Pontederia reflexa Sousa, 2020

Sousa, Danilo J. L., Siqueira, Gabriela B. & Giulietti, Ana Maria, 2020, Two new species of Pontederia L. (Pontederiaceae Kunth) to South America, Phytotaxa 432 (3), pp. 252-262 : 257-260

Pontederia reflexa Sousa , sp.nov., Type —: BRAZIL. Ceará:Caucaia,Lagoa Pedro Lopes, 3°41’9.64”S, 38°52’56.68”W,

19 October 2017, D.J.L. Sousa & D.M. Sousa 553 (Holotype HUEFS!, Isotypes ALCB!, CEPEC!, CGMS!, COR!,

EAC!, HURB!, K!, NY!, RB!). Figures 3 ; 4 A–J ; 5 A–F .

Diagnosis: — Pontederia reflexa resembles P. parviflora and P. ovalis as all have white flowers with long-sized trichomes over the perianth and inflorescence rachis, but P. reflexa can be differentiated from both by the reflexed and revolute spathe versus erect and not revolute. P. reflexa can also be differentiated from both species by leaves and floral characters.

Erect herb, 0,4–0,9 m tall. Stem greenish to vinaceous, glabrous, internodes short. Emerged leaves alternate, distichous, petiolate; petiole 25–40 × 0.2–0.3 cm, green, vinaceous at the base, glabrous; leaf blade narrowly lanceolate to widely ovate, 6–15 × 2–8 cm, green, acrodromous venation, glabrous, apex acute, base acute to obtuse; ligule membranaceus, 2–4 cm long, greenish to vinaceous, apex truncate; submerged leaves not seen. Reproductive branch 19–70 cm long., green, often vinaceous at the base, glabrous. Inflorescence in thyrses of cincinni, 50–180 flowers, 2–6 flowers per cincinnus unit; peduncle 12–27 cm long, green, glabrous; spathe widely lanceolate to obovate, cymbiform, not fused, revolute and reflexed at the apex, 2.5–5 cm long., green, glabrous, apex acute, mucronate, mucron 0.8–1 mm long; rachis 3.4–7 cm long, greenish, villous, trichomes 6–7 mm long, without a black cell. Flowers white, sessile, trystylous, tubular, homochlamydeous; perianth tube 4–8 mm long, white, outer surface villous, trichomes 6–7 mm long, without a black cell; perianth lobes 6, disposed 3+3; outer lobes 4.4–6 mm long, 1 lower lanceolate, 2 lateral upper lanceolate; inner lobes 4–6.5 mm long., 1 upper middle ovate, white with a yellow nectar guide at the base, 2 lower lateral elliptic; stamens 6, 3 longest, filaments 6–10.8 mm long. (short-styled flowers), 7.1–11 mm long (mid-styled flowers), 5–7.3 mm long. (long-styled flowers), white, puberulous, short trichomes with a big black subapical cell; 3 shortest, filaments 3.8–7 mm long (short-styled flowers), 2.5–4.5 mm long (mid-styled flowers), 3–5 mm long (long-styled flowers), puberulous at the apex; anthers sagittate, rarely oblong, subbasifixed, 0.8–1 mm long, brownish; gynoecium 3-carpellate, a single functional carpel; ovary 1.6–2.2 mm long., greenish, glabrous, 3-loculate, a single ovule in the single functional locule; style 0.7–1.8 mm long (short-styled flowers), 3.4–4.8 mm long (mid-styled flowers), 8–12 mm long (long-styled flowers), white, few trichomes at the apex, short trichomes without a black cell; stigma punctiform to trilobed, white. Fruit utricle 7.7–10.5 mm long, anthocarp not fleshy, greenish, with 6 longitudinal flattened ribs, rib margin dentate. Seed 1, ovoid, 4.2–6.5 mm long., whitish, smooth.

Distribution and habitat:— Pontederia reflexa is endemic to South America and occurs mainly in temporary ponds and lakes. It has a disjunct distribution between the Caatinga, in the semiarid region of Northeastern Brazil, and the western Brazilian Pantanal, reaching also Bolivia and Paraguay ( Figure 3 ). Conservation status:— Following the IUCN criteria (2016), we used GeoCAT to calculate an area of occupance of 256.000 km 2 ( Bachman et al. 2011). The abundancy of collections around the Pantanal and Northeastern Brazil support the category of Least Concern (LC) for Pontederia reflexa .

