Brazilian Orchids - Orchid News 30

Introduction
The genus Myoxanthus Poeppig & Endlicher had an agitating history. Just after its description, in 1835, the species-type, Myoxanthus monophyllus (Colombia, Ecuador, Peru) was transferred by Lindley to the genus Pleurothallis R. Brown. Later, Karsten described a species under the name of Duboisia reymondii (Colombia, Ecuador, Venezuela), nowadays, Myoxanthus reymondii. Six years after, Reichenbach has also transferred it to the genus Pleurothallis. In 1882, Barbosa Rodrigues described a species under the name of Chaetocephala punctata (nowadays Myoxanthus punctatus) which was transferred by Cogniaux to Pleurothallis.
In fact, that was Carl Luer who, in 1982, in the context of his monumental work on Pleurothallidinae, revived the genus gathering 38 known species until then, to which at about ten species more recently discovered have been added. They are typical inhabitants of tropical dense wood, with a bipolar geographical distribution and most species are found between Bolivia and Mexico with a small extension towards Venezuela and Guiana, while a small group (8 species) is Brazilian. In Espírito Santo, biological diversity pole, there are, nowadays, 5 registered species and between them, Myoxanthus ruschii C.N. de Fraga & L.J.C. Kollmann, described in 2003.
The discovery of a new species is not, in this way, a totally improbable occurrence and this one has been discovered by Nelson Sanson, a very competent amateur observer from Conceição do Castelo who tireless travels all over the few forests that still resist in this municipality, situated in lower part of the mountain of Espírito Santo. This species can be distinguished from the others by its small size and, in this particularly, it is comparable to Myoxanthus ruschii, but it can be mainly distinguished from the other known species by the purple color of its flowers, while the chestnut color, in the lack of white, seems to be the rule of the genus.

Planta herbacea, epiphyta, in genere parva, Myoxanthus lonchophyllus, punctatus vel seidelii affinis sed manifeste minor, folia maxime 10 cm longa cum marginibus nervo medianoque atropurpureis, floribus fasciculatis succedaneis nutantibus et lilaceis, labello 5,5 mm longo, 2 mm lato, antice canaliculato, postice cum marginibus recurvatis,saccum sphaericum atropurpureum nitensque formantibus, columna 3,5 mm longa, recta, pede mentum 1,5 mm formante, rosacea 5-plo roseolineataque.

Type : Brazil, Espírito Santo, Conceição do Castelo, Cachoeira da Fumaça, latitude 20° 22’ 40’’ S, longitude 41° 15’ 00’’ W, 620 m altitude, July 2003 (flowers), Nelson Sanson s.n. ex M. Frey 531 (Holotype: MBML, Isotype : M. Frey 531 : LY, the same plant).

Description
Herbaceous upright plant, epiphyte of wood, 15-18 (20) cm high. Cylindrical rhizome, 3 mm diameter, slightly rampant (3-6 mm between ramicaul), recovered by hispid sheaths; Brown yellowish roots, with until 10 cm long, and, at about, 1 mm de thick; upright ramicauls, 4-8 cm high, 1,2 mm thick, 4-articulate, recovered by imbricate sheaths garnished by brown trichomas; upright leaf, coriaceous, 7-10 cm long, 9-10 mm wide, 2 mm thick, narrowly lanceolate, cuneiform base, acute extremity, olive-green with purple margins and central nervures, glabrous, smooth margins; inflorescence arising from a very small bract, formed by fasculate succeeding flowers, in general one, sometimes, 2 at the same time; very small bract, peduncle 12-15 mm long, filiform, pendent, glabrous, slightly purple; pedicel 2 mm long; ovary 3 mm long and 0,6-0,8 mm diameter; nutant flower, purple color in general; dorsal sepal 8 mm long, 3 mm width, egg shaped, convex, obtuse apex, glabrous, smooth translucent light pink slightly recurved margins with 5 longitudinal dark purple lines; oval convex lateral sepals fused until 2/3, 8 mm long, 3 mm wide, rectangular apiculate apex, glabrous, smooth margins in the same color as the dorsal; filiforme straight petals 8,5-9 mm, long, 1 mm wide, with an slightly enlarged base and thick light pink translucent apex, with 3 longitudinal dark purple lines and recurved margins towards the middle, purple apex; lip 5,5 mm long, 2 mm wide, first caniculate than the margins are recurved to form a spherical brilliant dark purple pouch caniculated, the lower part pinkish with dark purple lines; straight column 3,5 mm long, 1,5 mm wide, forming a chin of 1,5 mm, the lateral forming slightly prominent light-pink wings and veined with 5 darker pink lines; yellow-sulphur anther. Seedrawing 1 and photography.

