Adiantum alan-smithii R.Y.Hirai, Sundue & J.Prado
Descripción
Rhizomes ca. 5 mm diam, moderately slender, short-creeping to suberect, compact, dark brown, scaly, the scales 1.4 X 0.2 mm, lanceolate, castaneous, concolorous, shiny, basifixed, apices acuminate, margins entire. Fronds closely spaced (1–3 mm apart), arching; stipes 5–7.5 cm 0.5–1.0 mm, 1/4–1/3 the frond length, castaneous to dark brown, lustrous, glabrous, with a few scales at the base similar in morphology to those of the rhizomes; rachis slightly flexuous, castaneous to dark brown, glabrous; laminae herbaceous, 12.5–16.0 X 6.2–10.2 cm, lanceolate to ovate-lanceolate, 2 or 3-pinnate proximally, 1 or 2-pinnate distally; pinnae 5–8 pairs, stalked, the stalks of the proximal pinna pair 2.5–4.0 mm long, apices gradually reduced, alternate; proximal acroscopic pinnule of each pinna often overlapping the main rachis; ultimate segments 0.9–2.2 X 0.7–1.6 cm, stalked, the stalk 2.5–3.5(–4.0) mm, non-articulate, with dark color passing into the pinnule bases, obovate to flabellate, cuneate to truncate at base, apices rounded, sometimes deeply incised, sterile margins lobed to slightly denticulate, abaxially and adaxially glabrous; veins free, forking, ending in the sinuses between marginal teeth; silicified fiber-like cells present, obscured by veins and inconspicuous; sori (2–)4–10 per pinnule, confined to the distal margins of the segments; indusia 1.0–2.0 mm wide, orbicular to reniform with deep sinuses, yellow-farinose, the farina deposited on the abaxial surface among the sporangia.A
Forma de vida
TerrestreA
Ejemplar revisado
Chis (San Fernan, localidad 2 km al NE del ejido La Pimienta, brecha del ejido La Pimienta a la cañada El Mojón del Diablo, 17° 00´ 25.57´´ N, 93° 14´ 13.92´´W, 5 Oct 2009, A. López C. 941 (MEXU, MO); Tuxtla Gutiérrez, at El Sumidero, 22 km north of Tuxtla Gutiérrez, 1,350 m, 1 Nov 1971, D. E. Breedlove & A. R. Smith 21589(DS).A
Distribución
México (país): Chiapas EndémicoA
Elevación
800 – 1350 mA
Tipo de vegetación
Selva alta, Selva medianaA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
This species differs from Adiantum raddianum by the presence of yellow-farinose indusia and the proximal, acroscopic pinnule of each pinna often overlapping the main rachis. It differs from A. poiretii by having orbicular to reniform indusia.
Adiantum alan-smithii is easily recognized when fertile by its yellow-farinose indusia. It is also distinct by having laminae with 5–8 pairs of pinnae, the proximal acroscopic pinnule of each pinna often overlapping the main rachis, the segments mostly broadly flabellate, the stalk non-articulate with its dark color passing into the pinnule bases, and the rachis ± flexuous toward the tip. By comparison, A. raddianum has non-farinose indusia and proximal acroscopic pinnules that do not overlap the main rachis. Adiantum poiretii also has yellow-farinose indusia, but has oblong to lunate sori and ciliate rhizome scales.
Thirty-five species of Adiantum have been recognized in Mexico, including fiveendemics (A. amblyopteridium Mickel & Beitel, A. galeottianum Hook., A. mcvaughii Mickel & Beitel, A. oaxacanum Mickel & Beitel, and A. shepherdii Hook.) (Mickel and Smith 2004). Our new species, A. alan-smithii, brings the number of endemic Mexican species to six, and the total number of species known from Mexico to 36. Adiantumalan-smithii was previously treated as A. raddianum by Smith (1981) and Mickel and Smith (2004), who applied the name broadly. With recognition of A. alan-smithii, we are aware of no remaining records of A. raddianum from Chiapas. This conclusion is based on the previous revision of Mexican collections by Smith (1981), Mickel and Smith (2004), our revision of material on loan from B, K, MEXU, MO, NY, P, S, UC, and US. Giventhat Adiantum raddianum is adventive inotherregions, Mickel and Smith (2004) suggested that it could be a nonnative element in the flora of Mexico; there are few remaining records, and the earliest dates from 1966. We agree with their suspicion; the remaining records of A. raddianum in Mexico may in fact be recent introductions. However, in the case of A. alan-smithii we believe that the recent age of the collections is because Chiapas has been, and remains, an undercollected region.
Etymology—The epithet honors Dr. Alan R. Smith (University of California, Berkeley Herbarium). A tireless worker, Alan has made extraordinary contributions to the systematics of ferns and lycophytes. His treatment of the pteridophytes for the Flora of Chiapas (Smith 1981) was highly influential as evident from our tattered and worn copies.A
Adiantum alan-smithii is easily recognized when fertile by its yellow-farinose indusia. It is also distinct by having laminae with 5–8 pairs of pinnae, the proximal acroscopic pinnule of each pinna often overlapping the main rachis, the segments mostly broadly flabellate, the stalk non-articulate with its dark color passing into the pinnule bases, and the rachis ± flexuous toward the tip. By comparison, A. raddianum has non-farinose indusia and proximal acroscopic pinnules that do not overlap the main rachis. Adiantum poiretii also has yellow-farinose indusia, but has oblong to lunate sori and ciliate rhizome scales.
Thirty-five species of Adiantum have been recognized in Mexico, including fiveendemics (A. amblyopteridium Mickel & Beitel, A. galeottianum Hook., A. mcvaughii Mickel & Beitel, A. oaxacanum Mickel & Beitel, and A. shepherdii Hook.) (Mickel and Smith 2004). Our new species, A. alan-smithii, brings the number of endemic Mexican species to six, and the total number of species known from Mexico to 36. Adiantumalan-smithii was previously treated as A. raddianum by Smith (1981) and Mickel and Smith (2004), who applied the name broadly. With recognition of A. alan-smithii, we are aware of no remaining records of A. raddianum from Chiapas. This conclusion is based on the previous revision of Mexican collections by Smith (1981), Mickel and Smith (2004), our revision of material on loan from B, K, MEXU, MO, NY, P, S, UC, and US. Giventhat Adiantum raddianum is adventive inotherregions, Mickel and Smith (2004) suggested that it could be a nonnative element in the flora of Mexico; there are few remaining records, and the earliest dates from 1966. We agree with their suspicion; the remaining records of A. raddianum in Mexico may in fact be recent introductions. However, in the case of A. alan-smithii we believe that the recent age of the collections is because Chiapas has been, and remains, an undercollected region.
Etymology—The epithet honors Dr. Alan R. Smith (University of California, Berkeley Herbarium). A tireless worker, Alan has made extraordinary contributions to the systematics of ferns and lycophytes. His treatment of the pteridophytes for the Flora of Chiapas (Smith 1981) was highly influential as evident from our tattered and worn copies.A