Paspalum cordatum Hackel (1910: 5)

Delfini, Carolina, Souza, Vinicius Castro & Zuloaga, Fernando Omar, 2017, Taxonomic revision and nomenclatural update of Paspalum sect. Pectinata (Poaceae, Panicoideae, Paspaleae), Phytotaxa 323 (1), pp. 1-26 : 10

3. Paspalum cordatum Hackel (1910: 5) . Fig. 1K–N

Lectotype (designated here):— BRAZIL. Paraná: “ Rio Tibagy in der Nähe des Städtchens Ponta Grossa, am Rande eines Sumpfes ”, 7 January 1904, P.K.H. Dusén 3248 (S 14-11070!, isolectotypes G 99848!, US 2942131! (fragment ex W), W 19160038099!).

Rhizomatous perennial, robust, 90–130 cm tall. Culms erect, compressed, nodes glabrous, with imbricate, arched, thick and rigid rhizomes, rhizomes pale yellow; aestivation convolute. Sheaths usually longer than the internodes, predominantly disposed at the apex of the culms, striated, hirsute mainly at the basal and apical portions, with hyaline trichomes, 1–2 mm long. Ligules 1.5–2 mm long, narrowly ovate, membranous, brown, the margins serrate. Blades 8– 50 × 0.5–1.3 cm, lanceolate, flat, densely hirsute; the apex acuminate, the margins entire, involute, ciliate, hyaline cilia, 1–2 mm long; nerves conspicuous; adaxial and abaxial surfaces densely hirsute, with simple and hyaline trichomes, 1–2 mm long. Inflorescences 8–20 cm long, 5–10 racemes, racemes 5–18 cm long, subdigitate, axillary inflorescences absent; peduncle 25–45 cm long, glabrous. Rachis 1.7–2.8 mm wide, ending in a naked point, linear to slightly sinuous, glabrous to slightly pilose, apical spikelet absent. Spikelets 4.5–6 × 2.5–3.5 mm, solitary, arranged into two series along the rachis, pedicellate, pedicels glabrous; lower anthecium 1.5–2 mm larger than the upper anthecium; upper glume pale yellow, ovate, widely winged, 3-nerved, the nerves conspicuous, midnerve present, the apex acute to obtuse, the margins ciliate, hyaline cilia, 0.5–1 mm long, the base cordate, the surface glabrous to scabrous; lower lemma slightly smaller than the upper glume, pale yellow, elliptic to lanceolate, not winged, 3-nerved, the nerves conspicuous, midnerve present, the apex acute, the margins papillose-ciliate, hyaline cilia, 0.5–1.6 mm long, not exceeding the margins of the upper glume, the base cordate, the surface pilose between the nerves, hyaline trichomes, 1–2 mm long; upper anthecium 3.1–4 × 1–1.6 mm, pale yellow, sessile, elliptic to lanceolate, frequently with a conspicuous tuft of trichomes at the apex of the upper lemma; upper lemma and upper palea minutely papillose, the midnerve absent, the apex acute. Anthers 1.5–2.3 mm long, purple. Styles 2, stigmas plumose, purple. Lodicules 2. Caryopsis 1.8–2.5 mm long, obovate to oblong, brown.

Distribution and habitat: — Colombia (Meta and Vichada) and Brazil (from Amazonas to Paraná), between 100 and 1200 meters ( Fig. 4 ). Paspalum cordatum is frequently found in sandy, humid or waterlogged soils of savannas and fields.

Comments: — Paspalum cordatum is characterized by having sheaths and blades hirsute, the upper glume glabrous and the lower lemma not winged. This species is morphologically close to (and frequently confused with) P. pectinatum , especially in terms of general aspect. This led Rodríguez (1998) to include P. cordatum within the synonymy of P. pectinatum ; however, these species can be readily separated by the number of racemes per inflorescence (5–10 racemes in P. cordatum vs. 2–3 racemes in P. pectinatum ), the size of spikelets (4.5–6 mm long vs. 6–8 mm long), the shape of the upper glume (ovate vs. lanceolate), the rhizomes imbricate, arched, and rigid (vs. short, not imbricate and rigid) and the length of marginal trichomes of the lower lemma (not exceeding the margins of the upper glume vs. exceeding the margins of the upper glume).

In the original publication of P. cordatum, Hackel (1910) cited a collector and collector number (Dusén 3248) but did not specify where the type was deposited. There are four sheets of Dusén 3248 distributed in different herbaria. Denham et al. (2002) cited the specimen housed in Vienna as the holotype, but there is no holotype and this statement cannot be corrected to lectotype since it was published after 1 January 2001 [see Section 2, Art. 9.23 in McNeill et al. (2012)]. The specimen used by Hackel is the one kept in Stockholm (S 14-11070), which is here designated as lectotype of the name P. cordatum .

