Dyckia pampeana Büneker, 2018

Büneker, Henrique Mallmann, Soares, Kelen Pureza & Witeck-Neto, Leopoldo, 2018, Dyckia pampeana, a new species of Bromeliaceae (Pitcairnioideae) from Pampa grasslands of Brazil and Uruguay, Phytotaxa 362 (1), pp. 97-104 : 98-102

Dyckia pampeana Büneker sp. nov., Figs. 1A–F , 2B–G and 4B .

Species morfologice proxima Dyckiae remotiflorae et Dyckiae leptostachyae. A prima faciliter differt petalis fulvis (vs. aurantiacis) et staminibus exsertis vel antheris partialiter exsertis (vs. staminibus inclusis). A secunda differt minori longitudine laminarum foliarum (6–13.5 vs. 28–47 cm), corolla trigona (vs. tubiformis) et petalis colore fulva (vs. aurantiaca).

Type: — BRAZIL. Rio Grande do Sul: Quaraí, saxícola em afloramento rochoso, 218 m elevation, 30°10’59.38”S 56°02’56,24”W, 10 May 2014, H. M. Büneker 276, R. C. Pontes & L. Witeck, fl. cult. 11 December 2014 (holotype HDCF!).

Plant saxicolous or terrestrial, stoloniferous or rarely rhizomatous, flowering 32–83 cm high; rosette 5–12 cm high, 9.5–20 cm in diameter. Leaves 21–64 in number, the inner ones erect, the outer ones reflexed; sheaths ca. 1.5 × 2.5 cm, suborbicular, white or bright greenish-white; blades 6–13.5 × 0.7–1.1 cm, very narrowly triangular, stiff, succulent, arched; adaxial surface nearly flat to slightly concave, green or purplish, sparsely to densely lepidote; abaxial surface convex, longitudinally finely nerved, subdensely white lepidote with trichomes arranged along the nerves, apex terminating in a spine to 2.5 mm long, margins spinose-serrate; spines predominantly antrorse, concentrated in the center-upper portion of the blade, ca. 2 mm long, thin, flexible, whitish at the base and brown or yellowish at the apex. Inflorescence lateral, at the base of the rosette, erect; peduncle 24–37 cm long, 2.7–4.6 mm in diameter, stout, terete, green, subglabrous to densely white floccose-tomentose; peduncle bracts polystichously arranged, the basal ones sometimes foliaceous, erect, 2.3–4.5 cm long, the upper ones erect, shorter than the internodes, adpressed to the peduncle, 0.9–1.2 × 0.6–2.5 cm, triangular to elliptic-suborbicular, slightly pubescent, green at the base, yellowish-brown at the upper part, slightly carinate at the apex, apex acuminate-attenuate, terminating in a spine, margins entire or laxly serrulate, often with inconspicuous spines; fertile part of the inflorescence 17–34 cm long, simple, 9–26- flowered, or paniculate of 1–7 short branches that sprout at the base during anthesis of the flowers of the main axis, with a total of 24–45 flowers; branches 4–6.5 cm long, erect or suberect; rachis green, white floccose-tomentose, trichomes concentrated below the bracts insertion; floral bracts 5–13 × 5–9 mm, ovate or broadly triangular to suborbicular, adpressed to the flower, slightly carinate at the apex, base green, upper portion yellowish-brown, subglabrous to sparsely white tomentose, shorter up to equaling the sepals, margins entire, apex shortly acuminate. Flowers polystichously arranged, sessile, 1.3–1.9 cm long, suberect at anthesis; sepals 5–9 × 4.6–7.4 mm, ovatetriangular, the base greenish, brown-yellow in the upper part, slightly carinate, sparsely tomentose-lepidote at the base and along the central portion of the abaxial surface, apex acute to rounded; corolla trigonous; petals 1–1.4 × 0.5–1 cm, obtrullate, unguiculate; the blades suberect to patent, carinate, revolute, yellow, glabrous, apex slightly rounded-cuculate or emarginate; hypanthium ca. 0.5 mm long; stamens exserted or partially exserted (by a fraction of the anthers); filaments ca. 1 cm long, 1–2 mm wide, yellowish-white, flat, straight, sublinear to triangular, free above the hypanthium, the antesepalous ones adnate to the sepals for ca. 0.5 mm, the antepetalous ones adnate to the petals for 2–4 mm; anthers yellow, basally dorsifixed, narrowly triangular, recurved at the apex; pistil 7–13 mm long; ovary 4–6 × ca. 2 mm, greenish; style 3–6 mm long, yellowish-white; stigma conduplicate-spiral, stigma lobes 1–3 mm long; ovules complanate with chalazal appendix conspicuously developed. Capsules ovoid, lustrous brown to black. Seeds discoid, asymmetric, with appendix subfalciform.

