Agrostis tolucensis Kunth, Nov. Gen. Sp. [H.B.K.] 1: 135. 1816

Sylvester, Steven P., Cuta-Alarcon, Lia E., Bravo-Pedraza, William J. & Soreng, Robert J., 2020, Agrostis and Podagrostis (Agrostidinae, Poaceae) from paramos of Boyaca, Colombia: synoptic taxonomy including a key to Colombian species, PhytoKeys 151, pp. 107-160 : 107

Agrostis tolucensis Kunth, Nov. Gen. Sp. [H.B.K.] 1: 135. 1816 Fig. 10

Agrostis tolucensis Willd. ex Steud., Syn. Pl. Glumac. 1: 164. 1855[1854], nom. inval.

= Agrostis glomerata (J. Presl) Kunth, Enum. Pl. [Kunth] 1: 219. 1833. Vilfa glomerata J. Presl, Reliq. Haenk. 1 (4-5): 239. 1830. Type: Peru. [ Huánuco] [Hab. in montanis Peruviae huanoccensibus], [1791; 1891 written on W isotype], T.P.X. Haenke s.n. [#196 written on W isotype] (holotype: [not found]; isotypes: HAL (HAL0106916 [image!]), PRC (PRC450953 [image!]), US (US00589472 fragm.), W (W0025326 [image!])).

= Agrostis hoffmannii Mez, Repert. Spec. Nov. Regni Veg. 18: 3. 1922. Type: Costa Rica. Irazu (holotype: [not found]; isotypes: [not found]).

= Agrostis nana var. andicola Pilg., Bot. Jahrb. Syst. 37 (5): 505. 1906. Type: Ecuador. Chimborazo: Chimborazo, N-Seite, Páramo-Region, 4500 m alt., July 1903, H. Meyer 146 (syntypes: JE (JE00020226 [image!]; JE00020228 [image!])); Napo: Antisana, in frigidis alpinis, 4600 m alt., July 1903, H. Meyer 145 (syntypes: JE (JE00020225 [image!]; JE00020227 [image!])).

= Agrostis nana var. aristata Griseb., Abh. Königl. Ges. Wiss. Göttingen 24: 294. 1879. Type: Argentina. Salta: Umgebungen des Nevado del Castillo [around the Nevado del Castillo], 10-15000 ft. [3048-4572 m alt.], 19-23 Mar. 1873, P.G. Lorentz & G.H.E.W. Hieronymus 82 (holotype: GOET (GOET006541 [image!]); isotypes: B, BAA (BAA00000724 [image!] fragm. ex B; BAA00000723 [image!] fragm. ex B), CORD (CORD00004693 [image!]), W (W19160036588 [image!]; W19160036664 [image!])).

= Agrostis virescens Kunth, Nov. Gen. Sp. [H.B.K.] 1: 135. 1816. Type: Mexico. Toluca, Sep., F.W.H.A. Humboldt & A.J.A. Bonpland s.n (holotype: P (P00669395 [image!]); isotypes: LE-TRIN (LE-TRIN1668.01; LE-TRIN1668.02), P (P00136912 [image!])).

Type.

Mexico. [prope Toluca et Islahuaca], F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: P (P00669394 [image!]); isotypes: B (B-W1704), BAA (BAA00000235 [image!] fragm. ex P), BM, K (microfiche), LE-TRIN (LE-TRIN1660.01), P (P00136914 [image!]; P00136915 [image!]; P00740426 [image!]), US (US00156505! fragm. ex P)).

Description.

Perennial herbs, tussock-forming or laxly to densely tufted, usually with short ascending rhizomes. Tillers extravaginal and intravaginal, with cataphylls usually present. Culms (3-)5.5-51(-80) cm tall, erect or arching, fairly firm, with 0(-2) nodes exerted at flowering, smooth or rarely scaberulous. Leaves mostly basal or more-or-less evenly spread along the culm, glabrous, smooth or scabrous; ligules 2-4(-6.2) mm long, of upper culm usually longer than those of lower culm and tillers, truncate to triangular, moderately to strongly decurrent with the sheath, abaxial surface usually scabrous, rarely scaberulous or smooth; blades 2.5-19 cm long, 1-3(-5) mm wide, at least in the upper culm filiform, folded or flat, usually lax to sometimes firm, sometimes basal and tiller blades involute or convolute and firm to rigid, smooth throughout or scabrous only on the margin and sometimes veins, apices blunt or slightly naviculate-acute. Panicles (1-)2-15 cm long, 0.1-1.5 cm wide, moderately to densely congested, sub-spikelike or spikelike, sometimes interrupted towards the base, subincluded in the basal foliage or slightly to greatly exerted, lateral branches with spikelets almost to the base, upper lateral branches short and held close to the central inflorescence axis, central axis and panicle branches scabrous; pedicels 0.7-3(-4.5) mm long, usually shorter than their spikelets, not or slightly dilated at their apex, scabrous. Spikelets (not including awn, if present) 2-3(-3.6) mm long; glumes equal or subequal, 1-veined, lower glume keel and surface usually scabrous at least in the distal half, infrequently smooth throughout, upper glume keel and surface scabrous for almost their entirety to at least in the distal half or surface sometimes smooth throughout, apices acute or acuminate; floret ½ -2/3(-3/4) the length of the glumes; calluses lightly pilose with 2 sparse tufts of short hairs on the lateral sides; lemmas 1.4-2.8 mm long, glabrous, smooth, 5-veined, apex truncate, denticulate, usually awned, awn 2-3.5 mm long, inserted in the lower, middle, or upper 1/3 of the dorsal keel, exerted from the glumes, geniculate, twisted, very rarely muticous or with a short straight awn, <1 mm long, inserted in the upper half of the lemma (see notes below regarding A. glomerata ); paleas absent or 0.1-0.2 mm long, < ¼ the length of the lemma; rachilla absent; anthers 0.5-1 mm long.

