Ludwigia erecta, H.Hara, 1953

Rocha, Amanda Macêdo & Melo, José Iranildo Miranda de, 2020, Diversity and distribution of Ludwigia (Onagraceae) in Paraíba State, Northeastern Brazil, European Journal of Taxonomy 639, pp. 1-24 : 8-12

Ludwigia erecta (L.) H.Hara

Figs 3 a–j, 4a–c, 5a

Material examined

BRAZIL – Paraíba • Alagoa Nova, Fazenda Roberto ; 8 Mar. 2012; fr.; E. Melo 11062; HUEFS • Alagoinha, Estação Experimental ; 10 Sep. 1942; Lauro Xavier s.n.; JPB [900] • Araruna; 19 Dec. 2016; fr.; A.M. Rocha 09; HACAM • Areia, Mata do Pau Ferro ; 5 Oct. 1999; M.R. Barbosa 1841; JPB • Bananeiras, Cachoeira do Roncador ; 15 Jan. 1998; fl. and fr.; C. Schlindwein 862; JPB • Boqueirão, Açude Epitácio Pessoa ; 9 Apr. 2017; fl. and fr.; A.M. Rocha 15; HACAM • Cabaceiras, Lajedo de Pai Mateus ; 3 May 2004; fl.; V.P.M. Coelho et al. 6278; JPB • Cajazeiras, bank of Açude de Lagoa de Arroz ; 21 Dec. 2014; fr.; H.O. Machado-Filho 532; CSTR • Camalaú, Açude Camalaú ; 15 Oct. 2013; H.O. Machado-Filho 17 6; JPB • Fagundes, Pedra de Santo Antônio ; 29 Aug. 2005; S. Pitrez & G. Trajano 639; EAN • Lagoa Seca, Cachoeira do Pinga ; 11 Jul. 2017; fl. and fr.; A.M. Rocha 24; HACAM • Monte Horebe ; 15 Mar. 2000; M.R. Barbosa et al. 2041; JPB • Monteiro ; 27 Jun. 2017; fl.; A.M. Rocha 21; HACAM • Passagem, Fazenda ABA ; 6 Apr. 2017; fl. and fr.; A.M. Rocha 13; HACAM • Patos, Açude São Bento ; 7 Dec. 2016; fl. and fr.; A.M. Rocha 07; HACAM • Poço Dantas ; 11 Oct. 2007; fl. and fr.; C.E.L. Lourenço et al. 285; JPB • Pombal ; 1 Dec. 1955; José Carneiro s.n.; JPB [2902] • Puxinanã ; 13 Jul. 2017; fl. and fr.; A.M. Rocha 26; HACAM • Remígio ; 13 Sep. 2005; fl.; L.P. Felix 10800; EAN • Santa Luzia ; 20 Apr. 2017; fl. and fr.; A.M. Rocha 17; HACAM • Santa Terezinha, RPPN Fazenda Tamanduá , inner forest, on the bank of a temporary river; 3 May 2011; fl.; D.S. Lucena et al. 111; CSTR • Sapé , margin of road PB-041; 1 Nov. 2017; fl.; A.M. Rocha 29; HACAM • Serra Branca, Serra do Jatobá ; 21 Jul. 2016; fl. and fr.; A.M. Rocha 01; HACAM • Sossego ; 4 Aug. 2008; fl.; S.G. Gerlandio 17; EAN • Sousa, Açude São Gonçalo ; 15 Oct. 2013; fl.; H.O. Machado-Filho 196; PEUFR • Várzea, Cachoeira de São Pórfiro ; 24 Aug. 2017; C.D. Ferreira et al. 36; CSTR .

Description

Herbs to subshrubs, 0.4–2 m high, erect; branches angular, scantily strigose. Leaves sessile; blade 7.1– 11.2 × 1.9–2.9 cm, with entire margin, membranous, elliptical to lanceolate, apex acute, base decurrent, margins and veins of the dorsal face sparsely strigose. Flowers tetramerous, sessile; bracteoles 2, near the base of hypanthium, smaller than 1 mm in length.; sepals 4.2–4.5 × 1.8–2 mm, green, lanceolate, with acute apex, external face sparsely strigose; petals 5.1–5.5 × 3.0– 3.3 mm, golden yellow, obovate, with rounded apex; hypanthium ca 8 mm in length, 4-locular; style ca 1 mm in length, stigma globose; stamens 8, anthers globose; plain nectariferous disk with depressed nectaries, pilose, surrounding the base of each epipetalous stamen. Capsule 15–16 × 2–2.5 mm, oblongoid, 4-angled, internally not dimorphic, sparsely strigose. Seeds smaller than 1 mm in length, oblongoid, pluriseriate, not embedded in the endocarp, raphe non-inflated, with diameter narrower than the body of the seed.

Distribution

The species is widely distributed in Neotropical region, from Mexico and Florida ( USA) to Brazil and Paraguay ( Goldblatt & Raven 1997). In Brazil, it occurs in the following regions and states: North (AM, AP, PA, RO), Northeast (AL, BA, CE, MA, PB, PE), Center-West (DF), Southeast (MG, RJ, SP) and South (PR), associated with Amazon, Caatinga, Savanna (Cerrado), Atlantic Rainforest and Pantanal phytogeographic domains (Vieira 2015).

Habitat and phenology

In Paraíba State the species may be found on the banks of lakes, dams, rivers, close to waterfalls or on humid sites, associated with Caatinga or the Atlantic Rainforest. Flowering and fructification occur between March and July and between December and January.

a. Ludwigia erecta (L.) H.Hara (), L. helminthorrhiza (Mart.) H.Hara () , L. hyssopifolia (G.Don)

Exell (). b. L. leptocarpa (Nutt.) H.Hara () , L. nervosa (Poir.) H.Hara () , L. octovalvis (Jacq.) P.H.Raven () . Maps by E. de Morais Rodrigues.

Conservation status (Paraíba State, Brazil)

The extent of occurrence (EOO) of Ludwigia erecta in the Paraíba State is 43 308.511 km 2, exceeding the upper limit for Vulnerable status under the criterion B1. The species has an area of occupancy (AOO) of 124 km 2, within the limit for Endangered status under the criterion B2; however, L. erecta is recorded from more than 5 locations, 33 in the Paraíba State, and there is currently no evidence of a particular threat to its habitat, and no decline in the populations. Despite the AOO that suggests it is in Endangered category, L. erecta is evaluated as Near Threatened (NT), due to its wide distribution in Paraiba State.

Note

Ludwigia erecta is mainly distinguished by its oblongoid, tetrangular capsule and pluriseriate seeds, which are not embedded in the endocarp. The name of the section Ludwigia sect. Pterocaulon to which the species belongs refered to its four-angled stems and capsules ( Ramamoorthy 1979).

Figures

Fig. 3. a–j. Ludwigia erecta (L.) H.Hara, A.M. Rocha 26. a. Habit. b. Flower. c. Sepal. d. Petal. e. Gynoecium. f. Detail of stigma. g. Bracteoles. h. Fruit. i. Transversal cut of the fruit. j. Seed. – k–r. L. helminthorrhiza (Mart.) H.Hara, A.M. Rocha and E.M. Rodrigues 27. k. Habit. l. Flower. m. Sepal. n. Detail of stigma. o. Fruit. p. Transversal cut of the fruit. q. Section of the endocarp. r. Seed. Illustrations by R.M.A. de Carvalho.