Danaea nasua Keskiniva & Tuomisto, 2024

Keskiniva, Venni & Tuomisto, Hanna, 2024, Danaea (Marattiaceae) keeps diversifying, part 1: eighteen new species, Willdenowia 53 (3), pp. 173-228 : 203-205

10. Danaea nasua Keskiniva & Tuomisto , sp. nov. (D. subg. Holodanaea) – Fig. 21.

Holotype: Ecuador, Carchi, trail between Coaiquer Amerindian communities San Marcos and San Antonio before Gualpi Bajo , 01°08'N, 78°22'W, 900–1000 m, 25 Nov 1983, Kvist 48941 ( AAU!; isotype: MO).

Diagnosis — Similar to Danaea humilis T. Moore but differing in caudate pinna apices (vs acute); largest lateral pinnae 2.2–2.4 times as long as wide without apex (vs 2.4–3.6 times); laminae rather concolorous (vs clearly bicolorous with abaxial side whitish).

Description — Rhizomes erect, leaves and root bases arranged radially, 0.5–1.2 cm in diam., to at least 13 cm long. Sterile leaves 23–38 cm long; petioles 6.0– 16 cm long, with 2 nodes, not winged; laminae 14–24 × 4.3–6.6 cm, parallel-sided, imparipinnate or possibly paripinnate, 13–20 pinna-pairs, medial pinnae 0.8–0.9 cm apart, concolorous to somewhat bicolorous, dark brownish green, texture thin, rachises winged in distal part of internodes in distal part of lamina, wings to 0.2 mm wide; terminal pinnae 2.2–5.8 × 0.6–0.9 cm, oblong or lanceolate, bases acute, apices 0.9–2.1 cm long, acuminate to caudate, margins of apices crenulate to serrulate; largest lateral pinnae 2.5–3.5 × 0.8–1.1 cm, 2.0–2.4 times as long as wide without apex, parallel-sided, perpendicular to rachises or slightly ascending, bases very asymmetrical (obtuse proximally, obtuse to acute distally), apices 0.5–0.8 cm long, short-caudate (to cuspidate), margins of apices serrulate at shoulder of pinna, crenulate at apex; veins 16–25 per cm, mostly simple, some forked at costa. Fertile leaves 38 cm long; petioles 24 cm long, 3 nodes; laminae c. 15 × 4 cm, parallel-sided, imparipinnate, 20 pinna-pairs; terminal pinnae c. 1.3 × 0.3 cm, lanceolate, bases acute; largest lateral pinnae c. 1.8 × 0.4 cm, oblong, slightly ascending, bases obtuse, apices mucronate. Juveniles not known.

Distribution and habitat — Known from three collections at the border of Ecuador (Carchi) and Colombia (Cauca), from 200–1000 m. Found growing in selectively logged forest and on hillsides in very wet forest. Fig. 8.

Conservation status — We place Danaea nasua in the Endangered (EN B1ab(iii)+2ab(iii)) category ( IUCN 2012). It has an Extent of occurrence of 503 km 2, an Area of occupancy of 12 km 2, and is known from only three locations, which correspond to the EN category. None of the collection localities are inside protected areas and one of them was mentioned to be under selective logging. The area, extent, and quality of suitable habitats were inferred to be suffering continuing decline from deforestation.

Etymology — Nasua is Latin for nose, referring to the short caudate pinna apices of this species.

Remarks — Danaea nasua is a small species endemic to Chocó. It has conspicuous drip tips typical of many species in wet climates, and these separate it from the similar D. chococola Christenh. , D. humilis , and D. pumila (described below), which have acute to acuminate rather than caudate (or cuspidate) apices. Like these species, D. nasua has parallel-sided laminae with many pairs of short, asymmetrical pinnae, but its pinnae are rounder (largest lateral pinnae 2.2–2.4 times as long as wide without apex vs 2.4–3.6 in D. humilis and even more in the other two relatives). In addition, D. nasua differs from D. humilis and D. pumila in having rather concolorous laminae (vs clearly bicolorous with abaxial side whitish) and from the concolorous D. chococola in that it dries to a dark, dull brownish green (vs dull green with a greyish sheen).

Danaea nasua is clearly smaller than the other species occurring in the same general area, namely D. tenuicaulis Tuomisto & Keskiniva, D. velona (described below), D. cuspidopsis (described above), and D. inaequilatera (sterile leaves <40 cm vs> 50 cm long, largest lateral sterile pinnae <4 cm vs> 6 cm long).

Additional specimens examined — COLOMBIA: CAUCA: San Juan de Micay valley , 200 m, 27 Dec 1946, Haught 5391 (US!) . — ECUADOR: CARCHI: border area between Prov. Carchi and Esmeraldas, about 20 km past Lita on road Lita-Alto Tambo , 550 m, 24 Jun 1991, van der Werff 11969 (MO!) .