As a result of a review of the grass family for Flora Mesoamericana, 13 new species (Arthrostylidium judziewiczii, A. merostachyoides, Aulonemia clarkiae, Merostachys latifolia, Rhipidocladum martinezii, Guadua macclurei, Arberella grayumii, Cryptochloa soderstromii, Pariana argentea, Danthonia chiapasensis, Pereilema diandrum, Digitaria breedlovei, D. clavitricha) and three new varieties (Eragrostis rufescens var. mesoamericana, Panicum aquaticum var. cartagoense, Andropogon gerardii var. hondurensis) are described, one new name (Elymus cordilleranus) is proposed, 17 new combinations (Guadua longifolia, Chondrosum hirsutum var. glandulosum, Dichanthelium sphaerocarpon var. floridanum, D. sciurotoides, D. sciurotis, D. aciculare var. ramosum, D. dichotomum var. unciphyllum, D. umbonulatum, D. cordovense, D. pantrichum, Paspalidium chapmanii, P. distantifiora, P. leonis, P. pradana, P. ophiticola, P. subtransiens, P. utowanaea) are made, and one name (Bromus exaltatus) is lectotypified. As a result of writing the account of the grass family for volume 6 of Flora Mesoamericana, a number of new taxa were recognized, and the need for several new combinations became apparent. These are published here under the authorship of the person(s) primarily responsible for the account of the taxon. The taxa are arranged in the taxonomic sequence used in Flora Mesoamericana, which for a large part follows the scheme of Clayton & Renvoize (1986). In the bamboo descriptions we refer to the two main types of leaves found in bamboos as the culm leaves and branch leaves. The latter leaf type has been more commonly known in recent years as foliage leaves. However, besides the redundancy implicit in the term foliage leaves, the term branch leaves, in parallel to culm leaves, is more precise in describing the location of these leaves. BAMBUSEAE: ARTHROSTYLIDIINAE Arthrostylidium judziewiczii Davidse, sp. nov. TYPE: Costa Rica. Heredia: primary forest along Rio San Rafael, Atlantic slope of Volcan Barva, 10?13'N, 84?05'W, 1,500 m, slenderstemmed, scandent and apparently epiphytic bamboo on mossy trunk of large tree, 3-4 m above ground, 12 Apr. 1986, M. H. Grayum 7024 (holotype, MO; isotypes, BM, CANB, CR, F, ISC, K, PMA, SI, SP, US). Bambusa lignosa caespitosa. Culmi cavi ad 4 m longi, 1-2 mm diametro, scandentes; nodis in medio culmi ramos singulares gerentibus. Folia culmorum caduca. Folia ramorum laminis 6-13 cm longis, 1-2 cm latis, glabris. Inflorescentiae bilaterales, spicatae terminales et axillares, terminales 8-14 cm longae; rhachidi recta ca. 1 mm lata, 4-6 spiculas gerenti. Spiculae singulares, 3.5-6.5 cm longae, sessiles; gluma inferna absenti; gluma superna NOVON 2: 81-110. 1992. This content downloaded from 157.55.39.108 on Fri, 17 Jun 2016 06:20:24 UTC All use subject to http://about.jstor.org/terms