Research Article |
Corresponding author: Jefferson Carvalho-Sobrinho ( jef.sobrinho@gmail.com ) Academic editor: Clifford Morden
© 2020 Jefferson Carvalho-Sobrinho, Aline C. da Mota, Laurence J. Dorr.
This is an open access article distributed under the terms of the CC0 Public Domain Dedication.
Citation:
Carvalho-Sobrinho J, da Mota AC, Dorr LJ (2020) A new species of Eriotheca (Malvaceae, Bombacoideae) from coastal areas in northeastern Brazil. PhytoKeys 167: 31-43. https://doi.org/10.3897/phytokeys.167.57840
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A new species of Eriotheca (Malvaceae, Bombacoideae) from coastal areas in the northeastern Brazilian states of Alagoas and Bahia is described and illustrated. Eriotheca alversonii inhabits Atlantic coastal forest and is found principally on sandy soils in restinga vegetation. It is most similar morphologically to E. parvifolia. Both species have 3-foliolate leaves and short petioles on fertile branches, but the new species has smaller flowers, truncate to crenulate calyces, and smaller globose to subglobose capsules. The affinities of E. alversonii to morphologically similar species and its phenology are discussed. A distribution map and preliminary assessment of its conservation status are provided.
‘Bombacaceae’, ‘embiruçú’, endemism, plant taxonomy, restinga, sandy soils
Eriotheca Schott & Endl. is one of 17 genera in the Bombacoideae (Malvaceae), a pantropical subfamily that includes ca. 160 species (
Molecular phylogenetic analyses place Eriotheca and Pachira Aubl. in a clade characterized by striate seeds (
Eriotheca differs in a number of characters from Pachira. In addition to the smaller flowers in Eriotheca (up to 55 mm long), it also has filaments freely originating from a staminal tube (phalanges are absent), a single whorl in the androecium (
Eriotheca is characterized by mostly medium to emergent trees, leaves that are palmately compound with leaflets articulate at the petiole apex, flowers with a persistent calyx that is accrescent in fruit, a receptacle often with external nectaries, an androecium with 18 to 170 stamens and dorsifixed anthers, capsules with copious brown kapok, and numerous, striate seeds usually up to 1 cm in diameter (
The taxonomy of Eriotheca is challenging because type specimens are often phenologically incomplete (cf.
Ongoing studies on the systematics of Neotropical Bombacoideae (
This study was based on examination of herbarium collections, field observations, and digital images of specimens. Specimens were studied by visits to or loans from the following herbaria: ALCB, ASE, CEPEC, F, HUEFS, K, MBM, MO, NY, RB, SP, SPF, and US. Images of additional herbarium specimens were studied through the following websites: JSTOR Global Plants (https://plants.jstor.org/) and INCT – Herbário Virtual da Flora e dos Fungos (http://inct.splink.org.br/). Descriptions and measurements are based on dry herbarium specimens. The distribution map was prepared using QGIS v.3.12.2 (
Similar to Eriotheca parvifolia (Mart.) A.Robyns in its 3-foliolate, glabrous leaves, and short petioles on fertile branches, but differing in its linear-oblong (vs. large elliptic) flower buds, smaller (3–4 × 3–5 vs. 7 × 8–11 mm) cupuliform (vs. campanulate) calyces with apices truncate to crenulate (vs. mostly 3–5-lobed), fewer stamens (ca. 70 vs. ca. 120), and smaller capsules (15–21 vs. 30–35 mm long).
Brazil. Bahia: Maraú, entrada à direita ca. 3 km da entrada da cidade, propriedade particular ‘Espaço 21’, 14°10'27"S, 38°59'53"W, 7 m a.s.l., 08 Jul 2011 (lf, fl buds, fl), J.G. Carvalho-Sobrinho et al. 3126 (holotype: HUEFS).
