Dyckia nobilis H. Büneker, K. Soares & L.C. Assis, 2016

Büneker, Henrique Mallmann, Soares, Kelen Pureza & Assis, Lucas Coelho De, 2016, The Dyckia sordida complex (Bromeliaceae, Pitcairnioideae) and a new species from Minas Gerais, Brazil, Phytotaxa 244 (1), pp. 57-68 : 60-63

2. Dyckia nobilis H. Büneker, K. Soares & L.C. Assis , sp. nov., Figs. 2A–H and 3A–H

Species morphologice proxima Dyckia sordida et Dyckia inflexifolia . A prima differt habitu semper in rosulis separatis (vs. planta caespitosa), rosulis cum minor numero foliorum (10–30 vs. 32–50), facies adaxialis laminarum foliaribus albo-cinereibus, dense lepidotae (vs. sparso et inconspicue lepidotae ad subglabris, cum laminis foliaribus viridibus ad rosaceas, bracteis floralibus cum marginibus integris (vs. sparso-spinoso-serratis), pedicellis brevioribus (2–3 mm vs. 3–5(–15) mm longis) et sepalis ovato-ellipticis (vs. ovatis). A secunda differt brevioris numero foliorum (10–30 vs. ca. 40), laminis foliaribus cum marginibus inermis vel generaliter inconspicuis spinoso-serratis cum face adaxiali semper albo-cinereis, dense lepidotis (vs. marginibus foliaribus denso spinoso-serratis cum spinis conspicuis et face adaxiali laminarum glabrarum, viridibus ad rubris), flores cum pedicellis brevioribus (2–3 cm vs. ca. 5 mm longis) et sepalis ovato-ellipticis (vs. ovato-triangularibus).

Type: — BRAZIL. Minas Gerais: Serro, cerca de 10 km da sede do município, 18 June 2014, fl., H. M. Büneker 296, L. C. de Assis & K. P. Soares (holotype HDCF!; isotype RB!) .

Plant saxicolous with short rhizomes and forming solitary rosettes, 28–55 cm in diameter, flowering 60–170 cm high. Leaves 10–30 in number, the inner ones straight, the outer ones suberect or reflexed, sometimes subsecund; sheaths ca. 6 × 4.5 cm, suborbicular, white, brown-greenish at the base; blades 25–80 × 2.1–6.2 cm, narrowly triangular, stiff, succulent, arched or rarely straight, adaxial surface concave or flat, with reddish-green epidermis, densely white-cinereous lepidote on both sides, abaxial surface convex, slightly longitudinally ribbed, the apex with a straight thorn up to 6 mm long, margins unarmed or laxly serrate, often with inconspicuous spines; spines up to 4 mm long, patent or rarely retrorse, more concentrated toward the base of the blade. Inflorescence lateral, erect; peduncle 30–90 × 0.4–1.1 cm, cylindrical, reddish, densely tomentose, of white trichomes in the basal 1/3 and brownish-ferruginous in the middle and upper third; peduncle bracts polystichously arranged, shorter than the internodes, the basal ones foliaceous, erect, ca. 5 cm long; the upper ones erect, triangular, the apex acute, 1–2.5 × 1.3–2.6 cm, margins entire or with few inconspicuous spines; fertile part of the inflorescence 25–95 cm long, simple or paniculate of up to 8 branches and 27–110 flowers; primary bracts ovate-triangular; branches erect or suberect to arching, positioned at the base of the fertile part of the inflorescence; rachis reddish, covered by tomentose brownish-ferruginous trichomes; floral bracts ovate-triangular, 0.8–1.5 × 1–2.1 cm, slightly carinate at the apex, brownish-ferruginous tomentose lepidote, the margins entire, the apex acute-attenuate, those at the base of the inflorescence exceeding the sepals, rarely exceeding the flowers, those at the apex of the branches exceeded by the sepals. Flowers laxly and polystichously arranged, pedicellate, ca. 1.5 cm long, patent or slightly reflexed during anthesis; pedicels 2–3 mm; sepals connate at the base for ca. 3 mm, ovate-elliptical, convex, reddish at the base, orange in the apex, 5–7 × 7–9.5 mm, carinate, succulent, appressed to the petals, sparsely brownish-ferruginous tomentose, the trichomes dendritic, with ciliate-fimbriate margins, the apex rounded-obtuse, rarely acute; petals erect suborbicular-rhomboidal, 1–1.3 × 1.8–2 cm, orange, sparsely lepidote on the basal abaxial surface, the apex rounded or emarginated; hypanthium ca. 2 mm; stamens included; filaments narrowly triangular, yellow-orange, flat, straight, ca. 2 × 9 mm, connate for ca. 1 mm above the hypanthium, free above the common tube with the petals, the antesepalous ones adnate to the sepals for ca. 2 mm, the antepetalous ones adnate to the petals for ca. 2.5 mm; anthers dorsifixed, triangular; pistil 9 mm long; ovary ca. 5 × 2.5 mm, yellowish, subcylindrical; style orange; stigma conduplicate-spiral. Capsules brown or black, globose-ovoid, lustrous, with persistent perianth. Seeds discoid, hyaline-winged.

