Dyckia nana Leme & Ribeiro ( Leme et al. 2010: 36 )

Guarçoni, Elidio Armando Exposto, Azevedo, Aristéia Alves De & Costa, Andrea Ferreira Da, 2017, The restablishment of Dyckia oligantha and D. nana (Bromeliaceae, Pitcairnioideae), belonging to the D. macedoi complex, Phytotaxa 306 (1), pp. 49-65 : 60

2. Dyckia nana Leme & Ribeiro ( Leme et al. 2010: 36) , Figs. 4 E–H , 5 D–E

Type:— BRAZIL, Minas Gerais: Diamantina, est. Diamantina para Conselheiro Mata, ca. 10 km de Conselheiro Mata, 18º18.50’S, 43º53.43’W, 1288 m elev., 25 June 2008, fl., E. Leme, C.C. Paula, T. Coser, R. Moura & O.B.C. Ribeiro 7484 (holotype RB!, isotype HB!).

Plant terrestrial, flowering 19–41.5 cm high. Leaves 8–17 in number, rigid, succulent, slightly recurved, forming an asymmetric rosette, caused by the second leaves, 4.4–7 × 7.2–8.7 cm; sheaths suborbicular, ca. 2 × 4 cm, white with the upper abaxial half brown, white lepidote on the upper third of both surfaces, inconspicuously spinose distally; blades narrowly triangular, 3–6.7 × 0.6–1.4 cm, distinctly canaliculate, green abaxially, vinaceous adaxially, white lepidote on both surfaces, slightly or not obscuring the leaf color, apex acuminate, pungent, margins spinose except for the apical third, spines the basal ones antrorse to patent in the median ones, brown, 0.6–1.4 × 0.1 mm, 4–10 mm apart. Inflorescence simple, erect, (21.4–) 28–39.6 cm long; rachis orange, 1.1–1.4 mm in diameter, white tomentose; fertile part of the inflorescence 4.7–9.5 cm; peduncle erect, terete, (15–) 23.3–31.7 cm long, 1–1.8 mm in diameter, green, glabrous, internodes (17–)23–35.1(–40.8) mm long; peduncle bracts shorter than the internodes, lower ones 1.3–3.4 × 0.2–0.4 cm, upper ones 4.6–8 × 1.2–3.4 mm, ovate to oblong, acuminate, ending in a spine, stramineous, carinate, the lower ones white lanate abaxially, the upper ones glabrous, margins entire. Floral bracts equaling or slightly exceeding the pedicels, 3.4–8 × 2.6–5.3 mm, orange, broadly ovate, patent, convex, ecarinate, acuminate, ending in a spine, white lanate abaxially, margins with fimbriate trichomes along the basal half. Flowers 5–13 in number, antrorse, 1.2–1.5 cm long; pedicels evident, orange, (3.2–) 4.2–6.8 mm long, sparsely white lanate; sepals symmetric, reaching the midpoint of the petals, orange, ovate to ellipitc, 4.7–8.3 × 3.1–5.1 mm, obtuse or with an inconspicuous apiculus, sparsely white lanate abaxially, margins with fimbriate trichomes; petals symmetric, orange, rhombic, 7.5–7.7 × 4.2–5.2 cm, obtuse, margins entire, glabrous; corolla tubular. Stamens included; filaments pale yellow, linear, 4.8–5.3 mm long, connate at the base for 1.4–1.5 mm to form a common tube with the petals, free above it; anthers linear, 1.5–1.7 mm long, acute, recurved at the apex, yellow, dorsifixed near the base. Ovary superior part oblong, yellow to pale orange, 3.8 mm long; style yellow, 1.3 mm long; stigma, 0.5–0.9 mm long, yellow. Capsules ovoid, dark brown, 8.6 × 6, 3 mm, suberect to erect.

Additional specimen examined:— BRAZIL, Minas Gerais: Diamantina, Km 165, estr. para Conselheiro Mata , MG-220, 25 February 1987, Zappi et al. ( SPF 46903 ) ; 15 March 1999, Rapini 746 & Kawasaki ( SPF) ; estr. Diamantina-Conselheiro Mata, 38 Km do trevo de saída de Diamantina , 31 January 2000, Forzza & Mello-Silva 1510 ( BHCB; SP; SPF) ; estr. para Conselheiro Mata , lado esquerdo, 1241 m elev., 18º18’24”S – 43º53’59”W, 25 May 2011, Guarçoni 1671 & Paixão ( VIC). Gouveia, estr. do lado esquerdo da BR-259 para Gouveia, 5 August 2010, Guarçoni 1478 et al. ( MACO). Presidente Kubitschek, estr. Datas to Serro, KM 438, 18º33’00”S – 33º33’00”W, 11 March 1998, Forzza et al. 679 ( RB) .

Distribution and habitat: — Dyckia nana is endemic to the Diamantina Plateau , occurring between 1000 and 1240 m elevation. The species habit can be terrestrial or saxicolous, and individuals usually occur on soils with quartz rubbles.

Phenology:—Flowering from January to May.

Conservation Status:—The species is critically endangered (CR), as it is known from only three localities, with a total estimated population of less than 250 individuals. These areas are severely affected by annual fires. The species does not occur in Conservation Units.

Comments:— Dyckia nana is mainly characterized by small and asymmetric rosettes with few slightly recurved leaves. Another character that can aid recognition is the suberect flowers at anthesis.

The species can be distinguished from D. oligantha by having fewer leaves (9–17 vs. 21–41), sheath white-lepidote on the upper third (vs. glabrous), peduncle bracts glabrous (vs. white-lepidote); flowers suberect (vs. slightly reflexed), pedicels 4.2–6.8 mm (vs. 2–4 mm), sepals obtuse (vs. acute), narrower petals (4.2–5.2 mm vs. 5.9–9.2 mm), and longer style (1.3 mm vs. 0.8 mm).

Dyckia nana had been synonymized with D. macedoi by Forzza et al. cont. upd. without additional comment.

Figures

FIGURE 4. A–L. Details of species from the Dyckia macedoi complex. A–D. D. macedoi. A. Detail of the leaf margin, showing the size of spines and the distances between them. B. Floral bract. C. Flower. D. Detail of the flower in longitudinal section. E–H. D. nana. E. Detail of the leaf margin, showing the size of spines and the distances between them. F. Floral bract. G. Flower. H. Detail of the flower in longitudinal section. I–L. D. oligantha. I. Detail of the leaf margin, showing the size of spines and the distances between them. J. Floral bract. K. Flower. L. Detail of the flower in longitudinal section. (Illustrations: Reinaldo Monteiro)

FIGURE 5. A–C. Dyckia macedoi. A. Population Km 5 (P1). B. Population from Serra do Estreito (P2). C. Population from Serrinha (P3). D–E. D. nana. D. Flowering. E. Rosette shape and the substrate over which it occurs. (Photo: Elidio Guarçoni)