Lachnagrostis filiformis (G. Forst.) Trin., 1820

Sánchez-Ken, J. Gabriel, 2018, Lachnagrostis filiformis (Poaceae: Pooideae: Poeae: Agrostidinae) in México: known distribution and suppression of lemma awn development in terminal spikelets, Phytotaxa 350 (3), pp. 223-234 : 225-228

Lachnagrostis filiformis (G. Forst.) Trin. ( Figs. 1–3 ).

Avena filiformis Forster (1786: 9) . Agrostis filiformis (G. Forst.) Sprengel (1807: 32) , nom. illeg. hom. Calamagrostis filiformis (G. Forst.) Cockayne (1908: 35) , nom. illeg. hom. Deyeuxia filiformis (G. Forst.) Petrie (1909: 474) , nom. illeg. hom. Agrostis avenacea J.F. Gmel. , a replacement name for Agrostis filiformis (G. Forst.) Sprengel , which was blocked by Agrostis filiformis Villar (1787: 78) , nom. illeg. hom. Calamagrostis avenacea (J.F. Gmel.) Oliver (1917: 127) . Calamagrostis avenacea (J.F. Gmel.) Becherer (1938: 519) , nom. illeg. hom. Lachnagrostis avenacea (J.F. Gmel.) Veldkamp (1992: 230) , nom. illeg. superfl. TYPE:— New Zealand, J.R. & G. Forster s.n., 1779 (lectotype B-W-2208! designated by Edgar (1995), isolectotypes BM000991495!, CHR-7911!, GOET-012524!, GOET-012525!, K-000098715!, KIEL, LE, LINN-Sm.-135.32!, MW-77, UPS).

Agrostis retrofracta Willdenow (1809: 94) . Vilfa retrofracta (Willd.) Beauvois (1812: 16) . Lachnagrostis retrofracta (Willd.) Trinius (1820: 128) . Deyeuxia retrofracta (Willd.) Kunth in Humboldt et al. (1829: 77). Calamagrostis retrofracta (Willd.) Link (1833: 247) . Lachnagrostis willdenowii Trinius (1824: 217) , nom. illeg. superfl. Based on Agrostis retrofracta Willd. Calamagrostis willdenowii (Trin.) Steudel (1854: 192) nom. illeg. superfl. TYPE:—Cultivated in Hort. Bot. Berol from material collected in Australia, Anonymous s.n. (holotype B-W-1692!, isotypes L, P?).

Agrostis debilis Poiret (1810: 249) . Vilfa debilis (Poir.) P. Beauvois (1812: 16) . TYPE:—Cultivated in the Jardin des Plantes de Paris, seeds from an unknown location (Herb. Desfontaines probably P). Specimen not found in the online database of P.

Agrostis forsteri Roemer & Schultes (1817: 359) , nom. illeg. superfl. Lachnagrostis forsteri (Roem. Ex Schult.) Trinius (1824: 217) . Deyeuxia forsteri (Roem. & Schultes) Kunth in Humboldt et al. (1829: 77), nom. illeg. superfl. Calamagrostis forsteri (Roem. & Schult.) Steudel (1840: 250) . TYPE:— New Zealand: locality unknown. The location of the type is unknown. In the protologue of the species, the locality is described as Insula Paschatis. The specimen BM-000991496! might be the type since this collector´s material is deposited in this herbarium. Written with ink on the upper right corner of this specimen is the text “ Nova Zelandia J.R. & G. Forster ” and below in the center is written in pencil “ New Zealand, Insula Paschatis”.

Agrostis leonii Parodi (1962 [1963]: 19). TYPE:— Argentina: Prov. Buenos Aires: Ruta 3 km 89, Partido de Lobos, R. León 516, January 1962 (holotype BAA-0000021!, isotypes BAA-00000673!, BAA-00000674!, SI-000503!).

Agrostis ligulata Steudel (1854: 173) . TYPE:— Australia: Nova Hollandia, Blondowsky 155 (holotype P, as cited by Veldkamp (1982)). The specimen was not found in the online P database.

