Dyckia oscari Guarçoni & Sartori, 2020

Guarçoni, Elidio A. E. & Sartori, Marcos A., 2020, Checklist of the Bromeliaceae of the Serra do Cabral, Minas Gerais, Brazil, with a description of a new species, Phytotaxa 443 (1), pp. 38-50 : 42-48

Dyckia oscari Guarçoni & Sartori , sp. nov. ( Fig. 2a & b , 8 and 9 )

Diagnosis: —The new species differs from Dyckia warmingii in having oblong to subelliptic peduncle bracts with serrulate margins on the median portion (vs. broadly ovate and entire); the lower floral bracts exceeding the sepals (vs. lower floral bracts nearly equaling the sepals); flowers spreading to suberect at anthesis (vs. spreading or reflexed); sepals obovate to elliptic and obtuse to apiculate (vs. broadly ovate and acute); and petals elliptical and retuse (vs. broadly obovate and obtuse).

Tipo:— BRASIL. Minas Gerais: Buenópolis, Vitória Farm, Ribeirão da Prata, 1.027 m elev. 17º56’35”S, 44º21’15”W, 17 April 2012, fl. cult. 11.III.2013, E.A.E. Guarçoni & M.A. Sartori 2585 (Holotype VIC!).

Plant terrestrial, heliophyte, 37–62 cm tall when flowering. Leaves ca. 20, rigid, stiff coriaceous, basal ones spreadingarched, to suberect-arched (median ones) or suberect (upper ones), forming a rosette of 20–22 cm in diameter; sheath 2.3–3.6 × 1.6–5.4 cm, suborbicular, white to greenish, lower part (ca. 2/3) glabrous with entire margins, upper third densely white lepidote and inconspicuously spinose; blade 9–17 × 0.9–1.4 cm, triangular, densely cinereous-lepidote on both surfaces, obscuring the color of the leaf, or glabrous to sparingly lepidote on the adaxial surface, green with basal third of the adaxial surface cinereaus green or reddish tinged leaves, the upper ones canaliculate, apex acuminate, pungent, margins densely spinose; spines complanate, 1–2 mm long, 0.4–0.9 mm wide at the base, brown, retrorse or the distal ones antrorse, 3.6–6.6 mm apart. Inflorescence 49–52.5 cm long, erect, straight, simple; rachis 1–2.5 mm in diameter, sparsely cinereous-tomentose, green to orange; peduncle 28.5–40 cm long, 3.1–4 mm in diameter, terete, white-tomentose, green; peduncle bracts the upper ones shorter than the internodes, 4.9–6.3 × 1.1–2.4 cm, erect, oblong to subelliptic, carinate, the distal third strongly canaliculate, nerved abaxially, densely cinereous-floccose, stramineous, margins serrulate at the median portion, apex aculeate, spines brown, 0.2–0.5 mm long, long acuminate, ending in a spine. Floral bracts the lower ones exceeding the sepals, 0.9–1.7 × 0.5 cm, triangular to subelliptic, convex, carinate, white-tomentose, stramineous, ferrugineous at the base, margins entire or sometimes fimbriate trichomes, acuminate, pungent. Flowers 12–25 in number, 1–1.5 cm long, campanulate, spreading to suberect at anthesis, suberect afterward; pedicel 1.5–3.5 mm long, 2.5–4.4 mm in diameter, white-tomentose, red; sepals 3.8–6.2 × 3–4.8 mm, obovate to elliptic, slightly white-tomentose, orange, margins fimbriate trichomes, obtuse to apiculate; petals asymmetrical, 8–10 × 5–7 mm, elliptical, orange, margins entire, retuse, connate at the base for 1–1.8 mm and forming a common tube with the filaments. Stamens exceeding the petals with a fraction of the anthers; filaments 5.2–8 mm long, complanate, connate for 1–4 mm above the common tube with the petals, yellow; anthers 3.1–4 mm long, erect, triangulate to elliptic, yellow, apex acute, dorsifixed near the base. Pistil exceeded by the stamens; ovary 3.9–5.1 mm long, obovoid-triangular, orange; style 0.4–1 mm long, orange; stigma 0.7–1.1 mm long, erect, conduplicate-spiral, orange. Capsules 1–1.1 × 0.8–1 cm, ovoid, dark brown.