Treelets or more often trees to 20 m tall; trunks to 50 cm dbh; buttresses 40 × 60 cm; branches often blackish in herbarium specimens. Terminal buds often persistent at branch apices, 5–11 mm long, attenuate and falcate apically. Leaves palmately compound; petioles on fertile branches up to 8 mm long (to 20 mm long on vegetative branches); petiolules absent to greatly reduced; leaflets 1–3(–5, in vegetative branches), 15–46(107) × 8–56 mm, coriaceous; proximal leaflets 8–27 mm wide; distal leaflets 8–56 mm wide; leaflet length-to-width ratio (1.5)1.9–2.5(3); leaflets narrowly obovate, elliptic to widely elliptic in fertile branches, rarely obcordate, apices retuse to emarginate, bases cuneate, margin entire, revolute, strongly revolute at base, glabrous on both surfaces, except for sparse microtrichomes on abaxial surface, discolorous, adaxial surface of fresh leaflets dark green and abaxial surface light green, abaxial surface of dry leaflets often reddish-brown, midrib prominent abaxially, secondary veins 7–10, impressed on both surfaces, intersecondary veins impressed on abaxial surface. Inflorescences axillary, 1–6-flowered cymes, borne on younger, terminal often leafy branches; pedicels 10–22 mm long, covered with blackish indumentum; bracteoles caducous. Flowers linear-oblong in bud, ca. 25 mm long; receptacles lacking glands; calyces 3–4 × 3–5 mm, cupuliform, truncate to crenulate, accrescent in fruit, outer surface covered with ferruginous indumentum, blackish when very young; petals 15–23 × 3–6 mm, oblanceolate, unilaterally apiculate, tomentose on both faces, internally with longitudinal lines of longer trichomes (sericeous) on one longitudinal half, whitish when fresh; stamens ca. 70, cream-colored when fresh; staminal tube 5 mm long, oblong, slightly expanded at apex, producing free filaments 11 mm long; ovary subglobose, the style inconspicuously 5–lobed. Capsules 15–21 × 13–20 mm, globose to subglobose, externally glabrous, kapok abundant, brown. Seeds numerous, 5 mm in diam., pyriform, glabrous.
Eriotheca alversonii A flowering branch B three-foliolate leaf C flower buds and vegetative terminal buds D flower bud E flower F, G petals; adaxial and abaxial views H staminal tube I ovary J, K anthers; undehisced and dehisced L stigma M fruit. All drawn from the holotype, except for fruit (L.A. Mattos Silva 1769). Scale bars: 3 cm (A, B); 1 cm (C, M); 5 mm (D–I); 0.5 mm (J–L).
Flower buds in June and July, open flowers in August and September and mature fruits in October and December to February.
Eriotheca alversonii is known from coastal vegetation mainly over quaternary white sand (restinga forest) or less frequently on clay-sandy soils in transitional vegetation between restinga forest and wet dense forest (“floresta ombrófila densa”), in the northeastern states of Alagoas and Bahia, Brazil.
Eriotheca alversonii is known from 19 collections from six different localities (municipalities). The extent of occurrence (EOO) of this species has been calculated to be 18,466 km2, which qualifies the species for the Vulnerable (VU) category, and the area of occupancy (AOO) was estimated to be 28 km2, which qualifies it for the Endangered (EN) category (
The specific epithet honors the North American botanist Dr. William (‘Bil’) Surprison Alverson (b. 1953) who has contributed greatly to our understanding of the phylogeny and systematics of Neotropical Bombacoideae.
