Nasa calycina (Benth.) R. H. Acuña & T. Henning 2025

Nasa calycina (Benth.) R. H. Acuña & T. Henning View in CoL comb. nov.

Basionym.

Loasa calycina Benth. , Pl. Hartw. [Bentham]: 132. 1844.

Holotype.

Ecuador • [Prov. Loja] Mountains near Loxa , July [1841], C. T. Hartweg s. n. (Holotype: K barcode K 000372874 !)

Description.

Plants to ca. 1 meter tall, covered with scabrid, glochidiate and stinging trichomes, glandular trichomes inconspicuous or absent. Stems erect, cylindrical to ca. 1 cm diam. Leaves opposite, petiolate, petiole 2–4 cm, leaf blades pinnately veined, 6–15 × (2 –) 3–7 cm, narrowly ovoid to ovoid or triangular, with 4–8 lobes per side, in some leaves shallow and poorly defined, triangular, from wider than long to longer than wide, apices acute, the largest of a leaf 0.5–2.5 × 0.5–2 cm, the second or third usually the largest, becoming progressively smaller apically, margins serrate, each tooth with a hydatode, base cuneate, rounded or truncate, apex acuminate. Inflorescence a monochasial or dichasial cyme, 10–50 cm long, bracts alternate, one per flower, usually shorter and proportionally much narrower than the vegetative leaves, elliptical, 1.5–4 × 0.3–0.7 cm, diminishing in length, and particularly width, towards the inflorescence apex. with 4–7, broadly triangular, shallow, often indistinct lobes, base cuneate to rounded. Pedicels 1.5–2.5 cm long in anthesis, straight, often horizontal but ranging between 45 ° above or below the horizontal, the apex deflexed. Flowers deflexed, 3–6 per inflorescence branch. Sepals 5, narrowly triangular or ovate, apex acuminate, yellowish-green, 1.2–2 × 0.5–0.7 cm, with 3 main veins, as long or slightly shorter than the petals. Petals 5, orange red to carmine, shallowly cymbiform, oblanceolate, base narrower than the limb but claw short and poorly differentiated (to 4 mm wide), 1.5–2 × 0.6–1 cm, with 3 evident main veins, tip rounded or obtuse, basal gaps between petals leave the scale bases visible (gaps often not visible because they are either very small or hidden by the sepals), corolla more or less cylindrical, as wide basally as distally. Nectar scales 5, orange or red, 10 mm long and 3 mm wide at base, with 2 distinct, broadly ovoid, seemingly smooth (when fresh) nectar sacs at the base, each one as wide as the nectar scale back (ca. 2.5 mm in diameter), nectar scale back rectangular, narrow, 5.5 × 2 mm, straight, surface papillose, with 0, 2 or 3 short filiform threads, inserted subapically, <1 mm long and with two horizontal wings, 3–4 × 1.5 mm. Staminodes 2 per scale, to 14 mm long, slightly sigmoid, narrowing apically, base papillose, apex filiform. Stamens in 5 antepetalous fascicles with 8–10 each, filaments to 12 mm long, anthers 1 × 0.5 mm, elliptical, cream before dehiscence, whitish when shedding pollen, black after pollen is shed. Ovary broadly conical to hemispherical, with a rounded base, ca. 5–6 × 5–6 mm, with 3 parietal placentae. Stigma lobes 3, shortly decurrent on the style surface, style to ca. 15 mm long. Fruit a broadly clavate to conical capsule on an erect pedicel, 3.5–5 cm long, with persistent sepals and a shortly tapering base, mature capsule 20–30 × 10–12 mm (width at sepal insertion), including an elongated conical apical projection, opening by the three apically dehiscing valves. Seeds not seen.

Notes.

Loasa calycina has been considered a synonym of Nasa loxensis since at least 1996 ( Weigend 1996; Jørgensen and León-Yánez 1999). The most important differences between both species are evident in the proportions of the calyx and corolla elements with N. calycina having proportionally longer sepals, ca. ≥ 75 % as long as the petals, while N. loxensis has sepals that are less than half the length of the petals (Table 2 View Table 2 , Fig. 3 View Figure 3 ). Also, the corolla in living anthetic flowers has a different shape in both species, as in N. calycina petals are arranged in a cylindrical shape with a proportionally wide corolla opening, while in N. loxensis the corolla tapers gradually, so distally the corolla is narrower than basally, with the petals leaving a very narrow opening (Fig. 3 A, B View Figure 3 ).

In the latest and most authoritative treatment of Loasaceae of Ecuador, Weigend (2000 b) discussed briefly the significant morphological variability of his broad concept of Nasa loxensis . But he recommended maintaining it until either more specimens from areas became available or it became clear that few or no additional specimens were known.

Weigend (2000 b) acknowledged the differences in floral proportions of some specimens from Loja (that we consider fit well under the concept of Loasa calycina of Bentham) from those of Azuay (e. g. near Cuenca and Cajas National Park) that conform better to Kunth’s concept of Loasa loxensis . However, it is important to note that the type material of both Nasa loxensis and Nasa calycina come from near the city of Loja, where still today plants that adjust very closely to these specimens grow. The wider availability of more specimens in the mosaic of habitats (from pretty much pristine to significantly anthropogenically modified) around the city of Loja, and further north, along with photographs of living plants in platforms like iNaturalist have allowed us to confirm the relatively modest but seemingly consistent morphological differences between Nasa loxensis and N. calycina . The lack of florally intermediate specimens in possible areas of contact near Loja suggests that hybridisation is so infrequent, that truly intermediate specimens have not been recorded so far. From the specimens and photographs available we know that both species approach each other but appear to be sympatric in only one locality, between La Argelia and La Palma, SW of the city of Loja, and no evident intermediates in floral characters have been observed. Living plants that fit closely Hartweg’s type material of Loasa calycina have been collected most frequently from what is now Podocarpus National Park

GenBank accessions AY 285722.1, MK 333044.1, MK 333010.1, MK 332976.1, MK 332944.1 and AY 769214.1 identified as belonging to Nasa loxensis and used in the studies of Weigend et al. (2004), Weigend and Gottschling (2006) and Acuña-Castillo et al. (2019, 2021) belong to Nasa calycina (voucher: J. R. Grant & L. Struwe 01-4063).