Paratypes: –– BRAZIL. Minas Gerais: Buenópolis, on the way up the mountain towards the Serra do Cabral State Park, 14 August 2009, L. Oscar Ribeiro s/nº ; 17º54’31”S, 44º13’20”W, 17 February 2017, fr., Elidio Guarçoni et al. 2518 ( BMA!) ; Vitória Farm, Ribeirão da Prata, 1027 m elev., 17º56’35”S, 44º21’15”W, 2 March 2013, fl. cult., E. A. E. Guarçoni & M. A. Sartori 2584 ( BMA!) ; idem., E. A. E. Guarçoni & M. A. Sartori 2586 ( BMA!) ; ibidem, 17 February 2017, fr., E. A. E. Guarçoni et al. 2524 ( BMA!) ; ibidem, E. A. E. Guarçoni et al. 2541 ( BMA!) ; ibidem, E. A. E. Guarçoni et al. 2542 ( BMA!) .

Distribution and habitat: –– Dyckia oscari was located at two localities in Buenópolis in the Serra do Cabral: in the Salto Grande region, on Vitória Farm (P1), and on the road to the Serra do Cabral State Park (P2). In P1, D. oscari has leaves with the abaxial surface densely cinereous-lepidote and the adaxial surface glabrous or occasionally cinereous-lepidote, showing its green color with the lower third dark red to brownish. In P2, D. oscari has leaves densely cinereous-lepidote on both surfaces or glabrous to sparsely lepidote on the adaxial surface, not masking the color of the leaf, which may be green with the basal third of the adaxial surface vinaceous or castaneous.

The morphological variation between P1 and P2 may be associated with the abiotical factors. At location P1, D. oscari occurs on sandstone rock outcrops, exposed to full sun always. At location P2, D. oscari occurs on sandy-clay soils, in partial shade, near a stony slab that borders the watercourse. According to Benzing (2000), a higher density of trichomes indicates greater exposure to sunlight and a drier environment

Dyckia oscari is associated with the cactus Melocactus sp. and the palm Syagrus evansiana Noblick (2009: 113– 118) . In both areas, rosettes can occur either isolated, most commonly, or forming clusters with up to five rosettes.

The variation in leaf color may be related to abiotic factors. Smith & Downs (1974) noted that both the level of illumination and the pH of the soil affect leaf color in Bromeliaceae .

Etymology: ––The specific epithet honors Oscar M. Ribeiro, owner of nursery “Bromeliário Imperialis”, for his dedication to bromeliads.

Phenology: –– Dyckia oscari was observed in flower in February. In cultivation the species blooms in November and December. One flower opens each day.

Taxonomic discussion: According to the identification key in Smith & Downs (1947), Dyckia oscari fits subkey IV because the inflorescence has a peduncle and the filaments are connate above the common tube with the petals. According to this key, D. oscari is morphologically close to Dyckia warmingii , a plant known only from fragments ( Table 2). It can also be confused with D. saxatilis and D. braunii (for differences see table 2).

Dyckia oscari differs significantly from D. spinulosa , also cited for Serra do Cabral and only known by fragments of the type material; e.g. plant size (37.2–61.8 vs. 85 cm), pedicel length (1.5–3.5 vs. 5 mm), floral bracts exceeding the sepals vs. equaling the midpoint of the sepal). In addition, D. spinulosa is known only from the type material, collected in the municipality of Várzea da Palma, in Minas Gerais ( Smith & Downs 1974; Versieux & Wendt 2006). Although the D. spinulosa holotype label includes “Fazenda Mãe d’Água” as its provenance, its location is still uncertain, but it possibly came from the “Mãe d’Água” settlement of the Landless Rural Workers Movement (MST), a locality adjacent to the Serra do Cabral.

Figures

FIGURE 2. A–D: Subfamily Pitcairnioideae—A. Dyckia oscari flowering in the Salto Grande range, Buenópolis. B. Dyckia oscari flowering on the slope of the Serra do Cabral.C. Encholirium subsecundum. D. Pitcairnia burchellii. (Photos: Elidio Guarçoni and Marcos A. Sartori).

FIGURE 8. A–L. Dyckia oscari. A. P2 population in the Serra do Cabral, showing variation in leaf color and type of substrate. B. P1 population on Vitória Farm, showing variation in leaf color and type of substrate. C. Fruiting individual on the mountain slope, beneath a rock outcrop. D. Two individuals, showing leaf color variation in the population of Salto Grande, at Vitória Farm. E. plant in flower. F. Detail of the inflorescence with flowers of the Serra do Cabral population. G. Detail of the inflorescence with flowers of the population of Salto Grande, at Vitória Farm. H. Bracts of the peduncle shorter than the internodes. (Photos: Elidio Guarçoni & Marcos A. Sartori).

FIGURE 9. A–D. Details of the floral parts of Dyckia oscari. A. Flower prepared in alcohol, showing the stamens slightly exserted by a fraction of the anthers. B. Longitudinal section of the flower, showing the stigma below the anthers. C. Floral bract. D. Sepal. (Photos: Elidio Guarçoni & Marcos A. Sartori).