Annual or short lived perennial plants, 32–86 cm tall, culms erect, sometimes slightly geniculate; internodes 5–6 cm long, 0.7–1.9 mm diameter, glabrous; nodes dark brown, glabrous; sheaths shorter than the internodes, the lowermost tending to shred, glabrous, margins membranous, overlapping; ligules (1.6–)2–7(–12) mm long, membranous, acute, sometimes lacerate, scabrellous on the abaxial surface; blades 5–10(–27) cm long, 1.5–3(–4.7) mm wide, linearlanceolate, flat, scabrellous on both surfaces; synflorescences 20–40 cm long, 20–34 cm wide, paniculate, open, weeping and disarticulating when mature, lowermost primary branches 12–20 cm long, in incomplete whorls or semiverticillate, branching up to six times, primary branches branching three times, each secondary branch branching three times, each tertiary branch branching once or twice into branchlets that bear a pair, or sometimes three short- and long-pedicelled spikelets, the primary branch with 10–48 spikelets, with 2–10 distal spikelets having a lemma with a reduced or totally suppressed awn, peduncle, axis and branches scabrous; pedicels 0.7–3 mm long, subclavate to clavate, scabrous; spikelets 3.4–5.5 mm long including the awn, those with a reduced or suppressed awn 2.3–2.8 mm long, 1-flowered with a rachilla extension, disarticulation above the glumes; glumes unequal, longer than the lemmas, linear, long-acuminate, 1-nerved, keeled, margins translucent; lower glumes 2.4–3.5 mm long, glabrous to scabrellous, the keel scabrous, margins translucent; upper glumes 2.5–3 mm long, the keel rarely glabrous to less scabrous than the lower glumes or scabrellous; callus rounded, pilose, the hairs 0.2–0.4 mm long; lemmas 1.2–1.4 mm long, membranous to subcoriaceous when mature, shiny, 5-veined, the veins nearly inconspicuous, hairy all over, the hairs up to 0.4 mm long, somewhat stiff, margins membranous, apex erose to slightly 4-toothed, awned, the awn 2.7– 4.7 mm long, inserted 1/3 below the apex of the lemma, once geniculate, with a 1–1.1 mm long column, the column twisted, brownish, scabrellous; paleas 1–1.2 mm long, 9/10 the length of the lemma, membranous, glabrous, 2-nerved, the nerves close to the middle forming a shallow furrow; rachilla extensions ca. 0.2 mm long, bristle-like, pilose, the hairs usually nearly as long as the rachilla extension; stamens 3, anthers 0.2–0.3 mm long; lodicules 0.4–0.5 mm long, thin, linear, membranous, translucent; caryopses 1–1.1 mm long, 0.3–0.4 mm wide, nearly as long as the paleas, widely elliptic, rugulose, embryos one tenth as long as the caryopses, hilum linear, as long as the caryopses.

Spikelets with lemmas with a reduced or totally suppressed awn 2.3–2.8 mm long, greenish to yellowish, rarely tinged with purple; glumes equal to subequal, lower glumes 2.3–2.8 mm long, upper glumes 2.1–2.6 mm long, linear, glabrous to minutely and sparsely scabrellous, scabrous on the midvein, at least distally, 1-veined, margins translucent, apices long-acuminate; callus hairs 0.2–0.5 mm long, abundant; lemmas 1.3–1.7 mm long, membranous to subcoriaceous, shiny, glabrous or with few hairs towards the margins, the hairs to 0.3 mm long, 5-veined, the veins inconspicuous, apices truncate, erose or 4-toothed, awnless or with an awn up to 0.7 mm long inserted just below the apex, the awn thin, scabrellous, straight; paleas 1.1–1.2 mm long, usually 4/5 the length of the lemmas, translucent, thin, veins close to the center forming a furrow; rachilla extensions from a minute glabrous bump to 0.1 mm long distally pilose bristle-like, with few hairs, about 0.3 mm; anthers 3, 0.2–0.4 mm long; caryopses 1.1–1.2 mm long, the embryo ca. 0.1 mm long, the hilum long, following the veins of the palea, endosperm solid.

