Plagiogyria pectinata (Liebm.) Lellinger
Descripción
Rhizomes, including old stipe bases, 1.5–4 cm diam.; fronds 30–140 cm tall, the fertile ones more erect than the sterile; stipes of sterile fronds short, 1⁄4–1⁄5 the frond length, stramineous, dark at base, glabrous; blades deeply pinnatisect or pinnate at base, 6–20 cm wide, truncate to greatly reduced proximally, the shortest pinnae 1⁄2–1⁄4(–1⁄10) length of longest pinnae, as little as 1 cm long, blade apices acute to abruptly acuminate; pinnae spreading, the largest 3–10 cm X 4–12 mm, linear, curved to straight, dilate at the base, frequently more surcurrent than decurrent, acute, margins subentire to serrulate to biserrate; veins simple or onceforked at the costae, or one or both veins of a fork sometimes forked again midway toward margin; fertile fronds pinnate, sessile or very short-stalked <1 mm, to 140 X 4–12 cm; stipes 1⁄3–1⁄2 the frond length; pinnae contracted, 3–7 cm X 2–4 mm; 2n=132(Jam).A
Forma de vida
TerrestreA
Ejemplar revisado
Chih (Correll & Gentry 23104, MO, UC). Chis (Breedlove 21995, DS, MEXU, NY). DF (Lyonnet 471200003, MEXU). Dgo (Palmer 124, NY). Gro (Lorea 3700, FCME). Hgo (Moore 3207, UC, US). Jal (Rose & Painter 7598, BM, NY, US). Méx (Hinton 2808, BM, K, NY). Mich (Rzedowski 42670, IEB). Mor (Lyonnet 1419, BM, K, MEXU, MO, UAMIZ, UC). Oax (Pringle 4999, B, BM, BR, GH, LE, MO, NY, UC, US). Pue (Pringle 15703, CAS, MO, UC, US). Qro (Díaz Barriga & Carranza 7378, IEB). Son (Van Devender 97-831, ARIZ). Ver (Ventura A. 9014, ENCB, NY).A
Elevación
1750 – 3250 mA
Tipo de vegetación
Bosque de neblina/mesófiloA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
We adopt a broader concept for this taxon in Mexico tan has been applied in most recent floristic and revisionary accounts (an approach that has been taken to an even greater extent by Tryon and Stolze (1989a: 101) and also by Zhang and Nooteboom (1998). We now suspect that much of the variation in neotropical Plagiogyria is contained within a single species, the oldest name for which is the one adopted here. Thus, we would also include within the circumscription of P. pectinata several Antillean species recognized by Lellinger (1971), including P. maxonii Copel. in Jamaica and P. serrulata (Willd.) Lellinger in Hispaniola. Taxa that seem slightly more distinct in the New World include P. costaricensis Mett. ex Kuhn, from Costa Rica, Venezuela, and Ecuador to Bolivia, and P. fialhoi (Fée & Glaziou) Copel. in southeastern Brazil.
Characters used by Lellinger (1971), Smith (1981), Mickel and Beitel (1988), and Lellinger (in Davidse et al., 1995) to distinguish the Mexican taxa include the degree and pattern of serrations on the margins of the sterile pinnae and the extent of reduction, if any, of the proximal pinnae. The former character we believe is largely a function of the number of vein forks (one or two), and hence a function of pinna width, which varies considerably in Plagiogyria; similarly, reduction of the proximal pinnae is extremely variable, even within populations and on a single plant. For example, specimens collected from around Lagunas de Zempoala, on the border between Edo. Morelos and Edo. México, show all possible transitional states, from virtually no reduction of the proximal pinnae to extreme reduction. We have observed that there is also great variation in size of plants in this and other populations, as well as size of fronds on a single plant. Possibly this is related to moisture and other environmental fluctuations, from year to year. Thus, we are unable to apply the characters and character states discussed by previous authors to delineate Mexican specimens into two or three species. Furthermore, we find no geographical correlation to the morphological differences that do exist, other than that plants become increasingly smaller as one goes northwestward in Mexico, into habitats that are often drier, colder, and less equable.
Evidence suggesting hybridity between species in Mexican specimens is suspect. Re-examination of spores of Mickel 6779 (NY, UC), cited by Mickel and Beitel (1988) as a putative hybrid between P. pectinata and P. truncata, shows that the spores are well formed, not particularly irregular as originally stated. We now regard this particular collection as simply one of the many variants in a variable species.
Plagiogyria pectinata is based on a Liebmann collection from Oaxaca. The collection comprises three sterile fronds, which are narrow (8–9 cm) and taper strongly to proximal pinnae that are 1⁄3–1⁄4 the length of the longest pinnae.A
Characters used by Lellinger (1971), Smith (1981), Mickel and Beitel (1988), and Lellinger (in Davidse et al., 1995) to distinguish the Mexican taxa include the degree and pattern of serrations on the margins of the sterile pinnae and the extent of reduction, if any, of the proximal pinnae. The former character we believe is largely a function of the number of vein forks (one or two), and hence a function of pinna width, which varies considerably in Plagiogyria; similarly, reduction of the proximal pinnae is extremely variable, even within populations and on a single plant. For example, specimens collected from around Lagunas de Zempoala, on the border between Edo. Morelos and Edo. México, show all possible transitional states, from virtually no reduction of the proximal pinnae to extreme reduction. We have observed that there is also great variation in size of plants in this and other populations, as well as size of fronds on a single plant. Possibly this is related to moisture and other environmental fluctuations, from year to year. Thus, we are unable to apply the characters and character states discussed by previous authors to delineate Mexican specimens into two or three species. Furthermore, we find no geographical correlation to the morphological differences that do exist, other than that plants become increasingly smaller as one goes northwestward in Mexico, into habitats that are often drier, colder, and less equable.
Evidence suggesting hybridity between species in Mexican specimens is suspect. Re-examination of spores of Mickel 6779 (NY, UC), cited by Mickel and Beitel (1988) as a putative hybrid between P. pectinata and P. truncata, shows that the spores are well formed, not particularly irregular as originally stated. We now regard this particular collection as simply one of the many variants in a variable species.
Plagiogyria pectinata is based on a Liebmann collection from Oaxaca. The collection comprises three sterile fronds, which are narrow (8–9 cm) and taper strongly to proximal pinnae that are 1⁄3–1⁄4 the length of the longest pinnae.A