Nasa katjae T. Henning, J. P. Allen & R. H. Acuna 2025, sp. nov.
Creators: name: Henning, Tilo
name: Allen, Joshua P.
name: Montesinos-Tubeé, Daniel
name: Rodríguez-Rodríguez, Eric F.
name: Peña, José Luis Marcelo
name: Acuña-Castillo, Rafael
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Cornales
Loasaceae
Nasa
Nasa katjae

description: Nasa katjae T. Henning, J. P. Allen & R. H. Acuña sp. nov.
Figs 2, 3 C
Type.
Peru • Departamento Cajamarca, Provincia Jaén, Distrito Colasay, Above Colasay near Agua Fria. In dense forest, along the trail to Agua Fria in streams, climbing in the vegetation. Just below the peak at ca. 2500 m, - 5.93990, - 79.05400, 01. Sep. 2023, D. B. Montesinos 10003, T. Henning, J. P. Allen (Holotype: HUT No. HUT-64640!, Isotype USM).
Diagnosis.
The new species is morphologically most similar to Nasa calycina comb. nov. (see below) and differs from it in its very elongated stems, subscandent habit, proportionately broader leaf blades with a conspicuously deeply cordate base, sepals and petals almost twice as long (to 4 cm and 4.5 cm respectively), sepals and petals of equal length and nectar scales with 3 conspicuous apical dorsal threads up to 5 mm long.
Description.
Plants to 1.5–3 (– 4) meters tall, covered with scabrid, and stinging trichomes, glochidiate trichomes restricted to the abaxial surface of the leaves along the veins. Stinging hairs (setae) scattered all over the plant but most densely on the stem, ovary, sepals (= fruit) and along the veins of the leaves. Apical parts of the petals set with few glandular hairs. Stems upright when young or growing in open areas, climbing through and leaning on adjacent vegetation when growing in dense undergrowth, base slightly woody. Leaves opposite, petiolate, petiole up to 13 cm long, leaf blades pinnately veined, 7–11 × 5–10 cm, widely ovoid to triangular, with 3–7 obtuse triangular lobes on each side, the lower ones up to 3 cm wide and 1.5 cm long, gradually decreasing in size towards the apex, the upper ones inconspicuous, margins serrate, each tooth with a hydatode, base conspicuously cordate (sinus to 1 cm deep). Inflorescence a monochasial or dichasial cyme, bracts alternate to 3 × 1.5 cm, one per flower, smaller than vegetative leaves, base shallowly cordate to truncate. Sepals 5, persistent, long acuminate, green, up to and 3.5–5 × 0.6–0.8 cm when fruiting, with 3 main veins, temporarily spreading in early anthesis, closely fitting on the petals later and further contracting in fruit. Petals 5, scarlet red, shallowly cymbiform, oblanceolate, base narrower than the limb but claw poorly differentiated, 3.5–4.5 × 1–1.5 cm, with 3 evident main veins, gaps between petals let the nectar sacs and scale bases visible when calyx lobes removed. Nectar scales 5, orange, 19–21 mm long and 5–6 mm wide at base, with 2 distinct, broadly ovoid, seemingly smooth (when fresh) nectar sacs at the base, each one as wide as nectar scale back (3 mm in diameter), nectar scale back rectangular, narrow 15 × 3 mm, straight papillose, margins with even longer papillae, ending in 3 conspicuous, distinct dorsal threads, inserted apically, up to 5 mm long and with two horizontal wings, seemingly smooth, 7 × 4 mm and diverging 90–120 ° from the back. Staminodes 2 per scale, c. 22 mm long, slightly sigmoid, base papillose, apex filiform. Stamens in 5 antepetalous fascicles with 10–20 each, anthers whitish when shedding pollen. Ovary broadly conical, with a rounded base, 5 × 5 mm, with 3 parietal placentae. Stigma lobes 3, decurrent on the style surface. Fruit a broadly clavate capsule with a globose base, 20–25 mm long (without sepals) and 8–10 mm wide at sepal insertion, opening with three apical valves. Seeds numerous, ovoid, 2.5 mm long and 1.5 mm wide, testa black and reticulate.
Paratypes.
