Amanoa tolimensis Villanueva & Corrales-Bravo, 2024

Villanueva-Tamayo, Boris, Corrales Bravo, Lina M. & Aymard-Corredor, Gerardo A., 2024, A New Timber Species of Amanoa (Phyllanthaceae; Phyllanthoideae) Endemic to Colombia’s Montane Forests and Critically Endangered, with an Updated Key for the Species of the Genus, Phytotaxa 672 (2), pp. 187-198 : 189-192

Amanoa tolimensis Villanueva & Corrales-Bravo , sp. nov. ( Figures 1 and 2 )

Type: — COLOMBIA. Tolima: Municipality of Villarrica, Vereda Galilea, Parque regional natural Bosque de Galilea , 3.785001011N, 74.6833340171W, 1.620 m, 15 September 2023 (fl ♂ – ♀), Lina Corrales & Harbey Amariles 2566 (holotype: JBB! [accession 40026]; isotypes: COL!, LAMUA!, TOLI!, UDBC!)

Diagnosis: — Amanoa tolimensis is morphologically related to Amanoa almerindae Leal (1951: 68) by its sessile staminate flowers, a well-defined androphore, and a pubescent floral rachis with simple trichomes, but can be differentiated from this species by it medium tree habit (24 m tall), having branches and inflorescente rachis lenticellate, with a ferruginuous tomentum; leaves oblong to oblong-elliptic; stipules 1.3–1.8 mm long; petioles 4.3–6.4 mm long; pistillate flowers pedicel 5–5.8 mm long, sepals 3.8–4.9 mm long, oblong to elliptic; ovary 2.4–3.5 mm long, bottle shaped, glabrous, stigma sessile trifid, each branch bifid.

Description: — Tree, with leaves falling seasonally, 24 m tall, diameter up to 52 cm, the outer bark, dark-red, lenticellate, the inner bark pink, wood cream color; the branches lenticellate with a ferruginuous tomentum. Leaves 3.4–15.7 × 1.37–5.17 cm, oblong to oblong-elliptic, coriaceous to coriaceous-membranaceous, glabrous on both sides, the midrib raised abaxially near the base, the secondary venation suppressed on both sides, become prominent when dry, base narrowly obtuse-cuneate to attenuate, apex acute to caudate; margin entire, discretely waved, revolute just at the base, petiole 4.3–6.4 × 0.9–1.6 mm, canaliculate, yellow-green, glabrous in fresh material, black, rugose when dry, seasonal leaf drop, followed by red regrowth; stipules 1.3–1.8 × 1.3–1.6 mm, triangular, glabrous on both sides. Inflorescence racemose sometimes forming panicles, terminal or lateral, 10–15 cm long, sub-erect, elongate, the rachis gray, lenticellate, ferruginous trichomes scattered, its compound by 5 or more cells, with few reduced leaves subtending flower clusters on the lower nodes, each node subtended by a prominent yellow-light triangular bract, 2.5–3 mm long, glabrescent to sparsely pubescent abaxially, 2–5 flowers per node, each flower with two bracteoles 1.7–1.8 × 0.6–0.8 mm with a row of short trichomes located in the middle abaxially. Staminate flowers: actinomorphic, 5-merous, 5.5–6.5 mm in diam., sessile; sepals 3.8–4.2 × 2.2–2.5 mm, elliptic ovate, glabrous on both sides, white; petals ca. 0.8 × 1 mm, flabellate, laciniate at apex, glabrous on both sides, clawed; with an irregular extra-staminal disc, stamens 5, fused at base, forming an androphore, filaments inclined outside and curved inside, 0.9–1.3 mm long, anthers 0.9–1.1 mm long, longitudinally dehiscent; pistillode ca. 1 mm long with a trilobed apex. Pistillate flowers: actinomorphic, 5- merous, 3.5–3.8 mm in diam., pedicel 5–5.8 × 1.3–2.9 mm, glabrous; sepals 3.8–4.9 × 1.4–2.2 mm, oblong to elliptic, glabrous on both sides, white-green, petals 0.8–1.3 × 1.2–1.6 mm, clawed, flabellate, laciniate, 0.2 mm; pistil 3–4 mm

tall, ovary 2-carpellate 2.4–3.5 × 2.9–3.3 mm; bottle shaped, glabrous, stigma sessile, trifid, each branch bifid. Fruits 9–11.3 × 9.2–11.2 mm, schizocarpic round to rounded, surface smooth and dull, yellowish-brown, peduncle terete striate when dry, 4.5–5.2 mm long, capsule 3-locular, dehiscing into 6 mericarps (cocci), the endocarp separating from mesocarp, the mericarp margins smooth, persistent in central axis. Seed 7–8.7 × 5.8–6.8 mm, spheroid, brown light, minutely maculate.

