Agrostis perennans (Walter) Tuck., Amer. J. Sci. Arts 45: 44. 1843, sensu lato.

Vigosa-Mercado, J. Luis, Delgado-Salinas, Alfonso, Alvarado Cardenas, Leonardo O. & Eguiarte, Luis E., 2023, Revision of the genus Agrostis (Poaceae, Pooideae, Poeae) in Megamexico, PhytoKeys 230, pp. 157-256 : 157

13. Agrostis perennans (Walter) Tuck., Amer. J. Sci. Arts 45: 44. 1843, sensu lato.

Figs 4L , 5L , 25

Cornucopiae perennans Walter, Fl. Carol. 74. 1788. Type: USA. South Carolina: at the intersection of cut off road and Fire Break 49 on Ft. Jackson Military Reservation, 11 Jul 1995, K.B. Kelly and J.B. Nelson 254 (neotype, designated by Ward (2007: 1099): GH (GH00247994 [image!])).

Agrostis cornucopiae Sm., Gent. Mag. 59: 873. 1789, nom. illeg. superfl.

Agrostis elegans (Walter) Salisb., Prodr. Stirp. Chap. Allerton 25. 1796.

Agrostis anomala Willd., Sp. Pl., 1(1): 370. 1797, nom. illeg. superfl.

Trichodium perennans (Walter) Elliott, Sketch Bot. S. Carolina 1(2): 99. 1816.

= Agrostis michauxii Zuccagni var. alpina Rupr., Bull. Acad. Roy. Sci. Bruxelles 52: 228. 1842, nom. nud. Type. Mexico. Oaxaca. Cordillera, 1840, H.G. Galeotii 5767 (holotype: P (P00740583 [image!]).

Agrostis scabra Willd. var. perennans (Walter) Alph. Wood, Class Book Bot. (3 ed.) 774. 1861.

= Agrostis schaffneri E. Fourn., Mexic. Pl. 2: 94. 1886. Agrostis schaffneri E. Fourn. ex Hemsl., Biol. Cent.-Amer., Bot. 3: 551. 1885, nom. nud. Type. MEXICO. Mexico City: Tacubaya, J.G. Schaffner 308 (lectotype, designated by Vigosa-Mercado (2022a: 3): P (P00740418 [image!]).

= Agrostis schaffneri E. Fourn. var. mutica E. Fourn., Mexic. Pl. 2: 94. 1886. Type. MEXICO. Mexico City: Tacubaya: J.G. Schaffner 1 (holotype: P (P00740419 [image!]).

= Agrostis tacubayensis E. Fourn., Mexic. Pl. 2: 95. 1886. Agrostis tacubayensis E. Fourn. ex Hemsl., Biol. Cent.-Amer., Bot. 3: 551. 1885, nom. nud. Type. MEXICO. Mexico City: Tacubaya, J.G. Schaffner 97 (holotype: P (P00740425 [image!])).

= Agrostis chinantlae E. Fourn., Mexic. Pl. 2: 96. 1886. Agrostis chinantlae E. Fourn. ex Hemsl., Biol. Cent.-Amer., Bot. 3: 550. 1885, nom nud. Type. MEXICO. Veracruz: Chinantla, May 1841, F.M. Liebmann 709 (lectotype, designated by Vigosa-Mercado (2022a: 2): C (C10016725 [image!]); isolectotypes: C (C10016726 [image!]), K (K000308372 [image!]), US (US00131733).*

Type.

Based on Cornucopiae perennans Walter.

Description.

Plants perennial, caespitose, sometimes developing short pseudostolons. Tillers extravaginal, with cataphylls. Culms 0.2-0.8(-1) m long, decumbent to erect, nodes 3-7(-10), glabrous, internodes glabrous, sometimes scaberulous. Leaves basal and cauline, the basal ones often drying at anthesis in mature individuals; sheaths 2-20 cm long, shorter or longer than the internodes, glabrous or scaberulous; ligules (0.5-)1.5-5(-7) mm long, longer than wide, dorsally scaberulous, rarely glabrous, apices acute to truncate, erose to lacerate, often ciliolate; blades 1-20 cm long, 1-6 mm wide, usually at least some blades larger than 2 mm wide, linear, usually flat, scaberulous on both surfaces. Panicles (3.5-)8-30(-40) cm long, (1-)2-20 cm wide, slightly contracted to open, dense to lax, lanceolate to ovate, long-exserted from the upper sheaths or partially included; branches ascending to spreading, rebranching slightly above mid-length, scaberulous, without spikelets near their base, inferior branches 4-12 cm long; pedicels 1-10 mm long, ascending to spreading, scaberulous. Spikelets (1.5-)1.8-3.2 mm long, greenish to purplish; glumes subequal to unequal, lanceolate, apices acute to shortly acuminate, 1-veined, scaberulous on the keel, lower glume (1.5-)1.8-3.2 mm long, upper glume 1.5-3.2 mm long; callus pubescent, with 2 bunches of trichomes; lemmas 1.3-2.2 mm long, elliptic, apices acute, entire to irregularly toothed, 5-nerved, veins inconspicuous to prominent, unawned, rarely awned from above mid-length, awn up to 1.5(-2) mm long, inserted above mid-length, straight or weakly geniculate; paleas absent or up to 0.2(-0.5) mm long, veinless, glabrous; anthers 3, 0.4-1 mm long. Caryopsis 1-1.9 mm long, elliptic: endosperm liquid to soft. 2n= 42 ( Harvey 2007).

