Poa annua L.
  • Sp. Pl.
  • Pastillo de invierno

This taxon is accepted by Poaceae
Notes: More details could be found in The Plant List v.1.1. Originally in The Plant List v.1.0

General Description

1. Poa annua L., Sp. Pl. 68 (1753). Tipo: Europa.

Por R.W. Pohl y G. Davidse.

Anuales cespitosas. Tallos 5-35 cm, erectos y fasciculados, o decumbentes en sitios húmedos. Hojas glabras; lígula 1-4 mm; láminas 5-11 cm x 1-4 mm, aplanadas, las láminas basales blandas, patentes. Panícula 1.5-11 x 1-5 cm, piramidal, abierta; ramas 1-2 en el nudo más inferior, patentes, desnudas en el 1/10-1/2 inferior. Espiguillas 4-5.5 mm, agrupadas; gluma inferior 1.5-2.7 mm, 1-nervia; gluma superior 1.5-2.7 mm, 3-nervia; flósculos 2-6; lemas 2.6-3.8 mm, las nervaduras y el callo pelosos; páleas pelosas en las quillas. 2n = 28. Áreas húmedas. Ch (Breedlove y Davidse 54708, MO); G (Smith 833, ISC); H (Pohl y Davidse 11957, MO); ES (Montalvo 4808, MO); N (Moreno 517, MO); CR (Pohl y Davidse 10508, ISC); P (Hammel 1409, ISC). 1000-3800 m. (Cosmopolita; presumiblemente introducida de Europa.)

Annuals, sometimes over wintering, infrequently stoloniferous. Culms loosely tufted, erect or oblique, often decumbent, often geniculate, soft, 6–30(–45) cm tall, smooth, nodes 1 or 2(or 3), 1(or 2) exserted. Leaf sheath slightly compressed, thin, smooth, uppermost closed for ca. 1/3 of length; blade light to dark green, flat or folded, thin, 2–12 cm × (0.8–)1–3.5 mm, margins slightly scabrid, apex acutely prow-tipped; ligules 0.6–3 mm, abaxially smooth, glabrous, apex obtuse, margin irregularly dentate, smooth. Panicle open, moderately congested, broadly ovoid to pyramidal, (1–)3–10 cm, as long as wide; branches ascending, spreading, or a few reflexed, 1 or 2(–3) per node, smooth, longest with usually 3–5 spikelets in distal 1/2. Spikelets ovate to oblong, dark to light green, (3–)4–5.5 mm, florets 3–5, distal fertile florets often female; vivipary absent; rachilla internodes 0.5–1.5 mm, smooth, glabrous, hidden or exposed; glumes unequal, smooth or rarely keeled with hooks, lower glume lanceolate and acute to subflabellate and obtuse, 1.5–2(–3) mm, 1-veined, upper glume elliptic, 2–3(–4) mm, 3-veined, the margin angled; lemmas ovate, 2.2–3.5 mm, apex and margins broadly membranous, intermediate veins prominent, keel and marginal, and usually intermediate, veins villous in the lower 1/2, rarely glabrous throughout; callus glabrous; palea keels smooth, densely pilulose to short villous. Anthers 0.6–1 mm, usually at least 2 × as long as wide, or vestigial. Fl. Apr–May, fr. Apr–Jul. 2n = 28.

Por Richard W. Pohl y Gerrit Davidse

Poa annua L., Sp. Pl. 68. 1753.

Anuales cespitosas; tallos 5–35 cm de largo, erectos y fasciculados, o decumbentes en sitios húmedos; plantas hermafroditas. Hojas glabras; márgenes de las vainas libres; lígula una membrana 1–4 mm de largo; láminas lineares, 5–11 cm de largo y 1–4 mm de ancho, aplanadas, el ápice cóncavo, navicular, las láminas basales blandas, patentes. Panícula terminal, 1.5–11 cm de largo y 1–5 cm de ancho, piramidal, abierta, ramas 1–2 en el nudo más inferior, patentes, desnudas en el 1/10–1/2 inferior; espiguillas 4–5.5 mm de largo, agrupadas, comprimidas lateralmente, con varios flósculos; desarticulación por encima de las glumas entre los flósculos; gluma inferior 1.5–2.7 mm de largo, 1-nervia, gluma superior 1.5–2.7 mm de largo, 3-nervia; flósculos 2–6, bisexuales; lemas 2.6–3.8 mm de largo, las nervaduras y el callo pilosos; páleas pilosas en las quillas. Fruto una cariopsis; hilo linear.