Brazil. Alagoas: Barra de São Miguel, 9°50'25"S, 35°54'28"W, 28 Aug 1981 (lf, buds), M.N.R. Staviski et al. 940 (MAC); ibidem, loteamento próximo ao Rio Niquim, 24 Jan 2008 (lf, fr), L. Omena 4 (MAC); Marechal Deodoro, APA de Santa Rita, Sítio Campo Grande, vegetação sobre cordões litorâneos, 25 Sept 1990 (lf, fl, fr), 10°11'4"S, 36°29'50"W, R.P. Lyra-Lemos 1750 (ALCB, MAC, SP); ibidem, APA de Santa Rita, Sítio Campo Grande, 25 Sept 1990 (lf, fl), R.P. Lyra-Lemos & J.E. de Paula 1762 (MAC, SPF); ibidem, APA de Santa Rita, próximo a Campo Grande, 10°11'4"S, 36°29'50"W, 24 Aug 1999 (lf, fl), R.P. Lyra-Lemos & I.A. Bayma 4207 (ESA, MAC, SP); ibidem, Dunas do Cavalo Russo, 04 Feb 2009 (lf), Chagas-Mota & L.M. Leão 1826 (MAC); ibidem, Dunas do Cavalo Russo, 12 Feb 2009 (lf), Chagas-Mota 1987 (MAC); ibidem, Dunas do Cavalo Russo, 9°42'37"S, 35°53'42"W, s.d. (st), J.C. Lemos 28 (MAC); ibidem, Dunas do Cavalo Russo, Povoado Cabreiras, 30 Aug 2008 (lf, fl), R.P. Lyra-Lemos et al. 11457 (MAC); ibidem, encosta de tabuleiro próximo às dunas do Cavalo Russo, 09 Dec 1998 (lf, fr), R.P. Lyra-Lemos 4086 (MAC, SP); ibidem, Mucuri, próximo a Campo Grande, vegetação sobre cordões arenosos, 24 Aug 1999 (lf, fl), R.P. Lyra-Lemos & I.A. Bayma 4235 (ASE, MAC); ibidem, próximo Praia do Francês, 31 Jan 1982 (fr), D. Araújo s.n. (RB1382616); ibidem, Sítio Bom Retiro, 09°41'52"S, 35°53'36"W, 07 Feb 2007 (lf, fr), A.I.L. Pinheiro & S. Mendes 327 (MAC). Penedo, Marituba do Peixe, 19 Aug 2006, M.N. Rodrigues et al. 1983 (lf, fl), 10°17'55"S, 36°25'37"W (MAC). Bahia: Cairu, Gamboa, 13 Aug 1993 (lf, imm fr), M.L. Guedes et al. s.n. (ALCB 26059); ibidem, Fazenda Bela Vista, 14 Sept 1993 (lf, imm fr), M.L. Guedes et al. s.n. (RB 426439); Maraú, estrada à direita para uma propriedade particular, a ca. 3 km da entrada da cidade de Maraú, 14°09'32"S, 39°00'1"W, 19 Aug 2008 (lf, fl), L.P. Queiroz et al. 13018 (HUEFS); ibidem, entrada à direita ca. 3 km da entrada da cidade, propriedade particular ‘Espaço 21’, 14°10'17"S, 38°53'53"W, 20 m a.s.l., 07 Jul 2011 (lf, buds), J.G. Carvalho-Sobrinho et al. 3125 (HUEFS); Nilo Peçanha, ramal para o povoado de Itiuca, ramal com entrada no km 8 da rodovia Nilo Peçanha/Cairu (BA 250), lado direito, piaçaval em capoeira, solo arenoso, 24 Oct 1984 (lf, fr), L.A. Mattos Silva & T.S. Santos 1769 (CEPEC).
Eriotheca alversonii is characterized by leaves on fertile branches 1–3-foliolate, petioles up to 8 mm long, leaflets coriaceous, elliptic to broadly-elliptic or narrowly obovate, proximal leaflets up to 27 mm wide, flower buds linear-oblong, and small capsules globose to subglobose up to 21 mm long with glabrous valves. On herbarium sheets, specimens are characterized by terminal vegetative buds with attenuate, falcate apices and by leaves on fertile branches often 1–2-foliolate and often reddish-brown on the abaxial surface.
