This paper presents phylogenetic results and a revised subfamilial classification of the grass family. This choice was based on previous work (summarized from Kellogg & Linder, 1995) showing that these represent the closest relatives of grasses. For the 31 final taxa in the matrix, all molecular data were taken from a single species;.
Chloroplast restriction sites-Davis and Soreng (1993); Soreng and Davis (1998)
Morphology-Soreng and Davis (1998, and ad- ditional members of the GPWG, this paper)
Consensus trees for individual data set analyzes are presented in Appendices III-A through H, and tree statistics in Tables 3 and 5. The differences between ndhF and rbcL are puzzling, however, because they are both part of the same linkage group. For example, a heuristic search of the entire dataset in PAUP* on a Macintosh G3 with 10 random addition sequences took 19.6 seconds.
- Joinvilleaceae are sister to Poaceae
- Poaceae are monophyletic
- The earliest diverging lineage of Poaceae is Anomochlooideae (even if Anomochloa and Strep-
- The next diverging lineage is Pharoideae
- The next diverging lineage is Puelioideae
- All remaining grasses form a clade, which ap- pears to have diversified well after the origin of the
The strict consensus topology (Appendix III-K) is similar to that of the combined tree except for the position of Zeugites, which is sister to Danthoniopsis, and Gynerium, which is sister to Panicoideae. Because of the strong support for the relationships found in the present study, we propose a revised subfamilial classification (see Taxonomic Treatment). Most of the molecular data comes from chloroplast genes, so it is not surprising that only the tree from the chloroplast closely matches the tree for the entire data set.
Flagellaria
31 Joinvillea
0-Streptochaeta
1o-AooCoPACCAD
Puelia
17 gLithachne
01 Pariana
Brachyelytrum
3 13202130 -Melica
Glyceria
Diarrhena
Bromus Triticum
Piptatherum
Nassella
Volume 88, Number 3 2001
Grass Phylogeny Working Group Phylogeny and Classification of Poaceae
OOO0-- Gynerium
Danthoniopsis
Pennisetum
Eria
Merxmuellera macowanii
1\33 ~-Karroochloa 0
1 Austrodanthonia
A3 Arundo
Centropodia
Pappophorum
Eragrostis
Distichlis
01001 o-Spartina
119 Sporobolus
The secondary epiblast gain (Map 35) is a possible synapomorphy (but not known for Thysanolaena), as is the fusion of styles (Map. All C4 lineages are included in the PACCAD clade, so palaeontological evidence for photosyn C4 - thesis can determine the minimum age for a common ancestor clade This suggests that the origin of the PACCAD clade occurred no later than 15 million years ago and possibly as early as 25 million years ago.
Other traits acquired later in the family's evolution may have been more important in its diversification and ecological success. Nevertheless, we have applied informal names to several of the well-supported clades (see above). Diagnoses of the subfamilies were drawn from various sources, including Clayton and Renvoize (1986) and Watson and Dallwitz (1992).
Inflorescence ultimate structures (earth equivalents) of uncertain homology to typical grass spikelets, but monofloral and bisexual; bracts within the spikelets equivalent to phyllotaxis distichous or spiral, without uncinate macrohairs, sometimes with awns, but if so the awns are simple; lodicules are absent, or, in Anomochloa, their position is occupied by a ring of short brownish cilia, borne on a low membranous ring; stamens 4 or 6; ovary glabrous, apical appendage absent, haustorial synergids probably absent, style 1, stigma(s) 1 or 3. In his original description of the tribe, Stapf specifically included Olyra (based on his uni-. Morales (1998) it was with Tzvelev agreed and rejected the name Pharoideae for this subfamily, in accordance with article 52.1 of the Code (Greuter et al., 2000), and replaced it with Leptaspidoideae.
Inflorescence spikes, racemose or paniculate, bracts outside the pedicels absent or rarely present (eg, Sesleria, Echinaria, Ammochloa).
