Eriotheca paganuccii Carv.-Sobr., A. C. Mota & Dorr

Carvalho-Sobrinho, Jefferson, da Mota, Aline C. & Dorr, Laurence J., 2024, Eriotheca paganuccii (Bombacoideae, Malvaceae), a new endangered species from montane forests in the Atlantic Forest of Bahia, northeastern Brazil, PhytoKeys 243, pp. 215-230 : 215-230

Eriotheca paganuccii Carv.-Sobr., A. C. Mota & Dorr sp. nov.

Figs 1 , 2 , 3 , Table 1

Diagnosis.

Similar to Eriotheca obcordata A. Robyns due to its absence of buttresses, obcordate leaflets, oblong to oblanceolate flower buds, oblanceolate petals, and stamens c. 80 in number, but differing in its caducous (vs. often persistent) bracteoles, larger calyces (7 × 7–9 mm vs. 5– 5 mm), globose to subglobose (vs. obovoid) capsules, scanty (vs. abundant) kapok, seed number (c. 10 vs. numerous) per fruit, seed size (10–19 mm vs. 5–7 mm) long, and marcescent, lignified calyces that often split into patent lobes (in herbarium collections, at least).

Type.

Brazil. Bahia: Castro Alves, Serra da Jiboia (= Serra da Pioneira), Mata higrófila , 12 ° 51 ' 11 " S, 39 ° 28 ' 19 " W, 22 Dec 1992 (lf, fr), L. P. Queiroz & T. S. N. Sena 3008 (Holotype: HUEFS barcode 000132176! Isotype: SP barcode 057771!) .

Description.

Trees 2.5–5 (– 8) m tall, lacking buttresses; branches glabrous, often lenticellate; fertile branches often suberized. Terminal bud often persistent at branch apex, 11–15 mm long, acute at apex of mature branches, often curved at apex of younger branches. Leaves palmately compound; petiole doubly-pulvinate, (15 –) 40–65 × 2–3 mm, cylindric, swollen at base when fresh; petiolule greatly reduced; leaflets 3–5 (often 1–2 - foliolate on canopy branches), coriaceous to strongly coriaceous, glabrous on both surfaces, discolorous, margin entire, revolute, the adaxial surface covered by dense indumentum of scales with irregular outline, the abaxial surface light green when fresh, the midrib yellowish adaxially, strongly prominent abaxially, secondary veins 10–13, prominent on abaxial surface, impressed on adaxial surface, the tertiary veins impressed on abaxial surface; leaflets often naviculate when young, distal leaflets 48–190 × 35–88 mm, length-to-width ratio 1.4–2.7, obovate, obcordate, widely-elliptic, or rarely elliptic, apex obtuse, truncate to retuse, base acute, decurrent or obtuse, rarely falcate; proximal leaflets 24–161 × 15–79 mm, length-to-width ratio 1.4–2, elliptic to widely-elliptic or elliptic-obovate, apex apiculate, base acute, decurrent, or obtuse. Inflorescences 1–8 - flowered umbelliform cymes, borne on terminal, often suberized, leafless branches; pedicels 11–25 × 2.5 (– 4 at apex) mm, with sparse scales, green to blackish-green when fresh, the bracteoles ovate, caducous. Flower buds oblongoid when young to narrowly obovoid just before anthesis, receptacle c. 1–2 mm long, glandular, rarely eglandular; calyx 7–8 × 7–8 (– 10 mm when compressed on herbarium sheets), glabrous except for sparse scales, urceolate when fresh, cupuliform to campanulate on herbarium sheets, apex inconspicuously crenulate to shortly 5 - lobed, the lobes irregularly-shaped to triangular, marcescent in fruit, the outer surface green to blackish-green covered with sparse ferruginous indumentum; petals 23–26 (31–32 when fresh) × 4 mm at the base to 8 mm at the apex, cream-colored to pale yellow on both faces when fresh, greyish-brown when dried, reflexed by the distal length, oblanceolate, unilaterally apiculate and curved, tomentose on both faces, internally with longitudinal lines of longer trichomes on one longitudinal half (sericeous); stamens c. 80, reddish-brown when fresh, the staminal tube 7 × 4 mm, slightly enlarged at ovary height, slightly constricted at apex, producing free filaments 20 mm long; ovary globose, densely ferruginous indument at the distal half, style white, glabrous, stigma light-green. Loculicidal capsules woody, globose to subglobose, 35–50 mm long (– 70 mm, when fresh), length-to-width ratio 0.8–0.9, externally ferruginous when young, the indument caducous at maturity, the kapok scanty, golden, the marcescent, lignified calyces often splitting into patent lobes on herbarium sheets. Seeds c. 10 per fruit, (11 –) 14 (– 19) × (10 –) 11 (– 14) × (9 –) 10 (– 12) mm (L × W × H), brown, glabrous, angulate, three-sided (two plane and one concave), 5 - striate, three striae often coinciding with seed corners, two striae on dorsal (opposite the hilum) side, striae the same color as the testa.

