Thelypteris palustris Schott
Categoría IUCN
Preocupación menor (LC)A
Categoría NOM-059-SEMARNAT-2010
No incluidaB
Discusión taxonómica
Thelypteris palustris var. pubescens Fernald, Rhodora 31: 34. 1929
Lastrea thelypteris var. pubescens G.Lawson, Edinburgh New Philos. J. 19: 277. 1864
Dryopteris tremula Christ, Notul. Syst. (Paris) 1: 234. 1910
Rhizomes long-creeping, 1–3 mm diam.; fronds monomorphic or slightly dimorphic, often 1–3 cm apart, fertile fronds more erect, narrower and with somewhat contracted pinnae and segments, 20–90 cm long; stipes stramineous above bases, 9–45(–60) cm X 1–3 mm, at bases sparsely set with tan, ovate, glabrous scales; blades lanceolate, 10–40(–55) cm long, proximal pinnae commonly slightly shortened, blades tapering gradually to pinnatifid apices; pinnae pinnatifid to within 1 mm of costae, 2–10 X 0.5–2 cm; segments oblong, somewhat oblique, entire; veins from adjacent segments meeting margins above sinuses, frequently forked; indument abaxially of sparsely to densely set hairs on costae and sometimes veins, costae also commonly with a few small, tan scales, tissue between veins glabrous on both sides; sori medial, with tan, often hairy indusia; sporangia glabrous; 2n=70 (USA).
Distribution. Along slow-moving streams and waterways, swampy areas; 1800–1850 m. E Canada, e USA; Mexico; Berm, Cuba; the distribution of the species (var. palustris) extends to Europe, Asia.
Specimens Examined. DF (Schaffner s.n., MEXU). Mich (Arsène 2562, 5907, s.n., US; Rzedowski 39234, IEB, XAL). State unknown (Schaffner 57, NY).
Distinctive characters are the very long-creeping, narrow rhizomes, the free, frequently forked veins, and the tan scales along the costae abaxially. The sole variety recognized by Tryon et al. (1980) in temperate North America is var. pubescens and, from the meager material available, the Mexican specimens seem to be the same variety. Eurasian material is referable to var. palustris, based on Acrostichum thelypteris L., Sp. Pl. 2: 1071. 1753. [Syn.: Theylypteris palustris Schott, Gen. Fil., t. 10. 1834. Dryopteris thelypteris (L.) A. Gray, Man., ed. 1, 630. 1848. Type. Uncertain, based on plants from Europe and citations to publications by Bauhin (with illustration) and Ruppius.]
Dryopteris tremula has been a puzzle since Christ first described it in 1910. It now seems likely that it is merely an outlier of the widespread north-temperate species, T. palustris, differing in no significant characters from that species. The Schaffner collection was made in 1875, from Xochimilco. The only recent collection since the early 1900’s is by Rzedowski, in 1985, from the mouth of Lago de Cuitzeo.
C
Lastrea thelypteris var. pubescens G.Lawson, Edinburgh New Philos. J. 19: 277. 1864
Dryopteris tremula Christ, Notul. Syst. (Paris) 1: 234. 1910
Rhizomes long-creeping, 1–3 mm diam.; fronds monomorphic or slightly dimorphic, often 1–3 cm apart, fertile fronds more erect, narrower and with somewhat contracted pinnae and segments, 20–90 cm long; stipes stramineous above bases, 9–45(–60) cm X 1–3 mm, at bases sparsely set with tan, ovate, glabrous scales; blades lanceolate, 10–40(–55) cm long, proximal pinnae commonly slightly shortened, blades tapering gradually to pinnatifid apices; pinnae pinnatifid to within 1 mm of costae, 2–10 X 0.5–2 cm; segments oblong, somewhat oblique, entire; veins from adjacent segments meeting margins above sinuses, frequently forked; indument abaxially of sparsely to densely set hairs on costae and sometimes veins, costae also commonly with a few small, tan scales, tissue between veins glabrous on both sides; sori medial, with tan, often hairy indusia; sporangia glabrous; 2n=70 (USA).
Distribution. Along slow-moving streams and waterways, swampy areas; 1800–1850 m. E Canada, e USA; Mexico; Berm, Cuba; the distribution of the species (var. palustris) extends to Europe, Asia.
Specimens Examined. DF (Schaffner s.n., MEXU). Mich (Arsène 2562, 5907, s.n., US; Rzedowski 39234, IEB, XAL). State unknown (Schaffner 57, NY).
Distinctive characters are the very long-creeping, narrow rhizomes, the free, frequently forked veins, and the tan scales along the costae abaxially. The sole variety recognized by Tryon et al. (1980) in temperate North America is var. pubescens and, from the meager material available, the Mexican specimens seem to be the same variety. Eurasian material is referable to var. palustris, based on Acrostichum thelypteris L., Sp. Pl. 2: 1071. 1753. [Syn.: Theylypteris palustris Schott, Gen. Fil., t. 10. 1834. Dryopteris thelypteris (L.) A. Gray, Man., ed. 1, 630. 1848. Type. Uncertain, based on plants from Europe and citations to publications by Bauhin (with illustration) and Ruppius.]
Dryopteris tremula has been a puzzle since Christ first described it in 1910. It now seems likely that it is merely an outlier of the widespread north-temperate species, T. palustris, differing in no significant characters from that species. The Schaffner collection was made in 1875, from Xochimilco. The only recent collection since the early 1900’s is by Rzedowski, in 1985, from the mouth of Lago de Cuitzeo.
C