Hohenbergia sparsiflora B. P. Cavalcante, E. H. Souza & Versieux 2024, sp. nov.
Creators: name: Cavalcante, Brayan Paiva
name: Silva, Clécio Danilo Dias Da
name: Souza, Everton Hilo De
name: Versieux, Leonardo M.
name: Martinelli, Adriana Pinheiro
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Poales
Bromeliaceae
Hohenbergia
Hohenbergia sparsiflora

description: Hohenbergia sparsiflora B.P. Cavalcante, E.H. Souza & Versieux, sp. nov. (Figs. 3–4)
Diagnosis: — Hohenbergia sparsiflora is closely related to H. hatschbachii, yet it can be readily distinguished by its infundibuliform rosette with sub-erect leaves (vs. broadly-crateriform with arcuate leaves), brownish leaves (vs. green), thinner peduncle (1 cm vs. 3 cm diam.), inflorescence partially nested within the tank (vs. completely exposed), inconspicuously white-lanate and narrowly-pyramidal (vs. densely brown-lanate and wide-pyramidal); spikes sparsely organized (vs. dense organized), and floral bracts suborbicular with a mucronate apex (vs. triangular, apex acuminate), distinctly shorter than the sepal (vs. exceeding the sepal).
Type:— BRAZIL. Bahia. Una, Refugio de Vida Silvestre de Una, inside of the forest, near the research center of the park, ca. 123 m. elevation, 15°10’29.9”S 39°03’59.1”W, 10 October 2018, E. H. Souza & B. P. Cavalcante 28 (Holotype HURB!, UFRN!).
Plant epiphytic, 90–130 cm tall when flowering, low formation of basal shoots, forming a infundibuliform tank of 35–45 × 25–40 cm. Leaves ca. 20 in number, suberect to spreading; leaf sheath 16–22 × 20–24 cm, broadly elliptic, either inconspicuously white lepidote to glabrous on both sides, dark castaneous except for the brownish to greenish distal part, stiffy and coriaceous, margins entire; leaf blade 50–60 × 19–24 cm, brownish or pale-greenish, brownlepidote indument, linear-oblong to lingulate, apex brownish, acute or cuspidate, sub-erect spreading towards the apex, ending in a rigid and spinescent point ca. 3 cm long, sparsely brownish-lepidote, with spinulose margins, marginal spines black, rigid, very close to each other. Peduncle 25–40 cm long, ca. 10 mm diameter, erect, green, white lanate, covered and concealed by the peduncle bracts; peduncle bracts 15–18 × 1.5–1.9 cm, lanceolate, with acuminate apex, pale-brown, imbricate, exceeding the internodes, glabrous or sparsely white-lepidote. Inflorescence 30–45 cm long, 30–45 cm in diam. at the widest point, paniculate, narrowly-pyramidal, 3-branched at the base, once-branched in distal part, erect, sparsely white-lanate indument or glabrous; primary bracts resembling the peduncle bracts in shape and color, but smaller, 5.5–7 × 2–2.2 cm, shorter than the branches but exceeding the stipe; primary branches 14–22 cm long, stipes 2–5 cm long, divergent to spreading, glabrous or sparsely white-lanate; secondary bracts ca. 1 × 1.5 cm, triangular, apex acuminate, resembling the primary bracts in color but smaller, shorter than the branches but exceeding the stipe; secondary branches 3–5 cm long, short-stipitate or sessile, stipes (0–) 0.2–2.5 cm long, flowers sparsely arranged along the rachis; spikes 3–5 cm long; floral bracts ca. 2 × 4 mm, green, broadly triangular-ovate, convexly embracing the ovary, apex spinescent caudate, nerved, margins entire, green and blackish towards the apex, covered by a sparse white lanate indument, surpassing the ovary, and inferior than the sepals in length. Flowers 16–19 mm, sessile, odorless; sepals 4–6 × 5–8 mm, green, broadly triangular-ovate, margins entire, apex mucronate, asymmetrical with a thin marginal wing that does not exceed the apex, glabrous; petals 13–16 × 4–6 mm, linear-oblong base, the blade divergent to spreading, apex acute, margins entire, free, white at base and lilac blade, nerved, bearing 2 appendages; petal appendages fringed ornamentation. Stamens 9–10 mm, emerging from the the corolla; filament 6–8 mm, white, complanate and slightly dilated distally; anther ca. 2 mm long, apex apiculate; ovary 4–6 × 11 mm, green, wide-ovoidal, placentation axial; ovules obtuse to caudate, with a prominent chalazal appendage; style 12–14 mm long, white, erect, surpassing the stamens, exposed by the divergent petal blades; stigma conduplicate-spiral. Fruits ca. 14 × 16– 15 mm, bluish when ripe; seeds ca. 1 mm long, sub-ellipsoidal, brownish.