Phenology: — Amanoa tolimensis was collected with staminate flowers in April, August, September and October (flowers in different ripening stages), pistillate flowers in September and October, and fruits in October.

Etymology: — The epithet “tolimensis ” refers to the name of Tolima Department, the political region where this new species occurs.

Common names and uses: — The name “Almanegra” was only name recorded for this species. Local people report that the wood of A. tolimensis ( Figure 2 ) is used as a timber, especially in carpentry and construction. The timber of A. guianensis is not well known as plumber because the wood is coarse-textured, irregular-grained, heavy, with a low resistance to rot when exposed ( Fern & Morris 2022). It can be used as fuel and to make charcoal, for light carpentry, but it is difficult to work (Ibidem). Julian A. Steyermark reported hard wood in the type specimen (J. A. Steyermark 93238, F, NY, VEN) of A. steyermarkii . In addition, A. caribaea is well known to be an important timber tree in forests of Dominica, it wood is extremely hard and heavy ( Nicolson 1991).

Distribution, ecology and associated vegetation: — Amanoa tolimensis is the first species of the genus endemic to Colombia, known to occur in “Parque Regional Natural Bosque de Galilea”, in Tolima department, Colombia ( Figure 4 ). This is a region of montane forests in the western flank of the eastern mountain range, upper Magdalena River basin, between 1488–1620 m elevation. This area is located southeast of Tolima department. This large area of wetlands was partially inhabited in the last century. It is characterized by their forest extension and biodiversity, which was preserved due to the social and armed conflict that kept them isolated from logging and deforestation. The signing of the peace agreement in 2016 opened these forests to colonization processes. However, the intensive explorations carried out in flora and fauna allowed helped to declare the region by the Colombian state such as natural regional park. This new protecting figure bordering a complex of protected areas that link the inter-Andean zone with the Amazonian foothills. In these forests was found Doselia galilensis A. Orejuela & Villanueva (2022: 84), a new rare liana species belongs to Solanaceae ( Orejuela et al. 2022) . This found was important to give the forest the current protection category.

In addition, five permanent plots of 1 hectare were established at different altitudes inside “Parque Regional Natural Bosque de Galilea”. A. tolimensis was only found in the plot locates at 1480 m. In this 5-hectare area, all individuals with a diameter at breast height (dbh) greater than 10 cm were recorded, totaling 3.231 individuals measured of them 58 belong to the new species. In these forests also are common species such as Colombobalanus excelsa (Lozano, Hern. Cam. & Henao) Nixon & Crepet (1989: 840) , the tree fern Cyathea delgadoi Pohl ex Sternberg (1825: 47) , the palm Euterpe precatoria var. longevaginata (Mart.) A.J. Hend. (1995: 111). and the endemic tree Magnolia caricifragans (Lozano) Govaerts (1996: 70) . It is very probable that A. tolimensis has been existed in the in the same altitude range in latter forests located in Eastern slopes in the north and south of “Cordillera Oriental”. However, no specimens were found in the national herbaria collections. An additional ecophysiological feature is that the new species presents a slow deciduous process. When the trees start new leaves production these are reddish, making the trees easily detectable both inside and outside the forest.

Phytogeographical notes: — The intensive botanical exploration in the Colombian Andes during the last fifteen years revealed that the distribution of Amanoa ( A. tolimensis ) extends to the western slopes of “Cordillera Oriental”, Tolima department (fig. 4). The type locality of Amanoa tolimensis is the Galilea Forest, located on the western slope of the Eastern Cordillera, on folded sedimentary rocks (sandstones and claystones) from the Cretaceous and Tertiary periods, mainly composed of conglomerates, clays, and sandstones on the ‘Guaduas’ formations ( IGAC 2004).

