Robert J. Soreng

A Phylogenetic Analysis of the Bluegrass Genus Poa Based on cpDNA Restriction Site Data

Abstract Poa, with about 575 species, is the largest genus of grasses, and has diversified throughout temperate, boreal, and arctic regions, and similar habitats through the tropics. This new phylogenetic study of Poa based on analysis of restriction site data from PCR amplified regions of chloroplast DNA (trnT-trnF, trnF-trnV, trnV-rbcL, rbcL-ORF106, trnH-trnK) expands previous sampling in the genus to where 1/5 to 1/6 of the species have been characterized for chloroplast DNA types. A broad phylogenetic structure detected in a previous study using restriction site mapping of Poa chloroplast DNA gained additional and robust support. Accounting for extended intra- and extrageneric sampling, Poa remains monophyletic if Austrofestuca and Parodiochloa are included as sections within P. subg. Poa, and if Poa subg. Andinae is removed from the genus. Two new combinations are made: Poa sect. Austrofestuca and Poa sect. Parodiochloa. This new analysis supports the recognition of five major clades within Poa: 1) ArcSyl, Poa subg. Arctopoa sects. Arctopoa and Aphydris, and P. subg. Poa sect. Sylvestres; 2) BAPO, P. subg. Poa sects. (Bolbophorum + Alpinae) (Parodiochloa + Ochlopoa); 3) SPOSTA, P. subg. Poa sects. (Secundae (Pandemos (Orienos + Stenopoa + Tichopoa + Abbreviatae))); 4) PoM, P. subg. Poa sects. (Poa + Macropoa); 5) HAMBADD, P. subg. Poa sects. (Homalopoa, Acutifolae, Brizoides, Madropoa, Austrofestuca, Dasypoa, Dioicopoa, and informal groups “Punapoa” and “Australopoa”). These clades diverge in the following arrangement from the outgroups: ArcSyl (BAPO (SPOSTA ((PoM) (HAMBADD))).

Phylogenetic relationships in subtribe Poinae (Poaceae, Poeae) based on nuclear ITS and plastid trnT-trnL-trnF sequences

The worldwide temperate subtribe Poinae comprises the largest grass genus, Poa (500+ species), and multiple additional small genera. We explore generic boundaries and relationships among genera of Poinae using nuclear ribosomal internal transcribed spacer data (ITS) and plastid trnT–trnL–trnF (TLF) sequence data. ITS and TLF analyses are mostly congruent with regards to circumscription of genera, and with respect to relationships among Poinae genera, but tree structure is generally better supported among genera in the ITS strict consensus tree. ITS and TLF both support two main Poinae lineages: (i) Poa and (ii) a clade comprising all other sampled Poinae. Nine small genera were nested within the large Poa clade, including Aphanelytrum, Dissanthelium, and Tovarochloa, supporting inclusion of these as sections within Poa. In the second clade, three subclades support close relationships among Nicoraepoa, Hookerochloa, and Arctagrostis; Arctophila and Dupontia; and Apera, Bellardiochloa, and Ventenata. Genera...

A Taxonomic Revision of the Eastern North American and Eastern Asian Disjunct Genus Brachyelytrum (Poaceae): Evidence from Morphology, Phytogeography and AFLPs

Abstract Morphological and phytogeographical data support the recognition of three distinct species in the genus Brachyelytrum: B. japonicum, B. erectum, and B. aristosum. Brachyelytrum japonicum is confined to eastern Asia and is characterized by narrow leaf blades (0.5–0.8 cm wide), long lower glumes (0.2–2.0 mm long), and long rachillas (6.8–8.8 mm long). Brachyelytrum erectum is distributed throughout much of the eastern United States, from northwestern Minnesota south to central Louisiana, east to northern Florida and north to northeastern New York. Brachyelytrum erectum is characterized by long hispid hairs (0.2–0.9 mm long) on the veins of the lemma, wide lemmas (0.8–1.8 mm wide), and a conspicuous lemma mid-vein. Brachyelytrum aristosum has a more northern distribution, occurring in southern Canada from southern Ontario to Newfoundland, the northern adjacent United States and through the Appalachian mountains to northwestern North Carolina. Brachyelytrum aristosum is characterized by short scaberulous hairs (0.06–0.2 mm long) on the lemma and narrow lemmas (0.7–1.4 mm wide) that are weakly veined. The distinctiveness of B. erectum and B. aristosum is further supported by amplified fragment length polymorphism (AFLP) data. We include a key to the taxa, synonymies, descriptions, and representative specimens. This study represents a recent monographic study of an eastern North American and eastern Asian disjunct genus.