Etymology: — The specific epithet “sparsiflora ” refers to the disposition of the flowers (“-flora”) in the spikes, which are sparsely arranged (“sparsus-”), creating a raceme-like pattern.
Distribution and habitat: — Hohenbergia sparsiflora is an epiphyte growing in the densest and shadiest parts of the protected forest within the Natural Biological Station of Una (Reserva Biológica de Vida Silvestre de Una), located in the municipality of Una, state of Bahia, but also extending into neighboring areas. The species shares its habitat with several other Hohenbergia species. Individual plants are scattered within the forest, typically growing on the highest branches of trees in shaded and areas with higher humidity. The area is a hotspot for Hohenbergia and also for Bromelioideae in general, hosting more than ten species within this fragment of the Atlantic Forest. These species include the closely related H. hatschbachii Leme (1999: 141), as well as H. pabstii Smith and Read (1976: 439), H. belemii Smith and Read (1976: 438), H. blanchetii, H. brachycephala Smith (1940: 129), H. burle-marxii, H. capitata Schulte & Schulte (1830:1252), H. halutheriana, H. nidularioides Cavalcante et al. (2021:200), and H. stellata.
Phenology: —Blooming plants have been observed from August through December, with fruiting starting after November. Pre-flowering plants were observed in June. In cultivated plants, blooming was observed from September through December.
Conservation status: — This new species is restricted to the Una Natural Biological Station, which is a federal conservation unit. However, the conservation of the species faces challenges due to the expansion of roads, intensifying the edge effect and threatening these bromeliads. The assessment of known occurrences of this species reveals that the estimated extent of occurrence (EOO) covers 170.443 km ², which the area of occupancy (AOO) is 43.5 km ², leading to a classification of this species as Endangered (EN). Although the species is already protected by Brazilian federal laws within the reserve, we recommend a preliminarily classification of this species as Endangered EN B2b (i, ii, iii, iv), following the IUCN criteria guidelines (IUCN, 2020).
Observation: — Hohenbergia sparsiflora is unique within the genus for the presence of loosely arranged spikes, which clearly distinguish it from other Hohenbergia species. This new species is a member of the “giant Hohenbergia species group” (Cavalcante et al. 2020, 2021 b, 2022, Souza et al. 2022b). These species inhabit the coastal region of Brazil, especially within the Atlantic Forest domain of Bahia. While the rosette of this species shares similarities with other giant Hohenbergia species, its sub-erect to arching leaves represents an unusual feature within the genus for this region. This characteristic facilitates a positive identification even when the plant is not in the flowering stage.
Hohenbergia sparsiflora is morphologically similar to H. hatschbachii and both coexist in southern Bahia. This new species is easily distinguished by the sparsely arranged flowers along the rachis of the spikes, a partially sunken inflorescence in the rosette (vs. fully exposed), a sparsely white-lanate indumentum in inflorescence (vs. densely brown-lanate) and the small wide triangular floral bracts, not completely concealing the sepals (vs. prominent, triangular and concealing the sepals). Focusing solely on foliage, the brownish leaves (vs. green) is the easiest feature distinguishing H. sparsiflora and H. hatschbachii. Comparative measurements of herbarium specimens of related taxa are provided in Table 1.
description: Published as part of Cavalcante, Brayan Paiva, Silva, Clécio Danilo Dias Da, Souza, Everton Hilo De, Versieux, Leonardo M. & Martinelli, Adriana Pinheiro, 2024, Hohenbergia alba and Hohenbergia sparsiflora, two striking new bromeliads from the Brazilian Atlantic Forest, pp. 233-242 in Phytotaxa 665 (3) on pages 238-241, DOI: 10.11646/phytotaxa.665.3.5, http://zenodo.org/record/14518747