Octomeria lilliputana W.Forst., F.Barros & V.C.Souza, 2013

Forster, Wellington, Souza, Vinicius Castro & Barros, Fábio De, 2013, Octomeria lilliputana (Orchidaceae), a new species from Brazilian Atlantic Forest, State of Paraná, Brazil, Phytotaxa 105 (2), pp. 39-44 : 40-42

Octomeria lilliputana W.Forst., F.Barros & V.C.Souza , sp. nov. ( Figs. 1 and 2 )

Ab omnibus speciebus notis generis plantis parvulis, foliis lineari-ellipticis emarginato-apiculatis, floribus successivis fasciculatis, roseo-hyalinis atropurpureo suffusis, sepalo dorsali anguste elliptico, acuto, sepalis lateralibus lanceolatis, acuminatis leviter falcatis, petalis anguste ellipticis vel elliptico-lanceolatis, acuminatis, labello trilobato lobis lateralibus suborbicularibus, lobo mediano late ovato, acuto margine eroso differt.

Type:— BRAZIL. Paraná: Morretes, Parque Estadual Pico Marumbi , Rochedinho, Floresta Atlântica do alto do morro, 27 October 1997, J. M . Silva , A . Soares & W . Maschio 2240 (holotype: MBM!) .

Epiphytic, erect, caespitose herb, ca. 5 cm tall; roots velamentous, cylindrical, 0.2–0.5 mm in diameter; rhizome inconspicuous; ramicauls ascending, 0.5–1.5 × 0.05–0.1 cm, cylindrical with 2–5 internodes enclosed by 2–3 thin, tubular sheaths, the lower smaller than the upper ones, which turn tear with age. Leaf erect, fleshy, slightly flattened to conduplicate, the blade 1.3–3.2 × 0.3–0.4 cm, narrowly elliptical to linearelliptic, the midvein sulcate adaxially and carinate abaxially, margin entire, apex emarginate-apiculate, base attenuate to narrowly cuneate below into a somewhat short petiole. Inflorescence arising from the base of the leaves and apex of the ramicauls, from scarious bracts, a 1–2-flowered fascicle; peduncles 0.5–0.6 mm long, cylindrical; floral bracts ca. 3 mm long, membranaceous, campanulate, enclosing the pedicel near the apex. Flowers minute, resupinate, glabrous; pedicel ca. 3 mm long; ovary ca. 2 mm long, somewhat obconical, slightly sulcate and arched; sepals rose-hyaline suffused with dark rose, membranaceous, 3-veined, margin entire; dorsal sepal slightly concave, 6 × 2 mm, narrowly elliptic, apex acute; lateral sepals spreading, free, slightly concave, 6 × 2 mm, lanceolate, slightly falcate, apex acuminate; petals rose-hyaline suffused with dark rose, membranaceous, 3-veined, flat, 5.5 × 1.0 mm, elliptic to narrowly lanceolate, apex acuminate, margin entire; lip rose, slightly fleshy, 3-lobed, 4 mm long, base broadly unguiculate, hinged to the column foot; lateral lobes erect, 1.75 mm wide, rounded, margin entire; midlobe slightly concave, 1.5 mm wide, ovate, apex acute, margin erose; the disk flat to slightly cuneate, somewhat channeled between a pair of slightly fleshy, lamellate calli, which extend from the lateral lobes to the base of the midlobe, 3-veined, the lateral veins sub-parallel extended to the base of the midlobe; the midvein reaching the apex of the lip; column 2.1 mm long, whitish-rose, subcylindrical, slender, arched, the base extending into a stout foot; stigma narrow, sub-apical, ventral, rostellum membranaceous, oblong; clinandrium shallow, 3-lobed, margin entire, anther apical, incumbent, operculate, pollinia 8, in 2 sets of 4, yellowish, clavate, attached to an ill-defined caudicle.

Distribution and habitat:—This species is only known from the type collection from Marumbi Peak State Park, located in Municipality of Morretes, State of Paraná, Brazil. Altitudes in the Marumbi region range from 495 m at the locality known as “Estação” to 1539 m at “Olimpo Peak” and include most physiognomies of the Atlantic Forest biome (Ombrophilous Forest, Veloso et al. 1991). Octomeria lilliputana grows as epiphyte in primary rainforest at “Rochedinho”, where the elevation reaches 685 m.

Phenology:— Octomeria lilliputana was collected with flower in October.