Distribution and ecology.

Mexico, Guatemala, Costa Rica, Panama, Colombia, Venezuela, Ecuador, Peru, Bolivia, Chile, Argentina. High-elevation open grasslands and forests, 2700-4900 m alt.

Other specimens examined.

Colombia. Sin loc., 1760-1808, J.C. Mutis 5521 (US1561906). Boyacá: Munic. Arcabuco, Páramo El Valle, 5.7445833N, 73.37118W, 3744 m alt., 16 Nov. 2017, S.P. Sylvester 3081 (FMB, K, US); Munic. Arcabuco, Páramo El Valle, just below high point of ridge to the W of site 14, 5.75436N, 73.38722W, 3747 m alt., páramo seco dominado por Espeletia barclayana [Cuatrec.], 16 Nov. 2017, S.P. Sylvester 3083 (K, US); Munic. Belén, Páramo de La Rusia, border with Santander, Boqueron El Consuelo, unprotected private land, 6.03598N, 72.57056W, 3975 m alt., páramo with limited grazing by horses and rodents with Espeletia brachyaxiantha [S. Díaz] and E. annemariana [Cuatrec.], steep slope on rock outcrop, 23 Nov. 2017, M. Vorontsova 2260 (FMB, K, SI, US); Munic. Belén, Páramo de La Rusia, near Páramo Le Consuelo, unprotected private land, somewhat disturbed páramo on top of the ridge, 6.02416N, 72.57242W, 3894 m alt., grazed by horses and rodents, with Espeletia boyacensis , 22 Nov. 2017, M. Vorontsova 2231 (K, UPTC, US); Munic. Chiscas, Páramo de Chacaritas, asociado a rocas de 4 m de altura, 6.62227N, 72.3904W, 4192 m alt., 4 Mar. 2018, S.P. Sylvester 3115 (US); Munic. Chiscas, Páramo de Chacaritas, límites entre páramo y superpáramo, 6.62865N, 72.3944W, 4064 m alt., 4 Mar. 2018, S.P. Sylvester 3104 (FMB, K, US); Munic. Chiscas, Páramo El Peñon, Chiscas, 6.63012N, 72.40073W, 4172 m alt., 5 Mar. 2018, S.P. Sylvester 3152 (UPTC); Munic. Chiscas, Páramo El Peñon, Chiscas, 6.62876N, 72.40283W, 4255 m alt., vegetación de pajonal frailejonal, páramo húmedo, 5 Mar. 2018, S.P. Sylvester 3153 (FMB, K, US); Munic. Mongua, Páramo de Ocetá, Valle de Laguna Negra, 5.69525N, 72.79133W, 3694 m alt., 29 Nov. 2017, L.E. Cuta-Alarcón 355 (FMB, K, UPTC, US); Munic. Mongui, Vereda Vallado, Sector La Pedrisca, Páramo de Ocetá, 5.69969N, 72.80891W, 3751 m alt., 30 Nov. 2017, L.E. Cuta-Alarcón 376 (FMB, US). Cauca: Macizo Colombiano, Valle de las Papas, alrededores de Valencia, [1.8831N, 76.6828W], 2910 m alt., 11 Sep.-1 Oct. 1958, Idrobo, Pinto & Bischler 3682A (US2540528). Cundinamarca: Páramo de Chisaca, [4.2747N, 74.2006W], 3750-3962 m alt., 5 Oct. 1966, T.R. Soderstrom 1312 (US3136708).

Notes.