Anatomy and micromorphology.

Leaf blades flat in transversal section; adaxial furrows shallow to deep, wide; adaxial ribs rounded; keel absent; first order bundles circular in outline, sheath interrupted abaxially, sometimes also adaxially, abaxial and adaxial sclerenchyma in strands or 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, pointed to rounded; colorless cells absent (Fig. 22J-L ). Lemmas with transversal thickenings oblong, wider than the unthickened portion of the wall; prickle hairs absent, or abundant to scarce (Fig. 7L ).

Distribution and habitat.

Agrostis perennans sensu lato is distributed from Alaska to Patagonia, in Argentina and Chile, and also in the West Indies ( Sylvester et al. 2020a). In the study zone, this species has been collected in Mexico City and the Mexican states of Chiapas, Chihuahua, Durango, Guanajuato, Guerrero, Hidalgo, Jalisco, México, Michoacán, Morelos, Oaxaca, Puebla, Querétaro, Tlaxcala, Veracruz, and Zacatecas; in the Guatemalan departments of Alta Verapaz, Baja Verapaz, Huehuetenango, Quetzaltenango, Quiché and San Marcos; in the Honduran state of Ocotepeque (Fig. 26A ). It has also been reported from the Mexican states of Coahuila and San Luis Potosí ( Dávila et al. 2018; Sánchez-Ken 2019), but no specimen from these states have been found. Records from the southern USA, in California, Arizona, New Mexico and Texas, appear to be misidentified specimens of A. scabra ( Harvey 2007). This species grows in open areas of temperate forests, with conifers and Quercus , in cloud forests, stream edges, roadsides, and often in marshy places, between 622-3847 m a.s.l. (Fig. 27A ).

Phenology.

Specimens with spikelets have been collected year round, but most of them between the months of July and October (Fig. 28A ).

Commentaries.

Agrostis perennans is a widespread and variable species. It is considered a “dustbin” taxon ( Sylvester et al. 2020a), which includes plants with basal and cauline leaves, usually flat leaf blades, more or less open panicles, usually unawned lemmas, and absent or minute paleas. More studies are necessary to clarify the relationships of the plants that have been included under this name, thus a wide circumscription of this species is adopted in this work.

Plants examined from the study zone fit well in A. perennans sensu lato, but at least three forms were observed: 1) fragile plants with open panicles; 2) more robust plants with open panicles; 3) robust plants with slightly contracted, denser panicles, and sometimes awned lemmas. The plants of the latter form have been called A. schaffneri , but despite the form of the panicles, no differences have been found in other characters, such as leaf anatomy and lemma micromorphology thus, this name is considered a synonym of A. perennans sensu lato.

Young plants of A. perennans sensu lato often have more conspicuous basal leaves and are confused with A. scabra , but differ from it in the leaf blades often greater than 2 mm wide, branches rebranching slightly above mid-length, and spikelets not clustered (vs. leaf blades up to 2(-3) mm wide, branches of the panicle usually rebranching in the upper third, with the spikelets usually clustered at the tips in A. scabra ).

Agrostis perennans sensu lato is often confused with several species distributed in the study zone, which share several macromorphological, leaf blade anatomy, and lemma micromorphology characters. These species are A. bourgaei , A. calderoniae , A. ghiesbreghtii , A. hyemalis , A. laxissima , A. idahoensis , A. perennans , A. scabra , A. subrepens , and A. turrialbae . In the identification key provided in this work, a reasonably good separation of the mentioned species was reached using a combination of characters.

Conservation status.

Agrostis perenanns is a common and widespread species in the study zone. It is represented by 229 collections, with several populations occurring in 18 protected areas. The EOO is 992,915 km2 and the AOO is 700 km2. Following the IUCN criteria, the preliminary assessment category is Least Concern (LC).

Representative specimens examined.