Phenology.

Eriotheca paganuccii was collected in flower in September (very young flower buds) and December, and in fruit in October (very young fruits), December to February.

Distribution and habitat.

Eriotheca paganuccii is endemic to montane wet forests found between 750 m and 850 m in elevation near granitic-gneissic rock outcrops on summits of mountains in the Atlantic Forest of Bahia, northeastern Brazil (Fig. 3 ). Remnants of Montane Forest in the Atlantic Forest of Bahia are known for their outstanding diversity and include several endemic angiosperm taxa in Bertolonia Raddi , Dichorisandra J. C. Mikan , Macrocarpaea (Griseb.) Gilg , and Quesnelia Gaudich. ( Coelho and Amorim 2014) . In particular, the Serra da Jiboia is also the type locality of several species of algae (e. g., Diplocladiella cornitumida F. R. Barbosa et al. ), fungi (e. g., Anteaglonium brasiliense D. A. C. Almeida et al. ; Diplococcium variegatum S. S. Silva et al. ; Thozetella submersa F. R. Barbosa & Gusmão ), and angiosperms (e. g., Heteropterys jardimii Amorim , Maranta villosovaginata N. Luna & E. M. Pessoa , and Passiflora jiboiaensis M. A. Milward de Azevedo ). These latter three species are endemic to the state of Bahia. Additional angiosperms endemic to Bahia that occur in Serra da Jiboia include Eugenia altissima Sobral & Faria (Endangered – EN category), Inga conchifolia L. P. Queiroz (Endangered – EN category), Ormosia timboensis D. B. O. S. Cardoso et al. (Critically Endangered – CR category), and Senna bahiensis A. G. Lima & V. C. Souza (Critically Endangered – CR category), all of which are threatened with extinction according to CNCFlora (2024).

Conservation status.

Eriotheca paganuccii is known only from seven collections made at three different localities ( IUCN B 2 a criterion), which qualifies it for the Endangered (EN) category. The extent of occurrence ( EOO) of this species has been calculated to be 1,738 km 2, which qualifies the species for the Endangered (EN) category, and the area of occupancy ( AOO) was estimated to be 12 km 2, which also qualifies it for the Endangered (EN) category according to B 1 criterion ( IUCN 2024 ). Two of the three known populations of E. paganuccii inhabit legally protected Reserves: one population occurs within a federal level Reserve “ Parque Nacional Serra das Lontras ” and one population within the state level protected “ Área de Proteção Ambiental Lagoa Encantada ”. However, the Atlantic Forest habitat has been lost at an accelerated rate due to anthropogenic pressures (B 2 b criterion). Therefore, due to the very restricted extent of the habitat of this species (montane wet forests on mountain summits), the rapid rate of deforestation of the surrounding Atlantic Forest, and the small AOO (12 km 2) and EOO (1,738 km 2) of E. paganuccii , we consider this species to be Endangered belonging to the EN B 1 ab (i, iii), B 2 ab (ii, iii) category based on available data and IUCN criteria ( IUCN 2024 ).

Etymology.

The specific epithet honors Luciano Paganucci de Queiroz, a distinguished Brazilian taxonomist who was the first to collect this new species and one of the first to promote and undertake floristic efforts on Serra da Jiboia, Bahia, its type-locality.

Additional specimens examined.

