Yolanda Herrera Arrieta

A molecular phylogeny and new subgeneric classification of Sporobolus (Poaceae: Chloridoideae: Sporobolinae).

The grass subtribe Sporobolinae contains six genera: Calamovilfa (5 spp. endemic to North America), Crypsis (10 spp. endemic to Asia and Africa), Psilolemma (1 sp. endemic to Africa), Spartina (17 spp. centered in North America), Sporobolus (186 spp. distributed worldwide), and Thellungia (1 sp. endemic to Australia). Most species in this subtribe have spikelets with a single floret, 1-veined (occasionally 3 or more) lemmas, a ciliate membrane or line of hairs for a ligule, and fruits with free pericarps (modified caryopses). Phylogenetic analyses were conducted on 177 species (281 samples), of which 145 species were in the Sporobo - linae, using sequence data from four plastid regions (rpl32-trnL spacer, ndhA intron, rps16-trnK spacer, rps16 intron) and the nuclear ribosomal internal transcribed spacer regions (ITS) to infer evolutionary relationships and provide an evolutionary framework on which to revise the classification. The phylogenetic analysis provides weak to moderate support for a paraphyletic Sporobolus that includes Calamovilfa, Crypsis, Spartina, and Thellungia. In the combined plastid tree, Psilolemma jaegeri is sister to a trichotomy that includes an unsupported Urochondra-Zoysia clade (subtr. Zoysiinae), a strongly supported Sporobolus somalensis lineage, and a weakly supported Sporobolus s.l. lineage. In the ITS tree the Zoysiinae is sister to a highly supported Sporobolinae in which a Psilolemma jaegeri-Sporobolus somalensis clade is sister to the remaining species of Sporobolus s.l. Within Sporobolus s.l. the nuclear and plastid analyses identify the same 16 major clades of which 11 are strongly supported in the ITS tree and 12 are strongly supported in the combined plastid tree. The positions of three of these clades representing proposed sections Crypsis, Fimbriatae, and Triachyrum are discordant in the nuclear and plastid trees, indicating their origins may involve hybridization. Seven species fall outside the major clades in both trees, and the placement of ten species of Sporobolus are discordant in the nuclear and plastid trees. We propose incorporating Calamovilfa, Crypsis, Spartina, Thellungia, and Eragrostis megalosperma within Sporobolus, and make the requisite 35 new combinations or new names. The molecular results support the recognition of 11 sections and 11 subsections

(2332) Proposal to conserve the name Sporobolus against Spartina, Crypsis, Ponceletia , and Heleochloa ( Poaceae : Chloridoideae : Sporobolinae )

1 Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, D.C., 20013, U.S.A. 2 M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine, 01601 Kiev, Ukraine 3 Instituto Politécnico Nacional, CIIDIR Unidad Durango-COFAA, Durango, C.P. 34220, Mexico 4 Botany Section, Research and Collections, Canadian Museum of Nature, Ottawa, Ontario K1P 6P4, Canada Author for correspondence: Paul M. Peterson, peterson@si.edu

Phylogeny and subgeneric classification of Bouteloua with a new species, B. herrera‐arrietae (Poaceae: Chloridoideae: Cynodonteae: Boutelouinae)

Bouteloua (Poaceae: Chloridoideae: Cynodonteae; Boutelouiane) is an important genus of forage grasses containing 60 species found primarily in the Americas with a center of diversity in northern Mexico. A modern subgeneric classification is lacking. The goals of our study were to reconstruct the evolutionary history among the species of Bouteloua using molecular data with increased species sampling compared to previous studies. A phylogenetic analysis was conducted on 209 samples, of which 59 species (206 individuals) were in Bouteloua, using two plastid (rpl32‐trnL spacer and rps16‐trnK spacer) and nuclear ITS 1&2 (ribosomal internal transcribed spacer) sequences to infer evolutionary relationships and produce a subgeneric classification. Overall, ITS and plastid phylogenies rendered similar patterns. However, the ITS phylogeny lacked backbone structure, recovering only four internal clades out of nine found in the plastid phylogeny. The ITS network shows a radiative evolutionary pattern and indicates a number of incompatible splits, suggesting past hybridization between species of different sections. The maximum‐likelihood tree from the combined plastid and ITS regions is well resolved and depicts a strongly supported monophyletic Bouteloua that includes ten strongly supported clades and one moderately supported clade. The molecular results support the recognition of 10 sections and two subsections within Bouteloua s.l.; three sections are new: Barbata, Hirsuta, and Trifida; four sections are new combinations: Buchloe, Cyclostachya, Opizia, and Triplathera; and two subsections are new: Eriopoda and Hirsuta. Based on our molecular results and the possession of unique morphological characters we describe a new species from Nuevo León, Bouteloua herrera‐arrietae.

A molecular phylogeny of the subtribe Sporobolinae and a classification of the subfamily Chloridoideae (Poaceae)

The classi cation of the subtribe Sporobolinae containing the following six genera is poorly understood: Calamovilfa ( ve species endemic to North Amer i ca), Crypsis (11 species endemic to Asia and Africa), Psilolemma (one species endemic to Africa), Spartina (17 species centered in North Amer i ca), Sporobolus (186 species distributed worldwide), and Thellungia (one species from Africa and Asia). The goal of this study was to reconstruct the evolutionary history of the Sporobolinae using molecular data with increased species sampling. Most species in this subtribe have spikelets with a single oret, oneveined (occasionally threeveined) lemmas, a ciliate membrane or line of hairs for a ligule, and fruits with free pericarps (modi ed caryopses). A phyloge ne tic analy sis was conducted on 161 species (250 samples), of which 134 species were in the Sporobolinae, using nuclear rITS (ribosomal internal transcribed spacer region) 1 and 2 sequences to infer evolutionary relationships. The maximum likelihood phylogram provides moderate support for a paraphyletic Sporobolus that includes Calamovilfa, Crypsis, Spartina, and Thellungia. The subtribe Zoysiinae (Urochondra and Zoysia) is sister to a highly supported Sporobolinae where the Psilolemma jaegeri−Sporobolus somalensis clade is sister to the remaining species of Sporobolus s.l. Within Sporobolus s.l. there are 15 major clades, of which 12 are strongly supported, two are moderately supported, and one is unsupported. A complete generic classi cation of the subfamily Chloridoideae is given.

Phylogeny of Muhlenbergia subg. Pseudosporobolus, including M. spatha (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) now found in Zacatecas, Mexico

Abstract Muhlenbergia spatha, previously known only from near the type locality in San Luis Potosí, is reported from two localities in Zacatecas, Mexico. Historically, botanists have overlooked this diminutive annual. To clarify affinities of M. spatha, we present a molecular phylogeny emphasising species in M. subg. Pseudosporobolus using sequence data from two plastid markers (rpl32-trnL and rps16 intron) and nrDNA ITS. In addition, we include an updated description, illustration and discussion of the habitat of M. spatha.