Orthophytum roseolilacinum Leme, 2015

Leme, Elton M. C., 2015, Two new species of Orthophytum (Bromeliaceae: Bromelioideae) from Minas Gerais, Brazil, Phytotaxa 205 (4), pp. 283-291 : 284-287

Orthophytum roseolilacinum Leme , sp. nov. ( Figs. 1 A–E , 2 A–J )

This new species can be distinguished from all known species of Orthophytum by the combination of its long caulescent habit (vs. usually stemless), leaves in most part thin in texture (vs. coriaceous or nearly so), leaf blades glabrescent or glabrous (vs. usually distinctly lepidote at least abaxially) with undulate margins (vs. not undulate), inflorescence sessile (vs. usually on a distinct peduncle), flowers 42–55 mm long (vs. usually to 30 mm long), fragrant (vs. odorless), petals broadly spathulate (vs. sublinear-lanceolate to narrowly spathulate), spreading at anthesis (vs. erect to suberect with recurved apex), rose-lilac to lilac-purple toward the apex (vs. white or green), petal blades suborbicular (vs. ovate, obovate or elliptic), petal appendages thick, cupuliform with downwardly curved margins (vs. usually fimbriate to lacerate), stamens deeply included and not visible (vs. not deeply included and at least partially visible), filaments distinctly unequal with the antesepalous ones twice as long as the antepetalous ones (vs. usually unequal, with the antesepalous ones slightly longer than the antesepalous ones), and the conduplicate-spiral stigma (vs. simple-erect).

Type:— BRAZIL. Minas Gerais: Conselheiro Pena, Serra do Padre Ângelo, Mata do Elias, 810 m elevation, 19° 17’ 14.71” S, 41° 34’ 13.47” W, May 2014, R. Vasconcelos Leitão & E. C. Ribeiro s.n., flowered in cultivation E. Leme 8885 (holotype RB!).

Plants terrestrial, long caulescent, flowering 30–60 cm tall, propagating by elongated shoots developed near the base of the inflorescence. Leaves 20–27 in number, thin in texture except for a thicker median zone mainly toward the base, spreading-recurved, more or less equally arranged along the stem, forming a subdense rosette; sheaths trapeziform, 2 × 3.5 cm, pale green, glabrescent, densely spinulose; blades narrowly lanceolate, long attenuate and caudate, 17–27 × 1.8–2.4 cm, green, concolor, glabrescent to glabrous, opaque, margins undulate mainly toward the base, densely spinulose; spines pale green, the basal ones narrowly triangular, 1–3 mm long, 2–4 mm apart, spreading to slightly antrorse, the upper ones triangular, 0.2–0.3 mm long, 1–3 mm apart, antrorse. Inflorescence sessile, 3.5–5 cm long, fasciculate compound at the base and unbranched toward the apex; primary bracts foliaceous, spreading-recurved, many times exceeding the fascicles; fascicles 1–2 in number, densely aggregated, 30–32 × 14–16 mm (excluding the petals), ca. 7 mm thick, 2–4-flowered, stipe inconspicuous, stout, ca. 5 mm long; floral bracts in the fascicles triangular, acuminate-caudate, membranaceous, green toward the apex, hyaline near the base, glabrous, nerved, slightly shorter than the sepals, alate-carinate (the outer ones) to obtusely if at all carinate (the inner ones), 20–26 × 14–15 mm, margins entire to spinulose at the apex; floral bracts of the unbranched apical part of the inflorescence subfoliaceous, many times exceeding (basal ones) to slightly shorter (apical ones) than the flowers (including the petals). Flowers all perfect, sessile, 42–55 mm long, fragrant; sepals 20–27 × 4–5 mm, sublinear-lanceolate to narrowly ovate-lanceolate, acuminate-caudate, connate at the base for 3–7 mm, green but drying dark castaneous soon after anthesis, glabrous, thin in texture, the adaxial ones alate-carinate with the keel continuating on the ovary, the abaxial one obtusely if at all carinate; petals broadly spathulate from a very narrow base, 35–44 × 15–20 mm, free, greenish-white toward the base, rose-lilac to lilac-purple toward the apex, the blades suborbicular, broadly acute, spreading at anthesis, at base with 2 longitudinal callosities equaling to exceeding the antepepalous filaments and 2 appendages; petal appendages ca. 2.5 mm above the base, thick, cupuliform with downwardly curved margins, margins minutely and obtusely crenulate; stamens deeply included and not visible; filaments the antepetalous ones 4–6 mm long, adnate to the petals for ca. 1.5 mm, the antesepalous ones 11–14 mm long, free; anthers 1.5–2 mm long, oblong, dorsifixed at ca. 1/3 from the base, base bilobed, apex obtuse or minutely apiculate; pollen ellipsoid, ca. 36 μm, sulcate, sulcus narrow, covered by small exine islands, with margins weakly defined, exine reticulate, muri narrowed; style slightly exeeding the antepetalous stamens and distinctly shorter than the antesepalous ones, white; stigma conduplicate-spiral, white, with elongated densely papillose blades; ovary 5–7 mm long, 5–8 mm in diameter at the apex, trigonous, white, glabrous; epigynous tube lacking; ovules numerous, obtuse; placentation median to apical. Fruits subglobose, whitish, ca. 8 × 7 mm; seeds numerous, narrowly ovoid to fusiform, ca. 2 × 0.7–1 mm, slightly to distinctly curved, dark castaneous.

