Danaea ampla Keskiniva & Tuomisto, 2024

Keskiniva, Venni & Tuomisto, Hanna, 2024, Danaea (Marattiaceae) keeps diversifying, part 1: eighteen new species, Willdenowia 53 (3), pp. 173-228 : 177-180

2. Danaea ampla Keskiniva & Tuomisto , sp. nov. (D.

subg. Danaea ) – Fig. 4, 5.

Holotype: Panama, Panamá, Barro Colorado Island , close to NE corner of 50-ha plot , 09°09'N, 79°51'W, 100–150 m, 23 Oct 2005, Tuomisto 15151 ( PMA! (mounted on 2 sheets: 121546 & 121547); isotypes: TUR! (mounted on 3 sheets), UC! (mounted on 2 sheets)) .

Diagnosis — Similar to Danaea nodosa (L.) Sm., but differs in usually fewer pairs of fertile pinnae (4–7 vs (6–)8–16); generally shorter and wider sterile pinnae (medial pinnae 2–6 vs 4–8 times as long as wide without apex); usually oblanceolate pinnae (vs usually oblong); genetically differs in locations 123 (G vs A), 282 (A vs G), 453 (G vs T) of trnL-F reference sequence; 621 (T vs C), 637–639 (gap vs AAA), 642 (A vs C), 673 (A vs G) of rpl32 reference sequence.

Description — Rhizomes creeping, dorsiventral, 2–5 cm in diam., leaf bases in two rows, to 15 cm long. Ster- ile leaves 56–150 cm long; petioles 26–68 cm long, no nodes, not winged; laminae 29 × 73 cm, (long-)obovate, lanceolate or oblong, imparipinnate, 4–13 pinna-pairs, medial pinnae 4.0–5.0 cm apart, concolorous, light yel- lowish grey green to green, texture thin to intermediate (border slightly thicker), rachises usually not winged or only winged in distal part of lamina, wings to 1 mm wide; terminal pinnae 14–24 × 3.4–5.0 cm, oblong, elliptic or lanceolate, bases acute, apices 2–4.5 cm long, (long-)acuminate, margins of apices slightly to very sinuate; largest lateral pinnae 14–26 × 3.1–4.9 cm, 2.4–5.6 times as long as wide without apex, parallel-sided or widest above middle, pinna apices symmetrical (acute) or asymmetrical (obtuse proximally, acute distally), apices 1.3–4.1 cm long, (long-)acuminate (rarely cuspidate or caudate), margins of apices entire to clearly sinuate (rarely serru- late at shoulder of pinna); veins 10–15 per cm, mostly forked at costae, sometimes above. Fertile leaves 69–117 cm long; petioles 41–67 cm long, no nodes; laminae 28– 50 × 17–21 cm, (long-)obovate to lanceolate, imparipin- nate, 4–7 pinna-pairs; terminal pinnae 9–12 × 1.3–2.2 cm, lanceolate, bases acute, apices acuminate to cuneate; largest lateral pinnae 11–18 × 1.4–2.1 cm, long-elliptic, parallel-sided or lanceolate, bases symmetrical (acute to cuneate) or asymmetrical (obtuse proximally, acute distally), apices 1.0– 2.5 cm long, acuminate to cuneate, margins of apices entire. Juveniles with elliptic, oblanceolate or oblong pinnae, rather wide, largest simple juvenile 7.5 cm long, smallest observed pinnate juvenile 5 cm long.

Distribution and habitat — Danaea ampla is known with certainty (based on DNA evidence) from Panama and Mexico but probably also occurs in the countries in between. It has been found in moist lowland forests up to 182 m elevation, sometimes at the edge of a creek. Fig. 3.

Conservation status — We place Danaea ampla in the Least Concern (LC) category ( IUCN 2012). It has an Area of occupancy of 28 km 2, which corresponds to the EN category, and an Extent of occurrence of 290,615 km 2, which corresponds to the LC category. Danaea ampla is known from at least 10 collections, most of them from protected areas (Los Tuxtlas biological field station in Mexico, Barro Colorado Island, Parque Nacional de Isla Coiba, and Parque Nacional Soberanía in Panama) and there appears to be no imminent threat to all its subpopulations.

Etymology — Ampla is a Latin word for wide, referring to the generally wider, shorter pinnae of Danaea ampla in comparison to D. nodosa , from which it was separated.

Remarks — Danaea ampla is a relatively small species in D. subg. Danaea . It is similar to D. nodosa but has generally shorter and wider pinnae (medial pinnae 2–6 vs 4–8 times as long as wide without apex) that are usually oblanceolate (vs usually oblong). Most remarkably, fertile leaves of D. ampla have only 4–7 pinna-pairs (vs (6–) 8–16 in D. nodosa ), and the sterile leaves also have generally fewer pinnae (4–13 vs (6–)10–16). Unfortunately, the morphological characters overlap between D. ampla and D. nodosa , and there are cases where DNA is needed for certain identification. We have sequenced specimens of D. ampla from both Mexico and Panama, so it can be assumed that some of the existing specimens from the intervening areas belong to this species, but we have not been able to identify any with confidence.

