Included in the PACMAD clade of the family Poaceae (Panicoideae, Arundinoideae, Chloridoideae, Micrairoideae, Aristidoideae, Danthonioideae), the tribe Paniceae s.l. is one of the largest tribes of the subfamily Panicoideae, with more than 2000 species. This tribe comprises a huge morphological, cytological and physiological diversity represented by different inflorescence types, several basic chromosome numbers, and at least four major photosynthetic pathways. The tribe Paniceae has been the subject of molecular studies that have confirmed its paraphyly: two major clades were recognized based on their basic chromosome numbers (x = 9, x = 10). The x = 10 Paniceae clade is sister to the Andropogoneae-Arundinelleae s.s. clade (x = 10), while the combined x = 10 clade is sister to the x = 9 clade that contains the remaining genera of Paniceae. As a result of a recent realignment within the tribe in terms of the phylogenetic position of minor and major Paniceae genera, a reanalysis of the whole sampling is performed and new underrepresented taxa are discussed. A total of 155 genera, currently considered within subfamily Panicoideae, are represented here by almost all genera of Paniceae s.l., representatives of Andropogoneae and Arundinelleae s.s., and the endemic and small tribe Steyermarkochloeae; we also included specimens of subfamily Micrairoideae, tribes Isachneae and Eriachneae. The sampling includes as outgroups 18 genera of the PACMAD clade (excluding Panicoideae) and four genera from the BEP clade (Bambusoideae, Ehrhartoideae, Pooideae), rooting with Bromus inermis. A matrix with 265 taxa based on the combined evidence from ndhF plastid sequences (2074 bp) and 57 morphological characters was subjected to parsimony analyses. Jackknife resampling was used to calculate group support. Most clades are characterized by morphological, cytological, anatomical, and ⁄ or physiological characters. Major tribal changes are based on the basic chromosome number; the pantropical x = 9 clade is here recognized as Paniceae s.s., while the American x = 10 Paniceae s.l. is restricted to the reinstated tribe Paspaleae. The optimization of the photosynthetic pathway for the Paspaleae-Andropogoneae-Arundinelleae s.s. clade, including the monotypic Reynaudia, shows a plesiomorphic C 4 state while the ancestral state for Paniceae s.s. is ambiguous. If Reynaudia were not included or placed elsewhere, the ancestral photosynthetic pathway for both the Paspaleae-Andropogoneae-Arundinelleae s.s. clade and the Paniceae s.s. would be unambiguously C 3 . In order to explore character evolution further, the morphological characters were mapped onto one of the most parsimonious trees. A relationship between photosynthetic pathways and inflorescence morphology is suggested here for the first time. Based on the optimization of morphological characters and additional data, we propose names for almost all inner clades at the rank of subtribe with a few groups as incertae sedis. With this extensive sampling, we resolved the phylogenetic relations...

AjiSriiACI'r\v ('nt\-(i\(' sppt'ies are tit'aU'[)(M-h-ninia not enclosing llu-t4> of the upper palea. Speeies ^rovs in Soutli Aineriea from Mexico to Argentina and Uruguay. A ehulistic analysis of suhgenus Crrrsia was conducted iu test its nionophyly. and to eslahlish ils relaliorislii[) willi other groujis u{ PasfHilum. A key to the speeies in sul)genus Crrrsia is given, as well as nior[)hoh)gical desi-riplion and illustration, and dislrihulion maps. kry fvifnls: America, Crrrsia, eladislies, Paspalnm. [\taeeae. /^/.s/>^////;n I., iiuludes a])[)roxiiiiat(dy 330 speeies ///// .suLg. Ceresia, eonsideniig; ve*i;etati\e and re- (lislril)ule(l in Lropieal and suhhopieal regions of prodnelive characters, analyzing hahilal and distri-Arn<'rica, with a few taxa growing in the Old World hution range. A cladi.slic analysis was furdicr p<^r- (Claylon & Kcnvoize, 19{56). Dne to its large iiuin-lornied in order to Icsl the monophyly of the bcr of s()ccies, and the tnorphidogical variali<»n snhgenus and to estahlisli the relationships of its present within the g(MUJs, PdsjHihim has been divided into suhgenera. sections, or iidornial groups mainly on the basis of morphological characters, such as infloresctMice type or features of the spikelet (Nees. 1829: Doidl. ir»77: Chase. 1927: Pilger. 1929 Clayton .^ Kenvoize, 19J56; Morrone ct ah. 1995 Morrone ct ah. , 1996, 2()()(); CialdeHa el ah, 1995). species llisiomCerrsia was estahlisluMl a! the g;enerle level hy Persoon (lo05-lo()7). on the basis <»f C. clci^dDs (P dspdhim memfmnHicciun Lam., non Walt., 17oo). StibscHjuenlly, Kcichetd)acdt treated Ccrcsia as a Chase (1929) divided Paspalum into subgenera subgenus of Paspalum (Chase, 1929). Several spe-Paspalum and Ccrcsia (Pers.) I{chb., characterizing ries were described in Cercsia in the 19th cenliny (riiigge, 1810; Trinius, 1826 Trinius, . 1828 Trinius, -1836 Ne(^s, 1829; Doell, 1877). N

