Heteropsis reticulata Croat & M. L. Soares, 2013

11. Heteropsis reticulata Croat & M. L. Soares sp. nov.

— TYPE: BRAZIL. Acre: Cruzeiro do Sul, próximo ao aeroporto, 13 Feb 1976, Monteiro & Damião 349 (holotype: INPA! fr).

Planta hemiepiphytica; internodia longitudinaliter striata, subcylindrica, gemmae axillares apice rotundatae; folia ramulorum plagiotropium petiolo 3–5 mm longo, lamina 13–17 cm longa, 3–4.5 cm lata, 0.24–0.62 mm crassa, ovata vel elliptica, coriacea, rigida, castanea in pagina abaxiali, venam marginalem destituta, venam infra-marginalem margine 0.5 –1 mm distanti instructa; pedunculus ca. 2 mm longus, spadix ca. 1.8 cm longus, 0.4 cm diam, cylindricus, stipite ca. 2.5 mm longo suffultus.

Plant a scandent hemi-epiphyte; aerial roots ca. 4.3 mm diam, subcylindric, rugose, chestnut-brown when young; internodes 2–2.5 cm long, 1.5–3 mm diam, subcylindric, strongly striate longitudinally, greenish-brown when dried; axillary buds ca. 2 mm long, with rounded apex. Petiole 3–5 mm long, 1.4– 1.8 mm diam, canaliculate, margin sinuate at the apex, slightly twisted; geniculum ca. 3 mm long, darkened; leaf blade 13– 17 cm long, 3–4.5 cm wide, ovate to elliptic, coriaceous, rigid, when dried adaxially greenish-brown, abaxially dark brown, opaque on both sides when dried, margin strongly revolute, slightly sinuate, 0.24–0.62 mm thick, apex acuminate, base obtuse to acute, midrib strongly sulcate adaxially, prominent, rounded abaxially, primary lateral veins and interprimaries prominent, infra-marginal collective vein prominent, 0.5–1 mm distant from the margin, external marginal vein lacking. Inflorescence terminal and axillary, flowering shoot 5 cm long, internodes 1–1.5 cm long, 1.4–1.8 mm diam, greenish-brown when dried, subcylindric, sulcate, axillary buds usually present on the first and second internodes; peduncle ca. 2 mm long, 1.7 mm diam; spathe not seen; spadix ca. 1.8 cm long, 4 mm diam, cylindric, apex acute, stipitate, stipe ca. 2.5 + 1.2 mm, cylindric, blackened when dried. Gynoecium with apex 4–5 mm diam, stigma oblong. Infructescence 4.5–7.5 cm long, 2–3 cm diam when mature; berry 14–17 mm diam, at apex; seeds 3– 4 per berry. Figures 3 View FIG , 21 View FIG (mature), Fig. 22 View FIG (immature).

Habitat and Distribution— Heteropsis reticulata occurs in dense ombrophilous terra firme forest and in flooded forest in Brazil (Acre) and Peru, at 100–150 m alt.

Phenology— Flowering specimens have been collected in November and fruiting material in January and February.

Conservation Status— Using guidance from the Geocat (2012) online tool, the preliminary conservation assessment of H. reticulata is data deficient (DD), since this species is currently known only from four localities.

Etymology— The specific epithet refers to the prominently reticulated finer venation of the abaxial leaf surface, particularly evident in immature attached leaves.

Notes— The fertile material described here ( Fig. 21 View FIG ) as Heteropsis reticulata shares with H. rigidifolia and H. robusta its rigid leaf blade and spadix size, but differs from these species in the ovate to elliptic leaf blade with obtuse base and strongly revolute margin.

The sterile collection cited below (Croat 62631), collected in dense ombrophilous terra firme forest at 150 m alt., is part of an immature attached stem ( Fig. 22 View FIG ), rather than a mature plagiotropic branch. It differs from the type and paratype material in the longer, smooth-margined petioles, larger size of the leaf blade with more strongly prominent fine reticulate abaxial venation, the less revolute leaf margins, the dried adaxial leaf surface greyish-brown and abaxial surface yellowish-brown. This specimen, however, agrees with the type and paratype collections in the striate and cylindric to subcylindric internodes, the infra-marginal collective vein close to the margin, and the absence of visible marginal veins.

Immature attached leaves of larger size and different appearance to the mature leaves of plagiotropic branches are characteristic of certain other species, notably H. rigidifolia , and we propose that Croat 62631 and the cited type and paratype specimens of H. reticulata belong to the same species. Since this taxon remains poorly known we provide here further descriptive details of the specimen Croat 62631, which may be useful in testing our proposal when new information becomes available:

Plant a scandent hemi-epiphyte. Internodes 3–8 cm long, ca. 3 mm diam, longitudinally striate when dried, cylindric, glossy, dark brown when dried, buds not seen. Petiole 1– 2 cm long, ca. 2 mm diam, strongly canaliculate, dark brown, margin smooth (not undulate); blade 22.5–32.0 cm long, 9– 13 cm wide, 0.26–0.36 cm thick, elliptic, subcoriaceous, glossy, adaxial surface dark green, dark greyish-brown when dried, abaxial surface yellowish-brown and opaque, apex abruptly acuminate, base acute to attenuate, midrib flattened at the base and sulcate towards the apex on adaxial side, prominent and convex on abaxial side, primary lateral veins 12–18 on each side, somewhat obscured on adaxial surface, prominent on abaxial surface, finer veins reticulate and prominent when dried, infra-marginal collective vein ca. 1 mm distant from margin.

Additional Specimens Examined— PERU. Departamento Loreto: Provincia Maynas, Carretera Nauta-Iquitos , 04 29 ' S 73 35 ' W, 23 Nov 1990, Grández & Ruíz 2118 ( MO fl) GoogleMaps ; 03 48 ' S 73 25 ' W, 17 Feb 1993, Grández et al. 5183 (MO, NY fr).

BRAZIL. Acre: Cruzeiro do Sul, between Cruzeiro do Sul and Rio Branco , 7 38 ' S, 72 35 ' W, Croat 62631 ( INPA, MO ster). GoogleMaps