Morphological Variation:— Spikelets and florets with awned lemmas tend to be longer than those with reduced or awnless lemmas. There is considerable variation in the height of the plants: some are small and others are much larger ( Fig.4 ). Regardless of the height of the plants, all the examined specimens have spikelets with awned and awnless lemmas.

Examined Specimens:— AUSTRALIA. Queensland, near R. R. Station at Glass house Mt. , 22 September 1943, M. S. Clemens 42786 ( MEXU) . MÉXICO [Only the Mexican specimens are organized chronologically within each state]. Guanajuato: Mpio. Cortazar: Victoria de Cortazar , localizada al SW de la cabecera municipal, [20º20’ N, 101º01’ W], 1770 m, 1 September 1981, A. Mora B. 132 ( MEXU) ; Mpio. San Miguel de Allende : El Charco, [20°55’05’’ N, 100°43’37’’ W], 1900 m, 24 November 1993, W. L. Meagher s.n. ( IEB) ; Mpio. San Miguel de Allende: El Charco del Ingenio, [20°55 ′ 05'' N, 100°43'37'' W], June 2005, W. L. Meagher 3380 ( IEB). México: Rancho Buenavista y Libertad , 2500 m, 8 August 1981, R. Guzmán M. 4226, 4332 ( MEXU) ; Mpio. Polotitlán, al SE de Encinillas , [20°08’45’’ N, 99°44’33’’ W], 2510 m, 4 February 1993, A. Ramírez A. 423 ( MEXU) ; Mpio. Aculco: Al SW del poblado Arroyo Zarco, [20°06’21’’ N, 99°43’27’’ W], 2490 m, 19 October 1993, A. Ramírez A. 407 ( MEXU) ; Mpio. Jilotepec: Rancho Xhitey, [19°59’49’’ N, 99°31’23’’ W], 2400 m, 17 April 1996, R. Mendoza D. 270 ( MEXU) ; Mpio. Ixtlahuaca: Ixtlahuaca, 19°34’ N, 99°44’ W, 2500 m, 01 January 2003, J. Pérez-Solís s.n. ( IEB, MEXU). Michoacán: Mpio. Epitacio Huerta: Balneario Guapamacátaro, 10 km al SE de Maravatío , [19°50’41’’ N, 100°23’11’’ W], 2050 m, 31 March 1988, J. Rzedowski 46314 ( IEB, MEXU) ; Mpio. Tzintzuntan: cerca de Sanabria, [19°34’22’’ W, 101°34’34’’ W], 2050 m, 2 June 1990, J. Rzedowski 49396 ( IEB) ; Mpio. Epitacio Huerta: 5 km W de La Cima , [20°07’ N, 100°16’ W], 2500 m, 28 October 1990, J. Rzedowski 50547 ( IEB, MEXU) ; Mpio. Zinapécuaro: Cerro El Cuate al S de las Adjuntas, [19º50’ N, 100º44’ W], 2500 m, s.f. [based on the collection number it was in collected in 1994], A. Pastor S. 76 ( MEXU). Puebla: Mpio. Xicotepec de Juárez: 1 km de la desv. a la Unión de la carr. Huachinango-Xicotepec de Juárez , [20°16’ N, 97°59’ W], 1220 m, s.f. [based on the collection number it was in collected in 1989], P. Tenorio L. 15772 ( IEB, MEXU). Querétaro: Mpio. Amealco : Km 4/5 camino a La Griega , 1885 m, 23 March 1982, E. Argüelles 1756 ( MEXU) ; Mpio. Huimilpan: arroyo La Beata, km 42 carretera Querétaro-Amealco-La Beata, [20°21’ N, 100°13’ W], 15 May 1996, M. Martínez 2936 ( QMEX) ; Mpio. Huimilpan: La Calle, km 33 carretera Querétaro-Amealco, hacia las afueras de Huimilpan, [20°22’05’’ N, 100°16’ W], 2280 m, 16 May 1996, M. Martínez 2952, 2953, 2955 ( QMEX) ; Mpio. Amealco: Km 31 carretera Amealco-San Juan del Río , 2 km al E de Amealco, [20°12’ N, 100°22’ W], 2280 m, 25 July 1996, M. Martínez 3331, 3333 ( QMEX) ; Mpio. Amealco : 3 km al N de Amealco rumbo a Querétaro, [20°12’50’’ N, 100°09’11’’ W], 2525 m, 28 September 1999, A. Novelo R. y L. Ramos 3811 ( IEB, MEXU) ; Mpio. Amealco : Km 5 carretera Amealco-San Idelfonso, [20°10’ N, 100°05’ W], 2640 m, 5 November 1996, M. Martínez 3667 ( QMEX) ; cerca de La Beata, [20°21’ N, 100°13’ W], 2400 m, 1 November 1996, J. Rzedowski 53250 ( IEB) . UNITED STATES OF AMERICA. California: Amador Co.: 2 mi. S of Ione , 28 May 1957, B. Crampton 4082 ( NY) ; Contra Costa Co.: San Pablo Reservoir between Orinda and El Sobrante , dried mud flats at S end of reservoir, 300 ft., 28 September 1991, B. Ertter & B. Olson 10831 ( NY) ; El Dorado Co.: 3 mi W of Rescue, Hollister Ranch , 1200 ft, 22 April 1953, B. Crampton 1122 ( NY) ; Marin Co.: weedy flat bordering S. F. Bay on road from san Rafael to McNear´s, 2 June 1971, J. T. Howell 47649 ( NY) ; Sacramento Co.: Along entrance road into Pacific Horse Center, Elk Grove, [ca. 20 m], 11 May 1983, J. Wingate 2329 ( COLO) ; Stanislaus Co.: 5 mi E of Turlock , depression along Santa Fe RR, 12 July 1954, B. Crampton 2207 ( NY). Hawaii. 27 mi, volcano Hawaii, roadside, 3 April 1973, O. Degener 33372 ( MEXU) ; S of Kilauea Kau , 10 April 1973, O. Degener 33375 ( MEXU) .

