Anathallis manausensis Krahl, Valsko & Chiron, 2016

Krahl, Amauri Herbert, Valsko, Jefferson José, Holanda, Ana Sofia Sousa De & Chiron, Guy, 2016, Anathallis manausensis (Orchidaceae, Pleurothallidinae), a new species from the Brazilian Amazon, Phytotaxa 245 (3), pp. 229-233 : 230-231

Anathallis manausensis Krahl, Valsko & Chiron , sp. nov. ( Figs. 1 and 2 )

Type:–– BRAZIL. Amazonas: Manaus, “Projeto de Dinâmica Biológica de Fragmentos Florestais ( PDBFF), Fazenda Porto Alegre”, 2021 ’19.19” S, 59057 ’31.81” W, 70 m, 13 October 2012, fl. in cult. 15 Mar 2013, J. J. Valsko 116 (fl.) (holotype INPA! 271194).

Haec species A. microphyta ( Barbosa Rodrigues 1882: 67) Azevedo & van den Berg (2005: 137) similis sed caulibus duplo brevioribus, inflorescencia cum flore solitario, floribus duplo minoribus, sepalis lateralibus fere haud connatis acutis, petalis apice rotundato, labello oblongo indiviso plano differt. Praeterea A. amazonica E.Pessoa & M. Alves similis sed plantis caespitosis, foliis latioribus, inflorescentia multo longiore et cum flore solitario, flore campanulato, labello sessile, columna apoda differt.

Epiphytic, small caespitose plant, ca. 10 mm tall. Roots fasciculate; rhizome inconspicuous. Ramicaul short, 2–3 mm long, unifoliate, covered by a membranous sheath; sheath tubular, ca. 3 mm long, grey, glabrous, acute. Leaf elliptic, 6–12 × 2–4 mm, green, coriaceous, glabrous, basally attenuate, acute, margin entire. Inflorescences 1–3, emerging below the apex of the ramicaul, shorter than the leaf, ca. 6 mm long, erect, 1-flowered; floral bract tubular, ca. 1 mm long, membranous, glabrous, acute. Flower cream with the apex of petals and labellum reddish; ovary ca. 1 mm long, forming an angle of 90° with the pedicel; pedicel ca. 1.5 mm long; sepals lanceolate, ca. 3 × 1 mm, membranous, 3- nerved, acute, margin entire, the dorsal free, the laterals briefly connate at the base, subfalcate; petals linear, ca. 3 × 0.1 mm, subfalcate, membranous, 1-nerved, obtuse, margin entire; labellum entire, hinged to the column-foot, oblong, ca. 2 × 0.5 mm, 3-nerved, with two appendages at the base, round at apex, margin ciliate; column straight, sub-cylindrical somewhat inflated at the apex, rather thick, ca. 1.5 mm long, without a column-foot, clinandrium margin rather high, not dentate but somewhat crenate, anther-cap semi-spherical, pollinia 2. Fruit not seen.

Etymology: ––The specific epithet refers to Manaus, the city where the plant was collected.

Distribution and ecology: ––Hitherto the species is known only from the type locality in central Brazilian Amazon. The type was collected in an area of forest near Fazenda Porto Alegre of which the project “Projeto Dinâmica Biológica de Fragmentos Florestais (PDBFF)” (2021 ’19.19”S, 59057 ’31.81”W) is part. This area is located at about 80 km from Manaus (AM, Brazil), in the north of the municipality. During the rain season the area can be flooded for a short time and small lagoons can be seen in the interior of the forest. The local vegetation is made of small-sized trees with a big quantity of epiphytes suggesting a high air humidity. The specimens collected in October 2012 were sterile and placed in cultivation until their blooming in March 2013.

Morphological affinities: –– Anathallis manausensis belongs to the morphogroup “ Anathallis microphyta ”. It is similar to A. corticicola (Schlechter ex Hoehne 1936: 18–19) Pridgeon & Chase (2001: 248) , a species with much larger flowers. However its closest relatives are probably A. amazonica Pessoa & Alves (2012: 13) , a species from Brazilian Amazon, and A. microphyta (Barb. Rodr.) C.O.Azevedo & van den Berg , a species from southeastern and northeastern Brazil. It differs from A. microphyta by its ramicauls twice shorter, its acute leaves that are not tridentate at the apex, its 1-flowered (versus few-flowered) inflorescence, its distinctly smaller flowers (sepals 3 mm long versus ca. 4 mm long), its lateral sepals connate only at base (versus at least on the basal third), acute (versus somewhat acuminate), its apically rounded petals (versus very acute to acuminate) as long as the sepals (versus distinctly shorter), its oblong labellum (versus somewhat 3-lobed), which is flat (versus with lateral margins curved upwards). It can be distinguished from A. amazonica by its caespitose habit (versus subrepent), its wider leaves (ratio length/width ~ 3 versus 4–6), its 1-flowered (versus few-flowered) and much longer inflorescence, its campanulate flowers (versus patent sepals), its acute lateral sepals (versus acuminate), its sessile labellum (versus unguiculate) and its very different column: column-foot absent (versus conspicuously present), clinandrium margin slightly crenate but not dentate (versus 5-dentate) Moreover, the flower colour is very different (cream versus reddish maroon).

Figures

FIGURE 1. Anathallis manausensis. A. Habit. B. Flower. C. Perianth. D. Labellum. E. Column (J.J. Valsko 116). Drawn by A.H.Krahl.

FIGURE 2. Anathallis manausensis. A. Habit. B. Flower. C. Detail of the eyelashes in the middle edge of the labellum (J.J. Valsko 116). Photographs by J.J.Valsko.