gradual changes in frequency British populations and, within those populations, according to latitude and proximity to the ocean, forms a minority of individuals. Nonetheless, its leading us to most commonly apply them at the level greater frequency in the Low Countries (e.g. Kreutz of variety and forma. & Dekker, 2000) has encouraged us to continue to Considering particular cases, D. traunsteinerioides recognise junialis at varietal level. ssp. francis-drucei differs from ssp. traunsteinerioides in a wide range of morphological characters, includ- Conservation implications ing, but by no means confined to, pigmentation; it We will conclude by briefly considering the conserva- also has a substantial and fairly well-defined dis- tion of British and Irish tetraploid marsh-orchids. tribution. Within this subspecies, var. ebudensis differs Within the United Kingdom, the 1999 Red List for from var. francis-drucei in fewer characters and is Vascular Plants (Wigginton, 1999) considered only highly restricted geographically – properties that Dactylorhiza ‘lapponica’ (Cowie, 1999). The presence support its varietal status. of this ‘species’ on Schedule 8 of the Wildlife and Dactylorhiza praetermissa ssp. schoenophila un- Countryside Act appeared inconsistent with its lowly questionably grades into ssp. praetermissa at most status of Near-Threatened in the Third British Red localities, suggesting that it might be better treated as Data Book and presumably reflected earlier paucity a variety than as a subspecies. However, it differs of knowledge. By the time of the next edition of the from ssp. praetermissa in several characters and has a Red List (Cheffings & Farrell, 2005), ‘lapponica’ had distinct habitat preference. From an evolutionary justly been subsumed into D. traunsteinerioides (cf. perspective, the molecular disparity strongly suggests Bateman, 2001, 2006a; Morrison et al., 2009), which that D. praetermissa ssp. schoenophila has converged was judged as being of Least Concern. However, morphologically on D. traunsteinerioides, presumably following Bateman (2006a), D. ebudensis was treated also reflecting adaptation to similar habitats that as a separate species that was (equally justly) judged support plant communities dominated by Schoenus Vulnerable, primarily on the grounds of its highly nigricans. Admittedly, we cannot yet rule out the restricted distribution. Despite the extensive biosyste- possibility that at least some of the morphological matic research conducted on the genus, Dactylorhiza Downloaded by [Botanical Socitey of the British Isles] at 03:15 14 March 2016 features of this subspecies represent ecophenotypic kerryensis (5 occidentalis) and D. purpurella var. responses; that is, are determined directly by its cambrensis (which is treated as a subspecies on the unusual environment, rather than requiring origina- Red List) were designated Data Deficient, presum- tion and propagation of advantageous genetic inno- ably reflecting ongoing uncertainties regarding their vations as an adaptive response to that environment. optimal circumscription and taxonomic status, which We hope to eventually determine whether the mor- in turn weakened attempts to determine their phological convergence toward D. traunsteinerioides respective distributions (cf. Carey & Dines, 2002; occurred once, followed by dispersal into the existing Bateman, 2006a; Hedreń et al., 2011a). The Irish Red populations, or has been a habitat-specific phenom- List (Curtis & McGough, 1988), which has become enon leading to the independent formation of each of seriously outdated, considered among the tetraploid the present populations. marsh-orchids only D. traunsteinerioides (as D. The relationship between populations of D. pur- traunsteineri), correctly recognising that it is not purella var. purpurella and the less frequent, relatively immediately threatened in the Republic; moreover, anthocyanin-rich var. cambrensis is even more clearly this lowly status has been inherited by the draft gradational, making any morphological threshold replacement Red List for Ireland (Kingston, 2005). between the varieties troublesome to define. It is However, in Ulster, D. ‘traunsteineri’ was placed on