Eriotheca alversonii is morphologically similar to E. parvifolia – a shrubby species to 2.5 m tall endemic to the arenitic-quartzite rock outcrops in the Espinhaço Mountain Range in the state of Minas Gerais – by the small petioles, the small, narrowly obovate leaflets with retuse to emarginate apices, and the often persistent leaves on fertile branches; furthermore, both species flower from July to September. However, E. alversonii differs from E. parvifolia in its oblong-linear (vs. large elliptic) flower buds, calyces 3–4 × 3–5 (vs. 7 × 8–11) mm that are cupuliform and truncate to crenulate (vs. campanulate and mostly 3–5-lobed), stamens ca. 70 (vs. ca. 120), and capsules 15–21 (vs. 30–35) mm long (Table
Character | E. alversonii | E. macrophylla | E. parvifolia |
---|---|---|---|
Leaves on fertile branches | Present | often absent | present |
Petiole length of terminal leaf | up to 8 | 21–45(–65) | 8–26(–37) |
Number of leaflets of terminal leaf | 1–3 | 3(–5) | (2–)3(–5) |
Proximal leaflets width (mm) | 8–27 | 24–66 | 8–31 |
Number of secondary veins | 7–10 | 12–18 | 14–20 |
Inflorescence position | younger, terminal, often leafy branches | old branches often leafless and modified brachyblasts | terminal, leafy branches |
Number of flowers per cyme | 1–5 | 2–7 | 1–3 |
Pedicel length (mm) | 10–22 | 14–25 | 10–15(–25) |
Flower bud shape | linear-oblong | broadly elliptic | broadly elliptic |
Calyx dimensions (mm) | 3–4 × 3–5 | 5–6 × 7–9 | 7 × 8–11 |
Calyx apex | truncate to crenulate | crenulate | mostly 3–5-lobed |
Calyx shape | cupuliform | cupuliform | campanulate |
Petal dimensions (mm) | 15–23 × 3–6 | 30 × 11 | 24–31 × 9–15 |
Number of stamens | ca. 70 | 140 | 125 |
Staminal tube length (mm) | 4–5 | 4 | 5 |
Fruit length (mm) | 15–21 | 38–60 | 27–60 |
Fruit shape | globose to subglobose | obovoid | obovoid |
Seed diameter (mm) | 4 | ca. 10 | 6–7 |
Flowering period | July to September | October to December | July to September |
Fruiting period | August to October and December to February | December to February | October to December |
Eriotheca alversonii emerged as sister to E. candolleana (K.Schum.) A.Robyns in a multi-locus DNA sequence-based phylogeny (labeled as ‘Eriotheca sp. CS3125’ in Fig.
Eriotheca alversonii has been frequently misidentified as E. macrophylla – a tree species inhabiting restinga and semideciduous forest in the Atlantic coast of northeastern Brazil – probably because in both species the calyces are cupuliform and the leaflets of the fertile branches are 1.5–2.3× longer than wide. However, E. alversonii can be readily distinguished from E. macrophylla by its terminal, falcate vegetative buds with attenuate apices (vs. straight buds with acute apices), linear-oblong (vs. broadly elliptic to oblong-obovate) flower buds, smaller calyces (3–4 × 3–5 mm vs. 5–6 × 7–9 mm), smaller petals (19–20 × 4–5 vs. 20–32 × 10–15 mm), fewer stamens (ca. 70 vs. 90–140), and smaller fruit (15–21 mm vs. 38–60 mm long) that are globose to subglobose (vs. obovoid). Moreover, E. alversonii is characterized by inflorescences borne on younger terminal and often leafy branches while the inflorescences of E. macrophylla are borne on old branches that are often leafless and modified as brachyblasts.
We thank the curators of the herbaria cited in the text for kindly sending material on loan; Natanael Nascimento for the line drawings; Jefferson Rodrigues Maciel for the map; Mário Terra for help during fieldwork; and PPGBot/UEFS for financial support for the fieldwork; Jacquelyn Kallunki and one anonymous reviewer for valuable suggestions on the manuscript.
Fieldwork was supported by the Fundação de Amparo à Pesquisa do Estado da Bahia (process APP0006/2011). JGCS thanks the Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq (processes 563546/2010-7-REFLORA and 158916/2014-0) for financial support. JGCS also thanks CAPES for a sandwich fellowship through the REFLORA program (process BEX 5415/13-6). The authors have declared that no competing interests exist.
Selected herbarium specimens of Eriotheca macrophylla and E. parvifolia examined for this study.