Additional specimens examined (paratypes):— BRAZIL. Rio Grande do Sul: Uruguaiana , 30°1’7.29”S 56°14’18.99”W, 16 December 2011, P. J. S. Silva Filho 1455 ( ICN) ; 10 May 2014, H. M. Büneker 271, R. C. Pontes & L. Witeck ( HDCF) ; Quaraí, Estância Meu Campicho, Fundão , 30°22’34”S 55°23’42”W, 2 December 2010, G. A. Dettke 486 et al. ( RB) ; Rio Quaraí Mirim , December 1995, T. Strehl 1422 ( HAS) ; December 1994, M. Hausen 10 ( HAS) ; Quaraí Mirim , April 1995, A. D. Nilson 391 ( HAS) ; entre Fazenda São Carlos e Cerro do Jarau , February 1996, T. Strehl 1594 ( HAS) ; Santana do Livramento , December 1999, A. D. Nilson s.n. ( HAS 101063 ) ; área contestada, 26 December 2012, H. M. Büneker 150, R. C. Pontes & W.- R. Abraham ( HDCF) ; Dom Pedrito , October 1992, T. Strehl 1428 ( HAS) ; São Francisco de Assis , January 1995, M. Hausen s.n. ( HAS 101029 ) . URUGUAY. Tacuarembó: 31°48’30.6”S 56°10’03.2”W, February 2009, H. F. Maia s.n., CRER Brasil 15 ( HDCF) .

Etymology: —The specific epithet “ pampeana ” refers to the Pampa Biome,or Pampean province,a phytogeographic region where this species was discovered.

Distribution and habitat: —This new species grows on rocky outcrops ( Figure 2A ), on shallow soils (neosoils) and clayey soils with basaltic origin of the “Serra Geral” formation in “campanha gaúcha” region. It is known from the eastern portion of the Uruguay River basin, in the southernmost Pampa Biome grasslands in Brazil and Uruguay. In Brazil, it was registered in the Rio Grande do Sul state, in the municipalities of Alegrete, Dom Pedrito (without precise location, data not included in the map), Quaraí, São Francisco de Assis (idem), Santana do Livramento, and Uruguaiana. In Uruguay this species was recorded in the Durazno, Río Negro, Rivera, Soriano, and Tacuarembó departments ( Figure 3 ).

Observations and discussion: — Dyckia pampeana ( Figure 4B ) is morphologically closely related to D. leptostachya Baker (1884: 198) ( Figure 4C ) due its stoloniferous habit and sessile flowers, obtrullated petals, stamens reaching the length of the petals or surpassing and free filaments above the hypanthium. It also differs from it by the shorter leaf blades (6–13.5 vs. 28–47 cm), trigonous corolla (vs. tubiform), and petals with yellow coloration (vs. orange).