NICORAEPOA (POACEAE, POEAE), A NEW SOUTH AMERICAN GENUS BASED ON POA SUBG. ANDINAE, AND EMENDATION OF POA SECT. PARODIOCHLOA OF THE SUB-ANTARCTIC ISLANDS1

Abstract Poa subg. Andinae Nicora (Poaceae, tribe Poeae) is raised to the rank of genus, here renamed as Nicoraepoa Soreng & L. J. Gillespie. Six specific and one infraspecific combinations are made: N. andina (Trin.) Soreng & L. J. Gillespie, N. chonotica (Phil.) Soreng & L. J. Gillespie, N. erinacea (Speg.) Soreng & L. J. Gillespie, N. pugionifolia (Speg.) Soreng & L. J. Gillespie, N. robusta (Steud.) Soreng & L. J. Gillespie, N. subenervis (Hack.) Soreng & L. J. Gillespie, and N. subenervis subsp. spegazziniana (Nicora) Soreng & L. J. Gillespie. Lectotypes are designated for N. pugionifolia and N. subenervis. Taxonomy and nomenclature of similar Southern Hemisphere island species of Poa L. and other related genera are discussed. Poa sect. Parodiochloa (C. E. Hubb.) Soreng is emended to include, in addition to P. flabellata (Lam.) Raspail, P. cookii (Hook. f.) Hook. f., P. foliosa (Hook. f.) Hook. f., P. hamiltoni Kirk, P. ramosissima Hook. f., and P. tennantiana Petrie. The one species of Tzvelevia E. B. Alexeev is reunited with Poa, and the genus is transferred to Poa sect. Tzvelevia (E. B. Alexeev) Soreng & L. J. Gillespie. Morphological and anatomical characteristics of Nicoraepoa, Poa sect. Parodiochloa, and similar genera in Poinae are compared. Leaf blade morphology and anatomy were found to be particularly useful in characterizing Nicoraepoa and related taxa. A key is provided to distinguish Nicoraepoa, Poa sect. Parodiochloa, and morphologically similar perennial genera of Poinae.

Molecular Phylogeny of Dissanthelium (Poaceae: Pooideae) and its Taxonomic Implications

Abstract We investigated the phylogeny of the New World grass Dissanthelium to explore its monophyly, to examine relationships within the genus, and to investigate its relationship with Poa. Molecular phylogenetic analyses including a thorough sampling of Dissanthelium (seventeen of the 20 species) and DNA sequences from the nuclear ribosomal ITS and plastid trnT-trnL-trnF regions suggest that Dissanthelium is not monophyletic and is nested within Poa. However, ten species form a strongly supported clade (the Dissanthelium clade) in the ITS tree. We propose treating Dissanthelium and Tovarochloa as taxonomic synonyms of Poa. We erect two new sections in Poa: sect. Dissanthelium, comprising the Dissanthelium clade and D. peruvianum, and the monotypic sect. Tovarochloa. The necessary new combinations (Poa aequalis, P. amplivaginata, P. calycina var. mathewsii, P. gigantea, P. macusaniensis, P. rahuii, and P. trollii) and new names (Poa sections Dissanthelium and Tovarochloa, P. apiculata, P. arcuata, P. boliviana, P. congesta, P. deminuta, P. linearifolia, P. parvifolia, P. serpaiana, P. swallenii, and P. thomasii) are effected herein.

Agrostopoa (Poaceae, Pooideae, Poeae, Poinae), a New Genus with Three Species from Colombia

Abstract Agrostopoa Davidse, Soreng & P. M. Peterson, a new genus endemic to the páramos of Colombia, is proposed. The genus includes two new species, A. barclayae Davidse, Soreng & P. M. Peterson and A. woodii Soreng, P. M. Peterson & Davidse, and a third species transferred from Muhlenbergia Schreber, A. wallisii (Mez) P. M. Peterson, Soreng & Davidse (lectotype designated here). A key for determining the species and illustrations of the three species are provided. Agrostopoa is placed in subfamily Pooideae because it has non-Kranz anatomy and lanceolate membranous lodicules, and in tribe Poeae where it differs from Agrostis L. by having carinate lemmas with a terminal awn or mucro, well-developed paleas, and peculiar synflorescences with recurved branches and fragile pedicels. It is classified near Poa L., but differs from that in its single-flowered spikelets that lack rachilla extensions and possess awned or mucronate lemmas.

Poa densa (Poaceae), an overlooked Turkish steppe grass, and the evolution of bulbs in Poa

Abstract: Poa densa Troitsky is a characteristic species of the high steppe to low alpine vegetation of Turkey. It was overlooked in the Flora of Turkey, and although subsequently reported from a few stations in W part of C Anatolia, is actually relatively common and widespread across the semi-arid C and N steppes. Here we provide a key to related species, a full description, photographs, 2C value of nuclear DNA content, and a distribution map, and discuss its classification in the genus. The synonym Festuca conferta is lectotypified. DNA phylogenetic analysis and morphology data indicate P. densa is allied to species of P. subg. Poa sect. Macropoa, rather than to the P. bulbosa complex of P. subg. Ochlopoa sect. Arenariae, and support multiple origins of the basal bulb in the genus Poa. Citation: Cabi E., Soreng R. J., Gillespie L. & Amiri N. 2016: Poa densa (Poaceae), an overlooked Turkish steppe grass, and the evolution of bulbs in Poa. — Willdenowia 46: 201–211. doi: http://dx.doi.org/10.3372/wi.46.46201 Version of record first published online on 28 July 2016 ahead of inclusion in August 2016 issue.

