Eriotheca alversonii Carv.-Sobr. & Dorr, 2020

Carvalho-Sobrinho, Jefferson, Mota, Aline C. da & Dorr, Laurence J., 2020, A new species of Eriotheca (Malvaceae, Bombacoideae) from coastal areas in northeastern Brazil, PhytoKeys 167, pp. 31-43 : 31

Eriotheca alversonii Carv.-Sobr. & Dorr sp. nov. Figs 1 , 2

Diagnosis.

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).

Type.

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).

Description.

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.

Phenology.

Flower buds in June and July, open flowers in August and September and mature fruits in October and December to February.

Distribution and habitat.

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.

Conservation status.

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 ( Bachman et al. 2011; IUCN 2019). Based on herbarium specimen labels, three collections of E. alversonii were made inside one state-level protected Reserve (APA de Santa Rita) as explicitly stated in collectors’ descriptions, and an additional four collections probably were made inside state- (APA Pratigi and APA Marituba do Peixe) or federal-level (Reserva Extrativista de Canavieiras) protected areas; nevertheless, all these protected areas allow sustainable use of natural resources and none of them are of the highest level of protection (level I or II) described by the IUCN ( Dudley 2008). Furthermore, restinga habitat currently is being lost at an accelerated rate due to anthropogenic pressures ( Rocha et al. 2007; Pergentino and Landim 2014) and most collections of E. alversonii were made on farms. Therefore, due to the rapid rate of deforestation of the much fragmented restinga vegetation and the small AOO (32 km2) of E. alversonii , we consider this species to be Endangered (EN category) according to IUCN criteria ( IUCN 2019).

Etymology.

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 .

Additional specimens examined.

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).

Figures

Figure 1. 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).

Figure 2. Distribution map of Eriotheca alversonii. Gray-shaded areas represent the original extent of Atlantic forest. State boundaries are indicated by continuous lines. Abbreviations for Brazilian states: AL: Alagoas; BA: Bahia; PE: Pernambuco; SE: Sergipe.