Circumscriptions of and relationships among many genera and suprageneric taxa of the diverse grass tribe Poeae remain controversial. In an attempt to clarify these, we conducted phylogenetic analyses of >2400 new DNA sequences from two nuclear ribosomal regions (ITS, including internal transcribed spacers 1 and 2 and the 5.8S gene, and the 3'-end of the external transcribed spacer (ETS)) and five plastid regions (matK, trnL-trnF, atpF-atpH, psbK-psbI, psbA-rps19-trnH), and of more than 1000 new and previously published ITS sequences, focused particularly on Poeae chloroplast group 1 and including broad and increased species sampling compared to previous studies. Deep branches in the combined plastid and combined ITS+ETS trees are generally well resolved, the trees are congruent in most aspects, branch support across the trees is stronger than in trees based on only ITS and fewer plastid regions, and there is evidence of conflict between data partitions in some taxa. In plastid trees, a strongly supported clade corresponds to Poeae chloroplast group 1 and includes Agrostidinae p.p., Anthoxanthinae, Aveninae s.str., Brizinae, Koeleriinae (sometimes included in Aveninae s.l.), Phalaridinae and Torreyochloinae. In the ITS+ETS tree, a supported clade includes these same tribes as well as Sesleriinae and Scolochloinae. Aveninae s.str. and Sesleriinae are sister taxa and form a clade with Koeleriinae in the ITS+ETS tree whereas Aveninae s.str. and Koeleriinae form a clade and Sesleriinae is part of Poeae chloroplast group 2 in the plastid tree. All species of Trisetum are part of Koeleriinae, but the genus is polyphyletic. Koeleriinae is divided into two major subclades: one comprises Avellinia, Gaudinia, Koeleria, Rostraria, Trisetaria and Trisetum subg. Trisetum, and the other Calamagrostis/Deyeuxia p.p. (multiple species from Mexico to South America), Peyritschia, Leptophyllochloa, Sphenopholis, Trisetopsis and Trisetum subg. Deschampsioidea. Graphephorum, Trisetum cernuum, T. irazuense and T. macbridei fall in different clades of Koeleriinae in plastid vs. nuclear ribosomal trees, and are likely of hybrid origin. ITS and matK trees identify a third lineage of Koeleriinae corresponding to Trisetum subsect. Sibirica, and affinities of Lagurus ovatus with respect to Aveninae s.str. and Koeleriinae are incongruent in nuclear ribosomal and plastid trees, supporting recognition of Lagurus in its own subtribe. A large clade comprises taxa of Agrostidinae, Brizinae and Calothecinae, but neither Agrostidinae nor Calothecinae are monophyletic as currently circumscribed and affinities of Brizinae differ in plastid and nuclear ribosomal trees. Within this clade, one newly identified lineage comprises Calamagrostis coarctata, Dichelachne, Echinopogon (Agrostidinae p.p.) and Relchela (Calothecinae p.p.), and another comprises Chascolytrum (Calothecinae p.p.) and Deyeuxia effusa (Agrostidinae p.p.). Within Agrostidinae p.p., the type species of Deyeuxia and Calamagrostis s.str. are closely related, supporting classification of Deyeuxia as a synonym of Calamagrostis s.str. Furthermore, the two species of Ammophila are not sister taxa and are nested among different groups of Calamagrostis s.str., supporting their classification in Calamagrostis. Agrostis, Lachnagrostis and Polypogon form a clade and species of each are variously intermixed in plastid and nuclear ribosomal trees. Additionally, all but one species from South America classified in Deyeuxia sect. Stylagrostis resolve in Holcinae p.p. (Deschampsia). The current phylogenetic results support recognition of the latter species in Deschampsia, and we also demonstrate Scribneria is part of this clade. Moreover, Holcinae is not monophyletic in its current circumscription because Deschampsia does not form a clade with Holcus and Vahlodea, which are sister taxa. The results support recognition of Deschampsia in its own subtribe Aristaveninae. Substantial further changes to the classification of these grasses will be needed to produce generic circumscriptions consistent with phylogenetic evidence. The following 15 new combinations are made: Calamagrostis × calammophila, C. breviligulata, C. breviligulata subsp. champlainensis, C. × don-hensonii, Deschampsia aurea, D. bolanderi, D. chrysantha, D. chrysantha var. phalaroides, D. eminens, D. eminens var. fulva, D. eminens var. inclusa, D. hackelii, D. ovata, and D. ovata var. nivalis. D. podophora; the new name Deschampsia parodiana is proposed; the new subtribe Lagurinae is described; and a second-step lectotype is designated for the name Deyeuxia phalaroides.