An unusual new Chaetopappa (Asteraceae-Astereae) from New Mexico

Chaetopappa elegans, a narrow endemic from the White Mountains of south-central New Mexico, is unusual in Chaetopappa because of its double pappus of numerous bristles and narrow scales, comparatively long, lanceolate stylar appendages, crinkled stem pubescence, alveolate receptacle, faint cypsela nerves, long ligules, and occurrence on granitic rock. Its chromosome number is 2n = 9, In habit it resembles C. hersheyi from the nearby Guadalupe Mountains, but characteristics of the head are more like those of C. bellioides and C. pulchella from north-central Mexico and the Big Bend region of Texas, and Leucelene ericoides, widespread in arid southwestern North America. In its alveolate receptacle it resembles some species of Aster and the West Coast genus Pentachaeta, whereas its double pappus is reminiscent of some species of Erigeron and Aster (sect. Ionactis). The crinkly stem hairs are like those of some Erigeron species. A portion of the front ranges of southcentral New Mexico, the White and Sacramento mountains, form a continuous north-south oriented chain about 130 km long. The northern, primarily igneous portion, the White Mountains, rises to about 3660 m on Sierra Blanca, the southernmost glaciated peak in North America. The southern portion of the chain, the Sacramento Mountains, are primarily limestone and are considerably lower, barely exceeding 2740 m. This small mountain chain is isolated from other mountain ranges in the Southwest by fairly broad low gaps of arid grassland or desert, gaps that serve as barriers to migration of montane vegetation. To the north and south these gaps are relatively small and not particularly low (cf. map on p. 34 in Patterson 1980). During elevational fluctuation of vegetation in the late Pleistocene (Van Devender and Spaulding 1979) these gaps were narrowed even more and were, therefore, even less of a barrier to vegetation migration. On the one hand, the isolation of these mountains has produced an area of comparatively high endemism for New Mexico, while on the other the isolation has not been so complete that the vegetation has sharply differentiated. Plants from the higher elevations are mostly conspecific with those to the north; plants from lower elevations find their congeners mostly to the south. Most endemics in these mountains apparently have diverged but slightly from ancestral stock and show patterns of relationship similar to that of the general composition of the vegetation with which they are associated. The new species described herein adds one more endemic element to the White Mountains, one that is associated with a small genus of more southern affinity. Species of Chaetopappa are found in the mountains, hills, and plains in and surrounding the arid grassland regions of the northern portion of the Mexican Plateau, extending onto the southern Great Plains as far north as Kansas. This new Chaetopappa is unusual in that it occurs on granitic rocks at relatively high elevations, whereas its closest relatives all occur well to the south and then on limestone. It is also unusual in a number of morphological features. Shinners (1946a) redefined Chaetopappa to include a number of smaller genera previously distinguished by pappus differences. The publication of C. plomoensis B. Turner (Turner 1977) added a new kind of pappus to the genus. Our new species, with its pappus of numerous bristles and scales, further adds to pappus types known in the genus. In addition, it has stylar appendages, stem hairs, and a receptacle unique in Chaetopappa but similar in these characteristics to at least some species in Pentachaeta, Aster, and Erigeron. The faint nerves of the cypsela of C. elegans contrast to the prominent nerves on all other Chaetopappa. Chaetopappa elegans Soreng & Spellenberg, sp. nov. (fig. 1).-TYPE: U.S.A., New Mexico,

2620) Proposal to reject the name Poa amabilis ( Eragrostis amabilis ) (Poaceae)

1 Smithsonian Institution, Department of Botany, National Museum of Natural History, Washington, D.C. 20013-7012, U.S.A. 2 Herbarium, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AE, U.K. 3 United States Department of Agriculture/Agricultural Research Service, National Germplasm Resources Laboratory, Bldg. 003, Beltsville Agricultural Research Center (BARC-West), Beltsville, Maryland 20705-2350, U.S.A. Author for correspondence: Paul M. Peterson, peterson@si.edu

Poa laegaardiana, a new species from Ecuador (Poaceae, Pooideae, Poeae, Poinae)

Abstract Poa laegaardiana sp. nov., is described and illustrated. The new species was found growing on sandy, volcanic soil in Festuca-Calamagrostis dominated grasslands southwest of Ambato and 2.2 km from Fecundo Vela in Provincia de Bolivar. The new species is morphologically similar to Poa gigantea but differs in having glumes 3/4 to 7/8 as long as the adjacent lemmas, a callus with a sparse, short, dorsal tuft of woolly hairs, culms 50–72 cm tall and spikelets 4.1–4.8 mm long. In addition, we include a key to the narrow-spikelike panicled species of Poa in Ecuador.