Danaea velona Keskiniva & Tuomisto, 2024

Keskiniva, Venni & Tuomisto, Hanna, 2024, Danaea (Marattiaceae) keeps diversifying, part 1: eighteen new species, Willdenowia 53 (3), pp. 173-228 : 223-226

18. Danaea velona Keskiniva & Tuomisto , sp. nov. (D. subg. Holodanaea) – Fig. 34, 35.

Holotype: Colombia, Caldas, 05°15'N 76°06'W, 1500 m, 7 Feb 2015, Kessler 14808 ( HUA! (201795); isotype: TUR!).

Diagnosis — Similar to Danaea tenuicaulis Tuomisto & Keskiniva , but differing in longer laminae (c. 47 cm vs 23–43 cm) and more pinna-pairs (16–19 vs 9–12). Danaea velona has unique caudate, very long and narrow (c. 2.3 × 0.1 cm) pinna apices whose margins are mostly entire but very tip and shoulder of pinna are crenulate to serrate. Genetically unique among Danaea in having a T (vs A or T) at position 631 of rpl32 reference sequence. Differs from all other species of D. subg. Holodanaea by having a T (vs C) at position 264 and an A (vs G or T) at position 867 of rpl32 reference sequence.

Description — Rhizomes radial, creeping, 1 cm in diam., at least to 20 cm long, leaf and root bases 1.5–4.0 cm apart. Sterile leaves 77 cm long; petioles 31–34 cm long, with 1–2 nodes, not winged; laminae 47–48 × 16– 20 cm, linear lanceolate, imparipinnate, 16–19 pinnapairs, medial pinnae 1.8–2 cm apart, bicolorous, dark green adaxially, light green abaxially when fresh, dries almost concolorous green, laminar texture thin, rachises winged distally, wings to 1 mm wide; terminal pinnae 7.4–9.3 × 1.3–1.6 cm, oblong, bases acute, apices caudate with narrow part 2.8–5.2 cm long, margins of apices crenulate at tip, serrate at shoulder of pinna, entire in between; largest lateral pinnae c. 10 × 2 cm, 2.8–3.9 times as long as wide without apex, parallel-sided, slightly ascending, bases asymmetrical (obtuse proximally, concave distally), apices caudate with narrow part 2.3 cm long, spathulate, margins of apices crenulate at tip, serrate to crenulate at shoulder of pinna, entire in between; veins 19 per cm, mostly simple. Fertile leaves not known. Juveniles not known.

Distribution and habitat — Only one specimen is known from a montane forest in the Pacific coast of Colombia (Caldas), from 1500 m. Fig. 8.

Conservation status — We place Danaea velona in the Critically Endangered (CR B1ab(iii)+2ab(iii)) ( IUCN 2012). It is only known from a single specimen, which suggests it is rare and endemic to a small area. The type was collected at a roadside outside of protected areas, and the area, extent and quality of the habitat were inferred to be in continuing decline from deforestation. Etymology — Velona is a Greek word for needle, referring to the long-caudate pinna apices of this species.

Remarks — Danaea velona is similar in rhizome and pinna shape to D. tenuicaulis , having caudate pinna apices and leaf and root bases to 4 cm apart. It differs in having more pinna-pairs (16–19 vs 9–12) that are more densely packed (c. 2 cm vs 2.3–4.0 cm apart) on longer laminae (c. 47 cm vs 23–43 cm long). Danaea velona has unique long-caudate pinna apices that have serrations at the tip and at the shoulder of the pinnae but are entire in the middle (vs serrate to crenate all the way in D. tenuicaulis ).

Danaea velona is genetically most closely related to D. vanderwerffii , D. robbinmoranii , D. bicolor Tuomisto & R. C. Moran and D. tenera . It differs from these species in having rhizomes with widely spaced leaf and root bases (vs more densely packed) and leaves with generally more pinna-pairs (16–19 vs 10–13 in D. vanderwerffii , 7–16 in D. robbinmoranii , 12–17 in D. tenera , and 3–6 in D. bicolor ). Danaea tenera is a translucent species (vs opaque) that has deeply serrate pinna apices and usually has the terminal pinnae replaced by a bud (vs terminal pinnae present). Danaea robbinmoranii has pinna apices that are serrate throughout, and its pinnae are more widely spaced (2.9–3.5 apart vs 2 cm apart). Danaea velona has a narrower terminal pinnae than D. bicolor and D. vanderwerffii (c. 1.3 cm wide vs 2.0–5.0 cm in D. vanderwerffii and 3.2–5.0 cm in D. bicolor ). In addition, D. vanderwerffii has very reduced proximal pinnae (vs proximal pinnae more than half the length of largest lateral pinnae in D. velona ).

Danaea velona differs from D. cuspidopsis in having abruptly caudate pinna apices (vs acuminate) that are longer and partly entire (vs serrate throughout), and creeping rhizomes (vs erect) with leaf and root bases to 4 cm apart (vs 0.5–1.5 cm apart).