Specimens examined.

Ecuador. Loja • Carretera Loja-Yangana, desvío al Parque Nacional Podocarpus, E del Nudo de Cajanuma , 2880–3000 m, 14 March 1989, A. Freire-Fierro 1323 ( GB, QCA) • Parque Nacional Podocarpus, E of Nudo de Cajanuma, hectare plot near “ Centro de información ” , c. 2900 m, 15 April 1989, B. Eriksen 91176 ( QCA) • Parque Nacional Podocarpus sector Cajanuma , 2900 m, 30 June 1996, P. Lozano 449 (Loja) • Cajanuma , 21 February 1985, F. Vivar 2310 (Loja) • Parque Nacional Podocarpus, above Nudo de Cajanuma , 2800–3000 m, 14–15 May 1988, B. Øllgaard et al. 74090 ( AAU, Loja) • Parque Nacional Podocarpus, S of Loja, wet montane forest at the “ Centro de Información ”, E of Nudo de Cajanuma, 2850– 1950 m, 21–22 February 1985, B. Øllgaard et al. 57847 ( AAU, Loja) • Cajanuma , 04°06'24"S, 79°11'22"W, 2600 m, 31 January 2002, P. Lozano et al. E- 600 (Loja) GoogleMaps • Entrada a Cajanuma, sendero a las Lagunas , 3100 m, 11 June 2002, P. Lozano et al. E- 1650 (Loja) • Uritushinga , 2800 m, 14 February 1978, F. Vivar 898 (Loja) • Sitio Ventanas, Cordillera Oriental, Or. Loja , ca. 2400 m, 27 December 1947, R. Espinosa & A. Espinosa 2279 (Loja) • Road La Argelia (southern Loja) - La Palma , along crest of mountain range just SW of Loja, 2700–2950 m, 4 March 1989, B. Øllgaard et al. 90792 ( AAU, Loja) • Zamora-Chinchipe: Parque Nacional Podocarpus (San Francisco entrance); trail leading west from San Francisco , 03°59'24"S, 079°05'48"W, 2100 m, 16 February 2001; J. R. Grant & L. Struwe 01-4063 with C. Rosales (Loja, QCA) GoogleMaps • Área del Parque Nacional Podocarpus, Cajanuma, rotundamente “ El Mirador ”, 3000 m, s. d., Rbu & SL 107 ( QCA) .

Photographic evidence (iNaturalist): ( Note : due to Nasa loxensis s. l. being considered threatened by the IUCN, it was not possible to obtain the precise locality of some observations): Ecuador. Loja • - 4.113259, - 79.174943, April 2024, Daniel Arias-Cruzatty, http://www.inaturalist.org/observations/2057414 GoogleMaps • April 2022, Lilia Cueva Cueva, http://www.inaturalist.org/observations/114005635 • December 2020, prengelv, http://www.inaturalist.org/observations/67754076 • Parque Nacional Podocarpus, Cajanuma, sendero a las Lagunas del Compadre , cerca del páramo, December 2020, Angel Hualpa Erazo http://www.inaturalist.org/observations/67015645 • Parque Nacional Podocarpus, Cajanuma , December 2020, Amarú Ramóm Salcedo, http://www.inaturalist.org/observations/66984658 • 04°07'3.34"S, 079°09'53.21"W, 3088 m, February 2017, dennisronsse, http://www.inaturalist.org/observations/37683383 GoogleMaps • Near Cajanuma Refuge , September 2007, Ruth Ripley, http://www.inaturalist.org/observations/35868409 • ditto, http://www.inaturalist.org/observations/35868095 • ditto, http://www.inaturalist.org/observations/34983697 • ditto, http://www.inaturalist.org/observations/34981561 • Cerca del Refugio Cajanuma , - 4.115681 - 79.171616, February 2019, Bodo Nuñez Oberg, http://www.inaturalist.org/observations/20486169 GoogleMaps • Cajanuma Field Station, and trail to Mirador , 04°06'45"S, 079°10'37"W, December 2007, Jason Grant, http://www.inaturalist.org/observations/20486169 GoogleMaps .

Distribution.

Nasa calycina is endemic to Loja and Zamora-Chinchipe (Fig. 1 View Figure 1 ), mostly known from areas near or within Podocarpus National Park (mostly around the Cajanuma sector), where Nasa loxensis is missing. There is a single record between La Argelia and La Palma in an unprotected area where it seems to meet the southernmost range of Nasa loxensis . Further south in Loja (and reaching Piura, Peru), both taxa seem to be replaced by Nasa amaluzensis , a species that is florally quite close to Nasa calycina but differs significantly in leaf morphology.

Phenology.

Flowering has been recorded during September and mostly from December to July.

Tentative conservation assessment.

The known range of Nasa calycina is diminutive, but most of the populations of the species appear to be protected within the Podocarpus National Park, where it is frequently encountered in the Cajanuma sector. We still recommend considering this species as EN B 2 abiii, due to a reduced AOO (125 km 2), the reduced number of known locations where the species can be found (only four) and the inferred decline of habitat quality where the only known population not found within or in the immediate vicinity of Podocarpus National Park grows.