Schizachyrium glaziovii Peichoto (2010: 314)

Dorneles Welker, Cassiano A. & Peichoto, Myriam Carolina, 2015, Considerations on the genus Schizachyrium (Poaceae-Andropogoneae) in Central America and West Indies, and confirmation of the occurrence of S. glaziovii, Phytotaxa 201 (1), pp. 87-95 : 89-93

Schizachyrium glaziovii Peichoto (2010: 314) . ( Figs. 1D–G , 2C–D ).

Type:— BRAZIL. Rio de Janeiro: Rio de Janeiro, Glaziou 2739 (holoype P!, isotypes C!, K!, W!).

Andropogon condensatus subsp. elongatus Hackel (1883: 297)

Andropogon condensatus var. elongatus (Hack.) Hackel (1889: 388)

Andropogon paniculatus var. elongatus (Hack.) Hackel (1906: 417)

Schizachyrium condensatum subvar. elongatum (Hack.) Roberty (1960: 229)

Schizachyrium microstachyum subsp. elongatum (Hack.) Rosengurtt et al. (1968: 37)

Lectotype (designated here): — BRAZIL. Rio de Janeiro: Rio de Janeiro, Glaziou 2739 ( P!, isolectotypes C!, K!, W!).

Perennial, caespitose, (40–) 50–180 cm high. Leaf sheaths glabrous; blades glabrous, 8–35 cm × 3–6 mm; ligule membranous, 0.8–2 mm long. Inflorescence panicle-like, narrowly oblong, (20–)25–45(–60) cm long, highly branched, with 40–150 racemes, each raceme protected by a spatheole. Spatheole open, 20–25(–28) mm long. Peduncle of each raceme 3–10 mm long, included within the spatheole. Racemes differentiated into nodes and internodes, disarticulating at the nodes; spikelets paired at each node of the rachis, one sessile and one pedicelled, both falling off together with a rachis internode at maturity. Rachis internodes and pedicels flexuous at maturity. Rachis internode (4–)4.5–5.5(–6) mm long. Sessile spikelet: lower glume chartaceous, two-keeled, 4.5–5.5 mm long; upper glume chartaceous, onekeeled, 4.5–6 mm long; lower lemma hyaline, 3–4.5 mm long; upper lemma hyaline, bifid, 3–4.5 mm long, with an awn 12–17 mm long. Caryopsis 2.5–3 mm long. Pedicellate spikelet: lower glume 1–2 mm long, with an awn 1–2.5 mm long.

Geographic distribution: — Schizachyrium glaziovii is widely distributed in South America (from Colombia and Venezuela to Argentina and Uruguay), Central America (from Guatemala and Belize to Panama) and West Indies (in Trinidad and Tobago) ( Fig. 3 ).

Habitat: —The species inhabits primarily dry grasslands, less commonly wet grasslands and disturbed areas, such as roadsides.

Phenology: —Flowering and fruiting mainly from December to March.

(TT).

Observations: —In the most recent revision of Schizachyrium for South America, Peichoto (2010) erroneously treated Andropogon condensatus subsp. elongatus (and other combinations based on this basionym) as synonyms of Schizachyrium spicatum ( Sprengel 1824: 254) Herter (1940: 135) . This error was caused by a misinterpretation of Hackel (1883: 297), who had considered Deyeuxia spicata Sprengel (1824: 254) (the basionym of Schizachyrium spicatum ) as a synonym of Andropogon condensatus subsp. elongatus . However, when describing Schizachyrium glaziovii as a new species in that paper, Peichoto (2010) commented that the herbarium specimens previously determined and/or cited as S. microstachyum subsp. elongatum correspond to S. glaziovii . We are here correcting this mistake, including the name Andropogon condensatus subsp. elongatus and other combinations of this basionym ( A. condensatus var. elongatus , A. paniculatus var. elongatus , Schizachyrium condensatum subvar. elongatum , and S. microstachyum subsp. elongatum ) in the synonymy of S. glaziovii .

Schizachyrium glaziovii differs from S. microstachyum mainly by the narrowly oblong inflorescences ( Figs. 1D , 2D ) and open spatheoles, which are longer than the respective peduncles (the peduncles remain included within the spatheoles at maturity) ( Fig. 1E–F ). On the other hand, S. microstachyum has wide inflorescences that are generally open ( Figs. 1H , 2E ), and strongly convolute spatheoles, which are slightly shorter than the respective peduncles (the superior portion of the peduncles are exserted at maturity) ( Fig. 1I–J ). Moreover, the inflorescences of S. glaziovii are generally pendulous ( Figs. 2C–D ), whereas in S. microstachyum they are erect ( Figs. 2E–F ). This character is easily observable in the field, but difficult to observe in herbarium materials ( Welker & Longhi-Wagner 2012b). Schizachyrium microstachyum is the most common species of the genus in America, occurring from Mexico to Argentina and Uruguay ( Filgueiras 2003, Peichoto 2010).

Schizachyrium condensatum differs from S. glaziovii and S. microstachyum mainly by the corymb-like inflorescences, generally strongly congested ( Figs. 1A , 2B ). The other two species have panicle-like inflorescences, varying in shape from open to narrowly oblong ( Figs. 2D–E ). Furthermore, S. condensatum has shorter spatheoles and awn of the sessile spikelet than the other two species. Schizachyrium condensatum occurs in South America, from Colombia to Argentina and Uruguay ( Peichoto 2010). The species is also cited for Mexico, Central America, and West Indies ( Manrique 1994, Filgueiras 2003), but its occurrence in these regions needs to be revised. All herbarium specimens from these regions previously identified as S. condensatum that we have examined so far were incorrectly identified and correspond to S. microstachyum or S. glaziovii . Additional investigation is required to determine the distribution of S. condensatum in America. Type materials and reference to specimens examined of S. condensatum and S. microstachyum are listed in the Appendix.