Mexico. Guatemala. Alta Verapaz: Municipio Cobán, Chicu’sha, 8 km al SO de Cobán, [15.43333333°N, 90.45°W], 1400 m alt., 22 Jul 1988, P. Tenorio 14646 (CIIDIR, MEXU [*]). Baja Verapaz: Municipio Salamá, 6 km al SO de Chilascó, [15.13333333°N, 90.11666667°W], 1700 m alt., 24 Jul 1988, P. Tenorio 14842 (CIIDIR, MEXU [*], US). Honduras. Ocotepeque: Municipio Belén de Gualcho, cordillera de Celaque, Cruz Alta, 3 mi N of Belén Gualcho long road to Cucuyagua [14.50722222°N, 88.785°W], 1890 m alt., 23 Jun 1994, G. Davidse et al. 35319 (MEXU). Mexico. Chiapas: Municipio Amatenango del Valle, NE slope of Zontehuitz near summit, [16.49659°N, 92.45225°W], 2130 m alt., Jan 1965, D.E. Breedlove and P.H. Raven 8119 (US). Municipio Unión Juárez, Volcán Tacaná, 500 m al E de Talquián, [15.09306218°N, 92.08369755°W], 1700 m alt., 26 Apr 1987, E. Martínez and A. Reyes 20291 (MEXU [*]). Chihuahua: Municipio Casas Grandes, near Colonia Garcia in the Sierra Madres, [29.97622543°N, 108.3352935°W], 2286 m alt., 22 Aug 1899, C.H.T. Townsend and C.M. Barber 276 (US). Durango: Municipio Durango, 5 mi W of Llano Grande along Durango-Mazatlán highway, [23.86°N, 105.25°W], 2500 m alt., 9 Sep 1967, J.R. Reeder and C.G. Reeder 4908 (MEXU, US). Guanajuato: Municipio San Felipe, club campestre El Vergel de la Sierra, [21.38504722°N, 101.6354389°W], 2627 m alt., 14 Jul 1997, J. Macías 898a (MEXU). Guerrero: Municipio General Heliodoro Castillo, cerro Teotepec, [17.46666667°N, 100.2166667°W], 3350 m alt., 5 Dec 1963, J. Rzedowski 18168 (ENCB). Hidalgo: Municipio Omitlán de Juárez, Santa Elena, km 15 de la carretera federal 105 Pachuca-Huejutla, [20.15722222°N, 98.65833333°W], 2640 m alt., 14 Jul 1994, J.P. Pérez 141 (MEXU [*]). Municipio Tepeapulco, cerro Santa Ana, [19.764°N, 98.5293°W], 2850 m alt., 8 Sep 1976, A. Ventura 2082 (FCME [**], MEXU, UAMIZ, XAL). Jalisco: Municipio San Gabriel, NW slopes of Nevado de Colima, above Jazmín, barranca near upper end of water-line 2-3 km above settlement of El Isote, [19.65°N, 103.7°W], 2600-2800 m alt., 26 Mar 1949, R. McVaugh 10048 (MEXU, US). México: Municipio Amecameca, km 18 de la carretera Amecameca-Tlamacas, [19.0917039°N, 98.67702965°W], 3400 m alt., 14 Jan 1982, R. Sánchez 81 (CIIDIR, IEB, MEXU). Municipio Ocuilan, carretera Santa Martha-Zempoala, km 2-14, [19.05°N, 99.33333333°W], 2900 m alt., 1 Aug 1987, J. Castañeda 280 (MEXU [*]). Mexico City: Alcaldía Magdalena Contreras, Eslava, [19.291667°N, 99.246389°W, 2530 m alt.], 19 Sep 1938, E. Lyonnet 2532 (CHAPA, MEXU, US). Los Dinamos, 2800 m alt., 27 Aug 1979, A. Ventura 3506 (FCME [*], MEXU, UAMIZ, XAL). Alcaldía Tlalpan, top of cerro Ajusco, [19.2069°N, 99.2597°W], 3937 m alt., 12 Jul 1959, J.H. Beaman 2794 (US). Michoacán: Municipio Erongarícuaro, 1 km al SE de Zínciro, sobre el camino a Eronguarícaro, [19.66463889°N, 101.7333194°W], 2400 m alt., 2 Nov 1989, J. Rzedowski 49202 (CHAPA, CIIDIR, MEXU). Municipio Salvador Escalante: alrededores de San Gregorio, [19.39238889°N, 101.5304389°W], 2650 m alt., 14 Sep 1988, E. Pérez-Calix 205 (CHAPA, CIIDIR, IBUG, IEB, MEXU [*,**], TEX). Morelos: Municipio Tlalnepantla, 2 km al S de CICITEC, Tlalnepantla, [19.06036734°N, 98.96226062°W], 2750 m alt., 26 Mar 1981, G. Ayala 19 (MEXU [*]); carretera Milpa Alta-Oaxtepec, camino viejo al CICITEC, [19.064835°N, 98.927786°W], 2770 m alt., 21 Oct 1993, A. Miranda et al. 881 (MEXU); Oaxaca: Municipio San Juan Yaeé, Santa María Lachichina, [17.43962564°N, 96.285451°W], 2700 m alt., 15 Apr. 2003, A. Flores s.n. (CHAPA, MEXU [*]). Municipio San Miguel Suchixtepec, campamento Río de Molino, 4 km al SO de San Miguel Suchixtepec, [16.07677493°N, 96.47030551°W], 2250 m alt., 21 Sep 1965, J. Rzedowski 21046 (CHAPA, IBUG, MEXU). Puebla: Municipio Hueytamalco, El Popual, [20.027434°N, 97.274122°W], 1450 m alt., 3 Jun 1970, F. Ventura 1211 (IBUG, MEXU). Municipio Tlatlauquitepec, Xucayucan, [19.89833333°N, 97.47833333°W], 1600 m alt., 5 Oct 1998, J.L. Contreras 5886 (MEXU [*,**]). Querétaro: Municipio Colón, parte más alta del cerro Zamorano, [20.93305556°N, 100.1797222°W], 3200-3270 m alt., 13 Nov 1971, J. Rzedowski and R. McVaugh 459 (US). Tlaxcala: Municipio Huamantla, ladera N del cerro de La Malinche, [19.23705301°N, 98.01935192°W], 3800 m alt., 12 Oct 1986, L. Aragón et al. 46 (MEXU). Veracruz: Municipio Jilotepec, El Rincón, 19.60694444°N, 96.94444444°W, 1100 m alt., 19 Jun 1993, M.J. Lizama 26 (CHAPA, CIB, MEXU [*], XAL); comunidad Jilotepec, camino La Cuesta-Zacatal, 19.61527778°N, 96.95138889°W, 1500 m alt., 12 Oct 1993, M.J. Lizama 81 (CHAPA, CIB, MEXU [*,**], XAL); comunidad El Pueblito, camino a La Concepción, 19.59722222°N, 96.925°W, 622 m alt., 17 Jan 1996, M.J. Lizama 622 (CIB). Zacatecas, Municipio Monte Escobedo, límite entre los estados de Zacatecas y Jalisco, por la terracería a Mezquitic, [22.31821648°N, 103.5748305°W], 2190 m alt., 21 Sep 1989, J. Balleza 2266b (CHAPA). See Suppl. materials 2, 3 for additional examined specimens.

