Hohenbergia densa B.P. Cavalcante

Cavalcante, Brayan Paiva & Silva, Maciel Florêncio Da, 2021, Hohenbergia densa (Bromeliaceae), a new species from Rio Grande do Norte, Brazil, Phytotaxa 520 (2), pp. 203-208: 204-207

publication ID

http://doi.org/ 10.11646/phytotaxa.520.2.7

persistent identifier

http://treatment.plazi.org/id/8D1187A4-4E2C-FFCA-FF5A-FF5171908B45

treatment provided by

Plazi

scientific name

Hohenbergia densa B.P. Cavalcante
status

spec. nov.

Hohenbergia densa B.P. Cavalcante   , spec. nov. ( Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 )

Hohenbergia densa   is closely related to H. flava   , but differs by its smaller size when flowering (ca. 70 cm vs. ca. 130 cm), narrow rosette (ca. 60 cm vs. 90 cm diam.), primary bracts exceeding the basal branches (vs. shorter than the basal branches), smaller inflorescence (ca. 40 cm vs. 70–110 cm long), stipes of the primary branches longer (up to 5 cm vs. less than 2 cm), short-stipitate secondary branches (vs. absent or nearly none), larger spikes (ca. 7 cm vs. 3–5 cm) and flowers (ca. 2.2 cm vs. 1.5 cm), floral bracts shorter than the sepals (vs. distinctly exceeding the sepals) and dark-purple petals (vs. yellow petals).

Type:— BRAZIL. Rio Grande do Norte. Espírito Santo. Arredores da Mata do pilão, Caatinga aberta próximo das trilhas que levam para gameleira, 6°23’40.0”S 35°17’19.0”W, 36 m. s.m. elev., 09 Feb. 2021, B. P GoogleMaps   . Cavalcante 102 (Holotype UFRN26874 View Materials !)   .

Plants 60–90 cm tall when flowering, terrestrial, heliophyte or rarely growing at the forest edges, reproducing by basal shoots, grouped in clumps of a few rosettes 50–70 cm in diam., with a great capacity to impound water. Leaves 30–45 cm long, more than 15 in number, yellowish, lustrous and inconspicuously white-lepidote abaxially; sheath 10–13 cm × ca. 13 cm, elliptic, coriaceous, margins entire, dark-brown on both surfaces, lepidote; blade 20–35 × 6–9 cm, lanceolate, slightly arcuate, inconspicuously lepidote abaxially only, with spinescence margins, with an acuminate and erect pungent apex, apical mucro ca. 1 cm long, dark brown; spines black, rigid, ca. 0.7 cm long. Peduncle 20–45 long, ca. 1 cm in diam., light-red, erect, not completely concealed by the peduncle bracts, densely white-lanate; peduncle bracts 5–9 cm long, light brown, densely white-lanate, lanceolate, margins entire, apex pungent, chartaceous, not imbricate, surpassing the internodes. Inflorescence (fertile portion), twice-branched, 20–40 cm long, 19–25 cm wide at the base, erect, sub-cylindrical, with erect to patent branches, light-red, covered by a dense white-lanate indument; primary bracts 12–16 cm long, lanceolate, margins entire, light-brown, strongly nerved, exceeding the basal branches; primary branches 8–12 cm long, elongate with short and erect to patent stipe; stipe of the primary branches 2–5 cm long, light-red, erect, covered by a white-lanate indument; secondary branches (spikes) 6–7 cm × ca. 2 cm, elongate, stipe short; stipes 0.5–1.5 cm long, light-red, erect, covered by a white-lanate indument; floral bracts ca. 1.4 × 1.3 cm, green with a pink apex, triangular with a prominent mucronate apex, nerved, shorter than the sepals; flowers diurnal (4 am–15 pm) and with a sweet fragrance, 1.9–2.1 cm long, flattened adaxially, corolla sub-tubular; sepals 10–12 × 11–13 mm, green, ovate-triangular, asymmetrical, with an one sided extended margin (marginal wing), apex acute, densely white-lanate indument in the apex; petals 17–19 × 7–8 mm long, dark-purple, spathulate, apex broadly rounded then obtuse to acute, sub-erect, bearing 2 appendages; appendages ca. 2 mm long, lacerate, situated in the basal third of the petals; stamens 14–15 mm long, white, included in the corolla, exceeding the gynoecium; ovary 2–3 mm long, ovoid-triangular; ovules numerous, with a prominent chalazal appendage; style 13–14 mm long, white, erect; stigma conduplicate-spiral; fruit ca. 1.7 cm long, blue when ripe; seeds ca. 2 mm long, ellipsoid and dark-brown.