Danaea ampla co-occurs in Panama with D. panamensis (described below) and D. leussinkiana , but it has a thinner lamina texture and dries light yellow-green (vs blue-green and usually dark). In addition, D. ampla has generally fewer pinna-pairs than D. panamensis (4–13 vs 9–16) and the pinnae are broader (2–6 vs 6–12 times as long as wide without apex) and oblanceolate (vs oblong). Danaea ampla differs from D. leussinkiana in having rhizomes with leaf bases in two rows (vs 3–5 rows), generally longer pinna apices (1.3–4.1 cm vs 0.9–1.5 cm long) and broader pinnae (2–6 vs 5–7 times as long as wide without apex).

Danaea ampla differs from D. pterorachis Christ in having rhizomes with leaf bases in two rows (vs 3–5 rows), having no nodes on the petioles (vs petioles often with 1 or 2 nodes, especially in juveniles), and having generally broader pinnae (2–6 vs 5–8 times as long as wide without apex) that are oblanceolate (vs oblong).

See Danaea alba (described above) for comparison with that species.

An earlier interpretation of the types by H. Tuomisto and M. Christenhusz (cited in Mickel & Smith 2004), led to considering D. elata Liebm. (type from Mexico) and D. pterorachis Christ (type from Costa Rica) as synonyms of D. media Liebm. (type from Mexico) but distinct from D. nodosa (type from the Greater Antilles). Accordingly, Christenhusz (2010) assigned most Central American material that had previously been identified as D. nodosa to D. media . We considered these names carefully before deciding to describe D. ampla as a new species. We agree that the type specimens of D. media (Liebmann 653, 654, 849 and 850 in C and P00251865 in P) are conspecific with the type of D. elata Liebm. (Liebmann 848 in C): the specimens were collected in the same population ( Liebmann 1849: 306), and we find it obvious that D. media represents the juvenile stage of D. elata . These specimens have a rather similar general appearance to material from La Selva Biological station in Costa Rica: the type of D. elata shares the narrow pinnae and some of the syntypes of D. media apparently have nodes on the petioles (which are common in specimens from La Selva but absent in true D. nodosa ). However, our scrutiny of the D. elata / media type material suggests that they actually do not have nodes on the petiole; the naked nodes on the juvenile specimens look like they used to have pinnae that have at some stage fallen off. In addition, the D. elata / media material has rhizomes with leaf bases in two rows rather than in 3–5 rows as in the La Selva material. On this basis, we conclude that the La Selva material is not conspecific with D. elata / media but can instead be assigned to D. pterorachis , which we hereby lift from synonymy and consider a distinct species. The Mexican sequenced material that morphologically resembles D. nodosa falls into two clades, one of which also contains true D. nodosa from the Greater Antilles ( Keskiniva & al. 2024). Although none of the Mexican sequenced material comes from the type locality of D. elata / media , the large number and narrow shape of pinnae in the type of D. elata conform with D. nodosa rather than with the smaller number and broader shape of pinnae of specimens in the other clade. On this basis, we consider D. elata and D. media to be synonyms of D. nodosa and give the material of the other clade the new name D. ampla . Since D. media has original material in two herbaria but has apparently not been lectotypified, we do so here: the lectotype is Liebmann 653 (C) and the other specimens with the same collecting locality and date information become isolectotypes (Liebmann 654, 849 and 850 in C and P00251865 in P).

Additional specimens examined — MEXICO: VERACRUZ: Los Tuxtlas biological field station, 18°35'N, 95°04'W, 100–150 m, 29 Jun 2017, Tuomisto 17491 (TUR! (6), UC-3!, XAL-4, Z-3!); Los Tuxtlas biological field station, 18°35'N, 95°04'W, 100–150 m, 29 Jun 2017, Tuomisto 17494 (TUR-2!, XAL-3). — PANAMA: PANAMÁ: Barro Colorado, behind Casa Amarilla, 1977, Béliz 71 (PMA!); San José Island, Perlas Archipelago, Gulf of Panama, (about 55 miles SSE of Balboa), 1944, Johnson 263 (GH!); Parque Nacional Soberanía, at P16, 09°08'N, 79°43'W, 182 m, 2 Apr 2008, Jones 986 (TUR!, US-2!); Canal Zone, Parque Nacional Soberania, Camino del Oleoducto, on banks of Río Limbo, 1980, Vásquez 246 (PMA!); VERAGUAS: Distr. De Montijo. Isla Coiba, Río Escondido, 1995, Araúz 287 (PMA!); Distr. De Montijo. Isla Coiba, Playa Hermosa, ascending to La Falla, 1996, Araúz 637 (PMA!); Distr. De Montijo, Isla Coiba, N of island, Yuma trail, 07°35'N, 81°43'W, 30 m, 1995, Galdames 2168 (PMA!).