Molecular phylogenetics of cool-season grasses in the subtribes Agrostidinae, Anthoxanthinae, Aveninae, Brizinae, Calothecinae, Koeleriinae and Phalaridinae (Poaceae, Pooideae, Poeae, Poeae chloroplast group 1).

We conducted phylogenetic analyses of plastid trnL-F and nuclear ribosomal ITS DNA sequence data to infer phylogenetic relationships among and within the five subtribes (Agrostidinae, Aveninae, Brizinae, Phalaridinae and Torreyochloinae) of the Aveneae-type plastid DNA clade of Poaceae tribe Poeae. We sampled widely across the clade by analyzing new and previously published DNA sequence data. Species of Calamagrostis from Mexico, Central America, and South America are part of the Trisetum lineage in subtribe Aveninae. Several genera of Agrostidinae do not appear to be monophyletic in their current circumscriptions, and most aspects of their relationships are not clear. Subtribe Brizinae is not monophyletic, as European species of Briza s.l. are a distinct lineage that is not closely related to South American species; the latter group is allied closely with subtribe Agrostidinae, but their interrelationships remain largely equivocal. Subtribe Phalaridinae probably is not monophyletic, as Anthoxanthum / Hierochloe and Phalaris are not inferred to be sister taxa. Keywords—Calamagrostis, grasses, ITS, Poaceae, Poeae, phylogeny, plastid DNA, taxonomy, Trisetum. Saarela et al.: phylogenetics of ‘aveneae-type plastid’ grasses 1120_kap_18_32_6k.indd 557 07/06/10 21.23 558 Saarela et al. The cool-season grass lineage, Pooideae Benth., is the largest of the 13-14 subfamilies (Grass Phylogeny Working Group 2001; Sánchez-Ken et al. 2007) in the diverse and cosmopolitan grass family (Poaceae Barn.). It includes wheat (Triticum L.), barley (Hordeum L.), and oats (Avena L.), which are the world’s most important temperate cereal crops. Multiple phylogenetic analyses have identified the major evolutionary lineages within Pooideae (e.g., Davis and Soreng 2007; Döring et al. 2007; Soreng et al. 2007; Bouchenak-Khelladi et al. 2008; Schneider et al. 2009); most of these are currently recognized as tribes and subtribes (Soreng et al. 2007). Pooideae tribe Poeae R. Br. s.l. – the single tribe of supertribe Poodae L. Liu – is the most species-rich of the major lineages, with some 2260 species distributed in cool-temperate, Mediterranean and arctic climates (Soreng et al. 2007). Over the last two centuries taxa now included in tribe Poeae s.l. have been variously arranged in multiple smaller tribes and subtribes (reviewed by Soreng et al. 2007; see also Quintanar et al. 2007; Gillespie et al. 2008). Of these the Aveneae Dumort. (the oat tribe) and the Poeae s.s. have been recognized most widely, distinguished on the basis of several morphological characters (e.g., Clayton and Renvoize 1986), most of which are quite homoplasious (Soreng et al. 2007). Multiple molecular phylogenetic studies have demonstrated that Aveneae and Poeae s.s. are not monophyletic in any of their traditional circumscriptions (e.g., Soreng and Davis 2000; Davis and Soreng 2007; Döring et al. 2007; Quintanar et al. 2007; Soreng et al. 2007; Schneider et al. 2009). These findings have resulted in a generally broad acceptance of an expanded circumscription of Poeae – similar to that proposed by Tzvelev (1989) – that includes all taxa previously included in Poeae s.s. and Aveneae (Soreng et al. 2003, 2007; Quintanar et al. 2007). Within Poeae s.l. two major clades have been identified repeatedly in analyses of plastid DNA. These lineages have been recognized informally as ‘taxa with Aveneae-type plastid DNA’ and ‘taxa with Poeae-type plastid DNA’ (Soreng and Davis 2000), names that reflect the morphology-based classifications of the most core taxa in each clade. The most recent classification of Poeae – developed on the basis of available phylogenetic evidence – recognized 16 subtribes in the Poeae-type plastid DNA clade and six subtribes in the Aveneae-type plastid DNA clade [subtribe Cinninae Caruel was placed in the Aveneae-type plastid DNA clade but subsequent work has indicated that it is part of the Poeae-type plastid DNA clade (Quintanar et al. 2007; Soreng et al. 2007; Gillespie et al. 2008). Evolutionary patterns have been addressed across several subtribes in the Poeae-type plastid DNA clade, including Airinae Fr. (Chiapella 2007), Loliinae Dumort. (Torrecilla and Catalán 2002; Catalán et al. 2004; Hunter et al. 2004; Torrecilla et al. 2004; Inda et al. 2008) and Poinae Dumort. (Gillespie and Soreng 2005; Gillespie et al. 2007, 2008). The Aveneae-type plastid DNA clade, however, has received considerably less detailed phylogenetic study. The five subtribes in the Aveneae-type plastid DNA clade sens. Soreng et al. (2007) – Agrostidinae Fr., Aveninae J. Presl, Brizinae Tzvelev, Phalaridinae Fr., 1120_kap_18_32_6k.indd 558 07/06/10 21.23 Phylogenetics of ‘Aveneae-Type Plastid’ Grasses 559 Torreyochloinae Soreng & J. I. Davis – are each comprised of two to several genera. Focused phylogenetic studies have been undertaken for Brizinae (Essi et al. 2008) and