Phenology:— Flowering and fruiting year round.

Etymology:— The specific epithet refers to its reflexed spathe.

Additional specimens examined (paratypes):— BOLIVIA. Santa Cruz, Ñuflo de Chávez, Est. Alta Vista , 15 Nov 1984, (fl.), T. J. Killeen 560 ( NY) . BRAZIL. Ceará, Caucaia, Catuana—Lagoa Pedro Lopes , 26 Sep 2001, (fl. fr.), A. S. F. Castro 1082 ( EAC) ; Crateús, Xavier, Baixada da Serra das Almas , 24 Jun 2003, (fl.), L. Q. Matias 450 ( EAC) ; Iguatu , B02 -CE060, 13 Mai 2010, (fl.), L. R. O. Normando 38 ( EAC) ; Independência , Br-226, 12 May 2011, (fl. fr.), L. Q. Matias 617 ( EAC) ; São Gonçalo do Amarante, Pecém, Lagoa do Gereraú , 10 Nov 2007, (fl.), M. F. Moro 283 ( EAC) ; Maranhão, Carolina, Lagoa Ilha dos Botes , 12 Sep 2009, (fl.) E. R. Santos 1987 ( HUTO) ; Palmeirândia , 06 Oct 2006, (fl.), C. M. Vieira 44 ( MAR) ; Mato Grosso, Cáceres, Porto Limão , 20 Aug 2005, (fl.), M. A. Carniello 852 ( HPAN) ; Poconé , 01 May 1999, (fl.), A. L. Sanches 109 ( CPAP) ; 01 May 1999, (fl.), A. L. Sanches 110 ( CPAP) ; 15 Jul 2006, (fl.), V. C. Souza 32414 ( ESA) ; 03 Apr 1982, (fl. fr.), G. Neto 635 ( MAC) ; 17 Apr 1993, (fl. fr.), J. M. F. Penha 1 ( CPAP) ; SESC Pantanal , 15 Jul 2006, (fl. fr.), V. C. Souza 32444 ( HUEFS, UFMT) ; Fazenda Ipiranga , porto das Araras, 27 Apr 1992, (fl.), A. L. Prado 2781 ( UEC) ; Parque Nacional do Pantanal , 23 Mar 2001, (fl.), V. J. Pott 4330 ( CGMS, CPAP) ; Rod. Transpantaneira, km 55—direção a Poconé , 25 Apr 1994, (fl.), A. L. Prado 2517 ( UEC) ; Rio Alegre , 24 Mar 2001, (fl.), V. J. Pott 4396 ( CGMS) ; Mato Grosso do Sul, Aquidauana, IPPAN — Base de Pesquisa da UNIDERP, 10 Nov 2001, (fl.), L. C. Costa 90 ( CGMS) ; Alojamento Betânia , 11 Dec 2014, (fl. fr.), M. G. Pereira 61 ( CGMS) ; Fazenda Rolândia , 15 Dec 2012, (fl. fr.), M. L. Z. Colado 10 ( CGMS) ; Fazenda Barranco Branco , 16 Aug 2005, (fl.), V. J. Pott 7909 ( CGMS) ; Fazenda Santana , 05 Feb 2006, (fl.), V. J. Pott 8631 ( CGMS) ; Bonito, Rio Sucuri— Fazenda São Geraldo , 25 Apr 1995, (fl.), E. Scremin-Dias 184 ( CGMS) ; Terras , 02 Dec 1998, (fl.), V. J. Pott 3806 ( CPAP) ; Chapadão do Sul, Pequena Central Hidroelétrica , 18 Aug 2009, (fl.), V. J. Pott 10591 ( CGMS) ; Corguinho , margem da MS-419, 03 Oct 2013, (fl.), D. Gris 101 ( CGMS) ; Salto do Taboco, rio Taboco , 08 Feb 2006, (fl. fr.) V. J. Pott 8727 ( CGMS) ; Corumbá, Embrapa , 30 Nov 2009, (fl.), E. L. M. Assis 96 ( COR) ; MS 228 , Porto da Manga , 30 Nov 2002, (fl.), A. L. F. Avellar 6 ( COR) ; Fazenda São Bento , 12 Nov 2011, (fl.), F. Bao 157 ( CGMS) ; Fazenda São João , 15 Dec 2014, (fl.), G. Catian 62 ( CGMS) ; Beira da Estrada parque, 28 Jul 2006, (fl.), J. S. Garcia 30 ( CGMS) ; Fazenda Alegria , 07 May 2009, (fl.), L. S. Rodrigues 6 ( CGMS) ; Lagoa do Jacadigo , 20 Apr 2011, (fl.), M. Rocha 165 ( CGMS) ; Região do Paraguai Mirim , 03 Jun 2009, (fl.), R. B. Rodrigues 66 ( CGMS) ; Baía 08, fazenda Nhumirim , 29 Nov 2008, (fl.), R. B. Rodrigues 93 ( CGMS) ; Estrada para Forte Coimbra , 20 May 1999, (fl. fr.), A. L. Sanches 103 ( UPCB) ; 1km do Mirante das Baias, 19 May 1999, (fl.), A. L. Sanches 96 ( UPCB) ; Em frente a fazenda Boa Sorte , 26 Jun 2003, (fl.), V. J. Pott 6389 ( CGMS) ; Costa Rica, Fazenda Pouso Frio , 26 Oct 2004, (fl.), A. S. Penha 69 ( CGMS) ; Inocência, fazenda Lagoinha , 19 Nov 2004, (fl.), V. J. Pott 7387 ( CGMS) ; Jateí, Parque Estadual das Várzeas do Rio Ivinhema , 13 Nov 2015, (fl.), L. M. Bergamo 5 ( CGMS) ; Miranda, Nhecolândia , 05 Aug 2012, (fl.), G. Catian 7 ( CGMS) ; Nioaque, Córrego Formiga , Br- 419, 24 Sep 2008, (fl.), V. J. Pott 10364 ( CGMS) ; Paranaíba, Estrada Parque , 25 Jun 2008, F. M. Leme 80 ( CGMS) ; Rio Verde de Mato Grosso, Estrada da Serra da Alegria , 02 Nov 2012, (fl.), F. M. Leme 20 ( CGMS) ; Rochedo, Córrego a 7 km da cidade, 28 Aug 1998, (fl.), G. A. Damasceno Júnio 1530 ( COR) ; Piauí, Parnaiba, Cipual , 15 Sep 2011, (fl. fr.), M. C. E. Nascimento 130 ( HDELTA) ; Delta , 22 May 2002, (fl.), L. Q. Matias 359 ( EAC) .

