Heteropsis macrophylla, A. C. Sm., J. Arnold Arbor.

Soares, M. Lourdes, Mayo, Simon J. & Gribel, Rogério, 2013, A Preliminary Taxonomic Revision of Heteropsis (Araceae), Systematic Botany (Basel, Switzerland) 38 (4), pp. 925-974 : 950-953

8. HETEROPSIS MACROPHYLLA A. C. Sm. ,

J. Arnold Arbor. 20: 290. 1939.

— TYPE: BRAZIL. Amazonas, Município de Humaitá, 11 Nov. 1934, B. A. Krukoff 7151 (holotype: NY!; isotypes: K!, U! fl) .

Plant a scandent hemi-epiphyte; stem thick, internodes 2.5–5.5 cm long, 2–8 mm diam, subcylindric, strongly striate longitudinally, subglossy to opaque, dark green, becoming black when dried; axillary buds 5–8 mm long, straight, apex rounded or obtuse. Petiole 1–3 cm long, 2–3 mm diam, strongly canaliculate, margin smooth; geniculum 1–1.5 cm long, dark green; leaf blade 16–38 cm long, 5 –9 cm wide, narrowly oblong, narrowly elliptic or lanceolate, rigid, coriaceous, olive-green adaxially, pale green abaxially, margin slightly sinuate, 0.4–0.8 mm thick, apex obtuse to shortly acuminate, 1–1.3 cm long, base cuneate, acute, subacute, obtuse, midrib slightly sulcate, impressed adaxially, prominent and dark green abaxially, primary lateral veins and interprimary veins numerous, distinct abaxially when dried, infra-marginal collective vein prominent, 0.25–0.9 mm distant from the margin, outer marginal vein usually absent. Inflorescence terminal and axillary, flowering shoot 2.8– 8 cm long, internodes 4–25 + 3–7 mm diam, dark when dried, subcylindric, without lateral buds on the internodes; peduncle 1–3 cm long, thick, dark green; spathe not seen; spadix 4–7.5 cm long, 1–1.8 cm diam, apex obtuse, pale yellow, shortly stipitate, stipe short or absent. Stamens 2.5– 3.5 mm long, 1–1.75 mm wide, anthers ca. 1 mm long; gynoecium 4.5 mm long, ca. 5 mm diam, truncate, apex 2.4–5.1 mm diam, ovary 1.3–1.8 mm long, 0.5–0.8 mm wide, 2-locular, locules full of white, sticky mucilage, ovules 1–2 per locule, 0.75–1 mm long, anatropous, subsessile, placentation sub-basal, stigma punctate-discoid. Infructescence berry cream when immature, orange when mature. Figures 1B , 4D , 18 .

Habitat and Distribution— Heteropsis macrophylla occurs in dense ombrophilous terra firme forest in Brazil (Amazonas), Colombia, Ecuador, Peru and Venezuela, at 100–400 m alt.

Phenology— Flowering specimens have been collected from November to February and in July, and fruiting material in November.

Conservation Status— Using guidance from the Geocat (2012) online tool, the preliminary conservation assessment of H. macrophylla is least concern (LC), based on 18 localities and a 50 km cell width (auto value cell size option for area of occupancy).

Etymology— The species epithet refers to the leaf size, which at the time of the first description was larger than most other species then known.

Notes— Heteropsis macrophylla is similar to H. flexuosa , but differs from the latter in its longer (1–3 cm), untwisted petioles, narrowly oblong, strongly coriaceous leaf blades that are olive-green adaxially, paler green adaxially, obtuse to shortly cuspidate at the apex, obtuse at the base, with numerous, abaxially prominent lateral veins, the infra-marginal collective vein close (ca. 0.25–0.5 mm) to the margin, usually lacking an external marginal vein, spadix shortly stipitate or sessile, and prominent, punctate, discoid stigma. Heteropsis flexuosa has an oblong or lanceolate, subcoriaceous, abaxially yellowish-green leaf blade with a cuspidate-acuminate apex, the veins obscured on both surfaces, infra-marginal collective vein 1–2.5 mm distant from the margin, and a single external marginal vein, the spadix is stipitate, the stigma discoid-oblong and neither prominent nor punctate. Although we have not examined a fresh infructescence of H. macrophylla , specimen label data states that the berries are cream when immature and orange when mature; however, there is no infructescence on the specimen where this information is recorded. Label data also show that the aerial roots of this species are used for cordage in the construction of traditional houses by the indigenous people of Amazonia.