for multiple genera of Aveninae, including Arrhenatherum P. Beauv. (Nisa et al., unpubl.), Avena (Rodionov et al. 2005; Nikoloudakis and Katsiotis 2008) and Helictotrichon Besser ex Schult. & Schult. f. (Grebenstein et al. 1998). The few studies that have sampled widely across the Aveneae-type plastid DNA lineages are mostly those that were more broadly assessing relationships among elements of the traditionally circumscribed Aveneae and Poeae (e.g., Davis and Soreng 2007; Soreng et al. 2007; Döring et al. 2007; Quintanar et al. 2007). The most densely sampled of these examined nuclear ribosomal ITS and plastid trnT-F data from over 100 Poeae s.l. species (Quintanar et al. 2007). Analyses of these data inferred several major clades that generally correspond to the subtribal circumscriptions sens. Soreng et al. (2007), but most aspects of relationship among the subtribes/major lineages were not inferred with strong support. A major finding was that the multiple sampled species of Trisetum Pers., Koeleria Pers., Rostraria Trin., Gaudinia J. Gay, Graphephorum Desv., and Parafestuca E.B. Alexeev (=Koeleria loweana Quintanar, Catalán & Castrov.; Quintanar et al. 2006) – all included in subtribe Aveninae by Soreng et al. (2007) – were considerably intermixed in both plastid and nuclear trees, raising questions about generic circumscriptions among these taxa. Subtribe Agrostidinae Fr. – the most species-rich lineage in the Aveneae-type plastid DNA clade – includes ca. 16 genera and some 550 species (Clayton and Renvoize 1986) distributed globally in temperate regions and tropical mountains, yet it remains one of the least studied of the major lineages of Poeae, at least from a phylogenetic perspective. The subtribe is characterized morphologically by its single-flowered spikelets. The lineage includes the diverse, ecologically important and taxonomically difficult genera Agrostis L. (ca. 220 spp.) and Calamagrostis Adans. s.l. (ca. 270 spp.), plus multiple genera that are smaller, often-monotypic and in some cases variously recognized: Ammophila Host (2 spp.), Ancistragrostis S. T. Blake (2 spp.), Bromidium Nees & Meyen, Chaetopogon Janchen (1 sp.), Gastridium P. Beauv. (2 spp.), Hypseochloa C. E. Hubb. (2 spp.), Lachnagrostis Trin. (ca. 20 spp.), Podagrostis (Griseb.) Scribn. & Merr. (ca. 6 spp.), Polypogon Desf. (18 spp.), Triplachne Link (1 sp.), Dichelachne Endl. (5 spp.), Echinopogon P. Beauv. (7 spp.), and Pentapogon R. Br. (1 sp.) (Soreng et al. 2007). The taxonomy of many of the larger genera in particular is complicated by apomixis and polyploidy (e.g., Greene 1984) and many species are morphologically similar. The principal taxonomic problems in subtribe Agrostidinae are centered on generic concepts, a problem shared by other large grass genera such as Bromus (Saarela et al. 2007) and Muhlenbergia (Columbus et al. 2010) in which numerous small segregate genera are (or have been) recognized on the basis of one or a few unique morphological features. The reed-grass genus, Calamagrostis, is typically characterized as having single-flowered spikelets, oneor three-veined glumes as long as or exceeding the floret in length (rarely slightly shorter), non-keeled 1120_kap_18_32_6k.indd 559 07/06/10 21.23 560 Saarela et al. lemmas that are membranous or cartilaginous (infrequently hyaline), usually with a single dorsally attached awn (rarely awnless), and a callus with a crown of hairs (Clayton and Renvoize 1986; Watson and Dallwitz 1992). Calamagrostis is widely recognized in North America, Central America and Europe (e.g., Hitchcock 1951; Conert 1989; Pohl and Davidse 1994; Peterson et al. 2004; Marr et al. 2007; Peterson and Saarela, in press). In parts of the Old World, however, many authors have recognized the segregate genus Deyeuxia Clarion ex P. Beauv. (e.g., Bor 1960; Lu 1987; Veldkamp 1996; Simon 1993; Lu and Phillips 2006; Lu et al. 2006), distinguished from Calamagrostis s.s. on the basis of differences in glume length, callus vestiture, rachilla presence/absence and rachilla vestiture (see key in Phillips and Chen 2003); other Old World authors have taken a more conservative taxonomic approach and recognized a more broadly circumscribed Calamagrostis that includes Deyeuxia (e.g., Tzvelev 1976; Koyama 1987). South American species of this generic complex, which comprise a substantial proportion of its diversity in the New World, are also generally recognized in Deyeuxia (Rúgolo de Agrasar 1978, 2006; Rúgolo de Agrasar and Villavicencio 1998). Two south Asian species previously considered as part of this group have been variously recognized in a third genus, Aniselytron Merr., but morphological and molecular evidence have revealed that Aniselytron is a member of Poeae subtribe Poinae (in the Poeae-type plastid DNA clade) and not closely related to Calamagrostis s.l. (Ma et al. 2005; Soreng et al. 2007; Gillespie et al. 2008). Generic circumscription of Agrostis is also problematic. The boundaries of Agrostis relative to the Calamagrostis / Deyeuxia complex are not clear because of the existence of morp

