Agrostis capillaris L., Sp. Pl. 1: 62. 1753.

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

3. Agrostis capillaris L., Sp. Pl. 1: 62. 1753.

Figs 4C , 5C , 12

= Agrostis capillaris Huds., Fl. Angl. 27. 1762, nom. illeg. hom., non L., 1753. Agrostis tenuis Sibth., Fl. Oxon. 36. 1794. Agrostis alba L. var. tenuis (Sibth.) Fiori, Nuov. Fl. Italia 1: 97. 1923. Type: England. Habitat in pratis et pascuis ubique (not located).

Agrostis polymorpha Huds. var. capillaris (L.) Huds., Fl. Angl. 1: 31. 1778.

Vilfa capillaris (L.) P. Beauv., Ess. Agrostogr. 147. 1812.

Trichodium capillaris (L.) Roth, Nov. Pl. Sp. 41. 1821.*

Type.

Herb. A. Van Royen s.n. (lectotype, designated by Widén (1971: 65): L [left hand specimen] (L (L0052645 [image!])).

Description.

Plants perennial, short rhizomatous, rarely stoloniferous. Tillers extravaginal, with cataphylls. Rhizomes up to 5 cm long. Culms 10-80 cm long, erect, decumbent at the base, nodes up to 7, glabrous, internodes glabrous. Leaves basal and cauline; sheaths 1-13 cm long, longer or shorter than the internodes, glabrous; ligules of the basal blades 0.2-1.5 mm long, the upper ones up to 2 mm long, usually shorter than wide, rarely longer than wide, dorsally scaberulous, apices rounded to truncate, erose, sometimes lacerate; blades 3-15 cm long, 1-5 mm wide, linear, flat, sometimes becoming convolute when drying, scaberulous on both surfaces. Panicles (3-)10-20 cm long, (1-)2-12 cm wide, open, lax, oblong to ovate, usually long-exserted from the upper sheaths; branches ascending to spreading, rebranching about or above mid-length, scaberulous, without spikelets near their base, inferior branches up to 7 cm long; pedicels 0.4-3.3 mm long, usually spreading, scaberulous. Spikelets (1.7-)2-3(-3.5) mm long, greenish to purplish; glumes subequal, lanceolate, apices shortly acuminate, 1-veined, scaberulous on the keel, lower glume 2.5-3.5 mm long, upper glume 2.2-3.3 mm long; callus glabrous or with a few trichomes, inconspicuous; lemmas 1-2.5 mm long, elliptic, apices entire, acute to obtuse, sometimes truncate, 3(5)-veined, veins usually prominent, sometimes two veins excurrent ca. 0.5 mm, unawned, rarely awned near mid-length, awn up to 2 mm, geniculate or straight; paleas present, 0.6-1.2(-1.4) mm long, 2-veined, glabrous; anthers 3, 0.8-1.4 mm long. Caryopsis 0.8-1.5, elliptic; endosperm solid. 2n= 28 ( Harvey 2007).

Anatomy and micromorphology.

Leaf blades flat to convolute in transversal section; adaxial furrows medium-sized, narrow; adaxial ribs rounded to triangular; keel absent; first order bundles circular to slightly elliptical in outline, sheath interrupted abaxially or also adaxially, abaxial and adaxial sclerenchyma in girders, narrowing towards the bundle; second order bundles circular in outline, sheath interrupted abaxially, abaxial and adaxial sclerenchyma; intercostal sclerenchyma absent; leaf margins with well-developed sclerenchyma caps, rounded; colorless cells absent (Fig. 6F, G ). Lemmas without transversal thickenings; prickle hairs abundant (Fig. 7C ).

Distribution and habitat.

Introduced. Agrostis capillaris is native to Europe. This species has been collected in Francisco Morazán, Honduras, and in the state of México, Mexico (Fig. 8C ). It grows in cloud forests and Pinus forests, at 2000-2830 m a.s.l. (Fig. 9F ).

Phenology.

Specimens with spikelets have been collected in June (Fig. 10F ).

Commentaries.

This species is often confused with A. castellana (see notes under excluded species). Some individuals of A. capillaris can develop ligules of the flowering culms longer than wide.

Conservation status.

Since Agrostis capillaris is an introduced species in the study zone, its conservation status is considered as Least Concern (LC).

Specimens examined.

Honduras. Francisco Morazán: Distrito Central , bosque denso, húmedo y nebuloso de Montaña La Tigra, al SO de San Juancito, [14.2°N, 87.1°W], 2000 m alt., 11 Jun 1963, A. Molina 12706 (MICH, US). MEXICO. México: Municipio Temascaltepec , Mesón Viejo, [19.16666667°N, 99.88333333°W], 2830 m alt., 1 Jun 1933, G.B. Hinton 3996 (MO, TEX [*, **], US) .

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 6. Leaf blade anatomy in transversal section of Agrostis species, in general view, and details of lateral bundles. A - C A. bourgaei D - E A. calderoniae F - G A. capillaris H - I A. elliottiana. Scale bars: 0.1 mm.

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 8. Map of known geographic distribution of Agrostis species, based on herbarium specimen data A A. bourgaei B A. calderoniae C A. capillaris D A. elliottiana E A. exarata F A. ghiesbreghtii.

Figure 9. Elevation histograms of Agrostis species A all records B native species C introduced species D A. bourgaei E A. calderoniae F A. capillaris G A. elliottiana H A. exarata I A. ghiesbreghtii J A. gigantea K A. hyemalis L A. idahoensis M A. laxissima N A. microphylla O A. pallens.

Figure 10. Phenology histograms of Agrostis species A all records B native species C introduced species D A. bourgaei E A. calderoniae F A. capillaris G A. elliottiana H A. exarata I A. ghiesbreghtii J A. gigantea K A. hyemalis L A. idahoensis M A. laxissima N A. microphylla O A. pallens.

Figure 12. Agrostis capillaris A whole plant B ligular area C branch of the panicle D spikelet E floret, abaxial view F palea. Based on Hinton 3996 (TEX). Scale bars: 3 cm (A); 1 mm (B); 4 mm (C); 0.5 mm (D, E); 0.2 mm (F).