Etymology:—The epithet is a reference to Lilliput, an imaginary island of Jonathan Swift’s famous novel “Gulliver’s Travels”, whose inhabitants were very small.

Conservation status: — It is uncertain to assign an IUCN (2001) conservation status category to a species known from a single collection, it is therefore ascribed to the Data Deficient category.

Discussion: — The description was based on dried material from the holotype only. Octomeria lilliputana is morphologically similar and presumably related to three species in section Octomeria subsection Octomeria (sensu Luer 1986): Octomeria cochlearis Reichenbach (1881: 266) , Octomeria montana Barbosa Rodrigues (1882: 108) and Octomeria ochroleuca Barbosa Rodrigues (1877: 31) and also similar to Octomeria rhodoglossa Schlechter (1918: 276) . These species are restricted to Southeastern and Southern Brazil and share a similar habit; they are small plants (2.5–9.8 cm tall), with inconspicuous rhizomes and essentially slender ramicauls. Height vary from 0.5–1.5 cm tall ( O. lilliputana and O. montana ), 2.8–3.1 cm tall ( O. ochroleuca ), 4.5–8 cm tall ( O. cochlearis ) up to 5–7 cm tall ( O. rhodoglossa ), but differs in reproductive characters ( Table 1). Octomeria ochroleuca and O. rhodoglossa have the leaf pseudopetiolate and twisted, while in O. cochlearis , O. lilliputana and O. montana the leaf is sessile. In addition to differences in vegetative morphology, O. cochlearis has long pedicels (7–10 mm) while in the other species, the pedicels are shorter (2–4 mm). Among these related species O. lilliputana appears to be morphologically more similar to O. montana . Although only a few collections of O. montana from Espírito Santo and Rio de Janeiro could be examined, when these were compared to the type collection of O. lilliputana from Paraná, the species could be clearly differentiated. Octomeria lilliputana has a rose hyaline perianth suffused with dark rose, while O. montana is a particular yellow-white color. The shape of the petals also differs; in O. lilliputana they are elliptic to narrowly lanceolate and straight, while in O. montana they are lanceolate to elliptic-lanceolate and strongly falcate. Furthermore, both species share ovate midlobe lips and the similar calli in the disc, but while in O. lilliputana it is dark rose colored with the margin of the midlobe distinctly erose, in O. montana it is yellow colored with two red-vinous rounded macules on the base, and the margin is entire to slightly sinuate.

Octomeria rhodoglossa Schlechter (1918: 276) was described without illustrations. In the description, Schlechter (1918) compared it with O. montana , due to the general size of the plants, but distinguished them by characters of the flowers, in particular the white colored sepals and petals, the lip rose-purple with an entire lamina. This is a species, known only from Brazil to state of Paraná and possibly not ever collected since the type specimen. A drawing of O. rhodoglossa was only made available to the public about five years after Schlechter’s death when a number of their original drawings of new species of orchids were published for the first time by Mansfeld (1930, t. 39, fig. 153). Near all holotypes of Schlechter’s species were destroyed when the Berlin herbarium was bombed during the Second World War, including the type of O. rhodoglossa and we were unable to find an isotype. However, Schlechter’s drawings of O. rhodoglossa clearly show some of its main features, e.g., petals and sepals curved forwards giving the flower a somewhat closed appearance, lanceolate sepals and petals and the ovate-elliptic lip, distinctly not lobed and with subtruncate-tridentate apex and a pair of parallel carinate calli on middle. In our opinion, by analysis of the protologue and original drawing, this obscure taxon is clearly distinct from O. cochlearis , O. lilliputana , O. montana and O. ochroleuca by significant characters of the lip. Nevertheless, further investigation and comparison of more material will be needed to make a decision about its actual identity. For the moment it is better to keep them as distinct species.

Figures

FIGURE 1. Map of Paraná State, Brazil, showing the known distribution of Octomeria lilliputana.

FIGURE 2. Octomeria lilliputana. A. Habit. B. Part of ramicaul, leaf and inflorescence. C. Flower in side view. D. Flower analysis (D1. Dorsal sepal. D2. Lateral sepal. D3. Petal. D4. Lip). E. Part of the pedicel, ovary, column and lip in side view, perianth removed. F. Lip in dorsal view. G. Column in abaxial view. H. Anther cap in abaxial view. I. Pollinia. (Drawn from the holotype).