Phylogenetic analyses of 131 terminals of Paspalum and related genera, based on both plastid and nuclear markers, were performed under maximum parsimony and Bayesian methods. The total evidence analyses generated a hypothesis showing that Paspalum would be monophyletic if Spheneria, Thrasyopsis and Reimarochloa are included within the genus. Paspalum inaequivalve and P. microstachyum, two species of the Inaequivalvia group were related to genus Anthaenantiopsis, excluded from Paspalum, or nested within it by plastid and nuclear markers, respectively. Subgenera Anachyris and Harpostachys were partially recovered as monophyletic assemblages, while subg. Ceresia and Paspalum resolved as polyphyletic. Within subgenus Paspalum, some informal groups were recovered as monophyletic, while others were resolved as paraphyletic or polyphyletic. Phylogenetic relationships among species of Paspalum were partially recovered possibly due to reticulation events among species, autopolyploidization and apomixis; all these processes being common in Paspalum, thus obscuring the infrageneric classification.

Lippia section Goniostachyum comprises plants distinguished by their numerous axillary florescences (three to six, sometimes up to nine) and tetrastichous floral bracts. Species of section Goniostachyum occur in the Neotropics, from Mexico to northern Argentina. Delimitation of the species grouped under Goniostachyum has remained unclear. Forty‐one names exist under this section, but only c. eight to ten names have been used frequently. To resolve the taxonomy of this group, a modified population aggregation analysis, based on the phylogenetic species concept, was employed. As a result, Goniostachyum is here circumscribed to only four species: L. grata, L. origanoides, L. sericea and L. stachyoides. These species are supported by different combinations of three characters of the 13 qualitative attributes analysed: canescent sericeous pubescence, frondose or frondose‐bracteose inflorescences and free or fused florescence apical bracts. Two varieties based on significant differences among quantitative characters are recognized: L. stachyoides var. stachyoides and L. stachyoides var. martiana comb. nov. Fifteen lectotypifications and four neotypifications are proposed. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170, 197–219.

Calyceraceae is a small family with six traditionally recognized genera and 47 species from southern South America. Most species grow along the Andes (of both Argentina and Chile) and in arid regions of the Patagonian steppe. This family belongs to the well‐supported MGCA clade within Asterales, which includes Menyanthaceae+Goodeniaceae+Calyceraceae+ Asteraceae. Calyceraceae is monophyletic and sister to Asteraceae, one of the five largest families of angiosperms. Although Calyceraceae is clearly distinct as a family, its genera are not, and taxonomic revisionary effort has confirmed the lack of sharp boundaries among genera. We performed a phylogenetic analysis of Calyceraceae with a broad taxon sampling (41 of 47 species), and with sequence data from multiple regions from the nuclear (ITS) and plastid genomes (ycg6‐psbM, psbM‐trnD, trnS‐trnG, trnH‐psbA, trnD‐trnT) using maximum parsimony and Bayesian approaches. We aimed at identifying monophylectic groups, their putative morphological synapomorphies and their geographical distribution; we also estimated divergence times and examined chromosomes numbers in an evolutionary context. We obtained well‐resolved and strongly supported phylogenies that show Calyceraceae to be divided into two major clades with geographically structured subclades within each. Our results indicate that an early split within Calyceraceae occurred about 27.4 Ma, probably related to differential changes in chromosome numbers, which allowed the two lineages to evolve in sympatry. We found that major natural subgroups diverged 15–12 Ma, following the Early‐Miocene South Andes construction stage. Finally, the diversification of the extant species is probably associated to Andean orogeny and climate changes in the last 5–4 Myr. We recovered Acicarpha as monophyletic, while the remaining traditionally recognized genera of Calyceraceae are para‐ or polyphyletic. Most species of Moschopis are included in the Glutinose group, but M. monocephala is more closely related to some Calycera species. Calycera is divided into two clades; the Calycera group and the Pilose group. All species of Nastanthus are placed in a well‐supported main group with species of Gamocarpha and Boopis. Gamocarpha could be monophyletic after exclusion of G. dentata and G. angustifolia, but is nested within Nastanthus and Boopis species. Boopis is clearly polyphyletic with its species distributed in all main groups.