Figures

Figure 4. Florets of Agrostis species observed with SEM A A. bourgaei B A. calderoniae C A. capillaris D A. elliottiana E A. exarata F A. ghiesbreghtii G A. gigantea H A. hyemalis I A. laxissima J A. microphylla K A. pallens L A. perennans M A. scabra N A. stolonifera O A. subpatens P A. subrepens Q A. tolucensis R A. turrialbae S A. variabilis. Scale bars: 0.3 mm.

Figure 5. Calluses of Agrostis species observed with SEM A A. bourgaei B A. calderoniae C A. capillaris D A. elliottiana E A. exarata F A. ghiesbreghtii G A. gigantea H A. hyemalis I A. laxissima J A. microphylla K A. pallens L A. perennans. Scale bars: 50 μm.

Figure 7. Lemma surface of Agrostis observed with SEM A A. bourgaei B A. calderoniae C A. capillaris D A. elliottiana E A. exarata F A. ghiesbreghtii G A. gigantea H A. hyemalis I A. laxissima J A. microphylla K A. pallens L A. perennans. Scale bars: 15 μm.

Figure 22. Leaf blade anatomy in transversal section of Agrostis species, in general view, and details of lateral bundles. A - C A. laxissima D - F A. microphylla G - I A. pallens J - L A. perennans. Scale bars: 0.1 mm.

Figure 25. Agrostis perennans A whole plant B ligular area C spikelet E floret, abaxial view F floret, adaxial view. Based on Ventura 1211 (MEXU). Scale bars: 3 cm (A); 5 mm (B); 0.5 mm (C); 0.3 mm (D, E).

Figure 26. Map of known geographic distribution of Agrostis species, based on herbarium specimen data A A. perennans B A. scabra C A. stolonifera D A. subpatens E A. subrepens F A. tolucensis.

Figure 27. Elevation histograms of Agrostis species A A. perennans B A. scabra C A. stolonifera D A. subpatens E A. subrepens F A. tolucensis G A. turrialbae H A. variabilis.

Figure 28. Phenology histograms of Agrostis species A A. perennans B A. scabra C A. stolonifera D A. subpatens E A. subrepens F A. tolucensis G A. turrialbae H A. variabilis.