Type. Colombia, Chocó, Istmia, Pepé, “cerca del río Peradó”, 1500 m, Fernández, García & Velayos 8515, 5 May 1990 (holotype, BM).
Sticherus species statura delicata, pinnibus longe-lanceolatis, indumento paginae abaxialis segmentorum ferrugineo. Aphlebiae subtiles, tripartitae, squamae
gemmorum basi induratae cellulis rotundatis, squamae costae stellatae margine ciliis induratis provisae.
Plants medium to large. Rhizome 2.5-3 mm thick, dark brown, deciduously scaly, the scales appressed, lanceolate, 3-4.5 x 1.5-2 mm, bicolorous, brown in the center with
clear margins, the margins weak or ciliate, cell texture stoutly grated-hyaline, more rigid in the scale center, basally with rounded cells. Petiole ca. 70 cm long and 3 mm
thick, dark brown, brittle. Rachis ca. 30 cm long between pinnae, subpaleaceus, aphlebiae long and narrowly trimerous. Fiddlehead ca. 6 mm in diameter, densely scaly, the scales appressed, dusty orange to brown, matted. Bud small, ascending, the
scales narrowly lanceolate to linear, 1.4-3.2 x 0.4-0.7 mm, ca. 12 cells wide at the base, bicolorous orange-dusty with darker bases, the margins with slightly curled with cilia 1/8-1/3 x the scale length, cell texture grated-hyaline to stoutly hyaline to rigid at the bases, the cells rectangular to irregular with dark and thicker cells walls, semiclathrate. Pinnae ca. 50-70 cm long, 2- to 3-forked, 1st axis shorter than the 2nd, 3-5 cm long and 2-2.5 mm thick, only with proximal internal, overlapping segments adjacent to the aphlebiae, 2nd axis ca. 8 cm long and 2 mm thick, when distal ca. 60 cm long, opposite axes of unequal length, partly or fully pectinate, 3rd axis ca. 50 cm long and 1.5 mm thick, pectinate-pinnatisect, 5-10 cm wide with segments, long lanceolate with overlapping proximal and internal segments, with 3 segments per cm;
adaxially scaly, the scales mixed, one type linear, basally hair-like, apically fringed, 0.8-1.8 x 0.05-0.1 mm, the second type square, 0.1-0.2 x 0.05-0.1 mm, the margins with numerous and straight with cilia 1-2 x the scale length, both scale types dark orange, cell texture grated-hyaline with linear to irregular cells; abaxially densely scaly, matted, the scales mixed, one type deciduous, arachnoid, appressed, the second type laterally arranged, spreading, linear lanceolate, apically fringed and/or glandular or extended to a long hair, 0.8-1.6 x 0.2-0.5 mm, the margins with cilia 1/4-1/2 x the scale length, both scale types dark orange to cinnamon, cell texture grated-hyaline, the cells square to irregular. Segments 3-5 x 2 mm, linear, apically pointed, the margins narrowly revolute and ciliate with arachnoid scales; adaxially glabrous;
abaxially sparsely scaly, the scales covering 20-35% of the leaf surface, arachnoid, 0.05-0.3 mm in diameter; veinlets thin, parallel, raised; midvein scales triangular to rhomboid, 0.2-0.4 x 0.1-0.2 mm, dark orange to cinnamon, the margins with thick
and straight cilia 1/2-1 x the scale length (thus looking star-shaped when seen
directly above the veins), cell texture grated-hyaline with well-defined irregular cells.
Fig. 12. Sticherus chocoensis J. Gonzales sp. nov., a) abaxial axis scales; b) bud scales, c1) midvein scales; c2) adaxial axis scales; d) arachnoid scales; Fernández, García & Velayos 8515 (holotype, BM).
Sori inframedial, restricted to the center of the segments, nested within arachnoid scales, 15-21 pairs per segment, 3-4 sporangia per sorus.
Distribution and ecology. In wet forest from sea level to 1500 m in western Colombia and adjacent Panama (Darién) and Ecuador (Esmeraldas), with a single record from Trinidad. Mostly grows in open situations, e.g., along roads, often on nutrient-deficient soils.
Sticherus chocoensis is a relatively delicate species with long-lanceolate and slender axes that is characterized by a completely orange-rusty indument, and star-shaped, marginally hard-ciliate midvein scales. The specimens of S. chocoensis were previously identified as S. bifidus, but S. chocoensis is characterized in having aphlebiae, bearing proximal internal segments on the 1st axes, in having overlapping segments on the distal axes, and in having grated-hyaline to basally rigid, strongly dusty to bicolorous bud scales. In contrast, S. bifidus lacks aphlebiae and internal proximal segments, has nonoverlapping segments, and has whitish, lax bud scales. In accordance with the harder scale texture, the marginal cilia in S. chocoensis are stouter and more widely spaced, while those of S. bifidus are much more delicate.
This is perhaps most readily visible on the midvein scales, which in S. chocoensis appear distinctly star-shaped while those of S. bifidus are diffuse and appear lanose.
Accordingly, both species can often be most easily distinguished by studying the abaxial midveins.
Sticherus chocoensis may also be confused with some specimens of S.
ferrugineus, specially those from Mexico, by the similar orange-dusty indument coloration. However, S. ferrugineus has generally more robust axes, longer, laxer scales with rectangular cells, and pinnatifid aphlebiae, whereas S. chocoensis has shorter scales with rounded cells, and trimerous aphlebiae. Other similar species are S. maritimus and S. tepuiensis. The scales of S. chocoensis resemble those of S.
maritimus in size and shape, but the latter species lacks the hardened cells that typically occur at the scale base in S. chocoensis. Sticherus tepuiensis, on the other hand, is much shorter, with shorter and usually completely rigid scales.
The only specimen of S. chocoensis with rhizomes shows very characteristic scales which are unique in the genus. They are rigid with dusty centers and whistish,
hyaline margins that are highly abraded. All other species of Sticherus have
concolorous or basally hyaline rhizome scales with usually well-preserved margins.