Malmea abscondita Chatrou & Gees, 2025

Malmea abscondita Chatrou & Gees sp. nov.

Fig. 4 View Figure 4

Type.

Peru • Dept. Loreto: Río Nanay, San Pablo de Cuyana, Estación Biológica Miguel Alejandro , 03°47'S, 73°21'W, 9 Nov 1994, L. W. Chatrou, P. J. M. Maas, H. Rainer & F. Ayala 8 (holotype: USM! [specimen number USM-135298 ]; isotype: U! [barcode U-0089935 , U-0089936 ]) GoogleMaps .

Diagnosis.

Malmea abscondita is distinct from congeneric species by a combination of the following characters: narrowly elliptic leaves, few secondary veins, fewer monocarps, and longer stipes of the monocarps. The new species combines characters mostly found in Malmea guianensis R. E. Fr. , M. manausensis Maas & J. M. S. Miralha , and M. surinamensis Chatrou. It differs from Malmea guianensis by the hairy inflorescences (vs. glabrous), the smaller number of monocarps (6–13 vs. 20), and shorter stipes (22–30 mm vs. 37–49 mm); from M. manausensis by the lower number of secondary veins (8–9 vs. 12–14 per side of the leaf), the longer and more slender stipes (22–30 mm long, 1 mm in diam. vs. 18–21 mm long, 2.5 mm in diam.); and from M. surinamensis by the lower number of secondary veins (8–9 vs. 10–13 per side of the leaf), the longer pedicels (43–57 mm vs. 40 mm), and the smaller number of monocarps (6–13 vs. 15–20).

Description.

Small tree, 2.5–4 m tall, 2 cm in diam. Young twigs and lower side of petiole and basal part of midrib sparsely to rather densely covered with brown, appressed (to erecto-patent) hairs ca. 0.5 mm long (simply hairs hereafter). Petiole 4–6 mm long, 1.5–2 mm in diam., verrucose to rugulose. Lamina 19–30 cm long, 5–8 cm wide, length-width ratio (2.9 –) 3.3–4.2, chartaceous, narrowly elliptic or narrowly obovate, base cuneate to obtuse, apex gradually acuminate, olive green and shiny above, olive green (slightly darker than upper side) below, glabrous above, (sub-) glabrous below, secondary veins 8–9 per side, irregularly spaced with distance between secondary veins 14–35 mm, angles with primary vein 55–75 °, loop-forming at right to obtuse angles, distance between loops and leaf margin 5–10 mm. Flowers unknown. Infructescences on leafy twigs, terminal or leaf-opposed, maximally 1 flower / fruit scar and 1 actual fruit on rhipidium, peduncles and pedicels sparsely to rather densely covered with short, yellowish-brown, appressed to erecto-patent hairs, bract densely covered with similar hairs. Peduncles 10 mm long, 1–2 mm in diam. Pedicels 43–57 mm long, 1 mm in diam. basally to 2.5 mm apically, sympodial rachis 3 mm long. Articulation 1 mm above axil of lower bract. Bracts 2.5 mm long, 2 mm wide, apex obtuse to rounded, semi-amplectent, lower bract near base of pedicel, upper bract halfway the pedicel. Fruit of 6–13 monocarps, blackish brown, ellipsoid, 13–16 mm long, 8–11 mm in diam., sparsely hairy except for densely hairy apex, verrucose; stipes blackish brown, 22–30 mm long, 1 mm in diam., sparsely to rather densely hairy; fruiting receptacle (sub) globose, 6–8 in diam., 6–9 mm high, (rather) densely hairy. Seeds ellipsoid, 12–15 mm long, 7–10 mm in diam., brown, surface pitted, raphe a slightly elevated rib, ruminations spiniform.

Distribution and habitat.

The species is known from two localities near Río Nanay, west to northwest of Iquitos, in the Peruvian department of Loreto (Fig. 3 View Figure 3 ). Both the occurrence in upland rainforest and periodically inundated rainforest have been reported.

Preliminary conservation status.

To date, Malmea abscondita is known only from two collections made in the vicinity of Río Nanay, with an AOO and EOO of 8 km 2. The collection label of Rimachi 479 does not include latitude and longitude, and we estimated the collection locality to be just north of the mouth of Río Nanay, near the carretera Nanay – Mazan. The species falls under the IUCN category of data deficient (DD). A more detailed analysis of the population must be done to correctly assess its conservation status. Given the general geographical pattern of Malmea , characterized by small allopatric distributions, this is likely to be accomplished by more thorough inventories of the known area of occurrence.

Etymology.

The specific epithet refers to the concealed, largely unnoticed existence of this species in the Amazonian forests of northern Peru, having been collected twice only in the past 52 years.

Additional specimen examined.

Peru • [Loreto], Maynas, Trocha de la Astoria hasta Mazan, near mouth of Río Nanay , 2 Aug 1973, M. Rimachi Y. 479 ( MO!) .