Relationships between the previously divergent lineages of the entire poid clade are only weakly supported and also require further investigation. The phylum classification presented here will almost certainly change as more data is collected, and should therefore only be taken as an indication of the taxa included within the subfamily. The exact generic membership of the subfamily remains to be determined; however, we include the following genera: Amphipogon, Arundo, Dregeochloa, Hakonechloa, Molinia (and Moliniopsis if recognized), and Phragmites.
Inflorescences paniculate or less commonly racemose or spiked, bracts outside the spikelets absent (but the underlying leaf + spatheate and disarticulate with the inflorescence in Tribolium pusillum). Bilobed profile may also be a synapomorphy, but this feature has not been sufficiently investigated in the rest of the family. Mesophyll non-radiated, often with an adaxial palisade layer, fusoid-like cells often present as extensions of outer parenchyma bundle sheath, arm cells absent; Kranz anatomy absent; midrib simple; adaxial bulliform cells large.
Most Centotheceae are characterized by unusual leaf anatomy, including the presence of unattached mesophyll and laterally elongated sheath cells. Annual or perennial plant (rhizomatous, stoloniferous, caespitose or decumbent), mainly herbaceous, of the tropics and subtropics, but also various in the temperate zone. Inflorescences racemes, racemes or spikes, or complex combinations thereof, bracts outside the pedicels present (Andropogoneae) or absent (Paniceae).
Inflorescences paniculate, paniculate with spicate branches, racemose or spicate, bracts outside the spikelets lacking.
Incertae Sedis
Sequences of the grass-specific insert in the chloroplast rpoC2 gene elucidate the generic relationships of Arundinoideae (Poaceae). Cell structure of the mesophyll and parenchymatous sheath of the Gramineae. Higher level systematics of monocotyledons: An assessment of current knowledge and a new classification.
A phylogeny of the grass family (Poaceae) based on ndhF sequence of the grass family (Poaceae) based on ndhF sequence data. Evolutionary analysis of the nucleotide sequence carboxylase large subunit (rbcL) Nucleotide carboxylase (rbcL) sequence dataset among grasses (Poaceae). Comparisons of the molecular evolutionary process in rbcL and ndhF in the grass family (Poaceae).
A molecular phylogeny of the grass subfamily Panicoideae (Poaceae) shows multiple Grass subfamily Panicoideae (Poaceae) shows multiple origins of C4 photosynthesis. Phylogeny of the subfamily Panicoideae with emphasis on the tribe Paniceae: Evidence from the chloroplast trnL-F cpDNA region. Intermolecular recombination between different tRNA genes is responsible for a large plastid DNA inversion during the evolution of the cereal.
A molecular phylogeny of the grass family (Poaceae) based on nuclear ribosomal DNA (ITS) sequencing.
- Everett (editors), Grasses: Systematics and Evolution
Nucleotide sequence of the maize chloroplast rpo B/C1/C2 operon: Comparison of the derived protein primary structures from different organisms with respect to functional domains. Phylogenetic affinities of grasses to other monocots as revealed by molecular analysis of chloroplast DNA M13 cloning and nucleotide sequence of the sorghum chloroplast gene for the large subunit of ribulose-1,5-bisphosphate carboxylase.
The phytochrome gene family in grasses (Poaceae): A phylogeny and evidence that grasses have a subset of loci found in dicots. Evolution of the phytochrome gene family and its utility for phylogenetic analyzes of angiosperms. Nucleotide sequence and gene expression for rice ribulose 5-bisphosphate carboxylase large subunit 1.
Phylogenetics and character evolution in the grass family (Poaceae): Simultaneous analysis of character sets for morphological and chloroplast DNA restriction sites. Grass Genera of the World: descriptions, illustrations, identification and information retrieval; Includes synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, global and local distribution and references.