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Phylogenetics of the Grass _Aveneae-Type Plastid DNA Clade_ (Poaceae: Pooideae, Poeae) Based on Plastid and Nuclear Ribosomal DNA Sequence Data

Nomenclatural notes and typifi cation are provided for three of Hooker's taxa (Calamagrostis tripilifera, C tripilifera var cumminsii, Deyeuxia triaristata) and one of Grisebach's species, Calamagrostis fi liformis The taxonomic position of C tri- pilifera is reconsidered A comparison of C tripilifera with Chinese D fl avens showed them to be conspecifi c C tripilifera var cumminsii and D triaristata are regarded as conspecifi c with Grisebach's C fi liformis, which until now has been considered a member of the separate species complex C lahulensis-C scabrescens My revision showed that Hooker misapplied Grisebach's C fi liformis The Yunnan record of Calamagrostis fi liformis sensu Grisebach is the fi rst one I have found from this province and the fi rst one confi rmed for China

Taxonomic revision of calamagrostis filiformis, c. tripilifera and their allies (poaceae: agrostidinae)

Deyeuxia sorengii B. Paszko & W. L. Chen, a new species of Deyeuxia from the Qinghai-Tibetan Plateau, China, is described and illustrated. The new species is morphologically similar to D. zangxiensis P. C. Kuo & S. L. Lu, but differs from it by having a well-developed and conspicuously hairy rachilla prolongation and a straight awn. Deyeuxia sorengii occurs in alpine meadows of central Xizang and central Qinghai. The first records of Deyeuxia zangxiensis are reported from western and eastern Xinjiang and northeastern Qinghai (China).

