Orthophytum caraibense Leme & O.B.C. Ribeiro, 2022

Leme, Elton M. C., Zizka, Georg, Souza, Everton Hilo De, Paule, Juraj, De Carvalho, Jordano D. T., Mariath, Jorge E. A., Halbritter, Heidemarie & Ribeiro, Otávio B. C., 2022, New genera and a new species in the “ Cryptanthoid Complex ” (Bromeliaceae: Bromelioideae) based on the morphology of recently discovered species, seed anatomy, and improvements in molecular phylogeny, Phytotaxa 544 (2), pp. 128-170 : 160-165

Orthophytum caraibense Leme & O.B.C. Ribeiro , sp. nov. (figs. 19 A to H)

Diagnosis:—This new species is morphologically related to O. duartei , but differs by its shorter stature (7–8 cm vs. 18–36 cm tall), propagation by short basal shoots (vs. slender stolons), leaf blades smaller (10–14 × 1–1.8 cm vs. 15–25 × 2–3 cm), shorter peduncle (1–1.5 cm vs. 5–7 cm long), shorter inflorescence (4–6 cm vs. 12–25 cm long), longer flowers (40–43 mm vs. 26–27 mm long), petals longer (35–39 mm vs. × 20–21 mm long), exappendiculate (vs. bearing distinct cupuliform appendages), apex acuminate (vs. rounded), and stigma conduplicate-patent (vs. simple-patent).

Type:— Brazil. Minas Gerais: Bonito de Minas , RPPN Vereda da Caraíba, saxicolous on sandstone outcrops in Cerrado vegetation, 780 m elevation, 14°43’11.79” S, 45°02’03.87” W, 27 January 2019, C . V . Vidal s.n., cult. E . Leme 9534 (holotype RB!) .

Description:— Plants stemless, 7–8 cm long when flowering, propagating by short basal shoots. Leaves 8–10 in number, not distinguishable from the primary bracts at anthesis, arcuate to subspreading at anthesis, forming a narrow rosette; sheath inconspicuous; blade narrowly lanceolate, apex caudate, 10–14 × 1–1.8 cm, thin coriaceous, canaliculate, green to greenish-bronze toward the apex, abaxially densely to subdensely and coarsely white lepidote, nerved, adaxially glabrous, margins straight to slightly undulate, densely to subdensely spinose; spines acicular, prevailingly straight to slightly antrorsely uncinate, 1–2 mm long, 2–5 mm apart. Inflorescence compound, 4–6 cm long (excluding the petals), 2–2.5 cm in diameter, slightly to distinctly elongated; peduncle inconspicuous, 1–1.5 × 0.7 cm, white lepidote; peduncle bracts foliaceous, densely arranged, arcuate to subspreading; primary bracts foliaceous, green, distinctly exceeding the fascicles, suberect to spreading at anthesis; fascicles sessile, inconspicuous, subflabellate, 5–7 in number, 2–4-flowered. Floral bracts narrowly triangular, attenuate-caudate, slightly to distinctly shorter than the sepals, 20–24 × 5–7 mm, thin in texture, greenish-white, glabrous or centrally with sparse and inconspicuous glandulose trichomes, carinate, nerved, entire. Flowers sessile, 40–43 mm long (with extended petals), slightly fragrant, anthesis starting at night and continuing during the next day; sepals subsymmetric, narrowly lanceolate, attenuate-caudate, erect, 21–27 × 2–3.5 mm, free, greenish-white or reddish toward the apex, glabrous or sometimes with inconspicuous and sparse fimbriate white trichomes at the apex, entire, ecarinate, membranaceous; petals narrowed toward the base, with a distinct narrowly ovate-lanceolate blade, apex acuminate, 35–39 × 5–5.5 mm, free, white, spreading at anthesis and forming a fan blade-like corolla of 20–25 mm in diameter, exappendiculate, bearing 2 longitudinal callosities about equaling the filaments and thickened from about 5 mm above the base. Stamens included but partially visible at anthesis; filament distinctly unequal in length, the antesepalous ones 24–27 mm long, free, the antepetalous ones 20–22 mm long, ca. 0.3 mm in diameter, adnate to the petals for 15–17 mm; anther 1.2–2 mm long, dorsifixed near the base, base obtuse, apex obtuse and inconspicuously apiculate, strongly laterally compressed at anthesis. Ovary ca. 4.5 × 3 mm, white, glabrous, trigonous; epigynous tube inconspicuous, ca. 0.5 mm long; stigma conduplicate-patent, lobes narrow, spreading-recurved, ca. 0.4 mm long, white, distinctly exceeding the anthers and visible above the corolla throat, margins irregularly and distinctly scalloped, undulate, inconspicuously and sparsely papillate toward the distal end; ovules many, obtuse; placentation subapical. Fruits baccate, 5–6.5 × 3–5 mm, white, with persistent sepals, 3–4.5 times longer than the fruit length; seeds 1–1.5 × 0.7–1 mm, 50–56 in number, subtriangular, proximal end acute, distal end obtuse.