Notes:— Pontederia reflexa has been traditionally misidentified in South American botanical collections and floristic studies as P. parviflora or P. ovalis Martius (1830: 1140) (e.g., Castellanos 1959, Pott & Pott 2000, Nascimento et al. 2013). Indeed, the whitish colored flowers, characteristic of this group of species, can make their distinction difficult. However, a detailed morphological analysis has shown that the reflexed spathe, and also the long-sized trichomes (6–7 mm) without a differentiated dark storage cell are distinctive. In general, Pontederia species present a relatively continuous geographic distribution, fragmented only by the nature of the aquatic environment.

Figures

FIGURE 3. Geographic distribution of Pontederia gigantea (circles) and Pontederia reflexa (stars); BOL—Bolivia, PRY—Paraguay.

FIGURE 4. A–J. Pontederia reflexa. A. Habit. B. Different leaves showing the leaf-shape variation. C. Inflorescence. D. Trichome of the inflorescence rachis and perianth. E. Detail of a flower sectioned in the middle. F. Stamens. G. Trichome of the filament. H. Gynoecium. I. Trichome of the style. J. Dispersion unit. (D.J.L. Sousa 553).

FIGURE 5. A–C. Habitats with populations of Pontederia reflexa. A. Temporary lake in the Caatinga of Ceará, Brazil, in the dry season. B. Temporary lake in the Caatinga of Ceará, in the rainy season. C. Temporary pond in the Pantanal of Corumbá, Brazil. D–F. Pontederia reflexa. D. Inflorescence. E. Inflorescence in fruits. F. Dispersion unit. (Photo D.J.L. Sousa).