Ctenitis submarginalis (Langsd. & Fisch.) Ching (1940: 250)

Viveros, Raquel Stauffer, Rouhan, Germinal & Salino, Alexandre, 2018, A taxonomic monograph of the fern genus Ctenitis (Dryopteridaceae) in South America, Phytotaxa 385 (1), pp. 448-450 : 448-450

23. Ctenitis submarginalis (Langsd. & Fisch.) Ching (1940: 250) . Polypodium submarginale Langsdorff & Fischer (1810: 12) . Dryopteris submarginalis (Langsd. & Fisch.) Christensen (1906: 296) . Type:— BRAZIL. Santa Catarina: Insula de Santa Catarina, Langsdorff s.n. (lectotype LE 00000006 [image!], designated here, isolectotypes LE 00000005 [image!], LE 00000007 [image!]).

Stems erect, ascending or short-creeping, 2.0– 5.5 cm diam., scales 10.0–30.0 × 0.5–1.5 mm, light castaneous, clathrate, lanceolate, entire or slightly denticulate, with or without some short fimbriae at base; leaves 70–175 cm

68 • Phytotaxa 335 (1) © 2018 Magnolia Press

VIVEROS ET AL.

long; petioles (20) 30–80 cm × 3.0– 5.5 mm, with 5 or 6 vascular bundles at base, stramineous or tan, scales 5.0–20.0 × 0.2–1.5 mm, light castaneous or castaneous, subclathrate or clathrate, tangled on petiole base, becoming patent or ascending towards distal portion, flattish, flaccid, linear or lanceolate with truncate or cordate base and filiform apex, entire or slightly denticulate, with or without some short fimbriae at base, catenate trichomes absent or sparse abaxially, glandular trichomes sparse; laminae 50–95 × 20–55 cm, width ca. 1/2 of lengh or wider, 1- pinnate-pinnatifid or 1-pinnate-pinnatisect basally, 1-pinnate-pinnatifid medially and apically, lanceolate or ovate, apex confluent; rachises stramineous, scales like those on distal portion of petioles, sparse catenate trichomes abaxially, sparse glandular trichomes; pinnae 15–25 pairs, the basal and medial ones stalked to 9 mm long, the apical ones sessile, basal pinnae basiscopically and acroscopically somewhat equally developed, the medial 10–30 × 1.5–5.0 cm, lanceolate, incised more than 3/4 of the distance between the segment apex and costa, basal segments shorter than the next at basal pinnae, but longer at the medial and apical pinnae, apex attenuate; adaxial pinnae axes with sparse scales on costa, 1.0–2.2 × 0.06 mm, light castaneous or castaneous, filiform, catenate trichomes, dense on costa, sparse on costule and veins, bacilliform trichomes absent; adaxial laminar surface between veins glabrous or with sparse catenate trichomes; abaxial pinnae axes with sparse scales on costa, 1.0–4.0 × 0.1–0.3 mm, light castaneous or castaneous, clathrate, ascending, mostly flattish, but can be vaulted at base, flaccid, lanceolate with cordate or rounded base and filiform apex, slightly denticulate, with some short fimbriae at base, proscales to 0.7 mm long sparse on costule, catenate trichomes absent or sparse on costa, costule and veins, bacilliform trichomes sparse on costa, costule and veins, glandular trichomes absent or sparse on costa, filiform trichomes absent; abaxial laminar surface between veins glabrous or with sparse catenate and bacilliform trichomes; segments 15–26 pairs, 4.0–8.0 mm wide, patent or subfalcate, entire or serrulate, apex apiculate, margin with catenate trichomes, the distance from each other is narrower than segments width; veins simple, rarely 1- forked basally, 8–15 pairs per segment, the basal ones from adjacent segments reach the margin at sinus, or somewhat or well above it; sori medial or supramedial, indusia absent, or small and inconspicuous or large and conspicuous, entire, with bacilliform trichomes; spores with coarse folds and large tubercles.

Notes:— Ctenitis submarginalis is the most widely distributed species of Ctenitis , occurring in different forest formations at wide elevation range. Unsurprisingly, this leads great morphological variation. Christensen (1913a) proposed six infraspecific taxa under this species, based on geographic ranges and characters too variable and uncorrelated, which easily overlap when examining many materials from all Neotropics. As pointed out by Tryon & Stolze (1991), the characters used to distinguish those infraspecific taxa were subtle differences on shape of segments and number of their veins, if the indusia are present or absent, the sori position and the abaxial laminar surface between veins glabrous or glandular-pubescent. However, these characters can be variable on a single lamina or overlap among specimens from different areas. A constant character, which proves useful, is the shape of scales on costa abaxially. Based on this, we recognize two varieties: C. submarginalis var. submarginalis and C. submarginalis var. tenuifolia . In both, there is a tuft of light castaneous scales on petiole bases, the basal veins from adjacent segments usually end at margin or somewhat above the sinus, rarely well above the sinus and the segment apex is apiculate.

In the protologue of Polypodium submarginale, Langsdorff & Fischer (1810) did not indicate any material, just the habitat (“in Insula St. Catharinae Brasiliae meridionalis”). In LE there are three sheets of original material, which are not clearly labeled as being part of a single specimen. Then, some authors attributed the type as being in LE (e.g. Mickel & Smith 2004), or even considered them as holotype (e.g. Tryon & Stolze 1991), unaware that there is more than one sheet. The authors who treated this species in their works have not seen those original materials ( Christensen 1913 a, Stolze 1981, Mickel & Beitel 1988, Tryon & Stolze 1991, Mickel & Smith 2004). During the visit in LE (by the first author), those materials could not be located, but the corresponding images available in Jstor Global Plants website (plants.jstor.org) in addition to the protologue enable us to consider those sheets as C. submarginalis var. submarginalis . Consequently, we propose the sheet LE 00000006 to be the lectotype, because it is likely the one used for the illustration of Polypodium submarginale ( Langsdorff & Fischer 1810, “tab. 13”).