Based on morphological study and corroborated by unpublished molecular phylogenetic analyses, five grass species of high-mountain grasslands in Mexico, Central and South America, Agrostis bacillata, A. exserta, A. liebmannii, A. rosei, and A. trichodes, are transferred to Podagrostis and bring the number of species of this genus recognized in the New World to ten. The name Apera liebmannii is lectotypified and epitypified. We provide an updated genus description for Podagrostis, and updated species descriptions, images, and notes on the new combinations. The diagnostic characteristics differentiating Podagrostis from Agrostis are: a) palea that reaches from (2/3) ¾ to almost the apex of the lemma; b) florets that usually almost equal the length of the glumes or are at least ¾ the length of the glumes; c) rachilla extension present and emerging from under the base of the palea as a slender short stub (rudimentary or up to 1.4 mm long, sometimes obscure in most florets in P. rosei), smooth or scaberulous, glabrous or distally pilulose (hairs < 0.3 mm long); d) lemmas usually awnless, sometimes with a short straight awn 0.2–0.6 mm long, inserted medially or in the upper 1/3 of the lemma, not surpassing the glumes (awn well-developed, straight or geniculate and inserted in lower 1/3 of lemma, not or briefly surpassing glumes in P. rosei). We include a generic key to distinguish the species of Podagrostis from other similar genera in Latin America and a key to distinguish the species of Podagrostis now accepted as occurring in these areas.

Calamagrostis (syn. Deyeuxia), as traditionally circumscribed, is one of the most speciose genera from páramo grasslands of northwest South America and southern Central America and often dominates these high-elevation habitats. However, it remains difficult for researchers to accurately identify the species due to a lack of floristic treatments for most of the countries containing páramo, with the distribution of many species still very poorly known. In an effort to ameliorate this, we present an updated list and identification keys in English and Spanish (as electronic appendix) to the species of Calamagrostis s.l. known or likely to occur in the páramos of Peru, Ecuador, Colombia, Venezuela, Costa Rica and Panama. Fifty-four species are accepted, constituting 47 species currently circumscribed in Calamagrostis and seven species recently transferred to Deschampsia. Included within this are two new species, Calamagrostiscrispifolius and Deschampsiasantamartensis, which are described and illustrated. Both new species are found in páramos of the Sierra Nevada de Santa Marta (departamento Magdalena), on the northernmost tip of Colombia, with C.crispifolius also found in the Serrania de Perija on the border with Venezuela. Calamagrostiscrispifolius differs from all other species of Calamagrostis s.l. by the presence of strongly curled, readily deciduous leaf blades, amongst numerous other characteristics including open inflorescences with generally patent branches, small spikelets, (3.5–)4–5.5 mm long, with sessile florets and a rachilla prolongation reaching from 2/3 to almost the apex of the lemma, with short hairs (< 1 mm long). Deschampsiasantamartensis is similar to Deschampsiahackelii (=Calamagrostishackelii) from austral South America but differs by its broad, rigid and erect, strongly conduplicate blades, 1.5–2.5 mm wide when folded, ligules of innovations 0.5–1 mm long, truncate or obtuse, ligules of upper flowering culms 3–4 mm long, broadly shouldered with an attenuate central point, ellipsoid spike-like panicle, 3–5.5 long × 1.5–2.5 cm wide, lemma surfaces moderately to lightly scabrous between the veins, lemma apex acute to muticous, entire, rachilla extension often absent and inside of the floret often with hyaline shiny sinuous trichomes to 1 mm long, emerging from the base of the ovary. We also present a broader circumscription of the common species Deschampsiapodophora (=Calamagrostispodophora), with the new variety D.podophoravar.mutica described and illustrated. Deschampsiapodophoravar.mutica principally differs from var. podophora by florets lacking awns and larger habit i.e. multiple taller culms with longer and wider leaf blades forming tussocks, with inflorescences often held within sheaths. Nomenclatural changes are presented, with Deyeuxiamacrostachya newly synonymised under C.macrophylla and C.pittieri, C.pubescens and Deyeuxiapubescens newly synonimised under C.planifolia. Lectotypes are designated for Agrostisantoniana, Calamagrostispisinna, Deyeuxiamacrostachya and Deyeuxiasodiroana. We also document and give notes on five new records of Calamagrostis for Colombia: C.carchiensis, C.guamanensis, C.heterophylla, C.pisinna and C.rigida.

We present taxonomic notes, including updated species descriptions and images, for the nine species of Agrostis and one species of Podagrostis found in páramos of Departamento Boyacá, Colombia (A. boyacensis, A. breviculmis, A. capillaris, A. foliata, A. cf. imberbis, A. mertensii, A. perennans s.l., A. stolonifera, A. tolucensis, Podagrostis trichodes). Agrostis cf. imberbis, previously known from austral South America, is newly recorded for Colombia, A. capillaris is a new regional record for Boyacá, and the name Agrostis stuebelii is lectotypified. We include keys in English and Spanish to distinguish the 15 species of Agrostis and two species of Podagrostis that are cited as occurring in Colombia.

The grass genus Poa L. is widespread throughout temperate areas of the Andes, being a common constituent in the highly diverse but threatened high-elevation páramo grasslands of northwest South America. Knowledge of Poa from these páramo areas is very limited, however, with no comprehensive taxonomic treatments available for Colombia, which contains the largest area of páramo in the Neotropics and its surrounding countries. We present a taxonomic revision of Poa for Colombia accepting 15 species, including two recent combinations of Poa previously circumscribed in Aphanelytrum (Hack.) Hack. We describe a new species, P. colombiana Soreng & Sylvester, and a new variety, P. subspicata (J. Presl) Kunth var. glabrata Soreng & Sylvester, for Colombia and Ecuador. Poa colombiana is similar to P. aequatoriensis Hack. but differs in having lemmas pubescent on the keel and marginal veins, lemma apices weakly acute, flag leaf sheath margins fused 20%–38% their length, and anthers generally larger, > 1.2 mm long. Poa subspicata var. glabrata differs from P. subspicata s. str. in having glabrous lemmas. We provide two new records for Colombia of P. huancavelicae Tovar, and P. mucuchachensis Luces. Two species, P. orthophylla Pilg. and P. reclinata (Swallen) Soreng & P. M. Peterson, are considered endemic to Colombia. Poa soderstromii Negritto & Anton is placed as a subspecies of P. orthophylla, and P. leioclada Hack. is synonymized under P. mulalensis Kunth. The names P. annua L. var. exilis Tomm. ex Freyn, P. humilis Ehrh. ex Hoffm., P. infirma Kunth, P. leioclada, P. orthophylla, P. pauciflora Roem. & Schult., P. pratensis L. subsp. irrigata (Lindm.) H. Lindb., P. puberula Steud., P. pubiflora Benth., P. subcaerulea Sm., P. subspicata, and P. trachyphylla Pilg. are lectotypified, P. mulalensis is neotypified, and P. trachyphylla is epitypified. Four species are exotic and introduced from Europe: P. annua, P. infirma, P. pratensis, and P. trivialis L. We provide a key, descriptions, illustrations, distribution and habitat information, vouchers, and notes for each species.