So far, some descriptive analyses have been conducted in vegetation types and species on white sand substrates in the Andes ( Aymard & Campbell 2007, Neill et al. 2014, Neill 2018, Giraldo-Cañas 2017, Aymard 2022, Clark & Neill 2023). Other studies have investigated the exchange of different plant lineages between the Andes, the Amazon, and other neotropical regions in families with Amazonian and Andean distribution such as Gentianaceae ( Gould & Struwe 2004) , Sapotaceae (Serrano et al. 2018) and Arecaceae ( Pichardo-Marcano et al. 2019) . However, for this particular case of the atypical distribution of Amanoa in the Colombian Andes, there is still insufficient information to elucidate the presence of this species there. Therefore, it is recommended to develop future additional edaphological and geological survey as well as floristic and genomic research focused on comparative studies of the Andean floras that occupy habitats on sandstones, or with similar edaphic characteristics found in the Guiana Shield and Amazon regions.

Additional specimens examined (Paratypes): — COLOMBIA. Tolima: Municipality of Villarrica, Vereda Galilea, antes de las mesas de Galilea en bosques en la montaña oriental, entre los bajos del río Chipas, 3.767983N, 74.679817W, 1537 m, 11 October 2016 (fr), Boris Villanueva-T., Milton Rincón & Lina Corrales 2961 (TOLI! [accession 17549]); Ibidem, Cerca camino entre Rio Naranjo y Rio Negro Parcela 1, 3.769833N, 74.670972W, 1564 m, 15 April 2018 (fl ♂), Lina M. Fonseca, Boris Villanueva , Lina Corrales & Guillermo Rivas 83 (TOLI! [accession 20801]); Ibidem, Bosques aledaños a humedales de mesas de Galilea, 3.764728N, 74.688561W, 1480 m, 9 August 2018 (fl ♂), Boris Villanueva-T., Mónica Sarmiento & Semillero de Maderas UT 4257 (JBB! [accession 40033]); Ibidem, Camino entre Río Naranjo y humedales de las mesas de Galilea. 3.771008N, 74.676739W, 1488 m, 4 October 2018 (fl ♂), Boris Villanueva & Lina Corrales 4334 (JBB! [accession 40028]); Ibidem, Camino entre Mesas de Galilea y alto de la Cominera. 3.7850010115N, 74.6833340171W, 1620 m, 21 August 2023 (fl ♂ – ♀), Lina Corrales, Jose Acelda & Harbey Amariles 2528 (JBB! [accession 39994]).

Preliminary assessment of conservation status:— Currently, Amanoa tolimensis is known from six collections (the type locality and near the type locality; see the additional specimens) made in “Parque Regional Natural Bosque de Galilea”, Villarrica municipality, Tolima department. Under IUCN (2022) guidelines, there are not sufficient data (DD) to accurately determine its conservation status. However, it should be regarded as Critically Endangered (CR) according to our calculations that estimate that extent of occurrence (EOO) in 2,207 km 2, Area of Occupancy (AOO) of <12,000 km ² and its timber extraction levels. The inventories conducted within the reserve area showing that A. tolimensis has only been recorded in an altitudinal range between 1400 and 1610 m elev.

Taxonomic notes:— By its sessile staminate flowers, a well-defined androphore, and a pubescent floral rachis with simple trichomes, A. tolimensis is morphologically related to two taxa: A. almerindae and A. condorensis . Nonetheless, this new species differs from these two species in the characters discussed in the diagnosis, and in the following key.

Figures

FIGURE 1. Amanoa tolimensis. A. Reproductive branch. B. Detail of the stipule and lenticels on branches. C. Detail of reduced leaves on the nodes inflorescence. D. Immature inflorescence with ferruginuous trichomes. E. Front and lateral views of the staminate flowers. F. Detail of the staminate flower, showing the extra-staminal disc and the flabellate petal. G. Pistillate flower showing the stigma sessile. H. Labellate petals on pistillate flower. I. Sepals. (holotype- Corrales & Amariles 2566). Lankester plate by Daniel Amaya-Jimenez.

FIGURE 2. Amanoa tolimensis. Wooden sample from the collection of the “Laboratorio de Maderas de la Universidad del Tolima. Villanueva 4257.

FIGURE 4. Geographic distribution of Amanoa tolimensis in the Colombian Andes.