Our field observations show that the leaves of climbing shoots are horizontally patent on the host tree trunk with cuneate leaf blade bases, but the leaf base is obtuse in mature plagiotropic shoots. This is a rare species in the Reserva Florestal Adolfo Ducke (RFAD) and the few recorded individuals were found at a height of over 20 m. In statistical analyses carried out in ecological studies in the Reserve ( Soares Morais 2008), this species showed preference for host trees of DBH (diameter at breast height) of at least 30 cm. However, this result should be treated with caution because only a few individuals were studied there. In addition, older trees are more likely to be colonized by Heteropsis than younger trees, simply because they have been present in the forest for longer.

Additional Specimens Examined— BRAZIL. Amazonas : Santa Isabel do Rio Negro, 20 Oct 1999, Soares et al. 460 ( INPA ster) ; Reserva Florestal Adolpho Ducke, 14 Feb 2002, Soares et al. 674 ( INPA fl) .

COLOMBIA. Caquetá: Amazonas, Araracuara , 0 34 ' S 72 08 ' W, 4 Nov 1989, Londoño et al. 1146 (MO fr) ; 0 34 ' S 72 08 ' W, 24 Nov 1989, Londoño et al. 1489 (MO ster); 0 36 ' S 72 10 ' W, 31 May 1990, Alvarez et al. 686 (MO ster); 0 39 ' S 72 8 ' W, 18 Oct 199, Alvarez et al.1098, (MO ster) ; 0 37 ' S 72 24 ' W, 9 Nov 1991, Duivenvoorden et al. 940 (MO ster); 0 50 ' S 71 50 ' W, 25 Nov 1991, Duivenvoorden et al. 1629 (MO ster); 0 50 ' S 71 50 ' W, 28 Nov 1991, Duivenvoorden et al. 1811 (MO ster); 0 50 ' S 71 50 ' W, 28 Nov 1991, Duivenvoorden et al. 1847 (MO ster); Município de São José del Guaviare, 02 46 ' 31.1 '' N 72 17 ' 33.6 '' W, 31 Oct 1995, Lopes et al. 576 (MO ster) .

ECUADOR. Napo: Parque Nacional Yasuní , 00 55S 76 11 ' W, 26 May– 8 Jun 1988, Ceron & Hurtado 3898 (MO ster) ; 13 Dec 1988, Ceron & Hurtado 11412 (MO fl); 00 57 ' S 76 13 ' W, 19 –13 Jan 1988, Palácios 2430 (K, MO fl).

PERU. Loreto: Maynas , 2 Nov 1988, Wallnofer 188 (K ster) ; 30 Mar 1979, Clark 7119 (MO ster); 03 15 ' S 72 54 ' W 29 Jul 1991, Vásquez & Grandez 17539 (MO fl); 04 10 ' S 73 20 ' W, 13 Dec 1988, Vásquez & Jaramillo 11412 (MO fl); 04 10 ' S 73 20 ' W, 15 Dec 1988, Vásquez & Jaramillo 11465 (MO fl). Madre de Dios: 30 Nov 1984, Young & Stratton 321 (MO fr) ; 2 Jul 1978, Plowman & Schunke 7514 (K, MO, U ster).

VENEZUELA. Amazonas: 3 02 ' 10 '' N 67 00 ' 00 '' W, 18 Apr 1990, Perez 963 (MO ster); 14 Jul 1986, Stanford Zent 786– 28 (MO ster); San Carlos de Rio Negro, 1 56 ' N 67 03 ' W, 30 Mar 1979, Clark 7119 (MO ster). Bolivar: Sucre, 04 59 ' N 64 49 ' W, 1 Feb 1989, Fernandez & Sanoja 4981 (MO fl); 6 30 ' N 64 50 ' W, 16 Jun1995, Knab-Vispo 398 (MO ster).

Figures

FIG. 1. Geographical distribution of species of Heteropsis. A. H. boliviana, H. croatii, H. duckeana, and H. ecuadorensis. B. H. flexuosa, H. linearis, H. longispathacea, and H. macrophylla. Drawn by Francisca D. A. Matos.

FIG. 4. Establishment of seedlings and flagelliform shoots of Heteropsis on host tree. A. H. steyermarkii, arrow shows anchor root. B. Seedling of H. spruceana on host tree. C. H. spruceana, lower arrow showing anchor root and upper arrow a plagiotropic lateral branch. D. Young H. macrophylla emitting a feeder root. E. Young H. steyermarkii emitting a feeder root (arrow). F–G. Plagiotropic shoot of an individual of H. flexuosa on a fallen tree, producing flagelliform shoot from a plagiotropic branch. A–E: images from Reserva Ducke by M. L. Soares, F–G: images from Amapá by L. Pereira.

FIG. 18. Heteropsis macrophylla. A. Habit. B. Venation on right abaxial surface of leaf blade. (A and B prepared from Soares et al. 674 (INPA)). Drawn by Felipe França.