Etymology: —The epithet “ nobilis ” refers to noble, whose Latin origin refers to something that deserves to be known, famous or beautiful, because it is one of the most beautiful Dyckia species to the authors opinion.

Observations: — Dyckia nobilis is morphologically close related to D. sordida and D. inflexifolia . It differs from the first one, D. sordida (sensu Forzza & Wanderley 1998) by always having isolated rosettes (vs. being caespitose, forming clumps, or rarely with isolated rosettes), by having less leaves in the rosettes (10–30 vs. 32–50), by having the adaxial side of the leaf blades densely white-cinereous lepidote (vs. sparsely and inconspicuously lepidote to subglabrous, with green to red leaf blades), by having floral bracts with entire margins (vs. sparsely spinose serrate), by having 2–3 mm long lower pedicels (vs. 3–5(–15) mm long) and by having ovate-elliptic sepals (vs. ovate).

It differs from D. inflexifolia by having less leaves (10–30 vs. ca. 40), by the leaf blades with unarmed margins or generally with margins inconspicuously and laxly spinose serrate, with the blades adaxially always densely white-cinereous lepidote (vs. leaf margins conspicuously spinose serrate and the blades adaxially always glabrous, green to red), by having shorter pedicels (2–3 mm long. vs. ca. 5 mm long) and by having ovate-elliptic sepals (vs. ovate-triangular).

An unusual characteristic in the genus Dyckia , but present in all specimens of D. nobilis studied, is having the sepals connate at the base for ca. 3 mm. Although the literature (including descriptions of related species) does not report this latter characteristic, it was also observed in D. inflexifolia by the present authors (Büneker 298 et al.). Also unusual in Dyckia is the inability of D. nobilis to reproduce by clonal division. After six years of in situ observation, no rhizomes or stolons linking to different rosettes were observed. The specimens studied ex situ, from germination to the semi-adult stage, did not show clonal divisions either.

Forzza (1997) considered the length of flowers pedicels a much variable character that does not fit for distinguishing D. sordida and D. duarteana (issue further clarified in the D. sordida comments). However, it has been observed that D. nobilis always has shorter pedicels in comparison to its closely related species. This is one of the most significant differences of the new species.

Dyckia nobilis is currently known from the type locality only, where it was found growing saxicolous in sedimentary rock. Due to the plant rarity and beauty, the geographic coordinates are not provided to avoid predatory collections. D. nobilis grows together with other saxicolous species, especially Bromeliaceae ( Alcantarea sp. , Encholirium subsecundum ( Baker 1889: 135) Mez (1896: 506) , Tillandsia aff. streptocarpa Baker (1887: 241) , Tillandsia sp. and T. recurvata ( Linnaeus 1753: 287) Linnaeus (1762: 410)) , Arecaceae ( Syagrus glaucescens Glaziou ex Beccari (1916: 470)) , Cactaceae ( Cipocereus minensis ( Werdermann 1933: 93) Ritter (1979: 57) and Pilosocereus aurisetus ( Werdermann 1933: 103) Byles & Rowley (1957: 66)) , Malvaceae ( Pseudobombax campestre ( Martius 1823: 86) Robyns (1963: 65)) , Orchidaceae ( Acianthera teres ( Lindley 1835: t. 1797) Borba (2003: 23), Hoffmannseggella sp. , Cyrtopodium sp. , Bulbophyllum sp. ) and Velloziaceae ( Vellozia spp. ).

Conservation Status: — Dyckia nobilis is possibly endemic to the type locality and its know population covers an area ( AOO) of ca. 0,01 km 2. It is subject to anthropogenic changes, and has low natural regeneration rate. According to the criteria B2 ac(ii, iv) ; D of IUCN (2012), it is considered a Critically Endangered species (CR).

Additional specimens examined (paratype):— BRAZIL. Minas Gerais: Serro cerca de 10 km da sede do município, 28 June 2013, fl., L. C. de Assis, A. Gabrielli & K. P. Soares 60 ( HDCF!).

Figures

FIGURE 2. A–H. Dyckia nobilis H. Büneker, K. Soares & L.C. Assis (Büneker 296 et al.). A. Habitus. B. Branched inflorescence. C. Flower in lateral view. D. Top flower. E. Section of a flower. F. Petal and stamen. G. Opened capsule (fruit). H. Seeds.

FIGURE 3. A–H. Dyckia nobilis H. Büneker, K. Soares & L.C.Assis (Büneker 296 et al.). A. Habitat. B. Grouped individuals in habitat. C. Fertile specimen in habitat. D. Rosette. E. Branched inflorescence. F. Flower in lateral view. G. Inflorescence detail. H. Inflorescence detail with flowers in bud.