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

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 perennans (Walter) Tuck. s.l., Amer. J. Sci. Arts 45: 44. 1843 Fig. 8

Cornucopiae perennans Walter, Fl. Carol. [Walter] 74. 1788.

Agrostis cornucopiae Sm., Gentleman’s Mag. 59 (2): 873. 1789, nom. illeg. superfl., also Smith in Frasier, Short Hist. 2,pl. Nov. 25. 1789.

Agrostis cornucopiae Lam., Tabl. Encycl. 161. 1791, nom. illeg. superfl.

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

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

Trichodium decumbens (Walter) Michx., Fl. Bor.-Amer. (Michaux) 1: 42. 1803, nom. illeg. superfl.

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

Agrostis scabra var. perennans (Walter) Alph. Wood, Class-book Bot. (ed. 1861) 774. 1861.

= Agrostis fasciculata (Kunth) Roem. & Schult., Syst. Veg., ed. 15 bis [Roemer & Schultes] 2: 362. 1817. Vilfa fasciculata Kunth, Nov. Gen. Sp. [H.B.K.] 1: 139. 1816. Type: Ecuador. Pichincha, May, F.W.H.A. von Humboldt & A.J.A. Bonpland s.n. (holotype: P (P00669402 [image!]; isotypes: HAL (HAL0106915 [image!]), LE-TRIN (LE-TRIN1610.01 fragm. ex P), P (P00740549 [image!]; P00740548 [image!]), US (US556249 fragm. ex P)).

= Agrostis humboldtiana Steud., Nomencl. Bot. [Steudel], ed. 2. i. 40. 1840. Agrostis pulchella Kunth, Enum. Pl. 1: 223. 1833, hom. illeg., non Roth, 1817, nom. superfl. Agrostis elegans (Kunth) Roem. & Schult., Syst. Veg., ed. 15 bis [Roemer & Schultes] 2: 362. 1817, hom. illeg., non. Salisb. 1796. Vilfa elegans Kunth, Nov. Gen. Sp. [H.B.K.] 1: 139. 1816. Type: Ecuador. [Crescit in planitie Cochapamba, in regione temperata regni Quitensis, alt. 1340 hexap. Floret Majo] Herbier de Amerique equatoriale, A.J.A. Bonpland & F.W.H.A. von Humboldt 3010 (holotype: P (P00669401 [image!]); isotypes: BAA (BAA-Col. typus 4256), BM (BM000938529 [image!]; BM000938530 [image!]), LE-TRIN (LE-TRIN1644.01 ex hrbr. Humb.), P (P00740586 [image!]; P00740588 [image!]; P00740587 [image!])).

= Agrostis weberbaueri Mez, Repert. Spec. Nov. Regni Veg. 18 (1-3): 1. 1922. Type: PERU. Huacapistana and Monson, Weberbauer s.n. (holotype: [not found]; isotypes: [not found]). Many other heterotypic synonyms.

Type.

USA. South Carolina: Richmond County, Fort Jackson Military Reservation, found at the intersection of Cut Off Rd. and Fire Break 49, 11 July 1995, K.B. Kelly, Jr. & J.B. Nelson 254 (neotype, designated by Ward (2007: 1099): GH (GH00247994 [image!])).

Description.