Distribution and habitat:— Orthophytum caraibense grows in the north of Minas Gerais state, close to the border with Bahia state, with a geographical range extending much inland when compared to the closest morphological relative, O. duartei , which lives in the Atlantic Forest domain of Espírito Santo state, closer to the Atlantic coast. This new species lives as a saxicole in crevices in vertical sandstone outcrops in Cerrado vegetation (figs 14 A–C), at an altitude of ca. 780 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” and its conservation status is inconclusive, despite its occurrence inside a private protected area.

Etymology:—The name chosen for this new species is a reference to the private reserve ‒ Reserva Particular do Patrimônio Natural (RPPN) Vereda da Caraíba ‒ where this new species was discovered.

Distinctive characters:— Orthophytum caraibense is an outlier species, like its closest morphological relative O. duartei , mainly due to its unappendaged petals (fig. 19 G) and conduplicate-patent stigma type (fig. 19 H) not observed in any other member of Orthophytum . Exappendiculate petals are also observed in Cryptanthus , Forzzaea , Hoplocryptanthus , and frequently in Orthocryptanthus , while the conduplicate-patent stigma type is only seen in Cryptanthus and Lapanthus , Krenakanthus has the conduplicate-spiral type. However, all other floral features are in accordance with Orthophytum .

According to the molecular phylogeny, both O. caraibense and O. duartei are part of an unsupported clade (0.53 PP, 57 BS) along with Orthophytum subgg. Orthophytum , Capixabanthus and Clavanthus (fig. 1). Orthophytum duartei remains without or with weak support (0.73 PP, 67 BS) as sister to Orthophytum subg. Capixabanthus and both are unsupported sister to the Orthophytum-Clavanthus clade. However, Orthophytum subgg. Orthophytum and Clavanthus are sister to each other with high support (1 PP, 98 BS).

The position of O. caraibensis in the phylogenetic tree is challenging. Despite of being well supported (1 PP, 98 BS), in all aspects its geographical range and morphology are not compatible with subgenus Clavanthus , to which it comes out in sister position.

Apart of its much smaller size (7–8 cm vs. 18–36 cm tall) and leaf blades (10–14 × 1–1.8 cm vs. 15–25 × 2–3 cm), the thin coriaceous leaf texture and the fan blade-like corolla with spreading petals of O. caraibense are similar to O. duartei (see Leme 2014, Leme et al. 2017b). This new species also differs from its closest relatives in the propagation by short basal shoots (vs. slender stolons), shorter peduncle (1–1.5 cm vs. 5–7 cm long), shorter inflorescence (4–6 cm vs. 12–25 cm long), longer flowers (40–43 mm vs. 26–27 mm long), longer sepals (21–27 mm vs. 10–12 mm), longer (35–39 mm vs. 20–21 mm long) and exappendiculate petals (vs. bearing distinct cupuliform appendages), with apex acuminate (vs. rounded), and stigma of the conduplicate-patent type (vs. simple-patent).

The reported affinity of O. caraibense and O. duartei and their equivocal position in the molecular phylogeny requires further investigation and refinement of the molecular approach and for the time being we therefore refrain from elevating Capixabanthus and Clavanthus to generic status, despite its well-circumscribed morphology and welldelimited biogeography.