Agrostis stolonifera L.
Descripción
Plants perennial, stoloniferous. Tillers extravaginal, with cataphylls. Stolons up to 1(–2) m long. Culms (8–)15–60 cm long, erect, decumbent at the base, nodes (2–)3–7, glabrous, lower nodes rooting, internodes glabrous. Leaves mostly cauline; sheaths 2.5–8 cm long, usually shorter than the internodes, glabrous or scaberulous; ligules 1–7 mm long, longer than wide, dorsally scaberulous, apices rounded to truncate, erose to lacerate; blades (1–)2–10 cm long, (1–)2–6 mm wide, linear, flat, becoming convolute when dry scaberulous on both surfaces. Panicles (3–)4–20 cm long, 0.5–3 cm wide, open at anthesis, becoming contracted, dense, lanceolate, sometimes spiciform; branches appressed to ascending, branching from below mid-length, scaberulous, inferior branches 2–6 cm long, lateral branches often with spikelets near their base; pedicels 0.5–3.3 mm long, appressed to ascending, scaberulous. Spikelets 1.6– 2 (–3) mm long, greenish, often tinged with purple; glumes subequal to unequal, lanceolate, apices acute to shortly acuminate, 1-veined, scaberulous on the keel, lower glume 1.6–2 (–3) mm long, upper glume 1.4–2(1.6–2 (–3) mm long; callus puberulous, with 2 bunches of short trichomes, sometimes inconspicuous; lemmas 1.4–2 mm long, elliptic to oblong, apices entire, acute to obtuse, sometimes toothed, 3(5)-veined, veins inconspicuous or prominent distally, unawned, rarely awned from above mid-length, awn up to 1.5 mm long, inserted 0.8–1.5 mm above the base, straight or weakly geniculate; paleas present, 0.7– 1.4 mm long, 2-veined, glabrous; anthers 3, 0.9–1.5 mm long. Caryopsis 0.9–1.3, elliptic; endosperm solid. 2n= 28, 35, 42 (Harvey 2007).
Anatomy and micromorphology. Leaf blades flat to convolute in transversal section; adaxial furrows medium-sized to deep, wide; adaxial ribs rounded; keel absent; first order bundles circular to slightly elliptical in outline, sheath interrupted adaxially and abaxially, abaxial and adaxial sclerenchyma in girders, narrowing towards the bundle; second order bundles circular in outline, sheath interrupted abaxially, abaxial and adaxial sclerenchyma in strands; intercostal sclerenchyma absent; leaf margins with well-developed sclerenchyma caps, rounded; colorless cells absent (Fig. 31D, E). Lemmas without transversal thickenings, prickle hairs abundant to scarce (Fig. 32B).A
Anatomy and micromorphology. Leaf blades flat to convolute in transversal section; adaxial furrows medium-sized to deep, wide; adaxial ribs rounded; keel absent; first order bundles circular to slightly elliptical in outline, sheath interrupted adaxially and abaxially, abaxial and adaxial sclerenchyma in girders, narrowing towards the bundle; second order bundles circular in outline, sheath interrupted abaxially, abaxial and adaxial sclerenchyma in strands; intercostal sclerenchyma absent; leaf margins with well-developed sclerenchyma caps, rounded; colorless cells absent (Fig. 31D, E). Lemmas without transversal thickenings, prickle hairs abundant to scarce (Fig. 32B).A
Forma de crecimiento
HierbaA
Forma de vida
TerrestreA
Nutrición
AutotróficaA
Floración
Jun–AugA
Ejemplar revisado
Type. Herb. A. van Royen s.n. (lectotype, designated by Widén (1971: 77): L (L0059234 [image!])).
