Smithsonian Institution Scholarly Press b107_sampleCvrFigsContactshtAltOrdr3 smithsonian contributions to botany • number 107 Smithsonian Institution Scholarly Press 1_S_spiciformis 2_M_tarahumara 3_M_longiligula 4_P_matri-occid... 5_M_rigida 6_F_tolucenisis 7_M_pereilema GrassesA Chronology of Chihuahua, of Middle MissouriMexico Plains Village Sites Yolanda Herrera Arrieta and Paul M. Peterson By Craig M. Johnson with contributions by Stanley A. Ahler, Herbert Haas, and Georges Bonani SERIES PUBLICATIONS OF THE SMITHSONIAN INSTITUTION Emphasis upon publication as a means of “diffusing knowledge” was expressed by the first Secretary of the Smithsonian. In his formal plan for the Institution, Joseph Henry outlined a program that included the following statement: “It is proposed to publish a series of reports, giving an account of the new discoveries in science, and of the changes made from year to year in all branches of knowledge.” This theme of basic research has been adhered to through the years in thousands of titles issued in series publications under the Smithsonian imprint, commencing with Smithsonian Contributions to Knowledge in 1848 and continuing with the following active series: Smithsonian Contributions to Anthropology Smithsonian Contributions to Botany Smithsonian Contributions to History and Technology Smithsonian Contributions to the Marine Sciences Smithsonian Contributions to Museum Conservation Smithsonian Contributions to Paleobiology Smithsonian Contributions to Zoology In these series, the Smithsonian Institution Scholarly Press (SISP) publishes small papers and full-scale monographs that report on research and collections of the Institution’s museums and research centers. The Smithsonian Contributions Series are distributed via exchange mailing lists to libraries, universities, and similar institutions throughout the world. Manuscripts intended for publication in the Contributions Series undergo substantive peer review and evaluation by SISP’s Editorial Board, as well as evaluation by SISP for compliance with manuscript preparation guidelines (available at https://scholarlypress.si.edu). For fully searchable PDFs of all open access series and publications of the Smithsonian Institution Scholarly Press, visit Open SI at http://opensi.si.edu. smithsonian contributions to botany • numb e r 1 0 7 Grasses of Chihuahua, Mexico Yolanda Herrera Arrieta and Paul M. Peterson WASHINGTON, D.C. 2018 ABSTRACT Herrera Arrieta, Yolanda, and Paul M. Peterson. Grasses of Chihuahua, Mexico. Smithsonian Contributions to Botany, number 107, x + 380 pages, 246 figures, 1 table, 2018.—Our revision of the grasses of Chihuahua includes 385 species in 95 genera, 15 subspecies, 29 varieties, and 4 forms. We provide keys for determination, detailed descriptions, nomencla- tural synonyms, ecological information on habitat, distribution based on herbarium specimens, and illustrations for 251 species and 8 varieties. We provide a new combination for Cenchrus polystachios subsp. setosus. RESUMEN Herrera Arrieta, Yolanda, and Paul M. Peterson. Grasses of Chihuahua, México. Smithsonian Contributions to Botany, número 107, x + 380 páginas, 246 figuras, 1 tabla, 2018.—Nuestra revisión de las gramíneas de Chihuahua incluye 385 especies en 95 géneros, 15 subespecies, 29 variedades y 4 formas. Se proveen claves para su determinación, descripciones detalladas, sinónimos nomenclaturales, información ecológica del hábitat, distribución con base en ejemplares de herbario e ilustraciones de 251 especies y 8 variedades. Proporcionamos una nueva combinación para Cenchrus polystachios subsp. setosus. This research was funded, in part, by the Consejo Nacional de Ciencia y Tecnología del Estado de Durango and the Instituto Politécnico Nacional. Cover images, from left to right: Sporobolus spiciformis spikelet (Figure 235C); Muhlenbergia tarahumara habit (Figure 178A); M. longiligula floret (Figure 162H); Poa matri- occidentalis subsp. mohinorensis ligule (Figure 207D); M. rigida inflorescence (Figure 170C); Festuca tolucensis stylized growth form (Figure 124B); M. pereilema portion of inflorescence (Figure 167G). Published by SMITHSONIAN INSTITUTION SCHOLARLY PRESS P.O. Box 37012, MRC 957, Washington, D.C. 20013- 7012 https://scholarlypress .si .edu Compilation copyright © 2018 Smithsonian Institution The rights to all text and images in this publication, including cover and interior designs, are owned either by the Smithson- ian Institution, by contributing authors, or by third parties. Fair use of materials is permitted for personal, educational, or noncommercial purposes. Users must cite author and source of content, must not alter or modify copyrighted content, and must comply with all other terms or restrictions that may be applicable. Users are responsible for securing permission from a rights holder for any other use. Library of Congress Cataloging- in- Publication Data Names: Herrera Arrieta, Yolanda, author. | Peterson, Paul M., author. | Smithsonian Institution Scholarly Press, publisher. Title: Grasses of Chihuahua, Mexico / Yolanda Herrera Arrieta and Paul M. Peterson. Other titles: Smithsonian contributions to botany ; number 107. 