Specimens examined: — BRAZIL. Amazonas: Aripuanã, Transamazon highway, 53 km W, of Aripuanã river , campina, 28 June 1979, C.E. Calderón 708 et al. (INPA, US). Distrito Federal: Brasília, área da Cascalheira, campo com tapete de herbáceas, 9 May 1957, M. Magalhães 9664 (BHCB). Goiás: Cristalina , 3 km N de Cristalina, 2 March 1966, H.S. Irwin 13241 (UB) ; Jataí, Queixada, s.d., A. Macedo 1543 (MBM). Mato Grosso : General Carneiro , Rodovia BR 070, km 205, entre Primavera do Leste e Paredão Grance , vereda ao lado W da estrada, 680 m, 10 April 2011, G.H. Rua 997 et al. (UB). Minas Gerais: Brumadinho, Retiro das Pedras, em solo brejoso, 15 February 2003, P.L. Viana 976 (BHCB). Uberaba, Campo tufoso hidromórfico, 1990, E.M. Teixeira s.n. & A.E. Brina (BHCB 36165) ; Uberlândia, Estação Ecológica do Panga-Meio , direto da vereda 4, 29 January 1990, A.A.A. Barbosa 1807 (HUFU) ; Reserva do Clube Caça e Pesca Itororó-Meio , braço esquerdo da vereda, 4 December 1998, A.F. Amaral 1737 (HUFU). Paraná: Balsa Nova, Ponte dos Arcos, várzea assoreada, 5 January 2006, C. Kozera 2825 & O.P. Kozera (MBM) ; Rodovia BR 277, ca. 2 km L do rio Papagaios , campo limpo seco, 14 January 1981, G. Hatschbach 43507 (MBM, US) ; Serra de São Luiz by the rodovia do Café, 14 January 1965, L.B. Smith 14438 et al. ( US). Campo Largo , São Luís do Parumã , campo úmido, 10 January 1977, L.T. Dombrowski 6897 (MBM). Carambei , Rodovia PR 340, Castro–Tibagi , ca. 16 km de Castro, logo após a subida da serra, campo seco, 1203 m.s.m., 12 February 2005, G.H. Rua 763 (CEN). Jaguariaíva, Parque Estadual do Cerrado , 14 January 2004, H.M. Longhi-Wagner 8963 et al. (ICN, MBM). Palmeira, córrego da Anta, campo levemente úmido, 2 February 1975, G. Hatschbach 35872 & T.M. Pedersen (MBM) ; Recanto dos Papagaios , 957 m. s.m., 18 December 2013, J.T. Motta 4175 et al. (MBM) ; Rio dos Papagaios , campo, solo arenoso, 21 January 1981, P.I Oliveira 303 (MBM) ; Without additional data, em campo, 18 January 1967, L.T. Dombrowski 2311 & Y.S. Kuniyoshi (MBM). Piraí do Sul , rocky campo and boogy brook, 16 January 1965, L.B. Smith 14579 et al. ( US) ; Serra das furnas ; Rodovia PR 090, para Ventania , campo de topo, humoso e arenoso, 14 January 2004, H.M. Longhi-Wagner 8940 et al. (ICN, MBM) ; Joaquim Murtinho, campo rochoso, 15 February 1982, R. Kummrow 1743 & J.G. Stutts (MBM). Ponta Grossa , brejo, 1000 m.s.m., 13 February 1949, A.C. Brade 19638 (RB) ; Nascente do rio Tibagi. campos hidrófilo sobre organossolo, 1096 m.s.m., 15 February 2009, B.O. Andrade 245 (MBM) ; Fazenda Cabujan , brejo, 1000 m.s.m., 13 February 1949, A.C. Brade 19638 ( US) ; Estação experimental, common in banhado and along stream, 29 January, J.R. Swallen 8349 ( US) ; Fazenda da Criação, common on wet ground along stream, 4 February, J.R. Swallen 8461 ( US). Sengés, Fazenda Morungava , rio do Funil , margens semi brejosas do rio, 12 December 1958, G. Hatschbach s.n. & R.P. Large (MBM 5274, US 2304293) ; Fazenda Morungava, Rio Funil , 19 January 1965, L.B. Smith 14858 et al. ( US) ; Without additional data, 20 December 1948, A. Macedo 1543 ( US) ; Without additional data, 23 January 1910, P. Dusén 9109 ( US) ; Without additional data, s.d., P. Dusén 16174 ( US). São Paulo: Assis , Estação Ecológica , campo úmido, 23 January 2003, W. Conteri s.n. (SPSF 37431) ; Itararé, Unidade de Pesquisa e Desenvolvimento de Itararé , campo úmido, em solo arenoso úmido e saturado, 21 December 2005, J.L.C. Tannus 1039 (HRCB, UEC) ; Ex. Herv. da Escola Politécnica de São Paulo , 30 January 1908, A. Usteri s.n. (US 1503191). COLOMBIA. Meta: Llanos Orientales, s.d., J. Blydenstein 939 (COL, MO). Vichada: Caño Urimica, s.d., A. Cabrera 2278 (COL) .

Figures

FIGURE 1. A–D: Paspalum aspidiotes: A. Upper glume; B. Spikelet, view of the lower lemma; C. Upper lemma; D. Upper palea. E–J: Paspalum cachimboense: E. Habit; F. Node detail; G. Spikelet, view of the upper glume; H. Lower lemma; I. Upper anthecium, view of the upper lemma; J. Upper palea. K–N: Paspalum cordatum: K. Upper glume; L. Lower lemma; M. Upper lemma; N. Upper palea. O–R: Paspalum imbricatum: O. Upper glume; P. Spikelet, view of the lower lemma; Q. Upper lemma; R. Upper palea. S–V: Paspalum lanciflorum: S. Spikelet, view of the upper glume; T. Lower lemma; U. Upper lemma; V. Upper palea. W–Z: Paspalum pectinatum: W. Upper glume; X. Spikelet, view of the lower lemma; Y.Upper lemma; Z. Upper palea. A’–D’: Paspalum reticulinerve: A’. Upper glume; B’. Spikelet, view of the lower lemma; C’. Upper lemma; D’. Upper palea. [A–D: N.A. Rosa 2369 (INPA); E–J: M.N. Silva 24 et al. (RB); K–N: H.M. Longhi-Wagner 8963 et al. (ICN); O–R: T.S. Filgueiras 970 (IBGE); S–V: A. Chase 11402 (RB); W–Z: A. Rizzo 4470 (RB); A’–D’: T. Killeen 4824 et al. (SI)]. Drawn by Maíra Mezzacappa.

FIGURE 4. Distribution map of Paspalum cordatum.