Dyckia oligantha L.B. Smith (1957a: 329)

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 : 60-61

3. Dyckia oligantha L.B. Smith (1957a: 329) . Figs. 4 I–L , 6 A–J , 7 A–E

Type:— BRAZIL, Minas Gerais: Serra do Cipó, km 131, 1400 m elev., 24 April 1950, A.P. Duarte 2748 (holotype RB!, isotype US Photo!).

Plant saxicolous, flowering 13.3–43.3 cm high. Leaves 9–24 in number, rigid, slightly succulent, suberect, secund, forming an asymmetric rosette, secund, 4.1–9.5(–11.6) cm × 6–16.8(–22.7) cm; sheaths suborbicular, 1.8–2 × 2.4– 2.9 cm, brown at distal end abaxially, glabrous on both surfaces, inconspicuously spinose at the distal part; blades very narrowly triangular, 4.2–11.6 × 0.4–0.9 cm, canaliculate, green, white lepidote on both surfaces, with trichomes concentrated between the ribs and not obscuring the leaf color in between, apex acuminate, pungent, margins spinose, spines the basal ones patent to antrorse in the median ones, brown, 0.7–1.4 × 0.4–0.5 mm, (3.3–)4.8–9.7(–12.6) mm apart. Inflorescence simple, erect, 11.7–25.3 cm long; fertile part of the inflorescence 1.4–5.9 cm; peduncle erect, terete, 8.9–19.7 cm long, 1.3–2.5 mm in diameter, green to orange, sparsely white lanate to glabrous, internodes 6.2–18.1(–21.3) mm long; peduncle bracts, the lower ones longer than internodes, green, ovate to linear-triangular, 0.7–3.3(–4.8) × 0.3–0.6 cm, the upper ones shorter than the internodes, stramineous with the lower third green to pale orange, ovate to triangular, 3.9–7.3(–10.6) × 1.9–5.7 mm, ending in a spine, carinate, white lanate on the abaxial surface, margins inconspicuously spinose along the basal third only; rachis orange, 1–1.4 mm in diameter, glabrous. Floral bracts equaling to exceeding the pedicels, 3.2–6.3 × 3.2–5.9 mm, stramineous, broadly ovate to triangular, patent to reflexed with the flowers, carinate, acuminate, ending in a spine, sparsely white lanate on the abaxial surface, margins with fimbriate trichomes. Flowers 3–13 in number, spreading to reflexed at the anthesis, 1–1.3 cm long; pedicels evident, orange, 2–4 mm long, sparsely white lanate; sepals symmetric, reaching the midpoint of the petals, orange, elliptic to ovate, 4.5–6.6 × 3.6–5.5 mm, acute or with an inconspicuous apiculus, sparsely white lanate on the abaxial surface, margins with fimbriate trichomes; petals asymmetric, orange, broadly obovate to obtrullate, 7.4–10.5 × 5.9–9.2 mm, retuse or obtuse, margins entire, glabrous; corolla tubular. Stamens included; filaments yellow, the antepetalous ones triangular, the antesepalous ones linear, 4.2–6.5 mm long, connate at the base for 1.1–1.7(–2.1) mm to form a common tube with the petals, free above it; anthers lanceolate, 2.8–3.5 mm long, acute or with an inconspicuous apiculus, dorsifixed near the base. Ovary superior part oblong, orange, 3.3–6.6 mm long; style orange, 0.5–1.4 mm long; stigma, 0.8–1.1 mm long, yellow to orange. Fruits ovoid, dark brown, 8.6–11 mm long, 6.3–10 mm in diameter, suberect to erect.

Additional specimen examined:— BRAZIL, Minas Gerais: Jaboticatubas, Km 139, ao longo da rodovia Lagoa Santa—Conceição do Mato Dentro — Diamantina, 17 April 1972, Joly s.n. ( SP 144937 ) ; Santana do Riacho, estr. calçada entre Santana do Riacho-Lapinha , 19º07’52’’S – 43º41’56’’W, 15 November 2011, Guarçoni 1713 ( MACO) ; idem, 15 December 2011, Guarçoni 1734 ( VIC) ; idem, 27 November 2012, Guarçoni 2082 ( VIC) .

Distribution and habitat:— Dyckia oligantha is known only from its type area, occurring on quartzite rocky outcrops in Serra do Cipó, at 1168–1290 m elevation.

The species can be rupicolous or saxicolous, rarely terrestrial but occur always near rocky outcrops on stony grounds. Individuals grow isolated, never forming clumps.

Phenology:— Flowering from November and December.

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

Comments:— Dyckia oligantha was described based on a specimen from Serra do Cipó. For four decades it remained known only from the type collection and was considered a synonym of D. saxatilis by Forzza & Wanderley (1998) and Versieux & Wendt (2006). However, D. oligantha differs morphologically from D. saxatilis by having a lower mean flowering plant height (25.1 cm vs. 52.9 cm); asymmetric rosettes with recurved leaves (vs. symmetric rosettes with straight leaves); slender (vs. robust) and longer pedicels (ca. 5.2 mm vs. ca. 2.5 mm), relative longer pedicel to total flower length ratio (40% vs. 19.2%), convex sepals (vs. not convex), and filaments free above the petal-stamen ring (vs. connate).

Inflorescences with more than five flowers have their apical half curved, with slightly secund flowers. Floral bracts enfold half of the pedicel diameter.

Rauh (1988) described D. oligantha var. cristalina (syn. nov.) from Goiás state, Brazil. However, after analysis of the type material, we found that the variety is similar to D. machrisiana L.B. Smith (1957b: 7) .

Guarçoni et al. (2010) revalidated D. oligantha , but erroneously indicated the collections numbers Guarçoni 1241, 1273, 1274, and 1281. Those collection numbers actually represent D. consimilis Mez , which is not morphologically related to D. oligantha . Dyckia oligantha differs from D. consimilis mainly by the slender and conspicuous pedicels (vs. robust) and free filaments above the petal-stamen ring (vs. connate) in the former.

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 6. A–J. Dyckia oligantha L.B.Sm. (Guarçoni 1747). A. Habit. B. Detail of a spine. C. Leaf. D. Lower peduncle bract. E. Upper peduncle bract. F. Floral bract. G. Flower. H. Sepal. I. Petal and stamen, with detail of their fusion. J. Detail of the style and stigma. (Illustrations: Reinaldo Monteiro)

FIGURE 7. A–E. Dyckia oligantha. A. Plant habit. B. Individual at flowering stage showing slightly secund flowers with conspicuous pedicels. C. Individuals at flowering and fruiting stages. D. Slightly secund flowers with conspicuous pedicels. E. Rosettes with second leaves, in the species natural environment. (Photo: Elidio Guarçoni)