Dyckia leptostachya can be easily confused with several species that belong to the morphological group of species headed by D. remotiflora Otto & Dietrich (1833: 129) , which includes D. pampeana , which is being reviewed by the first author of this work. It is important to mention that several specimens of D. remotiflora are misnamed in collections as D. leptostachya , being erroneously cited from the Brazilian southern Pampa in monographs like Flora Neotropica ( Smith & Downs 1974), Die Bromeliaceae von Rio Grande do Sul (Winkler 1979) and Flora Catarinense ( Reitz 1983). However, D. leptostachya doesn’t occur in the Pampa, but only in the Cerrado, Chaco and Atlantic Rain Forest. Smith & Downs (1974) broadened the taxonomical concept of D. leptostachya by means of the inclusion in it of many synonyms. However these synonyms still require reevaluation because they present substantially discrepancies when compared to the morphological boundaries originally conceived for this species. The identification problems in D. remotiflora group can be evidenced in Bromelias del Uruguay ( Berhouet & Riaño 2008), where specimens with yellow petals (corresponding to D. pampeana and D. aff. pontesii ) were identified as D. remotiflora var. montevidensis ( Koch 1874: 4) Smith (1943: 108) based on Flora del Uruguay, Bromeliaceae ( Smith 1972) , reinforcing the necessity of a taxonomic revision of this group. Originally described as a species ( D. montevidensis Koch (1874: 4)) , D. remotiflora var. montevidensis seems to be conspecific with the typical variety, however the identity of D. remotiflora and its varieties still need in-depth studies.

The distribution of D. pampeana overlap with that of D. remotiflora , which explains the confusions in their identification, since both are found in similar habitat, and present similar habit and generally stoloniferous propagation. Dyckia pampeana differs basically from D. remotiflora ( Figure 4A ) because it has yellow (vs. orange) petals and exserted or partially exserted stamens (by a fraction of the anthers) (vs. stamens included). The new species can also be compared to D. floribunda complex (which includes D. floribunda Grisebach (1879: 331) , D. velascana Mez (1894: 476) , D. ferox Mez (1896: 511)) because of the floral morphology (shape and color of the petals and partially exserted stamens), which is also a subject of study by the first author of this paper. However, D. pampeana has smaller size when in bloom, with sessile flowers, and occurs in the Pampa. In contrast, the diversity center of D. floribunda complex is predominantly in the Chaco, Puna, and “provincia del Monte” of Argentina, Paraguay, and Bolivia, in the proximities of Andes mountain range. Their species are characterized by large sized and pedicellate flowers, a useful and consistent character (i.e., presence or absence of flower pedicel) to distinguish species groups in Dyckia .

Conservation Status: — Dyckia pampeana has a wide distribution with well preserved populations. Its habitat has been converted by agriculture or silviculture, however the populations of this species have been kept relatively preserved in the rocky outcrops or very shallow soils not suitable for crops. The only source of concern is the possible implantation of the conversion system of native fields destined to extensive cattle raising for fields cultivated with winter grasses (mainly Lolium perenne Linnaeus (1753: 83)) . This system of planting tolerates shallow soils, such as those that serve as habitat for D. pampeana . In view of the above, the species can be placed in the LC (Least Concern) category of the IUCN.

Figures

FIGURE 1. A–F. Dyckia pampeana Büneker. A. Vegetative appearance and part of the peduncle (Büneker 276 et al.). B. Branched fertile part of the inflorescence (Büneker 276 et al.). C. Simple fertile part of the inflorescence (Büneker 271 et al.). C1. Basal portion. C2. Apical portion.D. Abaxial view of flower with floral bract (Büneker 271 et al.). E. Side view of flower (Büneker 271 et al.). F. Section of a flower (Büneker 150 et al.).

FIGURE 2. A–G. Dyckia pampeana Büneker. A. Habitat. B. Clumps formed by vegetative propagation through stolons (Büneker 478 et al.). C. Rosette of an individual (Büneker 478 et al.). D. Specimens in habitat (Büneker 276 et al.). E. Inflorescence detail with 3 open flowers (Büneker 271 et al.). F. Inflorescence branches detail (Büneker 150 et al.). G. Inflorescence fertile portion (Büneker 276 et al.).

FIGURE 3. Distribution map of Dyckia pampeana in Brazil and Uruguay.

FIGURE 4. Comparison of inflorescences of three similar species. A. Dyckia remotiflora Otto & Dietrich (Büneker 371 et al.). B. Dyckia pampeana Büneker (Büneker 271 et al.). C. Dyckia leptostachya Baker (Burle Marx s.n.).