Perennial herbs, laxly to densely tufted, sometimes stooling or with short ascending pseudostolons that have the appearance of rhizomes on herbarium sheets. Tillers extravaginal, with cataphylls present. Culms (21-)33-64(-100) cm tall, erect or decumbent to subgeniculate at their base, delicate to fairly firm, with 0-2(-3) nodes exerted at flowering, smooth to rarely scaberulous. Leaves mainly basal early in the flowering season but tending to become mostly cauline with maturity, glabrous, smooth or scaberulous; ligules 0.5-5(-7) mm long, of basal leaves and tillers 0.5-2.5 mm long, of upper culm 3-5(-7) mm long, truncate to obtuse-triangular, slightly to strongly decurrent with the sheath, abaxial surface scabrous to scaberulous, rarely smooth; blades (3-)6-15 cm long, (1-)1.5-3.5(-5) mm wide, usually flat or conduplicate and lax to slightly firm, sometimes involute and rigid in the basal leaves, smooth throughout or scaberulous on margins and sometimes surfaces, apices acute. Panicles (3.5-)10-22 cm long, 2-11 cm wide, open, lax, ovoid to pyramidal, slightly to usually greatly exerted from the basal foliage, lateral branches without spikelets near their base and for a large distance, long, ascending, spreading, to somewhat divergent and not held close to the central inflorescence axis, central axis and panicle branches smooth or lightly scaberulous; pedicels 1-4.5 mm long, usually longer than their spikelets, not or slightly dilated at their apex, smooth or lightly scaberulous. Spikelets (not including awn, if present) (1.5-)1.8-2.5(-3.2) mm long; glumes subequal, 1-veined, keels scabrous in the distal ½ -1/3, apices acute; floret usually 1/2-2/3 the length of the glumes, rarely longer; calluses lightly pilose with 2 sparse lateral tufts of short hairs; lemmas 1.5-2 mm long, glabrous, smooth, 5-veined, apex acute to more-or-less truncate, denticulate, muticous, mucronate or exceptionally with a short awn to 0.5 mm long (to 1.4-1.9 mm long in Argentina; Rúgolo de Agrasar 2012), inserted in the upper ( ½) 1/3 of the dorsal keel, usually not or rarely only slightly surpassing the glumes, straight, not twisted, weak and falling easily; paleas absent or to 0.5 mm long, usually < ¼ the length of the lemma; rachilla absent; anthers 0.7-1 mm long.

Distribution and ecology.

Stretching from Alaska, Canada and USA, through Central America and the Caribbean, to Argentina and Chile of South America. The species has an exceptionally large ecological amplitude, being found in maritime dunes, wetlands, and grasslands from sea level to> 4000 m alt.

Other specimens examined.

Colombia. Boyacá: Munic. Belén, Páramo de La Rusia, near Páramo El Consuelo, unprotected private land, somewhat disturbed páramo grazed by horses and rodents, with Espeletia boyacensis and E. discoides , near path, 6.02415N, 72.57289W, 3831, 22 Nov. 2017, M. Vorontsova 2247 (FMB, K, SI, UPTC, US); Munic. Duitama, Páramo de Agueros. junto a la casa, muy perturbado, pastizales junto a la plantación de pinos, 8.91069N, 73.07219W, 3377 m alt., 28 Oct. 2017, S.P. Sylvester 3039 (FMB, K, SI, UPTC, US); Munic. Duitama, Páramo de La Rusia, Guanenta Alto Río Fonce National Park, top of the ridge Peña Negra just below military base, ridge along the top of a steep rocky landscape, 5.58389N, 73.053263W, 3970 m alt., open Páramo with Espeletia cachaluensis , no signs of grazing, 21 Nov. 2017, M. Vorontsova 2203 (US); Munic. Duitama, Páramo de la Rusia, Vereda El Carmen, 5.95333N, 73.11019W, 3445 m alt., 30 Oct. 2017, S.P. Sylvester 3064 (FMB, K, SI, US); Munic. Duitama, Páramo de la Rusia, vía que conduce a vereda de Avendaños, 5.95011N, 73.09097W, 3795 m alt., 1 Oct. 2017, S.P. Sylvester 3002 (COL, FMB, K, SI, US); 5.93246N, 73.0798W, 3726 m alt., 4 Oct. 2017, S.P. Sylvester 3036 (COL, K, SI, UPTC, US); Munic. Sotaquira, protected area of Páramo El Valle, páramo just above riverine forest, 5.4605N, 73.21507W, 3220 m alt., 17 Nov. 2017, M. Vorontsova 2161 (K, SI, US); Sierra Nevada del Cocuy, Alto Valle Lagunillas, páramo pantanoso al sur de la Laguna Cuadrada, [6.3619N, 72.3345W], 4060 m alt., 26 Sep. 1972, A.M. Cleef 5579 (US2785750). Nariño: Páramo del Tábano, alto de la Cordillera, entre Pasto y El Escano, vertiente occidental, [1.1756N, 77.1867W], 3200 m alt., 11 Jan. 1941, J. Cuatrecasas 11908-A (US1798782).

