Hohenbergia capitata, Schultes & Schultes [1830:, 1252

Cavalcante, Brayan Paiva, Silva, Kleber Resende, Pereira, Mayara A., Souza, Everton Hilo De, Versieux, Leonardo M. & Martinelli, Adriana Pinheiro, 2021, Establishment of the Hohenbergia capitata complex (Bromeliaceae) with notes on leaf anatomy and description of a new endangered species, Phytotaxa 518 (3), pp. 196-208 : 198-199

Hohenbergia capitata complex ( Figs. 1–2 )

Hohenbergia capitata complex includes H. belemii , H. capitata , and H. nidularioides and can be distinguished from other Hohenbergia species mainly by the capitulate inflorescence with congested and short peduncle of primary branches (stipes) or sessile branches (vs. lax inflorescence with long pedunculate branches), the sub-orbicular basal primary bracts (vs. lanceolate basal primary bracts) plus the crateriform and wide rosette shape (vs. funnelform or lageniform rosette).

Distribution and life forms: — Hohenbergia capitata complex is distributed over the coastal region of Bahia State ( Fig. 3 ), between Maraú and the proximities of Porto Seguro municipality, growing terrestrially or epiphytically in the Atlantic Forest, especially on the edge of the fragmented forests. Hohenbergia capitata is the only taxon that can be found in higher elevation montane Atlantic Forests, at 500– 950 m. a.s.l., in preserved forest in the municipalities of Camacan, Buerarema, Arataca, and Una (see Leme 2010).

Phenology:— Hohenbergia belemii was collected in blooming from May to October, while H. capitata can be found blooming from February to July and H. nidularioides from October to January.

Conservation status: —When we plot the known occurrences of H. belemii and H. capitata in GeoCat (geocat. kew.org), both species are categorized as Endangered (EN B1). The estimated extent of occurrence was 44 km ² for H. belemii and 16 km ² for H. capitata , with an occupancy estimated area of 2,714.019 km ² and 138.227 km ², respectively. Natural populations of H. belemii were found in the Atlantic Forest edge, near federal roads, in areas of commercial expansion, close to the beach, while H. capitata occurs in small fragments on the top of mountains in the Atlantic Forest, specifically in the Serra Bonita mountain complex (Camacan municipally), where there is a private reserve. Both species live in degraded areas, with imminent risk of real estate expansion. Thus, we categorize both as Endangered (EN B1), following the IUCN definition ( IUCN 2012) and the new species as Critically endangered (CR), as described below.

Comments: —“ Hohenbergia capitata complex” is a small distinct group of species in the Hohenbergia genus, being recognized mainly by the combination of a capituliform inflorescence with sub-orbicular basal primary bracts and the wide crateriform rosette shape. Due to the high ecological plasticity of the species of Hohenbergia , we used the overall biogeographical distribution of the genus to present a comparison for the Hohenbergia capitata complex. Considering the whole genus, two groups may be defined (excluding the here-called H. capitata complex), namely the saxicolous group (i.e., species living in Campos Rupestres biome [rock fields]) and the Atlantic group (i.e., species living in the Atlantic Forest and nearby areas but lacking the capituliform inflorescence). The H. capitata complex can be distinguished from the saxicolous group by the crateriform rosette shape (vs. lageniform rosette), the leaf blades much longer than the sheath (vs. short leaf blades with broader sheaths [sheaths represent at least 40% of the total length of the leaf]), peduncle bracts densely imbricate (vs. shorter than internode), sub-orbicular distal peduncle bracts (vs. lanceolate distal peduncle bracts), congested inflorescence, with the peduncle of the primary branch commonly hidden by the fascicle or only partially visible (vs. lax inflorescence, and peduncle of the primary branches visible) with flowers commonly> 2.7 cm long (vs. flowers up to 2.5 cm long). When compared with other Atlantic Forest species of Hohenbergia , the H. capitata complex can be distinguished by their smaller size (up to 110 cm vs. more than 190 cm tall when flowering), the width of the leaf blade (up to 6 cm vs. more than 15 cm), the apex of the leaf (acuminate and erect vs. acute and reflexed), the shape of the basal primary bracts (sub-orbicular vs. lanceolate), the shape and length of the fertile portion of the inflorescence (dense and capitulate aspect up to 12 cm long vs. lax and longer than 100 cm), the shape of floral bracts (triangular vs. sub-orbicular) and the length of the flowers (longer than 2.7 cm vs. up to 2.5 cm long). Additionally, the pollen grains of these three species are commonly 3-porate (rarely 6-porate), similar to other Hohenbergia species , but different from other similar genera (see Leme 2010). Additional comparative characters are provided in Table 1.

Figures

FIGURE 1. Species within the Hohenbergia capitata complex. A–C: H. belemii (HURB18863); D–F: H. capitata (HURB25319); G–I: H.nidularioides (HURB18862). A, D, G: General aspect of the plant; B, E, H: Inflorescence shape; C, F, I: Details of flowering branches. Photographs by Brayan Paiva Cavalcante

FIGURE 2. Holotypes of the species of the Hohenbergia capitata complex. A. H. belemii Smith & Read (US00091435); B. H. capitata Schult. & Schult. f. (M0120820); C. H. nidularioides B.P. Cavalcante, E.H. Souza, A.P. Martinelli & Versieux (HURB18862).

FIGURE 3. Geographic distribution of the Hohenbergia capitata complex, endemic to the coastal region of Bahia State, Brazil. The map was prepared in QGIS software and the geographic points are available in biodiversity databanks.