Orthophytum minimum Leme

Leme, Elton M. C., Ribeiro, Otávio B. C., Souza, Fernanda Vidigal D., Souza, Everton Hilo De, Kollmann, Ludovic J. C. & Fontana, André P., 2020, Miscellaneous new species in the “ Cryptanthoid complex ” (Bromeliaceae: Bromelioideae) from Eastern Brazil, Phytotaxa 430 (3), pp. 157-202 : 186-188

4.4. Orthophytum minimum Leme & O.B.C.Ribeiro, sp. nov. ( Fig. 13 A–D )

Diagnosis:—This new species is morphologically close to O. saxicola , but differs by its narrower leaf blades (0.4–0.5 cm vs. 1–1.5 cm), flowers longer (30–35 mm vs. 17–24 mm), and petals larger (26–30 × 6–7 mm vs. 18–22 × 4–5), spreading to slightly recurved at anthesis and forming a compact fan-like corolla (vs. suberect).

Type:— BRAZIL. Minas Gerais: Riacho dos Machados, Morro do Capim, saxicolous on iron-rich outcrops known as “canga” in Campos Rupestres, 925 m elevation, 16°04’26” S, 42°45’04” W, December 2017, R.C. Mota s. n., fl. cult. E. Leme 9313 (holotype RB!).

Description:— Plants stemless, 5–7 cm long when flowering, propagating by slender stolons of 3–7 × 0.3–0.4 cm. Leaves 10–18 in number, divergent, arcuate, densely arranged; sheath subtrapeziform, ca. 0.6 × 0.8 cm, greenish, lepidote abaxially mainly near distal end; blade narrowly lanceolate, apex caudate, 3–6 × 0.4–0.5 cm, subcoriaceous, ca. 2.5 mm thick near the base, canaliculate, greenish-bronze, abaxially densely and coarsely white lepidote, with trichomes along the nerves, conspicuously nerved, adaxially glabrescent to glabrous, margins densely to subdensely spinose; spines acicular, prevailingly straight to slightly retrorsely uncinate, 2–3 mm long, 2–5 mm apart. Inflorescence (fertile part) ca. 2 cm long (excluding the petals), 1–1.5 cm in diameter, simple; peduncle 1–2 × 0.3 cm; peduncle bracts resembling the leaves, densely arranged, suberect; floral bracts the basal ones somewhat resembling the leaves, exceeding the sepals, the upper ones lanceolate, acuminate, ca. 17 × 6 mm, thin in texture, greenish-bronze, subdensely and coarsely white lepidote of lacerate trichomes, exceeded by the sepals, ecarinate, nerved, margins sparsely spinulose, spines 0.5–1 mm long. Flowers sessile, 3–5 in number, 30–35 mm long (with the petals extended), odorless; sepals narrowly lanceolate, attenuate, ca. 15 × 3 mm, free, greenish-yellow to light green, sparsely white lepidote of fimbriate trichomes mainly on the apical margins, entire or inconspicuously spinulose at the apex, obtusely carinate toward the apex; petals spathulate, apex acute, 26–30 × 6–7 mm, white except for the greenish part facing the anthers, spreading to slightly recurved at anthesis and forming a compact fan-like corolla ca. 18 mm in diameter, bearing 2 longitudinal callosities about equalling the anthers, as well as 2 appendages; petal appendages echinatiform, ca. 3 mm above the base, irregularly fimbriate with spreading ornamentation; filaments unequal in length, the antesepalous ones ca. 18 mm long, free, the antepetalous ones ca. 17 mm long, highly adnate to the petals; anthers ca. 1.5 mm long, dorsifixed near the middle, base obtuse, apex apiculate; ovary ca. 4 × 3 mm, greenish-white, white lanate; epigynous tube inconspicuous; stigma simple-dilated, lobes broadened, lip-shaped, spreading, ca. 0.5 mm long, white, papillate; placentation apical; ovules many, obtusely apiculate. Fruits not seen.

Distribution, habitat and conservation:— Orthophytum minimum grows in the north of Minas Gerais State, in the county of Riacho dos Machados, at a locality known as Morro do Capim. The individuals form dense groups in sun exposed sites on iron-rich soils, known as “canga” ( Fig. 13 A ), in the the domain of the Campos Rupestres, in altitudes above 900 m.

The size of the population and the extension of the occupied area is not clearly known, and so it is considered here a “data deficient” species (DD) and its conservation status still remains inconclusive.

Etymology:—The name chosen for this new species is based on the Latin word “ minimus ”, meaning very small, very short, which is a reference to the very small size of O. minimum .

Observations:— Orthophytum minimum is the smallest known species of the genus, not exceeding 7 cm in heigth when flowering. It is morphologically closely related to O. saxicola ( Ule, 1908: 193) L.B. Smith (1955:34 , Fig. 14 E–F ), another tiny species, but it differs from it in the narrower leaf blades (0.4–0.5 cm vs. 1–1.5 cm), with marginal acicular spines (vs. narrowly triangular) prevailingly straight to slightly retrorsely uncinate (vs. prevailingly strongly retrorsely uncinate), longer flowers (33–35 mm vs. 17–24 mm), larger petals (30 × 6–7 mm vs. 18–22 × 4–5), which spread at anthesis and form a compact fan-like corolla (vs. suberect), and acute apex (vs. subacute and inconspicuously cucullate).

This new species can be also confused with O. harleyi Leme & M. Machado (2006: 108. Fig. 14 D ) and O. braunii Leme (1994: 14) . However, O. minimum clearly differs from the first one by its smaller size when in bloom (5–7 cm vs. 13–15 cm high), smaller leaf blades (3–6 × 0.4–0.5 cm vs. 10–11 × 1.3–1.9 cm), with glabrescent to glabrous adaxial surface (vs. densely and coarsely lepidote), fewer flowers per inflorescence (3–5 vs. 25–35 in number), acute petals (vs. subobtuse) spreading at anthesis and forming a compact fan blade-like corolla (vs. suberect). In relation to O. braunii , this new species also can be distinguished by its smaller size when in bloom (5–7 cm vs. ca. 20 cm high), shorter marginal spines (2–3 mm vs. 3–5 mm), shorter peduncle (1–2 cm vs. ca. 6 cm), simple inflorescence (vs. distinctly compound), which is much shorter (ca. 2 cm vs. ca. 8 cm), and larger petals (30 × 6–7 mm vs. ca. 21 × 5), which spread at anthesis and form a compact fan-like corolla (vs. suberect).

Figures

FIGURE 13. Orthophytum minimum from Morro do Capim,Riacho dos Machados, Minas Gerais state:A. Group of saxicolous individuals on iron-rich rock outcrops known as “canga” in Campos Rupestres at the type locality. B–D. Specimens flowered in cultivation (Leme 9313). B. Habit and inflorescences. C. Inflorescence and flower. D. Detail of the flower. A. Photo R.C. Mota.

FIGURE 14. Orthophytum santosianum from Caraguataí, county of Jussiape, Bahia state (Leme 8977): A. Habit. B. Details of the inflorescence. C. Echinatiform type of petal appendages with spreading ornamentation. D. Orthophytum harleyi (Leme 6173). E. Orthophytum saxicola (Leme 6058). F. Orthophytum saxicola (Leme 7511). G. Orthophytum conquistense (Leme 6019 et al.). H–I. Orthophytum cearense (Leme 7700). J. Orthophytum triunfense (Leme 5548).