Habitat: —Based on specimen label data, in México Lachnagrostis filiformis grows in wet places such as springs, temporary and permanent ponds, ditches, channels, and edges of a lake.

Phenology: —Data from the Mexican specimens suggest that flowering occurs throughout the year with two peaks of flowering between March to July (spring) and September to November (summer and autumn). The rain seasons occur during spring and autumn; however, rain may occur during the rest of the year.

Figures

FIGURE 1. Lachnagrostis filiformis. A. Plant. B. Ligule somewhat lacerated upwards. C. Spikelet. D. Ventral and dorsal view of awned lemmas. E. Ventral and dorsal view of awnless lemmas. E. Ventral and dorsal view of the caryopsis (Meagher 24-11-02 (IEB)). Illustrated by Alfonso Barbosa.

FIGURE 2. Diagram of primary branches from two synflorescences of Lachnagrostis filiformis showing the number and position of the spikelets with awnless lemmas (circles). A = synflorescence with the lowest number of awnless lemmas and B = synflorescence with the highest number of awnless lemmas, of those examined.

FIGURE 3. Spikelets and lemmas. A. Spikelet with typically awned lemma. B. Spikelet with lemma with a reduced and apical awn. C. Pair of spikelets showing both awned (lower) and awnless (terminal) lemma. D. Lemma with a dorsal awn. E. Lemma with a subapical reduced awn. F. Awnless lemmas. F1. Immature lemma. F2. Mature lemma with caryopsis (Meagher 24-11-02 (IEB)).

FIGURE 4. Lachnagrostis filiformis. Left: small sized plant; inset (lower left)—primary branch of the synflorescence with trichotomous branching; inset (center)—ligule. Right: tall sized plant (Rule = 20 cm).