Notes.

Agrostis perennans appears to be a ‘grab-bag’ of many different taxa that come out in many different places amongst other taxa of Agrostis in molecular phylogenies (Konstantin Romaschenko pers. communication), with the species complex needing urgent revision. Specimens found in Boyacán páramos correspond in almost all characteristics with Agrostis perennans s.s. apart from sometimes being found with shorter spikelets (c. 1.5-2 mm long) and, what appear to be, short ascending rhizomes/pseudostolons, with these characteristics also found on type material of A. fasciculata , which is here considered a synonym of A. perennans until comprehensive systematic research is undertaken on the species complex. Cataphyllous extravaginal shoots are found on the neotype of A. perennans as well as other type material of species considered synonyms of A. perennans , e.g. A. decumbens E. Fourn., with it plausible that these ‘rhizomes’ are short pseudostolons that arise from growing through moss or between rocks.

Type specimens and specimens from North America, Central America, and northwest South America have lemmas without awns or with awns under-developed, to 0.5 mm long, straight and easily falling. Specimens noted by Rúgolo de Agrasar (2012: 119) to have awns to 1.4 mm long, or exceptionally to 1.9 mm long, may be a distinct taxon, but further research is needed to ascertain this.

Similar species.

Agrostis mertensii , which is principally differentiated in having a well-developed, flexuose to geniculate, twisted awn (1.8-)2.5-4.5 mm long, inserted in the middle or lower third of the lemma, and which is greatly exerted from the glumes (vs. unawned or exceptionally with a short straight awn to 0.5 mm long, inserted in the upper ( ½) third of the dorsal keel, usually not or rarely only slightly surpassing the glumes in A. perennans s.l. specimens from northwest South America, Central America and North America).

Agrostis subrepens , here considered to be excluded from Departamento Boyacá and possibly Colombia (see notes under 'Excluded species’ A. subrepens ), sometimes bears certain similar, but not equal, characteristics such as a) plants often stooling with notable pseudostolons and appearing long rhizomatous on herbarium sheets; b) culms 50-100 cm tall, slightly creeping or decumbent at their base but erect towards their apex; c) panicles open, lax, 5-10 cm wide; d) lemma unawned or awn to 0.5 mm long and straight, not twisted, inserted in the middle or upper 1/3 of the lemma or subapical; e) palea absent or < ¼ the length of the lemma. Agrostis subrepens can be differentiated from A. perennans s.l. by a) upper culm ligules 1-2.2 mm long, obtuse (vs. 3-5(-7) mm long, truncate to obtuse-triangular in A. perennans s.l.) b) leaf blades 0.5-1 mm wide in diameter as rolled or folded, convolute, involute, or conduplicate, rigid, surfaces scabrous (vs. leaf blades (1-)1.5-3.5(-5) mm wide, usually flat or conduplicate and lax to slightly firm, sometimes involute and rigid in the basal leaves, smooth throughout or scaberulous on margins and sometimes surfaces in A. perennans s.l.); anthers 1-1.3 mm long (vs. 0.7-1 mm long in A. perennans s.l.)

Agrostis turrialbae , here considered to be excluded from Departamento Boyacá and possibly Colombia, bears similarities and may possibly be part of the A. perennans s.l. species complex (see notes under 'Excluded species’ A. turrialbae ).

Agrostis vinealis , of Eurasian origin which is not recorded for Colombia, but found introduced and naturalized in Argentina and Chile ( Soreng and Peterson 2003; Rúgolo de Agrasar 2012), bears certain similarities (see also comments regarding this species under A. cf. imberbis ). It can be differentiated by having a) lemmas usually with a persistent, geniculate and twisted awn to 4 mm long, inserted near the base (sometimes absent); b) rhizomes conspicuous, long, lateral tending, and usually covered in bracts; c) panicles contracted and rather dense before and after flowering.

Figures

Figure 8. Agrostis perennans s. l. A spikelet, glumes in lateral view, with floret in dorsal view, detached and raised slightly above the glumes B whole plant. Images of Vorontsova 2247 (FMB).