Rara, nebliselvas, zona norcentral; 800–1500 m; fl y fr may, oct; Guzmán 2073, Moreno 517; cosmopolita, presumiblemente introducida de Europa. Género con ca 500 especies, cosmopolita en regiones árticas y templadas, y en grandes altitudes en los trópicos.

Soft, erect or decumbent-spreading annual; culms flattened, commonly 5-20 cm. high, glabrous; sheaths thin with hyaline margins, mostly longer than the internodes; ligule hyaline, about 5 mm. long; blades flat, mostly 5-10 cm. long, 1-3 mm. wide, the margins scabrous; panicle 3-10 cm. long, open with rather short ascending to spreading branches; spikelets short-pedicelled, crowded, 3- to 6-flowered; first glume 1.5-2 mm., the second 2-2.5 mm. long; lemmas about 3 mm. long, subobtuse, distinctly nerved, densely pubescent on the nerves, not webbed at the base.

Plantas 6–25(–35) cm, cespitosas, los talloserectos a decumbentes. Hojas con lígula 1.5–4 mm;lámina 4.5–10(–11.5) cm × 1–4 mm. Infl. 2–9 cm,abierta, verde, las ramas patentes. Espiguillas 4.5–5.5 mm; glumas 1–3-nervadas, la superior 1.5–2.5 mm;lemas 2.5–3.8 mm, las nervaduras pubescentes, elcallo glabrado a ± piloso.

"Tufted annual with few–several decumbent to ascending or seldom erect culms to 3 dm, sometimes rooting at the lower nodes; sheaths loose; blades soft, 2–3 mm wide; infl ovoid, 2–8 cm, with few ascending branches bearing rather crowded spikelets above the middle; spikelets green, 3–5 mm, 3–6-fld; glumes broadly lanceolate, acute, scarious-margined, indistinctly veined, the first 1.5–2.4 mm, the second 1.8–2.8 mm; lemmas thin, elliptic, 5-veined, obtuse, ± hairy on the veins only, not webbed, the lowest one 2.4–3.4 mm; anthers 0.8–1 mm; 2n=14, 28. Native of Eurasia; abundant in moist soil nearly throughout the U.S. and n. to Lab. and Alas.; often a lawn-weed."


Loosely tufted annual up to about 15 cm. high.

Distribution Map

  • Introduced distribution
Introduced into
  • Southern America Brazil Paraní
  • Rio Grande do Sul
  • Santa Catarina
  • Rio de Janeiro
  • São Paulo

 Information From

MBG Floras Images
Flora images. Missouri Botanical Garden. Accessed on Jun. 2018.
  • A Missouri Botanical Garden
Brazilian Flora 2020 project - Projeto Flora do Brasil 2020
Brazil Flora G (2014): Brazilian Flora 2020 project - Projeto Flora do Brasil 2020. v393.147. Instituto de Pesquisas Jardim Botanico do Rio de Janeiro. Dataset/Checklist. doi:10.15468/1mtkaw
  • B Group Brazil Flora, REFLORA Program
New York Botanical Garden
Descriptions of plants should be attributed to the full citation for each individual article, chapter or book that is the source for each record, which should include the authors of original publication.
  • C Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
Manual de Plantas de Costa Rica
Hammel, B. E.; Grayum, M. H.; Herrera, C.; Zamora, N. Manual de Plantas de Costa Rica. Missouri Botanical Garden Press, 2003-2014
  • D Missouri Botanical Garden
Flora Mesoamericana
Gerrit Davidse, Mario Sousa Sánchez, A. O. Chater, Universidad Nacional Autónoma de México. Instituto de Biología, Missouri Botanical Garden, Natural History Museum (London, England) UNAM, 1994
  • E Missouri Botanical Garden
Flora de Panama
Robert E. Woodson, Jr. and Robert W. Schery Annals of the Missouri Botanical Garden Vol. 67, No. 4 (1980), pp. ii-xxxiii
  • F Missouri Botanical Garden
Flora de Nicaragua
WD Stevens, CU Ulloa, A Pool and OM Montiel. Missouri Botanical Garden Press, 2001
  • G Missouri Botanical Garden
Plants Of the World Online Portal
  • H The Trustees of the Royal Botanic Gardens, Kew
Flora Of CHina @ efloras.org
'Flora of China @ eFloras (2008). Published on the Internet http://www.efloras.org/flora_page.aspx?flora_id=2 [accessed August 2016]' Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  • I Missouri Botanical Garden
  • J CC0 1.0 Universal (CC0 1.0).
World Flora Online consortium
World Flora Online Data. 2018.
  • K CC0 1.0 Universal (CC0 1.0).