Material examined: — BELIZE. Stann Creek: Sapodilla Lagoon, 8 March 2003, Woo & Farruggia 756 ( MO). Toledo: along the Southern Highway, 6 km W of the Bladden Branch , 15 March 1987, Brant & Davidse 1035 ( MO) . COSTA RICA. Alajuela: Santa Maria National Park, near park headquarters, 26 January 1978, Liesner 4570 ( MO). Guanacaste: La Cruz , Santa Rosa National Park , Cuenca de Santa Elena , Península de Santa Elena , 22 January 2003, Rodríguez et al. 7663 ( MO) ; Santa Rosa National Park, North edge of the park, 1 February 1978, Liesner 4826 ( MO). Puntarenas: Gulfo de Nicoya , Isla Tolinga , 6 February 1984, Khan et al. 832 ( MO) ; road to Monteverde and Santa Elena, a few km before Santa Elena, 28 January 1998, Clark & Reiners 1586 ( MO). San José: Cantón de Aserri , Cuenca del Pirris-Damas , Fila Bustamante , Alto Glória , 24 January 1999, Morales 6766 ( MO) . EL SALVADOR. Morazán: Perquín, Rio Sapo , 25 January 2000, Monterrosa et al. 50 ( MO) . GUATEMALA. Zacapa: 13 km E of El Lobo , 9 February 1970, Harmon & Fuentes 1847 ( MO) . HONDURAS. Comayagua: 8 km SE of Siguatepeque, 25 May 1972, Burch 6204 ( MO). El Paraíso: Las Casitas , 25 October 1951, Swallen 11098 ( MO) ; road to Danlí, km 78, 1 November 1951, Swallen 11232 ( MO). Francisco Morazán: region of Las Mesas , 15 October 1951, Swallen 10750 ( MO) ; Valle de San Pedro, 35 km SE of Tegucigalpa, 12 October 1983, Quintana 77 ( MO). Olancho: Jutiapa Forest Camp, near Salamá , 22 December 1978, Pohl & Gabel 13760 ( MO) . NICARAGUA. Rivas: Isla Ometepe, 8 February 1984, Robleto 161 ( MO). Zelaya: near Tala Has and Puente Mango (over Río Kisalaya ), 18 April 1978, Davidse 1979 ( MO) ; vicinity of junction of road to Alamikamba with road between El Empalme and Limbaika, 24 February 1979, Stevens et al. 12813 ( MO) . PANAMA. Chiriquí: 17 km NE of San Felix on road to Cerro Colorado copper mines, 18–19 March 1974, Nee 10697 ( MO). Coclé: Aguadulce, 5 January 1970, McDaniel & Cooke 12755 ( MO). Herrera: 16 km S of Ocú , 21 January 1966, Tyson et al. 2851, 2852 ( MO). Panamá: along the Corozal road, near Panama City, 13 December 1923, Standley 26804 ( MO) ; Panama City, 21 February 1981, Concepcion & Isos 70 ( MO) ; Taboga Island, 24 January 1935, Allen 112 ( GH, MO). Veraguas: trail between Cañazas and the foot of the Cordillera Central, headwaters of Río Cañazas , 8 February 1937, Allen 152 ( MO) ; Coiba National Park , 2 April 2004, Ibáñez & Rodríguez 2863 ( MO) ; San José, 1 March 1984, Carrasquilla 1940 ( MO) ; 18 km S of Santa Fe, vicinity of San José on Santiago- Santa Fe road, 18 November 1973, Nee 8168 ( MO) . TRINIDAD AND TOBAGO. Trinidad: St. Joseph savanna, 24 March 1920, Britton et al. 980 ( GH) .

Additional material examined: — A large number of specimens from different countries from South America was also examined. These herbarium specimens are listed in Peichoto (2010) and Welker & Longhi-Wagner (2012b).

Figures

FIGURE 1. Illustrations of the type materials of Schizachyrium glaziovii and morphologically similar species in Central America and West Indies.A–C. Schizachyrium condensatum (Humboldt & Bonpland s.n., P). A. inflorescence. B. raceme with the spatheole. C. pair of spikelets and rachis internode. D–G. Schizachyrium glaziovii (Glaziou 2739, P). D. inflorescence. E. raceme with the spatheole. F. open spatheole with the peduncle included within it. G. pair of spikelets and rachis internode. H–K. Schizachyrium microstachyum (Desvaux 8, P). H. inflorescence. I. raceme with the spatheole. J. convolute spatheole with the superior portion of the peduncle exserted at maturity. K. pair of spikelets and rachis internode. Illustrations by Liliana Gómez.

FIGURE 2. Photos of Schizachyrium glaziovii and morphologically similar species in the field. A–B. Schizachyrium condensatum (Longhi-Wagner & Welker 10757, ICN – Brazil). A. habit. B. inflorescence. C–D. Schizachyrium glaziovii (Longhi-Wagner & Welker 10577, ICN – Brazil). C. habit. D. inflorescence. E–F. Schizachyrium microstachyum (Welker 203, ICN – Brazil). E. inflorescence. F. habit. Photo credit: H.M. Longhi-Wagner (A–D), C.A.D. Welker (E, F).

FIGURE 3. Distribution map of Schizachyrium glaziovii in Central America, West Indies and South America. Countries with solid fill (inset) represent the occurrence of the species. Dots indicate the locations of specimens examined from Central America and West Indies. Countries: Belize (B), Costa Rica (CR), El Salvador (ES), Guatemala (G), Honduras (H), Nicaragua (N), Panama (P), Trinidad and Tobago