Volume 88, Number 3
Phylogeny and Classification of Poaceae
Continued
Thorne Pappophorum bicolor E. Fourn
Chusquea Oryza Leersia Stipa Avena Bromus Bardeum Aristida Stipagrostis Amphipogon Arundo Moliniopsis Phragmites Merxmuellera Karroochloa Danthonia Centropodia Eragrostis Enneapogon Eriachne Thysanolaena Gynerium Chasmanthium Pennisetum Sorghum2. Stipagrostis Amphipogon Arundo Moliniopsis Phragmites Merxmuellera Karroochloa Danthonia Austrodanthonia Merxmuellera Centropodia Eragrostis Enneapogon Spartina Micraira Thysanolaena Gynerium Chasmanthiuml Panicum Pennisetum Sorghum Zea G. Phyc Phragmites Danthonia Eragrostis Sporobolus Thysanolaena Chasmanthium Danthoniopsis Panicum Pennisetum Miscanthus Zea.
Bromus Triticum Aristida Amfipogon Arundo Molinia Phragmites Danthonia Eragrostis Uniola Zoysia Distichlis Spartina Sporobolus Chasmanthium Panicum Pennisetum Miscanthus ITS. Referenca e kuponit të gjinisë së llojit GenBank #. donax blu australis macowant'i purpur califoricn. triseta Nees cx Steud. . subulifolia F. Mucl. . më i madhi sagtttaturn latij6lium . )isalcatl rntr rThunth. Avena Bromus Hordeum Aristida Stipagrostis Amphipogon Arundo Molintia Phragmites Merxmuellera Karroochloa Danthonia Rytidosperma Merxmuellera Centropodia Eragrostis Spartina Sporobolus Eriachne Micratir(L Thysanolaena Gynerium Patroniculetum Husmanthim.
Taxa in the matrix appear in groups according to what was known about the phylogeny at the time the matrix list for sampling taxa was shown in groups according to what was known about the phylogeny at the time the list for taxon sampling. Thus, first there are four outgroups, followed by early diverging taxa, then bambusoids, rices, pooids, etc.
Continued
Flagellaria Baloskion
Eremitis
Brachyelytrum
62 Piptatherum
68 ~ Avena
Diarrhena X Melica
Amphipogon Arundo
Molinia Phragmites
Danthonia - Danthoni
58j Chasmanthium Centothec
Miscanthus Panic
Panicum Pseudosasa
I• Arundo Molinia Arundin
Pueli
D, rpoC2
F, ITS
G, GBSSI
Puelia Eremitis
Molinia Phragmites
Notes on morphological characters
Thus, two lodicules may be a synapomorphy of the BEP + PACCAD group, with a reversal to three lodicules in the Bambusoideae/Ehrhartoideae group, and a reversal to two lodicules in the Ehrhartoideae. The loss of this stamen is a synapomorphy of the BEP + PACCAD clade, but is regained at least three (possibly four) times in Ehrharta, Oryza (but not Leersia), Pseudosasa and Pariana. Hilum shape: This character is recognized as a characteristic of the caryopsis and thus does not apply to non-grasses.
All groups except the PACCAD Clade have a long hilum greater than one-third the length of the grain in our sample. Thus, this may be a synapomorphy of grasses (ie the plesiomorphic state for caryopsis), but because the character is treated as inapplicable outside the grasses, there is no observed transformation at the origin of the family. This embryo type is absent outside the grass family and is found in all grasses for which there are observations (unobserved in Merxmuellera rangei), and is therefore interpreted as a unique and unreversed synapomorphy of the grasses.
Within the Bambusoid/Ehrhartoid clade, the loss of the scutellar tail is unambiguously interpreted as an unreversed synapomorphy of Oryzeae. Margins overlap in all observed taxa in the alliance between bambusoids and ehrhartoids, as well as in Brachyelytrum and Phaenosperma of the Pooideae (also diarrhea is polymorphic). Transformation to the latter state is thus an unequivocal and irreversible synapomorphy of the sister.
They are present in Joinvillea and all three early divergent lineages within the grasses.
