Heteropsis longispathacea, Engl., Pflanzenr. IV

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

7. HETEROPSIS LONGISPATHACEA Engl. ,

Pflanzenr. IV, 23 B: 53. 1905.

— TYPE: BRAZIL. Amazonas, Rio Juruá , Nov. 1901, Ule 6016 (holotype: B! fl).

Plant a scandent hemi-epiphyte; aerial roots ca. 5 mm diam, subcylindric, pale brown when dried, fissured longitudinally; shoot slender, somewhat flexuose, internodes 2.7–4 cm long, 2.4–4.5 mm diam, somewhat striated longitudinally when dried, subcylindric with one side slightly flattened, pale brown when dried; axillary buds ca. 2–3 mm long, straight to introrse, apex rounded. Petiole 2–4 mm long, ca. 2 mm diam, canaliculate, margin paler and sinuate at apex; geniculum ca. 2 mm long; leaf blade 12–19 cm long, 4–5 cm wide, lanceolate to oblanceolate, subcoriaceous, pale brown on both surfaces when dried, 0.12–0.16 mm thick, apex acuminate, base cuneate, midrib somewhat sulcate adaxially, prominent abaxially, primary lateral veins and interprimary veins prominent only abaxially, infra-marginal collective vein prominent, 1.5–2 mm distant from the margin, external marginal vein 1, closely adjacent to the collective vein. Inflorescence terminal and axillary, flowering shoot 4.5–6 cm long, internodes 1.3–2 cm long, ca. 1.8 mm diam, pale brown, slightly sulcate; peduncle 0.3–0.7 mm long, 1.3–3.5 mm diam, subcylindric; spathe ca. 7 cm long, 2.5 cm wide when expanded, 8 cm long, 1.4 cm wide when closed, oblong, apex strongly cuspidate; spadix 3.5–4.2 cm long, ca. 7 mm diam, subcylindric, apex acuminate, stipitate, stipe 0.3 – 0.6 + ca. 1.2 mm. Gynoecium with apex 2–2.5 mm diam, stigma elliptic. Infructescence not seen. Figures 1B , 17 .

Habitat and Distribution— Heteropsis longispathacea is known from Brazil (Acre, Amazonas, Maranhão, Pará), Peru, and Surinam, occurring at 300–800 m alt.

Phenology— Flowering specimens have been collected in flower in December, February, April and July and fruiting material in December.

Conservation Status— Using guidance from the Geocat (2012) online tool, the preliminary conservation assessment of H. longispathacea is least concern (LC), based on 7 localities and a 50 km cell width (auto value cell size option for area of occupancy).

Etymology— The species epithet refers to the spathe which is relatively much longer than the spadix.

Notes— Heteropsis longispathacea is easily recognized when fertile because of the long, cuspidate spathe, much longer than the slender spadix. It is morphologically similar to H. salicifolia , but differs from the latter in the longer and wider, usually lanceolate, leaf blade and by the introrse axillary buds, longer cuspidate spathe and longer spadix. In contrast, H. salicifolia has an elliptic-oblong leaf blade, extrorse lateral buds, shorter spadix and the spathe has a much shorter apex. The type material of H. longispathacea is from the Rio Juruá in Amazonas State ( Brazil) occurring in a clear water region near the Andes. However there are records from the state of Pará, possibly from terra firme forest, at Castanhal, near Belém. Given this distribution, it may be inferred that Heteropsis longispathacea probably occurs in central Amazonia and has so far gone unrecorded due to lack of collections. Specimen label information records that according to local people in Amazonia, the juice of the aerial roots of this species causes irritation and itching, perhaps because of the presence of calcium oxalate.

Additional Specimens Examined— BRAZIL. Acre: Porto Alegre, Alto Purus , 8 Apr 1904, Huber s.n. ( MG 4391 fl) ; 10 Apr 1904, Huber s.n. ( INPA, MG 4432 fl) ; Tarauacá, Dec 1956, Bockermann 298 ( SP fl). Maranhão: Alzilandia, Rio Turiac¸u , 1 Jul 1978, Jangoux & Bahia 124 ( MG fl) ; 29 May 1979. Pará: Castanhal, 22 Feb 1966, Silva et al. 549 ( MG fl). Óbidos, 29 May 1979, Jangoux & Bahia 979 ( MG fl) ; Porto Alegre, próximo à Tucuruí , 10 Apr 1904, Huber et al. 4432 ( MG fl) .

PERU. 30 Jul. 1974, Berlin 1871 ( 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. 17. Heteropsis longispathacea. A. Habit. B. Venation on abaxial surface of leaf blade. (A and B prepared from Bockermann 298 (SP)). Drawn by Felipe França.