Eriotheca macrophylla (K.Schum.) A.Robyns
Brazil. Alagoas: São José da Lage, BR 104, 11 Nov 2010, Chagas-Mota 9270 (MAC). Bahia: Ilhéus, on road to Vila Brasil, 10 km West of junction with BA001, the junction ca. 40 km south of Ilhéus, just north of the Rio Acuípe, 15°06'S, 39°04'W, 10 May 1993 (lf, fl), W. Thomas et al. 9843 (CEPEC, NY, SP). Itacaré, entre a Praia do Farol e a Praia da Ribeira, 14 Dec 1992 (lf, fl), A. Amorim et al. 951 (CEPEC). Itapebi, Faz. Dois Irmãos, Rodovia para Potiraguá, 10 Nov 1970 (lf, fl), R.S. Pinheiro & T.S. Santos 419 (CEPEC). Jequié, Fazenda Brejo Novo, a 10,5 km da Av. Otávio Mangabeira entrado pela Exupério Miranda no Bairro do Mandacaru, 13°56'53.6"S, 40°06'42"W, 716 m a.s.l., 08 Dec 2004 (st), G.E.L. Macedo & J.L. Paixão 1499 (HUEFS). Morro do Chapéu, na rodovia, ca. 20 km antes da cidade, 21 Jan 2012 (lf, fr), J.G. Carvalho-Sobrinho et al. 3305 (HUEFS). Porto Seguro, parte sul entre os municípios de Ajuda e Porto Seguro, 08 Nov 1963 (lf, buds), A.P. Duarte 7999 (RB, SP). Santa Cruz de Cabrália, Res. Bio. Pau-Brasil, 11 Dec 1971 (lf, fl), A. Eupunino 94 (CEPEC). Santa Terezinha, 14,5 km na rodovia Elísio Medrado/Sta. Teresinha, Torre da Embratel, ca. 7 km distante do Distr. de Pedra Branca, Serra da Jiboia, 12°51'13"S, 39°28'33"W, 750 m a.s.l., 24 Feb 2000 (lf, fr), J.G. Jardim et al. 2808 (HUEFS, NY, SPF). Espírito Santo: Conceição da Barra, Área 157 da Aracruz Celulose S.A., 28 Oct 1993 (lf, buds) O.J. Pereira et al. 5163 (VIES). Linhares, Reserva Natural da CVRD, estrada Flamengo, km 08, 03 Dec 2004 (lf, buds), D.A. Folli 4999 (CVRD); ibidem, Reserva Natural da CVRD, estrada Flamengo, km 07, próximo ao pátio, 14 Jan 1994 (lf, fr), D.A. Folli 2170 (CVRD). Pernambuco: Brejo da Madre de Deus, Mata do Bituri, Serra do Prata, próximo do mirante, 08°12'27"S, 36°23'32"W, 920–1030 m a.s.l., L.M. Nascimento s.n. (HUEFS 57136, PEUFR).
Eriotheca parvifolia (Mart.) A.Robyns
Brazil. Minas Gerais: Grão Mogol, estrada para o Rio Ventania, ca. 16°32'S, 42°49'W, 900 m a.s.l., 05 Sept 1990 (lf, fl), G.L. Esteves CFCR 13348 (HUEFS, SPF); ibidem, Serra do Espinhaço, área N Diamantina, campo rupestre near Córrego Lajeado and the junction of the side road from Cristais with the Road Diamantina-Biribiri, ca. 9km NNW-N Diamantina, 1080 m a.s.l., 18°10'S, 43°37'W, G.L. Esteves CFCR 15511 (NY, SPF); ibidem, estrada para Josenópolis, 17 Jul 1998, G. Hatschbach et al. 67961 (MBM); ibidem, Vale do Rio das Mortes, a oeste da cidade, 24 Jul 1986 (lf, fl), D.C. Zappi et al. CFCR 9892 (BHCB, MAC, R, SPF). Monte Azul, estrada de terra para Formosa, 15°12'S, 42°48'W, 1192 m a.s.l., 27 Oct 2010 (lf, fr), J.G. Carvalho-Sobrinho et al. 2870 (HUEFS).