Etymology
The specific name pays homage to in the municipality Conceição do Castelo where the plant has been discovered and also Nelson Sanson home town.

Habitat and geographical distribution
Myoxanthus conceiçoensis has been found in 2003, by Nelson Sanson, habitant of Conceição do Castelo and attentive expert in orchids from the region, in a small, in a small remained area of tropical dense forest, one of the relic of Atlantic Forest which still last in the region, alongside São João de Viçosa river, in a place known as Cachoeira da Fumaça (Smoke Falls). The plant was in the trunk of a tree, three meters far from the ground. It is also reported to the north of Espírito Santo (Pedro Canário) and next to the capital city, Vitória. There is an exsiccate deposited at the 'Museu de Biologia Mello Leitão's Herbarium in Santa Teresa from a plant collected in 1986, by Hélio Q. B. Fernandes, in São Joaquim farm in the same municipality. By this time, the was not totally identified and now is considered Myoxanthus conceiçoensis. This plant is rare in the region. The climatic conditions of the place are: quite warm, due to the altitude (620 m), humid but not excessively, quite shady. The blooming period is in June, it means at the beginning of the winter (in South hemisphere), but it seems to be able to bloom from time to time, out of this period.

Discussion
The comparison to Myoxanthus lonchophyllus, Myoxanthus punctatus and Myoxanthus seidelii is justified. Myoxanthus conceiçoensis differs from the mentioned species by its small size, rarely exceeding 18 cm, while the first three are big (height of the adult plants: from: 2 to 40 cm). The leaves of M. seidelii are resistant and coriaceous, reaching 2,5cm across an they are not purple while those from M. conceiçoensis rarely reaches 1 cm, besides to be ever green with purplish edges and central nervure. Its flowers presentent light pink sepals and petals, almost translucid with 3 lines dark-purple punctated giving the impression of being purple colored. The extremety of the lip tooks the shape of a smooth and brillant dark purple hemispherical ball, what differentiates definitively this plant from the close species where the lip is more or less warty as in Myoxanthus lonchophyllus (Barbosa Rodrigues) Luer (lip with « hispid-papillose » apex according to Luer), in Myoxanthus punctatus (Barbosa Rodrigues) Luer (warty lip according to Luer) or in Myoxanthus seidelii (Pabst) Luer (lip with “spiculato-verrucose” apex according to Luer). The other species of the genus found in southern and east Brazil have, in general, brown flowers, some species somewhat yellow or green. M. lonchophyllus flowers are brown yellowish and purple spotted. Those from M. punctatus are dark green and purple spotted and a light purple lip at the base e and dark purple at the edge. A variety quite well spread is brown. M. seidelii flowers are green and brown, with white yellowish flowers and the lip is yellow-orangish. Besides, the flowers of the three compared species are big [sepal s 9-10 mm × 4-5 (7) mm while as those from this species are 8 × 3 mm].

Bibliography (authors)
- Barbosa Rodrigues, J., 1996. Iconographie des orchidées du Brésil, Vol I, pp 188 & 189, Friedrich Reinhardt Verlag, Basle.
- de Fraga, C.N. & L.J.-C. Kollmann, 2003. Myoxanthus ruschii (Orchidaceae) uma nova espécie da Mata Atlântica, Espírito Santo, Novon : A Journal for Botanical Nomenclature :Vol 13, N° 1, pp 49-51.
- Luer, C.A., 1992, 1997. Icones Pleurothallidinarum : Vol IX, Systematics of Myoxanthus, pp 52 & 53 , 74 & 75, Vol XV, Systematics of Trichosalpinx, pp 132,134 & 135, Missouri Botanical Garden.

Acknowledgments (Authors)
To Nelson Sanson who discovered this plant in 2003 and, since then, has been carefully cultivated it, allowing the observation in excellent conditions.
To Carl Luer who, by his advices, has really helped to confirmed the novelty of this plant.
To Claudio Nicoletti de Fraga and Ludovic J. Charles Kollmann who, knowing the exsiccate deposed at the Museu de Biologia Melo Leitão, have encouraged the description of this species.
To Josiene Rossini for having done the high quality drawing, even under not favorable conditions.

Acknowledgments ( Brazilian Orchids & Orchid News)
To Guy Chiron, Richardiana editor, for having gently sent the files and photos for this work, as well the authorization for the reproduction.