0081-024X Description: Washington, D.C. : Smithsonian Institution Scholarly Press, 2018. | Series: Smithsonian contributions to botany, ISSN 0081-024X ; number 107 | Includes bibliographical references and index. Identifiers: LCCN 2017055384 Subjects: LCSH: Grasses—Mexico—Chihuahua (State)—Identification. | Grasses—Mexico—Chihuahua (State)— Classification. Classification: LCC QK495.G74 H445 2018 | DDC 584/.92097216—dc23 | SUDOC SI 1.29:107 LC record available at https://lccn.loc.gov/2017055384 ISSN: 1938- 2812 (online); 0081- 024X (print) Publication date (online): 10 April 2018 Ó The paper used in this publication meets the minimum requirements of the American National Standard for Permanence of Paper for Printed Library Materials Z39.48–1992. Contents LIST OF FIGURES v INTRODUCTION 1 Synopsis 4 Acknowledgments 4 FAMILY DESCRIPTION: POACEAE 5 KEY TO THE GRASS GENERA OF CHIHUAHUA 5 DESCRIPTIONS 15 REFERENCES 371 INDEX TO SCIENTIFIC NAMES (GRASSES) 375 Figures 1. Municipios in Chihuahua 2 2. Achnatherum curvifolium 16 3. Achnatherum eminens 17 4. Achnatherum hymenoides 18 5. Achnatherum robustum 19 6. Aegilops cylindrica 20 7. Agropyron cristatum 20 8. Agrostis exarata 22 9. Agrostis hyemalis 23 10. Agrostis scabra 24 11. Agrostis stolonifera 25 12. Alopecurus geniculatus 26 13. Andropogon gerardii 27 14. Andropogon glomeratus 28 15. Anthoxanthum odoratum 29 16. Aristida adscensionis 31 17. Aristida arizonica 33 18. Aristida divaricata 33 19. Aristida gypsophila 35 20. Aristida havardii 36 21. Aristida longespica 37 22. Aristida pansa 38 23. Aristida purpurea var. fendleriana 40 24. Aristida purpurea var. longiseta 40 25. Aristida purpurea var. nealleyi 41 26. Aristida purpurea var. perplexa 41 27. Aristida purpurea var. purpurea 42 28. Aristida purpurea var. wrightii 42 29. Aristida schiedeana var. orcuttiana 43 30. Aristida ternipes var. gentilis 45 31. Aristida ternipes var. ternipes 45 32. Arundo donax 46 33. Avena fatua 48 vi • SMITHSONIAN CONTRIBUTIONS TO BOTANY 34. Avena sativa 49 35. Avenella flexuosa 50 36. Bothriochloa barbinodis 52 37. Bothriochloa laguroides var. laguroides 53 38. Bothriochloa springfieldii 55 39. Bothriochloa wrightii 55 40. Bouteloua aristidoides var. aristidoides 59 41. Boutloua barbata var. rothrockii 61 42. Bouteloua breviseta 61 43. Bouteloua curtipendula var. caespitosa 64 44. Bouteloua curtipendula var. curtipendula 65 45. Bouteloua eludens 67 46. Bouteloua eriopoda 68 47. Bouteloua gracilis 69 48. Bouteloua hirsuta var. hirsuta 71 49. Bouteloua parryi 73 50. Bouteloua radicosa 74 51. Bouteloua ramosa 75 52. Bouteloua repens 75 53. Bouteloua simplex 77 54. Bouteloua trifida 78 55. Bouteloua uniflora 78 56. Bromus anomalus 81 57. Bromus catharticus 83 58. Bromus frondosus 84 59. Bromus japonicus 85 60. Bromus richardsonii 87 61. Bromus tectorum 87 62. Cenchrus americanus 90 63. Cenchrus ciliaris 90 64. Cenchrus clandestinus 91 65. Cenchrus echinatus 93 66. Cenchrus myosuroides 94 67. Cenchrus polystachios 95 68. Cenchrus spinifex 96 69. Chloris gayana 98 70. Chloris submutica 99 71. Chloris virgata 100 72. Cortaderia selloana 101 73. Cynodon dactylon 103 74. Dactylis glomerata 105 75. Dactyloctenium aegyptium 106 76. Dasyochloa pulchella 106 77. Deschampsia danthonioides 108 78. Deschampsia elongata 112 79. Digitaria bicornis 112 80. Digitaria californica 113 81. Digitaria ciliaris 114 82. Digitaria sanguinalis 116 83. Dinebra panicea subsp. brachiata 119 84. Diplachne fusca subsp. fusca 121 85. Disakisperma dubium 123 86. Distichlis spicata 125 87. Echinochloa colona 127 NUMBER 107 • vii 88. Echinochloa crus-galli 129 89. Echinochloa crus- pavonis 130 90. Echinochloa muricata 131 91. Echinochloa oplismenoides 132 92. Echinochloa walteri 133 93. Eleusine indica 134 94. Elymus elymoides subsp. brevifolius 138 95. Elymus trachycaulus 140 96. Enneapogon desvauxii 141 97. Eragrostis barrelieri 144 98. Eragrostis cilianensis 145 99. Eragrostis ciliaris 146 100. Eragrostis curvula 147 101. Eragrostis echinochloidea 148 102. Eragrostis erosa 149 103. Eragrostis intermedia 150 104. Eragrostis lehmanniana 151 105. Eragrostis lugens 152 106. Eragrostis mexicana subsp. mexicana 153 107. Eragrostis palmeri 154 108. Eragrostis pectinacea var. pectinacea 156 109. Eragrostis pilosa 157 110. Eragrostis secundiflora subsp. oxylepis 158 111. Eragrostis sessilispica 159 112. Eragrostis spectabilis