Heteropsis duckeana, 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 : 942

3. HETEROPSIS DUCKEANA M. L. Soares ,

Kew Bull. 64: 264. 2009.

— TYPE: BRAZIL. Amazonas, Manaus , Reserva Florestal Adolfo Ducke , km 0.35 caminho alojamentotorre, 8 Nov. 2002, M. L. Soares 503 (holotype: INPA! fl; isotypes: K!, MG!, MO!, RB! fl).

Plant scandent climbing to 35 m high, shoot leafy, aerial roots ca. 7–8 mm diam, subcylindric, reddish brown when young, grey when mature; internodes 2–3 cm + 4–9 mm, brown, longitudinally striated when dry, somewhat flattened on one side, rounded on the other; lateral bud 1–2 mm long, apex rounded. Petiole 5–8 + 2–3 mm, usually twisted, margin paler; geniculum ca. 3 mm long, darker than petiole; leaf blade 9–17 + 2.5–4 cm, elliptic-lanceolate, subpatent, olive-green when fresh, becoming brown when dry, glossy, subcoriaceous, 0.22–0.28 mm thick, apex acute, base cuneate, margin revolute, slightly sinuate, lateral veins numerous, obscure on both sides when fresh, visible when dry, submarginal collective vein 2–3 mm distant from margin, external marginal veins 1–2. Inflorescence terminal and axillary, flowering shoot 2.5–7 cm long, internodes 0.5–1.5 cm + 3 mm, with 1–2 small, persistent euphylls at the most apical nodes; peduncle short, 1–1.5 cm long, 3–4 mm diam; spathe 2.5–5 + 4–5.8 cm when expanded, yellow on both sides, inflated, convolute, apex shortly acuminate, margin cream, spathe of floral buds 2–3 cm + ca. 8 mm, dark green; spadix 3.8–5.3 + 1–1.5 cm, cylindric, apex weakly acuminate, pale yellow, stipitate, stipe 1.5–2 + ca. 3 mm. Stamens 3–4 + 1.25– 1.7 mm, anthers 1 + 1.5 mm; gynoecium 3–3.5 + ca. 3.5 mm, obpyramidal, ovary 2.5 + 1.8 mm, locules 2 per ovary, ovules 2 per locule, 0.6–1 + 0.7 mm, anatropous, subsessile, placenta basal to sub-basal, stigma 1–1.5 mm long, oblong-elliptic. Infructescence: 6–6.5 + 2.3–3.2 cm; berry 10–17 + 9–18 mm, apex 6–8 mm diam, subobovoid, yellow, pulp yellow; seeds 1–2 per berry, 10–15 + 9– 13 mm, obovoid, testa rugose. Figures 1A , 7A , 8A , 9A , 13 .

Habitat and Distribution— Heteropsis duckeana occurs in terra firme plateau forest (floresta de platô) at altitudes of approximately 150 m. It is so far known only from Central Amazonia, Brazil.

Phenology— Flowering specimens have been collected between October and December, and fruiting material in January.

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

Etymology— The specific epithet refers to the collecting locality where this species was first recognized: the Reserva Florestal Adolfo Ducke which belongs to the Instituto Nacional de Pesquisas da Amazônia (INPA), in the municipality of Manaus, Brazil.

Notes— Heteropsis duckeana is morphologically similar to H. rigidifolia from the Atlantic Forest but differs in the less coriaceous, non-rigid, and less spreading leaf blade, longer internodes and petioles, and especially in the larger size of the spadix and seeds. In H. rigidifolia the internodes are 1.5–2 cm long, the petiole 3–5 mm long, the leaf blade is coriaceous, rigid and spreading, the spathe is 2–3 cm long, the spadix 1.5–3 cm long, 0.6–0.8 cm diam, and the seed 8 mm long, 4– 5 mm diam. The aerial roots of H. duckeana have lenticels throughout and the anchor roots adhering to the host tree are flattened and velvety reddish-brown. The ovary locules contain a transparent mucilaginous substance which dries rapidly on exposure to air.

A study of the root anatomy of Heteropsis species in the Reserva Adolfo Ducke ( Soares Morais 2008) showed that H. duckeana differs from other species in the presence of brachysclereids in the central cylinder.

Additional Specimens Examined— BRAZIL. Amazonas: Itacoatiara, Mil Madeireira , 12 Dec 1999, Soares et al. 486 ( INPA fl); Manaus, Reserva Florestal Adolfo Ducke , 6 Jan 2005, Soares & Pereira 759 ( INPA fr); 13 Oct 1994, Vicentini 747 ( INPA fl). Pará: Itaituba, Parque Nacional do Tapajós , km 60 da estrada Itaituba-Jacarecanga 20 Nov 1978, Silva & Rosário 3852 ( K, MG, U, fl).

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. 7. A–M. Inflorescences in bud and at anthesis. A. Heteropsis duckeana. B–C. H. flexuosa. D–E. H. oblongifolia. F–G. Bud and open inflorescence of H. salicifolia, respectively. H. H. spruceana. I–J. Bud and open inflorescence of H. steyermarkii, respectively. L–M. H. tenuispadix. (photos A–C, H–J and M by M. L. Soares; D–G by Hélio; L by Projeto Flora Reserva Florestal Adolfo Ducke).

FIG. 8. A–G. Inflorescences after anthesis. A. H. duckeana. B. H. flexuosa. C. H. salicifolia. D. H. spruceana. E–F. H. steyermarkii. G. H. tenuispadix. (photos: A, B, D-F by M. L. Soares; C by M. Nadruz; G by Projeto Flora Reserva Florestal Adolfo Ducke).

FIG. 9. A–F. Mature and immature infructescences of Heteropsis. A. H. duckeana. B–C. Immature and mature infructescences of H. spruceana, respectively. D. H. oblongifolia. E–F. Immature and mature infructescences of H. tenuispadix, respectively. (photos: A, C, E, F by M. L. Soares, B by Projeto Flora Reserva Florestal Adolfo Ducke, D by André Amorim).

FIG. 13. Heteropsis duckeana. A. Habit. B. Venation on right abaxial surface of leaf blade. C. Frontal view of stamen. D. Lateral view of flower. E. Longitudinal section of gynoecium. F. Transverse section of ovary. G. Lateral view of ovule. H. Infructescence. (A–H prepared from Soares et al. 503 (INPA) and Soares & Pereira 759 (INPA)). Drawn by Felipe França.