Examined material: — Brazil, Rio Grande do Norte   : São Tomé, próximo à rodovia RN – 203, Caatinga aberta. 5°59’43.0”S 36°02’27.0”W, 9 February 2021, B. P GoogleMaps   . Cavalcante 103 ( UFRN26875 View Materials ! Paratype). Rio Grande do Norte: entre Rio de Fogo e Zumbi, Praia de Zumbi , Mata de tabuleiros (ou restinga). 20 Aug. 1998, C   . Martinelli 15075 & T   . Barbará, J. A   . Medeiros Neto ( RB 341729 View Materials ). Rio Grande do Norte: Espírito Santo, Próximo a rodovia, estrada que leva a Mata do Pilão. Fev. 2021, B. P   . Cavalcante 101 ( UFRN26873 View Materials !). Rio Grande do Norte , Monte das Gameleiras próximo ao portal de entrada da sede municipal. 21 Dec. 2015, Tomaz 96, ( UFRN18232 View Materials !). Rio Grande do Norte, Monte das Gameleiras, embasamento do embasamento cristalino. 30 Dec. 2016, G. S   . Garcia 452 ( UFRN22954 View Materials !). Rio Grande do Norte, Natal, Parque da Cidade Dom Nivaldo Monte. 29 Jun. 2015, A. A   . Roque 1659 ( UFRN20243 View Materials !)   .

Etymology:— The specific epithet “densa” refers to the aspect of the plant, that commonly is seen as a short and robust plant, with a denser inflorescence and primary branches than other Caatinga-endemic species.

Distribution and habitat: — Hohenbergia densa   was found in fully sun exposed sandy soils or close to the forest edges, in Caatinga forest or in transitional areas between Caatinga and Atlantic forest. Plants of this species can be seen in Caatinga of almost all southern part of Rio Grande do Norte state, associate with others bromeliads, like Wittmackia patentissima Mez (1891: 278)   and Encholirium spectabile Schultes & Schultes (1830: 1233)   . It is commonly seen growing in sympatry with E. spectabile   , and they share many ecological traits (except the rupiculous habit of E. spectabile   ) in the dry vegetation of Rio Grande do Norte.

Phenology:— Hohenbergia densa   has been found flowering in the rainy season, between November and February.

Conservation status: — The species is only known for the Caatinga vegetation of the Rio Grande do Norte state. The region suffers constantly by fires, both caused by dry weather as well as human activity (burning for cattle forage of these areas is common). Nevertheless, the species occurs in a vast area, and by plotting its knowing occurrences in Geocat software (geocat.kew.org), the estimated extent of occurrence (EOO) is 25,636.338 km ², and the area of occupancy (AOO) is 52.000 km ², evaluating this species as Near Threatened (NT C2ab (ii)).

Observations: — Hohenbergia densa   is the smallest member of the H. catingae   group, sharing many traits with H. flava   , and with H. catingae   , such as the funnelform rosette with lanceolate leaf blade, the reddish inflorescence, the elongate spikes and the sharp mucronate floral bract apex, plus the occurrence in dry environments. Hohenbergia densa   can be easily recognized ( Tab. 1) and distinguished from close relatives by its, narrow rosette (ca. 70 cm diam. vs. 80–110 cm in H. flava   and 90–150 cm in H. catingae   ), the smaller inflorescence (20–40 × 19–25 cm vs. 70–110 × 12–28 cm in H. flava   and 80–100 × 35–50 cm in H. catingae   ) and by the dark-purpled petals (vs. yellow in H. flava   and light-lilac in H. catingae   ). Another species that can be confused with H. densa   is H. horrida Harms (1935: 525)   , but H. densa   can be distinguished from it by its smaller size (60–90 × 50–70 cm vs. 70–100 × 80–100 cm in H. horrida   ), wider leaf blade (8 cm vs. ca. 4 cm), smaller (30 × 22 cm vs. 70 × 44 cm) reddish inflorescence (vs. whitish), and erect petals at anthesis (vs. reflexed) ( Tab. 1).

Furthermore, Hohenbergia densa   can be mistaken for H. ridleyi   , that can be seen growing close to the occurrence area of this species, but only inside the forest and presenting a lax-pyramidal inflorescence with lilac and reflexed petals. However, Hohenbergia densa   has shorter leaves (30–45 vs. 70–120 cm long), acuminate and erect leaf apex (vs. cuspidate and reflexed), smaller inflorescence (20–40 × 19–25 cm vs. 100–130 × 40–70 cm) with the primary bracts exceeding the branches (vs. shorter than the branches), elongate spikes (vs. short and slightly globose) and by the erect petals (vs. reflexed) that conceal the gynoecium and androecium (vs. exposed them) ( Tab. 1).

B

Botanischer Garten und Botanisches Museum Berlin-Dahlem, Zentraleinrichtung der Freien Universitaet

P

Museum National d' Histoire Naturelle, Paris (MNHN) - Vascular Plants

C

University of Copenhagen

T

Tavera, Department of Geology and Geophysics

J

University of the Witwatersrand

A

Harvard University - Arnold Arboretum

RB

Jardim Botânico do Rio de Janeiro

G

Conservatoire et Jardin botaniques de la Ville de Genève

S

Department of Botany, Swedish Museum of Natural History