Specimens examined. Mexico. Baja California: Municipio Ensenada, Sierra San Pedro Mártir, La Grulla, [30.88916°N, 115.46223°W], 2100 m alt., 21 Aug 1967, R. Moran and R.F. Thorne 14466 (SD). Veracruz: Municipio Tatatila, camino Las Vigas–Tatatila, 1 km antes de La Mancuerna, 19.675°N, 97.125°W, 1800 m alt., 7 Jun 1996, H.R. Sandoval and B.V. Hernández 370 (CIB), 380 (CIB, MEXU [*, **], XAL).A
Specimens examined. Mexico. Baja California: Municipio Ensenada, Sierra San Pedro Mártir, La Grulla, [30.88916°N, 115.46223°W], 2100 m alt., 21 Aug 1967, R. Moran and R.F. Thorne 14466 (SD). Veracruz: Municipio Tatatila, camino Las Vigas–Tatatila, 1 km antes de La Mancuerna, 19.675°N, 97.125°W, 1800 m alt., 7 Jun 1996, H.R. Sandoval and B.V. Hernández 370 (CIB), 380 (CIB, MEXU [*, **], XAL).A
Distribución
México (país) not native - invasiveA: Baja California PresenteA; Chiapas PresenteA; Chihuahua PresenteA; Coahuila de Zaragoza PresenteA; Distrito Federal PresenteA; Hidalgo PresenteA; Jalisco PresenteA; Michoacán de Ocampo PresenteA; México PresenteA; Nuevo León PresenteA; Puebla PresenteA; Tlaxcala PresenteA; Veracruz de Ignacio de la Llave PresenteA, Norteamérica al N de México PresenteA
Elevación
1800 – 2100 mA
Ecología y Hábitat
Introduced. Agrostis stolonifera is native to Eurasia and northern North America (Harvey 2007). In the study zone, this taxon has been collected from the Mexican states of Baja California and Veracruz (Fig. 26C). Agrostis has also been reported from the southern United States and Mexico City, also from the states of Chiapas, Chihuahua, Coahuila, Hidalgo, Jalisco, México, Michoacán, Nuevo León, Puebla, and Tlaxcala (Dávila et al. 2018; Sánchez-Ken 2019), but no specimens from these states have been seen. This taxon has been collected on stream edges and open areas of pine forests (Fig. 27C). There are more records of this species in the study zone, on databases (GBIF 2023d), but not all of them have images, and thus we were unable to confirm their identity.A
Tipo de vegetación
Bosque de pinoA
Conservación
Since Agrostis stolonifera is an introduced taxon in the study zone, its conservation status is considered as Least Concern (LC) IUCN (2012).A
Estatus del taxón
(A) Como definida actualmente, probablemente una entidad natural (monofilética)A
Discusión taxonómica
Agrostis stolonifera is often confused with A. gigantea (see the note under the description of that species). This is a variable species and several infraspecific taxa have been recognized (e.g., Pohl and Davidse 1994; Rúgolo and Molina 1997). The plants from the study zone fit well in A. stolonifera var. palustris, which is distinguished from the typical variety in the more contracted panicles, up to 3 cm wide, and smaller spikelets of 1.6–2 mm long (vs. more open panicles, up to 6 cm wide, spikelets 2–2.5 mm long in the typical variety). The width of the panicles could be related to the age of the panicles, since they become contracted after anthesis, and thus varieties are not recognized here.
This taxon is also confused with Polypogon viridis (Gouan) Breistr., from which it is distinguished in the spikelets disarticulating above the glumes (vs. disarticulation below the glumes, with a pedicel fragment in P. viridis).
Phenology. Specimens with spikelets have been collected from June to August (Fig. 28C).A
This taxon is also confused with Polypogon viridis (Gouan) Breistr., from which it is distinguished in the spikelets disarticulating above the glumes (vs. disarticulation below the glumes, with a pedicel fragment in P. viridis).
Phenology. Specimens with spikelets have been collected from June to August (Fig. 28C).A
Bibliografía
A. Vigosa-Mercado, J. L., Delgadillo-Salinas, A., Alvarado-Cárdenas, L. O. & Eguiarte, L. E. 2023: Revision of the genus Agrostis (Poaceae, Pooideae, Poeae) in Megamexico. – PhytoKeys 230: 157-256. https://doi.org/10.3897/3897
C. SEMARNAT 2019: MODIFICACIÓN del Anexo Normativo III, Lista de especies en riesgo de la Norma Oficial Mexicana NOM-059-SEMARNAT-2010: 101 pp. – https://www.dof.gob.mx/nota_detalle.php?codigo=5578808&fecha=14/11/2019#gsc.tab=0 [accessed 2023-05-04 06:16]
D. Dávila, P., Mejía-Saulés, M. T., Soriano-Martínez, A. M. & Herrera-Arrieta, Y. 2018: Conocimiento taxonómico de la familia Poaceae en México. – Bot. Sci. 96 (3): 462-514
E. Harvey, M.J. 2007: Agrostis. In: Barkworth M.E., Capels K.M., Long S, Anderton L.K., Piep M.B. (Eds) Flora of North AMerica North of Mexico (Vol. 24) Oxford University Press, New York, 633-662. http//floranorthamerica.org/Agrostis
F. IUCN 2012: Red List Categories and Cirteria: Versión 3.1. Second edition. Internationl Union for Conservation of Nature, Gland Switzerland, 1-32. https://portals.iucn.org/librari/node/10315
G. Pohl, R. W. & Davidse, G. 1994: Agrostis, pp. 237-240. – In: Davidse, G., Sousa Sánchez, M. & Chater, A. O. (eds.), Flora Mesoamericana 6, pp. 1-543. – México D.F.: Universidad Nacional Autónoma de México
H. Rúgolo, Z.E. & Molina, A.M. 1997: Las especies del género Agrostis L. (Gramineae: Agrostideae) de Chile. Gayana. Botánica 54: 91-156
I. Sánchez-Ken, J. G. 2019: Riqueza de especies, clasificación y listado de las gramíneas (Poaceae) de México Species richness, classification and a checklist of the grasses (Poaceae) of Mexico. – Acta Bot. Mex. 126: e1379. https://doi.org/10.21829/abm126.2019.1379