Sunday, July 7, 2024

[Botany • 2024] Eriotheca paganuccii (Malvaceae: Bombacoideae) • A New endangered Species from Montane Forests in the Atlantic Forest of Bahia, northeastern Brazil


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

in Carvalho-Sobrinho, da Mota et Dorr, 2024. 

A new species of Eriotheca (Bombacoideae, Malvaceae) from montane wet forests in the Atlantic Forest of Bahia, northeastern Brazil, is described and illustrated. It is known from only three populations situated between 750 m and 850 m in elevation on mountain summits and categorized as Endangered (EN) based on IUCN criteria. Eriotheca paganuccii is distinct from all congeners by the combination of coriaceous to strongly coriaceous leaves and remarkable few-seeded, globose to subglobose woody capsules that contain scanty kapok and the largest seeds known in the genus to date. The affinities of E. paganuccii to morphologically similar species as well as the importance of obtaining phenologically complete collections are discussed.

Key words: Bahian southern Atlantic Forest, ‘Bombacaceae’, ‘embiruçú’, endemism, plant taxonomy

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.

Habitat and morphological aspects ofEriotheca 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.

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

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.

Jefferson Carvalho-Sobrinho, Aline C. da Mota, Laurence J. Dorr. 2024. Eriotheca paganuccii (Bombacoideae, Malvaceae), A New endangered Species from Montane Forests in the Atlantic Forest of Bahia, northeastern Brazil. PhytoKeys. 243: 215-230. DOI: 10.3897/phytokeys.243.125708