Although in Bolivia ( Renvoize 1998) and austral South America ( Rúgolo de Agrasar 2012) A. tolucensis is mentioned to be notably rhizomatous, lateral tending rhizomes were not notable on specimens from the páramos of Boyacá, which had short, ascending rhizomes/pseudostolons and formed small tussocks or were laxly to densely tufted. Type specimens and original material of A. tolucensis and other species now considered synonyms of A. tolucensis , i.e. Agrostis glomerata , A. nana var. andicola , A. nana var. aristata , and A. virescens , also had either short ascending rhizomes or lacked notable rhizomes, but with all having obvious extravaginal cataphyllous shoots.

Discrepancy was sometimes also found in the form of the leaf blades, with specimens encountered in Boyacá, Colombia, and Venezuela sometimes having more rigid, convolute to folded, often recurved, basal leaf blades instead of the lax and filiform leaf blades more common to this species. These specimens did usually still have flat upper culm blades to help differentiate them from e.g. A. laegaardii (see notes on similar species below). While Renvoize (1998) and Rúgolo de Agrasar (2012) state the blades in A. tolucensis to be flat, folded, or filiform and generally lax, the type material also has fairly firm blades which are narrow and folded to slightly convolute and sometimes cylindrical in outline. Agrostis nana , here considered a synonym of A. tolucensis , also has more convolute, curved and rigid leaf blades.

Similar species.

See notes under A. foliata for how to differentiate from that species. Agrostis breviculmis and A. laegaardii bear similarities in having mainly basal, narrow, usually convolute, rigid, leaf blades and densely congested spikelike panicles that are usually short (<5 cm long), and spikelets with an absent or reduced palea < ¼ the length of the lemma. Agrostis tolucensis principally differs from these by the leaf blades being usually laxer and folded or flat, at least in the upper culm. However, as noted above, specimens can be found with convolute basal blades that makes distinguishing these species more difficult. In these instances, A. tolucensis can be differentiated from A. breviculmis by its larger spikelets 2-3(-3.6) mm long (vs. 1.5-2.1(-2.5 in Bolivia?; Renvoize 1998) mm long in A. breviculmis ), usually the presence of a well-developed geniculate and twisted awn inserted dorsally usually in the lower third of the lemma (lemmas very rarely muticous or with a short straight weak awn, <1 mm long, inserted in the upper ½; see notes on A. glomerata below) (vs. lemmas muticous or with a short straight weak awn inserted above the middle in A. breviculmis ), panicles generally wider, 1-15 mm wide (vs. 0.5-2(-6) mm wide in A. breviculmis ), and short prickle hairs on the glume keels (vs. coarse and shiny in A. breviculmis ). While A. laegaardii has characters of often larger spikelets and dorsally inserted awn, A. tolucensis can be differentiated from A. laegaardii by its extravaginal cataphyllous shoots and distinct ascending rhizomes with rhizome internodes usually> 7 mm long (vs. purely intravaginal innovations, without cataphyllous shoots or distinct ascending rhizomes, rhizome internodes <2 mm long in A. laegaardii ), generally wider panicles, 1-15 mm wide (vs. 0.5-2(-6) mm wide in A. laegaardii ), and short prickle hairs on the glume keels (vs. coarse and shiny in A. laegaardii ). Specimens can sometimes have laxer inflorescences that could lead to confusion with A. mertensii , but this species does not form small tussocks.

Agrostis meyenii , a species known from drier high-elevation puna grassland and pampa of Argentina, Chile and Bolivia ( Renvoize 1998; Rúgolo de Agrasar 2012), is similar in its overall appearance, usually being tufted and with rhizomes, having similar ligules and filiform or flat leaf blades, and having a condensed spikelike panicle with spikelets of similar size. Agrostis tolucensis can usually be differentiated from A. meyenii by the presence of an awn inserted in the lower third of the lemma, 2-3.5 mm long, twisted and bent and exerted from the glumes (vs. muticous or, if awn present, inserted in the middle or upper third of the lemma, to 1.2 mm long, straight or slightly flexuous in A. meyenii ). However, specimens akin to A. glomerata , a species described from Peru and here considered a synonym of A. tolucensis , can sometimes be found in Colombia, albeit not in the Cordillera Oriental, which have muticous lemmas or with a short straight awn inserted in the upper half of the lemma (e.g. Idrobo 3882a, Mutis 5521). These can be differentiated from A. meyenii by the plants being generally taller, 20-60 cm tall, condensed panicles often> 10 cm long that are often interrupted and with the central inflorescence axis notably wider compared to the lateral branches, and the pedicels, panicle branches, and sometimes central inflorescence axis, being notably scabrous. The blades of these are variable and can be filiform to flat and to 5 mm wide. The characteristic of notably scabrous pedicels, panicle branches, and sometimes central inflorescence axis of A. tolucensis are considered to be key in differentiating these from A. meyenii , which are usually smooth or exceptionally lightly scaberulous.

Figures

Figure 10. Agrostis tolucensis A spikelet, glumes in lateral view, floret in dorsal view, detached and raised above the glumes B whole plant. Images of Cuta-Alarcon 376 (FMB).