Ludwigia leptocarpa H. Hara
Creators: name: Rocha, Amanda Macêdo
name: Melo, José Iranildo Miranda de
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Onagraceae
Ludwigia
Ludwigia leptocarpa

description: Ludwigia leptocarpa (Nutt.) H.Hara
Figs 5b, 6 l–u, 7a–c
Material examined
BRAZIL – Paraíba • Areia, UFPB; 2 Dec. 2016; fl.; A.M. Rocha 06; HACAM • João Pessoa, riparian vegetation of the Rio do Cabelo, Mangabeira; 19 Nov. 2010; fl.; L.A. Pereira 45; JPB • João Pessoa, AeroClube; 18 Nov. 2008; bud and fl.; A.C.C. Almeida 141; JPB • Patos, Assentamento Patativa do Assaré; 20 Jan. 2012; fl.; C. Torres 144; CSTR • Pirpirituba; 9 Sep. 2016; fl.; A.M. Rocha 03; HACAM • Poço Dantas; 11 Oct. 2007; fl.; G.A. Costa et al. 34; JPB • Rio Tinto, Gameleira; 6 Apr. 1989; fl.; L.P. Felix 3685; EAN • Sapé; 19 May 2014; fl.; H.O. Machado-Filho 426; PEUFR.
Description
Subshrubs, 1–1.6 m high, erect; branches cylindrical, hirsute. Leaves subsessile; blade 7–12.2 × 2.1– 2.6 cm, with entire margin, membranous, elliptical, with acute apex and decurrent base, with hirsute nervure. Flowers pentamerous (sometimes hexamerous), pedicels ca 7 mm long.; bracteoles 2, near the base of hypanthium, smaller than 1 mm in length; sepals 10–11 × 3.5–4 mm, green, lanceolate, with attenuate apex, external face hirsute; petals 15–16 × 12–13 mm, golden yellow, obovoid, shortunguiculated, with rounded apex; hypanthium ca 2 cm long, 5-locular; style ca 4 mm long, stigma capitate; stamens 10, anthers oblong; convex nectariferous disk with depressed nectaries, densely pilose, surrounding the base of each epipetalous stamens. Capsule 3.5–3.6 × 2.6 cm, cylindrical, internally nondimorphic, hirsute. Seeds ca 1 mm long, ellipsoid, uniseriate, embedded in horseshoe-shaped endocarp from which the seeds are easily detached, raphe non-inflated, with diameter narrower than the body of the seed.
Distribution
The species has a wide distribution in Neotropical region, from southeast USA to Argentina and Africa (Zardini & Raven 1997). In Brazil, it occurs in almost all phytogeographic domains in North (AC, AM, PA), Northeast (AL, BA, CE, PB, PI, SE), Center-West (DF, GO, MS, MT), Southeast (ES, MG, RJ, SP) and South (PR, RS, SC) Region (Lima et al. 2013; Vieira 2015).
Habitat and phenology
In Paraíba State, L. leptocarpa may be found on the banks of lakes and in the flooded areas, in the vegetation of Caatinga and Atlantic Rainforest. It is flowering from September to December and fruiting in September.
Conservation status (Paraíba State, Brazil)
The extent of occurrence (EOO) of Ludwigia leptocarpa is 15 683.720 km 2 (within the limit for Vulnerable status under the criterion B1) and its area of occupancy (AOO) is 32 km 2 (within the limit for Endangered status under the criterion B2). It is known from eight specimens representing a total of eight locations, within the threshold for Vulnerable under criterion B, no population has been recorded in a protected area. In the Paraíba State, the species falls under the category Vulnerable (VU), defined according to criterion B1ab(ii,iii).
Note
Ludwigia leptocarpa is characterized by a yellow pentamerous corolla, which is a unique feature within the genus, as all other species of the genus have a tetramerous yellow corolla or a pentamerous white corolla. Uniseriate seeds embedded in horseshoe-shaped endocarp are the most relevant characteristic of L. leptocarpa. The horseshoe-shaped endocarp is a diagnostic feature of Ludwigia sect. Seminuda, a section to which L. leptocarpa belongs (Zardini & Raven 1992; Wagner et al. 2007).
description: Published as part of Rocha, Amanda Macêdo & Melo, José Iranildo Miranda de, 2020, Diversity and distribution of Ludwigia (Onagraceae) in Paraíba State, Northeastern Brazil, pp. 1-24 in European Journal of Taxonomy 639 on pages 15-17, DOI: 10.5852/ejt.2020.639, http://zenodo.org/record/3786601