Heteropsis croatii, M. L. Soares, Kew Bull.

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 : 940-942

2. HETEROPSIS CROATII M. L. Soares ,

Kew Bull. 64: 264. 2009.

— TYPE: BRAZIL. Acre, Cruzeiro do Sul, Rio Moa , 7 38 ' S, 73 36 ' W, 21 Aug. 1986, T. B. Croat & A. Jr. Rosas 62424 (holotype: INPA! fl; isotypes: K!, MO! fl) .

Plant hemi-epiphytic, scandent; internodes 3–5 cm + 2.8– 5 mm, longitudinally striate when dried, quadrangular, usually sulcate, grey-greenish brown; lateral bud ca. 1–2 mm long, straight to introrsely curved, with pointed apex. Petiole 5–8 + 1.6–2.8 mm; sheath often sinuate at the margin, especially those of the flowering shoot; geniculum ca. 4 mm long; leaf blade 15–26 + 5–8.4 cm, oblanceolate, subcoriaceous, greenish-brown on both surfaces when dried, 0.11–0.27 mm thick, apex 1.5–2.5 cm long, acuminate-attenuate, base shortly attenuate, midrib weakly sulcate, primary and secondary lateral veins impressed on the upper surface, prominent on lower surface, submarginal collective vein prominent, c. 1.5 mm from margin, with a single outer submarginal vein. Inflorescence terminal and axillary, flowering shoot 3.5–10.5 cm long, internodes 1.5–3 cm + 1.8–3 mm, matte brown, weakly quadrangular; peduncle 0.5–0.6 + 0.2 cm, usually extrorsely twisted at apex; spathe ca. 3.5 + 1.5 cm, convolute, longer than spadix, cuspidate, yellowish, apex acuminate; spadix 1.5 – 2 cm + 6–7 mm, cylindric, apex rounded, cream, stipitate; stipe 3–6 mm + 1.4–1.7 mm, subcylindric to weakly quadrangular. Stamens ca. 1.5 + 0.75 mm; gynoecium ca. 2.5 + 2.5 mm, prismatic, apex 2.5–3.5 mm wide, locules 2 per ovary, ovules 2 per locule, 1–1.5 mm long, anatropous, subsessile, usually one smaller than the other, placentation sub-basal, stigma discoid. Infructescence ca. 5.5 cm + 3.3 cm; berry 6–10 + 5– 8 mm, bright orange, pulp orange; seed 6–10 + 6–7.5 mm, obovoid, testa subrugose. Figures 1A , 12 .

Habitat and Distribution— Heteropsis croatii occurs in Plateau Forest (terra firme) in western Amazonia in Brazil (Acre, Amazonas) and Peru (Loreto) at altitudes of 120– 230 m.

Phenology— This species has been collected in flower in April, May, August to October, and in fruit from January to May.

Conservation Status— Using guidance from the Geocat (2012) online tool, the preliminary conservation assessment of H. croatii is least concern (LC), based on 9 localities and a 50 km cell width (auto value cell size option for area of occupancy).

Etymology— The specific epithet honors the outstanding work of Dr. Thomas B. Croat of the Missouri Botanical Garden, the leading specialist of our era in Neotropical Araceae systematics, whose numerous important contributions include his unrivalled collections and extensive and numerous publications on the family.

Notes— Heteropsis croatii is morphologically similar to H. robusta in the quadrangular internodes, oblanceolate leaf blade and inflorescence size, but differs by the midrib which is not yellowish on the lower surface in dried material, the adaxially impressed primary lateral veins, the thicker floral shoot axis, and especially by the short, usually extrorsely twisted peduncle and cuspidate spathe much longer than the spadix. In H. robusta the midrib is yellowish on the abaxial surface of the leaf blade, the floral shoot axis is slender, the peduncle is not extrorsely twisted and the spathe is not cuspidate and only slightly longer than the spadix.

Additional Specimens Examined— BRAZIL. Amazonas: Município de Coari, Rio Urucu , base da PETROBRÁS, 28 May 1991, Freitas & Mota 394 ( INPA fr ); Município de Maraã, Rio Japurá , Lago Maraã 1 51 ' S 65 36 ' W, 4– 5 Dec 1982, Plowman et al. 12189 ( INPA, MO fl, fr) ; Colonia dos Índios Canamarís , Rio Japurá , 1 50 ' S 65 35 ' W, 31 Oct 1982, Cid & Lima 3443 ( INPA fl) .

PERU. Loreto: Provincia de Maynas , 3 50 ' S 73 30 ' W, 23 Feb 1981, Gentry et al. 31560 ( MO fr) ; 16 Aug 1988, McDaniel 30195 ( MO ster) ; Distrito Las Amazonas, Comunidad Piloto “Roca Eterna” 3 25 ' S 72 33 ' W, 27 Mar 1991, Grández et al. 2304 ( MO fr) ; Puerto Almendraz, Rio Nanay , 13 Jan 1976, Gentry & Revilla 15878 ( MO fr) ; 20 km WSW of Iquitos , 3 46 ' S 73 20 ' W, 30 Mar 1989, Chota 14 ( MO ster) ; 3 48 ' S 73 35 ' W, 9 Jan 1986, Vásquez & Jaramillo 7080 ( MO fr) ; Santa Maria de Nanay and Iquitos , 23 Feb 1981, Gentry et al. 31560 ( MO fr) ; 3 55 ' S 73 35 ' W, 30 Sep 1990, Pipoly et al. 12616 ( MO fl) ; Rio Nanay 3 40 ' S 73 30 ' W, 6 Jul 1984, Vásquez & Jaramillo 5214 ( MO fl) ; 3 55 ' S 73 35 ' W, 25 Sep 1986, Vásquez & Jaramillo 7980 ( MO fr) ; Rio Yavari , 14 Apr 1964, Schunke 6391 ( MO fr) .

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. 12. Heteropsis croatii. A. Habit. B. Venation on left abaxial surface of leaf blade. C. Inflorescence. D. Frontal view of flower. E. Lateral view of ovules. F. Infructescence. (A, B, D, E prepared from Croat & A. Jr.Rosas 62424 (INPA); C from Cid & Lima 3443 (INPA); F prepared from Gentry & Revilla 15878 (MO)). Drawn by Felipe França.