Dilkea hebes Feuillet, 2011

Feuillet, Christian, 2011, Two new species of Dilkea subgenus Dilkea (Passifloraceae) from Loreto, Peru, PhytoKeys 2, pp. 1-8 : 2-4

Dilkea hebes Feuillet sp. nov. Fig. 1

Latin

Dilkea hebes foliis super hebeti, exocarpio 4-5 mm crasso, multistrato, suberis simulanti, a subgeneris Dilkea speciebus mihi notis distincta. Liana in sylva riparia inundata, in Loreto (Peruvia) crescit.

Type:

PERU. Loreto: Maynas, District of Iquitos, Río Nanay, above Bellavista, between Pampa Chica and Santa Clara, shoreline forest frequently inundated, 1 June 1976, fr., M. Rimachi Y. 2336 (holotype: US-3393830!; isotype: IBE).

Woody climber, growth continuous, internodes subequal or gradually unequal, twigs drying brown to black; glabrous throughout. Stipules not seen. Leaf: petiole terete, reduced to the pulvinus, 3-6 mm long, swollen but not wrinkled when dry, drying nearly black; blades coriaceous, narrowly elliptic to oblanceolate, widest ca. 2/3 from base, 7.5-19 × 3.5-6.5 cm, base usually slightly acute, angle ca. 45° each side of the midrib, apex acute or round and short–acuminate, margin undulated on herbarium specimens, probably due to dorsiventrally curved midrib, adaxially dull, drying dark olive–green, abaxially dull, drying pale olive–green, midrib adaxially in a groove, abaxially strongly raised, main veins obscure, 15-20 on each side of the midrib of well–developed leaves. Inflorescences axillary; peduncle axillary, thicker than the stem, bearing 1-2 flowers; bracts thick scale-shaped, 0.5-2 mm long, long and narrow to short and wide under the same fruit; pedicel and peduncle forming a narrow cone 0.5-1.5 cm long, 0.4-0.6 cm diam. at apex under the fruit. Flowers not seen. Fruits subterminal by withering of the apical part of the stem, spherical, observed still green but well-developed, fruit wall hard, 4-5 mm thick, corky, with 1-2 seeds, partly empty with at least partially dividing membranes; seeds peanut-shaped, slightly asymmetric, 1.7 × 0.7-0.8 cm.

Distribution.

Endemic to the district of Iquitos, Maynas, Loreto, Eastern Peru.

The specimen labels did not give geographical coordinates for the collection localities of Dilkea hebes in Peru, Loreto, Maynas, Distr. Iquitos. The localities cited for the two specimens, "quebrada de Morropón” or "Pampa Chica", are not in the gazetteer published by the United States Board on Geographic Names ( USBGN 1989), and Santa Clara and Bella Vista are common village names in Peru. A search in the National Geospatial–Intelligence Agency database (NGA web site) on Santa Clara brought 11 occurrences in Loreto and Bella Vista / Bellavista 16. Coordinates for those are too uncertain to be presented in the specimen citations, but it is possible that they are Puerto Bellavista Nanay, port of Iquitos on the Río Nanay, ca. 3°42'S, 73°15'W, and Santa Clara de Nanay, near the far end of Iquitos airport on the bank of the Río Nanay, ca. 3°47'S, 73°20'W.

Ecology.

Dilkea hebes is growing in inundated riparian forest, known only from the vicinity of the type locality, ca. 90 m elev.

Phenology.

Fruits immature when collected in February and June.

Preliminary conservation status.

Dilkea hebes is known from two collections from the same district in Maynas, Loreto, Peru. The data are insufficient to assess an informed status for this species, therefore I suggest that it be classified as DD (Data Deficient) according to IUCN (2001, 2003) categories.

Discussion.

Dilkea hebes has a few fruit characteristics that distinguish it from all other species of Dilkea and that may be related to its frequently inundated habitat. The thick corky fruit wall, the small number of seeds leaving empty space in the fruit, and possibly the thin membranes inside the fruit increase the floatability of the fruit suggesting that the fruits may be disseminated during floods. Cork has been found in some species of Passiflora , for example on the bark of mature stems of Passiflora suberosa L. and Passiflora sexocellata Schlecht. in subg. Decaloba (DC.) Rchb. supersect. Cieca (Medic.) J.M. MacDougal & Feuillet or even on the young stems and the petioles of Passiflora phellos Feuillet in subg. Passiflora supersect. Laurifolia (Cervi) Feuillet & J.M. MacDougal. The vegetative characters are rather similar to Dilkea johannesii Barb.Rodr., which differs by its thin-walled fruit tapering at base and having an apical hard cone (cf. original illustration, reproduced from the Smithsonian Library, Feuillet 2010b).

Etymology.

The Latin epithet hebes (= dull), refers to the upper surface of the leaves that is not shiny, in contrast with Dilkea nitens Feuillet, another species from Loreto described below.

Paratypes.

PERU. Loreto: Maynas, District of Iquitos, Río Nanay, quebrada de Morropón, inundated bank, ca. 90 m, 14 Feb 1985, fr., M. Rimachi Y. 7755 (US!; IBE).

Figures

Figure 1. Holotype of Dilkea hebes Feuillet: M. Rimachi Y. 2336 (US).