Peru, Cajamarca, Prov. Jaén, Dist. Colasay • Sector Aguas frias, bosque montano húmedo, 5 ° 56 ' 14.69 " S, 79 ° 03 ' 19.33 " W, 2542 m, 28 March 2024, José Luis Marcelo-Peña, Marisela Rojas, Robert Zurita 11923 (ISV) • Ditto, 5 ° 56 ' 23.07 " S, 79 ° 03 ' 14.28 " W, 2550 m, 30 March 2024, José Luis Marcelo-Peña, Marisela Rojas, Robert Zurita 12127 (ISV) • Ditto, 5 ° 56 ' 23 " S, 79 ° 03 ' 14 " W, 2550 m, 30 March 2024, José Luis Marcelo-Peña, Marisela Rojas, Robert Zurita 12128 (ISV).
Photographic evidence (iNaturalist): Peru, Cajamarca, Prov. Jaén, Dist. Colasay • - 5.92834, - 79.05414, April 2022, biomonstrando, http://www.inaturalist.org/observations/143704890 (type locality) • - 5.93739, - 79.0351, December 2023, biped_cub, http://www.inaturalist.org/observations/194322389 • - 5.93739, - 79.04139, December 2023, biped_cub, http://www.inaturalist.org/observations/194324117.
Affinities.
The species appears to be morphologically closest to Nasa calycina comb. nov., a species endemic to a small area of southern Ecuador, in SE Loja and adjacent Zamora-Chinchipe. This taxon has been considered a synonym of the more northerly Nasa loxensis (Weigend 1996; Jørgensen and León-Yánez, 1999; Weigend 2000 b), but detailed examination of their floral morphology showed that both taxa are best treated as closely related, but separate species (see below). The species can be found in forest edges and relatively open understories of wet montane “ cloud ” forest. Habit, leaf shape, perianth parts size and proportions, as well as size and insertion of the nectar scale dorsal threads separate the new species from Nasa calycina comb. nov. (Table 2), rehabilitated to species level in this article (see below).
Our first encounter with this species took place on iNaturalist (http://www.inaturalist.org/observations/143704890), where, at first, we suspected it was an unusual Nasa loxensis (a species whose concept has been quite broadly applied in the most recent revisions of Loasaceae of Ecuador: Weigend 1996; Jørgensen and León-Yánez 1999; Weigend 2000 b). After a more thorough analysis, it is evident to us that both species could be quite closely related but have important and consistent differences that support the distinctiveness of this new taxon. However, the most striking difference that was impossible to assess in the iNaturalist observations, but obvious at the natural habitat, is the sheer size of the plants. Whilst a few plants along the path resemble the typical upright and medium-sized habit of most species of Ser. Alatae (e. g. N. loxensis), some specimens found off the path in dense vegetation, were leaning on and climbing through the dense undergrowth (e. g. bamboo). These plants can grow several meters long until they reach open areas to present their flowers freely, which are then presumably visited and pollinated by hummingbirds. Another striking character unique to the new species are the conspicuous elongated sepals. Although sepal length is subject to a large variation in many species of Nasa and usually of moderate systematic value, the characteristic sepals found in Nasa katjae are exceptional. They are as long as the petals and, in some cases, even longer and the persistent calyx closes after flowering and shows a further elongation (Fig. 2 D). Whilst the function of the long calyx in fruiting remains unknown (possibly moisture regulation), the calyx lobes are visually striking during anthesis and greatly influence the floral display. They are initially nestled up to the petals and start spreading and bending out their apices with beginning anthesis, giving the flower an elegant, slightly bell-shaped appearance. The sepals (half-) spread in peak anthesis and bend back after the flower sheds and fruit development starts.
Etymology.
The new species is named after Katja Lohse, beloved partner of the first author, mother of their children and steady supporter of his scientific endeavors.
Distribution and ecology.
Nasa katjae has so far only been collected a few times. The type collection was made about 5 km north of Colasay (Cajamarca, Peru, Fig. 1 A). It grows only in, and at the edges of small streams in the highest part of this isolated forest fragment (Fig. 1 B – D). It is associated with the typical floristic elements in these “ bosques montanos húmedos ” such as Chusquea sp., Fuchsia sp., Vernonanthura sp., Saurauia sp., Miconia spp. and Viburnum sp. The forest in the uppermost regions is largely intact and only disturbed by small paths and some recent, small-scale clearings. However, the increasing negative impact of livestock farming is evident from the cattle tracks visible everywhere along the paths and already within the forest fragments.