52 New Journal of Botany 2012 VOL.2 NO.1 Bateman and Denholm Tetraploid marsh-orchid systematics

Schedule 8, due primarily to the small number of by the work of Yohan Pillon, Ovidiu Paun, Henrik recorded localities and their apparent restriction to Pedersen, and especially Mikael Hedreń, while Clive Antrim (cf. Carey & Dines, 2002). Stace is thanked for nomenclatural advice that has Given this legislative context, what are the con- not always been taken. We thank Mikael Hedreń and servation implications of the above taxonomic Karel Kreutz for informed reviews, and Paula Rudall changes? Although we have removed from D. and Wolfgang Eccarius for further critical readings of traunsteinerioides all of its former southern records, the text. Fred Rumsey kindly gave access to the these constitute only a minority of its total localities collections of the Natural History Museum. Small in the British Isles; also, new sites are steadily being fieldwork grants from the Botanical Research discovered, especially in Scotland. We regret that Fund and the Botanical Society of the British Isles downgrading ebudensis from its brief sojourn as a to RB, and from the Systematics Research species/subspecies (moreover, not just any species, Fund (Systematics Association/Linnean Society) but a rare British endemic (Lowe, 2003; Bateman, to ID, have considerably assisted the underlying 2006a)) to a variety of a much more widespread (albeit research. possibly also endemic) species is likely to render this interesting and vulnerable ‘metapopulation’ invisible References to conservation legislation. As circumscribed here, D. Allan, B., Woods, P. & Clarke, S. 1993. Wild orchids of Scotland. traunsteinerioides ssp. francis-drucei represents only a Edinburgh: HMSO. Averyanov, L. 1984. Taxonomic and nomenclature variations modest expansion in numbers and geographic range of in the genus Dactylorhiza (Orchidaceae) [in Russian]. the previous circumscription of D. ‘lapponica’ in Botanicheskii Zhurnal, 69: 875–876. Bateman, R.M. 2001. Evolution and classification of European Britain. However, we are confident that ‘lapponica’ is orchids: insights from molecular and morphological charac- sufficiently frequent, and its localities sufficiently ters. Journal Europaischer Orchideen, 33: 33–119. remote, that it did not merit its previous, high status Bateman, R.M. 2006a. How many orchid species are currently native to the British Isles?, in Bailey, J.P. & Ellis, R.D., eds. on Schedule 8. Continued discoveries of new popula- Current taxonomic research on the British and European flora. tions of ssp. francis-drucei in Scotland, combined London: Botanical Society of the British Isles, pp. 89– 110zplate 1. with recognition that the subspecies most likely also Bateman, R.M. 2006b. Identity and longevity of the ‘Mystery occurs in Antrim, must reduce its overall vulner- Orchid’: a serendipitous week in the life of a BSBI referee. BSBI News, 102: 22–25zplate 3. ability. The apparent rarity of D. traunsteinerioides Bateman, R.M. 2009. What’s in a name? Journal of the Hardy within Northern Ireland places a premium on both Orchid Society, 6: 53–63, 88–99. Bateman, R.M. 2011a. Glacial progress: do we finally understand seeking additional localities and correctly distin- the narrow-leaved marsh-orchids? New Journal of Botany,1:2– guishing between ssp. traunsteinerioides and ssp. 15. francis-drucei in the region. Bateman, R.M. 2011b. Two steps forward, one step back: deciphering British and Irish marsh-orchids. Journal of the The taxon arguably most in need of national Hardy Orchid Society, 8: 48–59. conservation re-assessment is the newly described D. Bateman, R.M. 2011c. The perils of addressing long-term challenges in a short-term world: making descriptive taxonomy praetermissa ssp. schoenophila, which on present predictive. In: Hodkinson, T.R., Jones, M.B., Waldren S. & evidence occurs at 20–25 localities in the fens of Parnell J.A.N., eds. Climate change, ecology and systematics. Systematics Association Special Volume 78. Cambridge: East Anglia (cf. Beckett et al., 1999; Carey & Dines, Cambridge University Press, pp. 67–95. 2002; Sanford & Fisk, 2010). As some of these Bateman, R.M., Bradshaw, E., Devey, D.S., Glover, B.J., populations are relatively large, ssp. schoenophila is Malmgren, S., Sramko´, G., Thomas, M.M. & Rudall, P.J. 2011. Species arguments: clarifying concepts of species

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