Luehea conwentzii K.Schum.

Gerace, Samuele, Peruzzi, Lorenzo, Baumgratz, José Fernando A. & Bovini, Massimo G., 2025, Flora of Rio de Janeiro: the genus Luehea (Malvaceae: Grewioideae), Rodriguesia (e 00512024) 76, pp. 1-13 : 6

2. Luehea conwentzii K.Schum. , in Martius, Fl. bras. 12(3): 154. tab. 31. 1886.

= Luehea eichleri K.Schum. in Martius, Fl. bras. 12(3): 158. 1886. Figs. 1 ; 2 c-d; 3a

Trees, 5–22 m hight. Petiole 0.55–1.3 cm long. Leaves 5.7–13.1 × 2.2–5.8 cm, semi-coriaceous, elliptic to lanceolate, base cuneate to rounded, adaxial surface green, the younger with stellate trichomes, the adults glabrous, abaxial surface white, with densely arachnoid trichomes and sparse stellate trichomes. Inflorescence 10–40 flowers, 3.5–13.5 cm long, terminal and axillary; pedicel 0.4–1.1 cm long. Flowers 2–4 cm wide. Epicalyx with 7–9 bracteoles, 0.35–0.6 × 0.1–0.15 cm, linear. Sepals 0.85–1.2 × 0.15–0.3 cm, lanceolate to ovate, plane. Petals 0.9–1.7 × 0.2–0.34 cm, white, linear, margin entire. Androecium grouped in 5 phalanges, free; staminodes 0.35–0.75 cm long; stamens 0.5–0.8 cm long. Ovary 0.2–0.3 × 0.2–0.3 cm, globular to elliptic, angular in transversal sect ion; st yle 0.38 – 0.6 cm long, completely pubescent, stigma 0.13–0.22 cm diam., 0.03–0.1 cm long. Capsule 1.2–1.7 × 0.6–1.1 cm, elliptic to ovate, base rounded to cuneate, apex acute to obtuse, villose, valve with dorsal surface deeply sulcate with central relief, angular cross section, margins plane, not crest-like. Seeds 0.75–1.14 × 0.25–0.4 cm. Selected examined material: Armação dos Búzios, mata da Fazenda José Gonçalves , 27.II.1997, fl., P.R. Farag 348 ( RB). Cabo Frio, Campos Novos , 10.VII.1997, fr., C. Farney et al. 3578 ( RB). Guapimirim, Estaçao Ecológica Estadual de Paraiso , 18.II.1992, fl., H.C. de Lima et al. 4367 ( RB). Maricà, Serra do Camburi , 17.IV.2016, fr., G.A. de Quieroz et al.363 ( RB). Miguel Pereira, Governador Portela, Monte Sinai , 21.VII.1932, fl. and fr., G.M. Nunes 195 (R). Rio de Janeiro, Jardim Botanico Rio de Janeiro, canteiro 26D, 23.III.2016, fl. and fr., J.R. Mattos et al. 339 ( RB). São Pedro da Aldeia, São Mateus, estrada para Macaé , 30.VII.1987, fr., H.C. de Lima & J. Caruzo 3093 ( RB).

Luehea conwentzii is endemic to the phytogeographic domain Atlantic Forest of the Brazilian Southeast and South, restricted to the states of Rio de Janeiro, EspÍrito Santo, São Paulo, and Paraná ( Souza & Esteves 2002; Gerace & Bovini 2020). In Rio de Janeiro state, Luehea conwentzii occurs at elevations that range from 30 to 700 m in submontane to montane ombrophilous forests and dense ombrophilous forests, rarely along roadsides ( Fig. 1 ). This species is found in the following conservation units: Área de Proteção Ambiental Bairro de Grumari (Rio de Janeiro), Parque Nacional da Tijuca (Rio de Janeiro), and Estação Ecológica Estadual de ParaÍso (Guapimirim). Flowering was recorded from February to July, and fruiting from March to August.

Luehea conwentzii shows the smallest flowers and leaves among the studied species.Furthermore, with a height that can exceed 20 m, this species is one of the few in the genus to prefer more closed and humid environments. This feature is also observed in L. cymulosa Spruce ex Benth. , an Amazonian species. Luehea conwentzii can be easily identified both for the flower, much smaller than the other species, with linear petals and staminodes as long as the stamens, and for the fruits with reduced size and dorsal surface valves deeply sulcate with central relief ( Figs. 2d ; 3a ). These characteristics of the fruit are typical of this species.

Figures

Figure 1 – Geographical distributions of Luehea candicans var. candicans, L. candicans var. gracilis, L. conwentzii and L. divaricata in the state of Rio de Janeiro.

Figure 2 – a-b.Luehea candicans – a. leaf; b. capsule.c-d.L. conwentzii – c. leaf; d. capsule. e-f.L. divaricata – e. leaf; f. capsule. g-h. L. macrophylla – g. leaf; h. capsule. i-j. L. ochrophylla – i. leaf; j. capsule. k-l. L. paniculata – k. leaf; l. capsule. m-p. L. speciosa – m. leaf; n-p. capsules. (a-b. S. Lima 406; c-d. C. Farney et al. 3578; e-f. J.F.A. Baumgratz et al. 1724; g-h. S. Gerace 128; i-j. T.M. Scarponi; k-l. D.N.S. Machado & L.A. Ribas 285; m-o. G.A. de Queiroz 408; n. B.N. Riguetti 18; p. D. Costantino). Photos by Samuele Gerace.

Figure 3 – a. Luehea conwentzii – fruiting branchlet. b-c. L. divaricata – b. fruiting branchlet; c. flower. d-e. L. macrophylla – d. fertile branchlet; e. detail of the fertile branchlet. f. L. speciosa – fruiting branchlet. Photos: a. Massimo Bovini; b-c. Marcus Coelho; d-e. Samuele Gerace; f. Carlos Ferreira.