The plants are adapted to the very dense vegetation by a flexible growth habit. In the few more open areas where the path crosses the streams, the plants grow upright and begin to flower at a height of 1 to 1.50 m. In the wettest parts, where the dense primary vegetation consists mainly of impenetrable bamboo thickets (Chusquea sp.), the plants continue to grow in length until they reach an open area to display their flowers. Although difficult to measure, some individuals easily reach a size of more than 4 m. The flowers are typical “ hummingbird-pollinated ” flowers thus having open space around them is vital for successful pollination. All Nasa species are protandrous and exhibit a thigmonastic stamen movement and staggered stamen maturation (Weigend et al. 2010; Henning and Weigend 2012). In the taxa pollinated by hummingbirds, this movement is reduced to a minimum both geometrically (i. e. the angle the stamens bend) and temporally (the number of moved stamens = pollen packets in time). N. katjae sp. nov. has erect petals (in contrast to spreading petals in insect-pollinated taxa), therefore the stamen hardly move towards the center, and the pollen dispersal is limited to a successive maturation and dehiscence of the anthers. This is a secondary adaptation to the unreliable visitation probability and the random and long distances hummingbirds transport the pollen (Henning et al. 2018). However, we could not observe any visits to the plants. Ripe fruits with full seed set were found.
The new species must be considered narrowly endemic to the overall area. It has been found twice at a spring area called “ Agua Fria ” which is the type locality. Only very recently, two new observations have come to our knowledge that, according to the locality-data on iNaturalist, have taken place some approximately 2.5 km further east. However, it is very likely that the species follows the streams downhill through the forest and inhabits suitable areas within the primary forest in all directions.
Phenology.
The known populations have been visited four times now by different people between February 2023 and March 2024. All visitors report flowering and fruiting plants, and it can be assumed that the plants flower throughout the year without a substantial break reflecting the constant climate and minor seasonal variation in temperature and precipitation in this wet montane forest.
Preliminary conservation status.
The forest near Colasay represents the southeasternmost part of a larger forest system that is often referred to as the “ Bosques Montanos de Jaén’ ’. A former protected area called “ Área de Conservación Municipal de Bosque de Huamantanga’ ’ was recently expanded to become the “ Área de Conservación Regional Páramos y Bosques Montanos de Jaén y Tabaconas ” (D. S. N ° 005-2021 - MINAM see https://www.gob.pe/institucion/sernanp/normas-legales/1896920-005-2021-minam, Fig. 1 A) and covers almost 32000 hectares of the north-western parts of this forest system in the districts of Sallique, Chontalí and San José del Alto. Unfortunately, the southern district of Colasay and the surrounding forests are not yet part of this protected area. Although large areas are still intact, recent deforestation and the expansion of agricultural land are threatening the forests at higher altitudes, which not only harbor great biodiversity, but also represent an important watershed whose streams are the main tributaries for a number of important river systems. There is no evidence that N. katjae is present in other parts of the larger forest system. Given the peculiar habitat preference and the lack of other collections or reports of the species, even in a wider area, N. katjae appears to be very narrowly endemic. It presumably only occurs along a small number of streams in a few remote spots in the south-eastern part of the forest system and seems isolated from the other parts by the steep topography and its adaptation to flowing water. The forest patch north of Colasay has an extension of approximately 25–30 km 2. It is only connected to the northwards running chain of forests in the west at lower altitudes that might represent a barrier for high-altitude taxa. The Extent of Occurrence (EOO) can thus be estimated as this single forest patch and the Area of Occupancy (AOO) is even smaller, and it appears possible that only a small number of populations exists at and near the type locality. Due to the visible expansion of agricultural activities from the lower towards the higher altitudes, the forest is being pushed back from all sides and is getting even more isolated from the other forests further north. Given these observations, the new species must be considered as Critically Endangered (CR) based on the criteria A 3 (conditions c and d) B 1 and B 2 (conditions a and b) according to the IUCN guidelines (2024). Unlike in N. loxensis and N. calycina comb. nov., we did not use Geocat to calculate the EOO and AOO for N. katjae. Since the whole forest only has the size of one grid cell (25 km 2) a comparison would be pointless and misleading. In fact, the de facto suitable habitat is much smaller, since only the uppermost parts of the forest appear moist enough.
description: Published as part of Henning, Tilo, Allen, Joshua P., Montesinos-Tubeé, Daniel, Rodríguez-Rodríguez, Eric F., Peña, José Luis Marcelo & Acuña-Castillo, Rafael, 2025, No end to endemism – contributions to the difficult Nasa Weigend Series Alatae (Loasaceae). A new species from Peru and the rehabilitation of " Loasa " calycina Benth., pp. 163-186 in PhytoKeys 252 on pages 163-186, DOI: 10.3897/phytokeys.252.141635