Brazil. Bahia: Arataca, RPPN do IESB, Serra do Peito de Moça , Rod. Arataca / Una , entrada 9, 5 km da cidade, mais 8, 9 km da entrada, topo da serra, 15 ° 10 ' 27 " S, 39 ° 20 ' 22 " W, 20 Dec 2008 (lf, fr), A. B. Jardim et al. 168 ( CEPEC 127300 !, RB barcode 00734410) . Barro Preto, estrada de terra para Pedra Lascada , cume da serra, 14 ° 46 ' 17 " S, 39 ° 32 ' 10 " W, 841 m alt., 13 Feb 2011 (lf), J. G. Carvalho-Sobrinho & A. C. Mota 2902 ( HUEFS barcode 000132932!) . Santa Terezinha, Serra da Jiboia, c. 4 km de Pedra Branca, Mata Higrófila , 12 ° 51 ' 11 " S, 39 ° 28 ' 19 " W, 27 Sept 2000 (lf, fl buds), L. P. Queiroz 6370 ( CESJ 44810 , HUEFS barcode 000132068!, SP barcode 057770!) . Same municipality, 14, 5 km na rod. Elísio Medrado / Santa Terezinha, Torre da Embratel, c. 7 km do distrito de Pedra Branca, Serra da Jiboia, Campos de Altitude , 12 ° 51 ' 13 " S, 39 ° 28 ' 33 " W, 750 m alt., 24 Feb 2000 (lf, fr), J. G. Jardim et al. 2808 ( ALCB barcode 062988, BAH 5228 , CEPEC 88453 !, HUEFS barcode 000138269!, NY barcode 00566377!, RB barcode 00778244!, SPF barcode 00161825, UESC 7099 , UFRN 13793 !) ; same municipality, Serra da Jiboia, Morro da Pioneira , cume, 12 ° 51 ' 18 " S, 39 ° 28 ' 33 " W, 817 m alt., 28 Oct 2023 (lf, fl), J. G. Carvalho-Sobrinho & A. C. Mota 4022 ( CEPEC, HUEFS, IPA, RB, SP, SPF) ; same locality, 28 Oct 2023 (lf, very young fruits), J. G. Carvalho-Sobrinho & A. C. Mota 4023 ( HUEFS, IPA) ; same locality, 25 Jan 2024 (lf, fr), J. G. Carvalho-Sobrinho 4038 ( HUEFS barcode 000100270218!) ; same locality, 25 Jan 2024 (lf), J. G. Carvalho-Sobrinho 4039 ( HUEFS barcode 000100270219!) ; same locality, 25 Jan 2024 (lf, fr), J. G. Carvalho-Sobrinho 4040 ( HUEFS barcode 000100270220!) .

Figures

Figure 1. Eriotheca paganuccii A vegetative branch from the top of the tree canopy B details of a leaflet also from the top of the tree canopy C leafless branch with umbelliform cymes D flower bud (note the glands on receptacle) E flower at anthesis (note the unilaterally apiculate petals) F staminal tube (detached from the receptacle and slightly pulled up) G gynoecium H globose woody capsules before dehiscence I capsule with one valve detached showing scanty kapok and large seeds J dehisced fruit with marcescent calyx, exposing the columella and remaining kapok after seed dispersal K seeds relative to a fruit valve L angulate, striated seeds; each seed with two plane and one concave sides. A, B, I – L drawn from J. G. Carvalho-Sobrinho 4040, C – G drawn from J. G. Carvalho-Sobrinho & A. C. Mota 4022.

Figure 2. Habitat and morphological aspects of Eriotheca paganuccii A crown of E. paganuccii individuals in the canopy B detail of leaves at the top of the tree canopy showing smaller, more rigid leaves that are comprised of 1–2 leaflets oriented upward C bark of E. paganuccii D leaves with less exposure to the sun that have 5 leaflets, which are larger, less rigid, and patent (not oriented upward) unlike those in the canopy E flower at anthesis F seeds relative to a fruit valve and scanty kapok.

Figure 3. Distribution map of Eriotheca paganuccii and type-locality with montane wet forest between 750 m and 850 m in elevation near granitic-gneissic rock outcrops on the summit of Serra da Jiboia in the Atlantic Forest of Bahia, northeastern Brazil.