Deyeuxia sorengii sp. nov. (Poaceae, Agrostidinae) from the Qinghai-Tibetan Plateau

To investigate the evolutionary diversification and morphological evolution of grass supertribe Poodae (subfam. Pooideae, Poaceae) we conducted a comprehensive molecular phylogenetic analysis including representatives from most of their accepted genera. We focused on generating a DNA sequence dataset of plastid matK gene-3′trnK exon and trnL-trnF regions and nuclear ribosomal ITS1-5.8S gene-ITS2 and ETS that was taxonomically overlapping as completely as possible (altogether 257 species). The idea was to infer whether phylogenetic trees or certain clades based on plastid and nuclear DNA data correspond with each other or discord, revealing signatures of past hybridization. The datasets were analysed using maximum parsimony, maximum likelihood and Bayesian approaches. Instances of severe conflicts between the phylogenetic trees derived from both datasets, some of which have been noted earlier, unambiguously point to hybrid origin of several lineages (subtribes, groups of genera, sometimes genera) such as Phalaridinae, Scolochloinae, Sesleriinae, Torreyochloinae; Arctopoa, Castellia, Graphephorum, Hyalopodium, Lagurus, Macrobriza, Puccinellia plus Sclerochloa, Sesleria, Tricholemma, American Trisetum, etc. and presumably Airinae, Holcinae and Phleinae. ‘Calamagrostis’ flavens appears to be an intergeneric hybrid between Agrostis and Calamagrostis. Most frequently there is good agreement of other regions of the trees, apart from intrinsic different phylogenetic resolution of the respective DNA markers. To explore the to date rather unclear morphological evolution of our study group a data matrix encompassing finally 188 characters was analysed for ancestral state reconstructions (ASR) using the tree from the combined molecular dataset as presumably best approximation to the species phylogeny. For 74 characters ASRs were feasible and yielded partly surprising results for the study group as a whole but also for some of their subdivisions. Considering taxonomy and classification it became evident, that many morphological characters show a very high degree of homoplasy and are seemingly able to change within comparatively short timespans in the evolution of our grasses. Most of the taxonomic units distinguished within our study group, e.g. as subtribes, are defined less by consistent morphological characters or character combinations and should be rather understood as clades revealed by molecular phylogenetic analysis. One reason for this extreme homoplasy concerning traditionally highly rated characters of inflorescences or spikelets and their components might be that they have little to do with pollination (always wind) or adaptation to pollinators as in other angiosperms but rather with dispersal and diaspores. Easily changing structure of spikelet disarticulation, of glume, lemma or awn characters might be advantageous in the rapid adaptation to different habitats and micro-habitats, which was evidently most successfully accomplished by these grasses. A partly revised classification of Poodae is presented, including a re-instatement of tribes Aveneae and Poeae s.str. Following a comparatively narrow delineation of preferably monophyletic subtribes, Antinoriinae, Avenulinae, Brizochloinae, Helictochloinae, Hypseochloinae are described as new. New genera are Arctohyalopoa and Hyalopodium. New combinations are Arctohyalopoa lanatiflora, A. lanatiflora subsp. ivanoviae, A. lanatiflora subsp. momica, Colpodium biebersteinianum, C. kochii, C. trichopodum, C. verticillatum, Deschampsia micrathera, Dupontia fulva, Festuca masafuerana, Hyalopodium araraticum, Paracolpodium baltistanicum, Parapholis cylindrica, P. xpauneroi. Festuca masatierrae is a new name.

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Phylogeny, morphology and the role of hybridization as driving force of evolution in grass tribes Aveneae and Poeae (Poaceae)

Two problematical species from the Himalaya that lie on the boundary between Agrostis and Deyeuxia are discussed. One is transferred to De- yeuxia as Deyeuxia petelotii with the new synonym D. continentalis. The name Deyeuxia abnormis J. D. Hooker is retained for the second species, which is confirmed as distinct from D. zenkeri. Two other spe- cies are transferred to Deyeuxia from Calamagrostis: Deyeuxia sichuanensis and Deyeuxia korotkyi.

Sylvia M. Phillips

Papers

Notes on Grasses (Poaceae) for the Flora of China, I: Deyeuxia