Sticherus antillensis J.Gonzales, 2011

Gonzales, Jasivia & Kessler, Michael, 2011, A synopsis of the Neotropical species of Sticherus (Gleicheniaceae), with descriptions of nine new species, Phytotaxa 31, pp. 1-54 : 16-18

Sticherus antillensis J.Gonzales , sp. nov. ( Fig. 8 )

Affinis Stichero lanoso, differt squamis rhachidis et costis laxioribus et pallidioribus, cellulis squamarum rhachidis rotundatis, marginibus ciliis longioribus et tenuioribus provisis.

Type: — DOMINICAN REPUBLIC. La Estrelleta: Sierra de Neiba , 31–34 km by road NNW of La Descubierta, 11–14 km N of Angel Felix, 1850–1900 m, 21 February 1983, Mickel 8748 (holotype NY!) .

Rhizomes (2–) 3–5 mm thick, dark orange to brown, densely to moderately scaly, the scales narrowly lanceolate, long acuminate, 3–6 × 0.4–0.8 mm, dark orange, the margins with thin setulae, cell texture semirigid with linear cells. Petioles 3–6 mm thick, castaneous. Rachises ca. 15–25 cm long between pinnae, paleaceous, scales pale orange to whitish or bicolorous with dark orange at the bases; aphlebiae simple or pinnatifid with a long central segment. Fiddleheads ca. 1.5 cm in diameter, densely scaly, the scales large, pale orange to bicolorous. Buds medium sized, the scales appressed, lanceolate with rounded bases, 1.5–2.0(3.0) × 0.4–0.6(1.0) mm, gradually bicolorous with dark orange bases and whitish margins, the margins always translucent with numerous, delicate, slightly curled cilia 1/5–1/8 times the scale length, translucent, with lattice-like cell texture, or with subrigid bases, the cells rectangular to narrowly hexagonal; the shape and size of the bud scales are quite consistent in a given plant. Pinnae 30–60 cm long, 3(–4)-forked, 1 st branch 6–11 cm long and 2.0– 2.5 mm thick, occasionally with scattered proximal internal segments adjacent to the aphlebiae, 2 nd branch (3.5–)6.0–15.0 cm long and 1.5–2.0 mm thick, opposite branches of unequal length, longer than the 1 st and ca. 1/3–1/2 times the length of the distal branch, pinnatifid, 3 rd branch 20–35 cm long and 1.0– 1.5 mm thick, deeply pinnatifid, (1.8) 2.5–4.5 mm wide with segments, with 2.5–3.0 segments per cm, proximal internal segments gradually reduced, not overlapping, fusiform to acerose; scales adaxially mixed, one type arachnoid, 0.2–0.8 × 0.2 mm, the second type linear, ca. 2 × 0.01 mm, whitish, usually with dark centers, cell texture translucent with rectangular-linear to irregular cells; abaxially moderately scaly, the scales lanceolate with rounded bases or narrowly lanceolate with shortened bases, 1–2 × 0.2–0.4(–0.5) mm, whitish to finely speckled orange, the margins with long, delicate and usually twisted cilia 1/4–1/2 times the scale length, cell texture translucent with square to long hexagonal cells forming a lattice-like cell structure. Segments (0.9–) 1.5–2.3 cm × 2.0– 2.5 mm, oblong to cylindrical, subchartaceous, the margins flat to narrowly revolute; adaxially glabrous; abaxially with parallel, thick and raised veinlets, these conspicuous despite being covered by scales; veinlet scales arachnoid, ca. 0.4 × 0.1 mm; midvein scales dense, narrowly lanceolate to rectangular, apically fringed, 0.4–0.6(–1.0) × 0.1–0.2 mm, whitish, the margins with long, twisted cilia 1/2–1 times the scale length, translucent with rectangular to irregular cells. Sori inframedial, restricted to the segment center, nested within arachnoid scales, 8–16 pairs per segment, 3–4 sporangia per sorus.

Distribution and ecology:— A common species in humid montane forests, at 900–2800 m in the Dominican Republic, and less common in Haiti, Cuba, and Jamaica.

Specimens examined (paratypes):— CUBA. Santiago de Cuba: Pico Turquino, 1800 m, 1915?, Ekman 5441 ( US); Sierra Maestra between Pico Turquino and La Bayamesa, 1350 m, 27–28 October 1941, Morton 3671 pp ( US) . JAMAICA. Portland: Port Antonio, Marmelade, near Ginger House , 150 m, 26 December 1966, Gastony 42 pp ( BM) . HAITI. Sud: Massif de La Selle, 1500 m, 13 February 1925, Ekman 3229 ( S, US); Massif de La Hotte , Morne l'Etang , 1400 m, 21 July 1928, Ekman 10364 ( BM, NY, S, US) . DOMINICAN REPUBLIC. Barahona: Sierra de Bahoruco, 1300 m, 15 February 1982, Mickel 8064 ( NY); Sierra de Bahoruco, Loma Remigio , 18°04’N 71°12’W, 1150–1290 m, 24 March 1990, Zanoni 44214 ( NY). Estrelleta: Sierra de Neiba , Km 204 , 18°41’N 71°47’W, 1850 m, 15 July 1988, Zanoni 39991 ( NY). La Vega: La Nevera, road San Jose de Ocoa – Constanza, 2040 m, 22 February 1982, Mickel 8313 ( NY); 5–5.4 km W of la Culata de Constanza , 1500–1525 m, 23 February 1982, Mickel 8366 ( NY); La Golondriana , 19°03’N 70°34’W, 1100 m, 13 April 1982, Zanoni 20005 ( NY). Peravia: La Nuez , 18°40’N 70°35’W, 1800 m, 7 July 1982, Zanoni 21401 ( NY). Sabaneta: Laguna de Cenobí , 20 August 1929, Valeur 50 ( US) .

Notes: — Sticherus antillensis is closely related to S. lanosus but differs in having laxer, paler branch and midvein scales, narrower and shorter segments, more rounded cells of the branch scales, and less rigid scale margins with longer, delicate cilia. Sticherus antillensis frequently has different segment lengths on branches of different order on the same plant, with long segments on the 1 st branches and shorter segments on the distal branches. In S. lanosus (and S. tomentosus ) the segment length is more constant on a given plant. The two species occupy disjunct ranges.

Most specimens of S. antillensis were formerly identified as S. ferrugineus in herbaria because of the presence in both of aphlebiae and lax, translucent midvein scales. However, the relationship between these ferns is probably not very close. Sticherus antillensis is readily distinguished from S. ferrugineus by the much larger, basally partly rigid bud scales with shorter, more densely packed cells, thicker branches, shorter, more ovate segments, and abaxially parallel, thick, and raised veinlets. In most cases, S. antillensis can be easily recognized by the much longer 2 nd branches (relative to the 1 st branches) and shorter segments. Specimens from Cuba have a more reddish indument than those from Hispaniola; more collections are needed to evaluate the geographical variation in this species.

Figures

FIGURE 8. Sticherus antillensis. A. abaxial branch scales; B. bud scales; C. detail of the bud scale margin; D. midvein scales. Mickel 8748. Scale bars in A–C are all 1 mm long.