Anathallis amazonica E.Pessoa & M.Alves, 2012

Pessoa, Edlley & Alves, Marccus, 2012, A new Anathallis (Orchidaceae: Pleurothallidinae) from the Brazilian Amazon, Phytotaxa 73 (1), pp. 13-16 : 13-15

Anathallis amazonica E.Pessoa & M.Alves , sp. nov. ( Fig. 1 )

Type :— BRAZIL. Amazonas : Coari, Campo Petrolífero do Rio Urucu, 04º08’25”S, 65º33’13”W, 70 m, 9 May 1993, J . da Cruz 242 (fl,fr) (holotype INPA!, isotypes, HUAM!, UFP!)

A. amazonica is morphologically related to A. holstii ( Carneváli & Ramírez 1986: 18) Luer (2009: 258) , A. polygonoides ( Grisebach 1864: 609) Pridgeon & Chase (2001: 250) and A. sertularioides ( Swartz 1788: 122) Pridgeon & Chase (2001: 250) , but differs especially by having an oblong entire lip (trilobed in the others).

Epiphytic, subrepent herb. Roots fasciculate, about 0.5–1.0 mm wide. Rhizome 0.9–1.1 mm wide, branched. Secondary stem 2.2–5.1 × 0.4–0.7 mm, cylindrical, unifoliate, concealed by one white to gray, close-fitting, membranaceous sheath, 2.5–5.0 mm long, acute or obtuse apex, striate, entire margin. Leaf 5.0–19.0 × 1.2–3.0 mm, oblanceolate to elliptic, pale green, coriaceous, glabrous, acute apex, rarely minutely tridenticulate, attenuate to obtuse base, entire margin. Inflorescence terminal, congested, fasciculate, erect; peduncle and rachis inconspicuous; floral bracts about 1.0– 1.1 mm long, amplexicaul, membranaceous, acute to acuminate apex, entire margin. Flowers 1–4, reddish maroon (according to the collector), these opening successively; pedicellate ovary 1.2–1.5 × 0.1–0.3 mm; dorsal sepal 3.0–3.5 × 0.8–1.3 mm, free, lanceolate, membranaceous, acute apex, entire margin, 3-nerved; lateral sepals 3.0–3.5 × 0.6–1.0 mm, connate up to ¼ from base, lanceolate, sub-falcate, membranaceous, acute apex, entire margin, 3-nerved, forming a small mentum with the column foot; petals 1.8–2.6 × 0.3–0.6 mm, free, narrow elliptic, sub-falcate, membranaceous, acute to rounded apex, entire margin, 1-nerved; lip 1.5–2.0 × 0.3–0.5 mm, free, oblong, rounded apex, with two basal appendages, ciliate margin from the base up to the middle, entirely ciliate or sometimes not ciliate, papillose, 3-nerved, articulated with the column foot; column about 1.0– 1.3 mm long, broadly winged, clinandrium 5-dentate, obtuse apex, entire margin, column foot about 0.2 mm long. Fruit 2.5–3.0 × 1.2–1.5 mm, obovoid, glabrous.

Distribution and Ecology: —This species is known only from the type locality, in the central Brazilian Amazon, state of Amazonas. The vegetation in the area is characterized by moist tropical lowland forest, locally called terra firme forest ( Lima et al. 2008). The flowering period is poorly known, but based on the specimens cited, flowers can be observed from February to July.

Etymology: —This new species is named on behalf of the area of occurrence, Brazilian Amazon basin.

Morphological affinities: — Anathallis amazonica is morphologically related to species placed in Panmorphia by Luer. The new species has a subrepent habit like A. holstii and A. polygonoides . Leaf shape appears to vary: the leaves on the mature branches are oblanceolate like A. sertularioides , while on the immature branches they are elliptic as is found in A. holstii and A. polygonoides . The inflorescences have an inconspicuous peduncle and the flowers appear to arise from the same point like A. holstii and A. polygonoides . In A. sertularioides , the inflorescence is long pedunculate. The flowers on A. amazonica have narrow elliptic petals like A. sertularioides , but A. polygonoides and A. holstii have broadly elliptic petals. The lip of A. amazonica is oblong and ciliate from the base up to the middle, entirely ciliate or sometimes not ciliate. However, the three related species have a slightly trilobed to clearly trilobed lip with an entire margin ( Table 1).

Additional specimens examined (paratypes): — BRAZIL. Amazonas: Coari, Campo Petrolífero do Rio Urucu , 10 February 1992, fl., J . da Cruz 240 ( INPA); 03 April 1992, fl., J . da Cruz 241 ( INPA); 11 May 1992, fl., J . da Cruz 243 ( INPA); 17 June 1992, fl., J . da Cruz 239 ( INPA); 03 July 1992, fl., J . da Cruz 244 ( HUAM) 05 May 1996, fl., J . da Cruz et al. 471 ( HUAM) .

Figures

FIGURE 1. Anathallis amazonica A. Flowering habit with oblanceolate leaves. B. Fruiting habit with elliptic leaves. C. Tridenticulate leaf apex. D. Acute distended leaf apex. E. Acute twitched leaf apex. F. Detail of the inflorescence. G. Dissected perianth. H. Lip ciliate on the base (J. da Cruz 242). I. Lip entirely ciliate (J. da Cruz 240). J. Lip not ciliate (J. da Cruz 243). K. Column. Drawn by Regina Carvalho.