Distribution and habitat:— Orthophytum roseolilacinum is only known from the type region, in the counties of Alvarenga and Conselheiro Pena, Minas Gerais. It foms large and dense terrestrial groups of plants in organic-rich, shallow soils accumulated on rocky surfaces in shady spots inside fragments of wet Atlantic Forest, from 255 to 810 m elevation.

On the basis of the criteria “B1a” and “B2a” of IUCN (2010), O. roseolilacinum must be considered a critically endangered species.

Etymology:—The name chosen for this new species refers to the rose-lilac color of its petals, which is a feature reported for the first time for the “Cryptanthoid Complex”, whose species have white, green, yellowish or orange colored petals.

Additional specimen examined (paratype):–– BRAZIL. Minas Gerais:Alvarenga, Barra Mansa, near Manhuaçu river, 255 m elevation, 19º 25’ 20.05” S, 41º 38’ 28.95” W, 10 July 2014, R. Vasconcelos Leitão s.n, cult. E. Leme 8922 (RB!).

Observations:— Orthophytum roseolilacinum is a unique species without closer morphological affinity to any known species, making difficult even its inclusion into the genus Orthophytum . Its general vegetative appearence characterized by the combination of long caulescent habit, comparatively thin-textured leaves and undulate leaf blades margins give it a very distinct appearance similar to some species of Cryptanthus subg. Hoplocryptanthus from the mountains of Espírito Santo State, like C. exaltatus Luther (1990: 16) and C. pseudoglaziovii Leme (1991: 10) . In Orthophytum , the long caulescent habit is only reported for three species of the “vagans complex”, composed by O. pseudovagans Leme & Kollmann (2007: 155) , O. vagans Foster (1960: 59) and O. zanonii Leme (2004b: 72) . These three species were considered by Leme (2004a) a subcomplex of the complex of species with sessile inflorescence (i.e. Sincoraea spp. ), and the molecular investigation by Louzada et al (2014) grouped them in the so called “vagans clade” including also O. foliosum Smith (1941: 58) . Except for O. foliosum , the three long caulescent species of Orthophytum have somewhat clavate corollas with the petals obtuse-cucullate at the apex, a marked difference to petal characteristics of O. roseolilacinum .

Further similatities of O. roseolilacinum with subg. Hoplocryptanthus species are the fragrant flowers (vs. odorless in Orthophytum ) and the broadly spathulate petals with suborbicular blades spreading at anthesis (vs. sublinear-lanceolate to narrowly spathulate, erect to suberect petals with recurved apex in Orthophytum ). The rose-lilac to lilac-purple color of the petals (vs. white, green, yellowish or orange), the stamens deeply included and not visible (vs. not deeply included and at least partially visible), and its conduplicate-spiral stigma blade (vs. conduplicate-patent or simple-erect) have never been reported for any other member of the “Cryptanthoid Complex”.

Despite the differences in flowers features, O. roseolilacinum has thick, cupuliform petal appendages with downwardly curved margins very similar to the petal appendages of the species of the “vagans complex” in general and to O. zanonii in particular. In contrast, petal appendages are usually fimbriate to lacerate in typical Orthophytum and absent in all Cryptanthus . About the subject, Brown & Terry (1992) pointed out the late ontogenetic development of appendages in the petals of Bromeliaceae , being the last formed external multicellular structures, which has spread the idea of the non-importance of the use of presence/absence of petal appendages as an diagnostic character in genera segregation. However, Barfuss et al. (2005) verified the importance of this morphological feature when combined with other characters for the differentiation of genera in Tillandsioideae . The same can be said regarding the “Cryptanthoid Complex”, in which the presence/absence of petal appendages and their structure together with other characteristics are useful in grouping morphologically related species and in the establishment of the conceptual boundaries of their genera (i.e., Cryptanthus vs. Orthophytum vs. Lapanthus ). So, the presence of petal appendages combined with the length of the sepals, which are 1.5-3 times longer than the fruits in Orthophytum (vs. shorter to equaling the fruit length in Cryptanthus ), the free petals (vs. connate in Cryptanthus ), the unequal stamens (vs. equal in Cryptanthus ) at this moment justify the inclusion of this new species in Orthophytum until the ongoing molecular research will be completed.

Besides the features highlighted above, this new species can also be distinguished from all known species of Orthophytum by the glabrescent or glabrous leaf blades (vs. usually distinctly lepidote at least abaxially), sessile inflorescence (vs. usually on distinct peduncle, except for Sincorea), and 42–45 mm long flowers [vs. usually to 30 mm long, except for O. macroflorum Leme & Machado (2005: 171) with 50–65 mm long flowers].

Figures

FIGURE 1. Orthophytum roseolilacinum (Leitão s.n.). A. Paratype locality, a subpopulation of the species and the collector Reginaldo Vasconcelos, a bromeliad enthusiast. B. General view of the habitat at the locality of the holotype. C. Frontal view of the flower. D. Side view of the flower. E. Habit at the locality of the holotype.

FIGURE 2. A–J. Orthophytum roseolilacinum (Leitão & Ribeiro s.n.). A. Leaf. B. Floral fascicle. C. Floral bract from a fascicle. D. sepal. E. Style and stigma. F. Antesetalous stamen. G. Petal and antepetalous stamen. H. Petal appendages. I. Lateral view of the anther at anthesis. J. Frontal view of the anther before anthesis. K–Q. Orthophytum vasconcelosianum (Leme 8673 et al.). K. Basal floral fascicle. L. Floral bract from a fascicle. M. Flower. N. Sepal. O. Antesetalous stamen. P. Petal with antepetalous stamen. Q. Leaf. (Bars = 10 mm, unless otherwise indicated).