Elaphoglossum
Description
Generally epiphytic in wet montane forests and evergreen cloud forests, a greater percentage terrestrial at high elevations; rhizomes short- to long-creeping, rarely erect, slender to stout (1–15 mm diam.); rhizome scales orange to black, basally attached or peltate, entire to toothed; fronds 2–200 cm long, erect, arching or pendent; stipes glabrous or scaly, sometimes also with minute glandular hairs, long or very short, bases often darker (phyllopodia) with abscision at their distal demarcation rather than at the rhizome; blades simple (flabellately divided in E. peltatum, pedate in one South American species), linear to ovate or oblanceolate, apices acuminate or caudate to obtuse, bases rounded to long-attenuate; costae grooved adaxially, usually with scales like those of the stipes abaxially; veins generally free, rarely netted or with a marginal commissural vein, simple to 2-forked, ending near the blade margins and lacking hydathodes, or stopping well short of the margins and usually ending in conspicuous hydathodes; blade scales frequently differing from those of the rhizomes or stipes, abundant to absent, often greatly reduced and appearing as stellate hairs; fertile fronds longer or shorter than the sterile fronds but generally with narrower blades and proportionally longer stipes; fertile blades completely covered abaxially with sporangia (acrostichoid sori); indusia absent; sporangia long-stalked, the annuli erect, each interrupted by the stalk; paraphyses generally absent, present in some species; spores bilateral, most with high crests or low ridges, but some echinate or verruculate without ridges or crests; x=40, 41.A
A. Mickel, J. T. & Smith, A. R. 2004: The Pteridophytes of Mexico Vol. 88
Discussion
There are probably well over 600 species in Elaphoglossum, about three-fourths of them occurring in tropical America. There are 58 species recognized in Mexico, although our knowledge of them is far from complete. Several are known from only one or a few specimens. The genus is very difficult taxonomically. There are few characters, and the genus has not had a usable subgeneric breakdown until recently. Variation of the characters, such as plant size, blade shape and size, scale color, and scale type, is not fully understood in terms of species delimitation. The characters lie mostly in the scales of the rhizomes and blades. The fertile fronds add characters of relative size, intersporangial scales, and spore details, but virtually all the species can be identified on the basis of vegetative material alone. Unfortunately, collectors are hesitant to collect sterile material, and thus many records have gone uncollected.
In the following descriptions, rhizome diameter excludes the scale covering. Rhizome scales may be appressed or widely spreading and might distort the rhizome diameter measurements were they included. Stipe bases are differentiated into evident phyllopodia in some but not all species. Blade measurements apply to sterile fronds unless otherwise stated. Blade texture is difficult to determine on the basis of dried material and is given only for those species in which it is clearly distinctive. Although the veins seem to run to the blade margins in some species, they end just short of it, leaving pale, narrow margins 0.5–1 mmwide, which are often difficult to see, especially in very coriaceous or heavily indumented fronds. Vein angles and intervein distances are measured at mid-blade, halfway between the costa and margin. Scales of the rhizomes and blades are generally quite distinct from one another, and on the stipes they intergrade or remain distinct. Blade scales, although basically similar on adaxial and abaxial surfaces, are more highly dissected abaxially; in some this means longer teeth, but in more extreme cases scales are reduced to stellate hairs or even to resinous dots. Some dark scales are reduced and dissected so as to resemble spiders, a condition for which the term “arachnidoid” is used (vs. “arachnoid,” which is used for “web-like”). In species with subglabrous fronds, the blade scales are reduced minute stellate trichomidia that are visible only with a hand lens or dissecting scope. On fertile blades, scales of the adaxial surfaces are similar to those of sterile blades, but abaxially the scales are generally limited to the costae and in only a few species are there scales among the sporangia. Another type of indument consists of minute erect glandular hairs, which are found in varying degrees on the stipes and occasionally on the blades in E. lindenii, E. erinaceum, E. pallidum, and their relatives.
Elaphoglossum is distinct by its simple blades (rarely with finely dissected blades in subsect. Peltapteris), free veins (rarely netted, but not in ours), and acrostichoid sori. Relationships to other genera are not clear. Elaphoglossum is commonly thought to be close to Lomariopsis, but molecular evidence suggests that Bolbitis is closer.
The distinctness of many of the species described in the Rojas publications seems dubious and will require a great deal more study before one has confidence in their definition. Many seem no more than minor variants of already recognized species. Supposed new records are often based on misidentifications or misinterpretations.
Species of Uncertain Status
Elaphoglossum trichomallum Rovirosa, Pteridogr. Sur México 252. 1909. Type. Mexico. Chiapas: L. Martínez 1101 “in his herb.” The combination of cited characters (creeping rhizomes, scales reddish, linear-lanceolate, crisped sparse piliform scales on both sides of blades, stipes 14–22 mm, with gold-castaneous subulate scales, blades 27–39 X 3–6 cm, elongate lanceolate, papyraceous, attenuate at both ends; fertile fronds with blades 21 X 2 cm, costal scales similar to those of stipes, epiphytic) suggests it may be E. setigerum, but we have not located a type specimen.
Elaphoglossum venustum T. Moore, Index Fil. 16. 1857. Acrostichum venustum Fée, Mém. Foug. 8: 68. 1857. hom. illeg., non Liebm. 1849. Type. Mexico. Mecameca, la Puebla, Schaffner 332b, c, in 1855 (P?, not found). Both Christ (1899) and Christensen (1905) considered this to be synonymous with E. araneosum D. C. Eaton [= E. muelleri of this treatment]. Christ’s characterization of E. venustum certainly applies to E. muelleri, but the description by Fée suggests otherwise: blade scales ciliate, long acuminate (stellate hairs in E. muelleri), and scales of the proximal parts of the stipes entire. Elaphoglossum petiolatum has conspicuous entire scales on the stipes proximally and ciliate scales on the blades. The name E. venustum may apply to E. petiolatum.
B
B. Mickel, J. T. & Smith, A. R. 2004: The Pteridophytes of Mexico Vol. 88
In the following descriptions, rhizome diameter excludes the scale covering. Rhizome scales may be appressed or widely spreading and might distort the rhizome diameter measurements were they included. Stipe bases are differentiated into evident phyllopodia in some but not all species. Blade measurements apply to sterile fronds unless otherwise stated. Blade texture is difficult to determine on the basis of dried material and is given only for those species in which it is clearly distinctive. Although the veins seem to run to the blade margins in some species, they end just short of it, leaving pale, narrow margins 0.5–1 mmwide, which are often difficult to see, especially in very coriaceous or heavily indumented fronds. Vein angles and intervein distances are measured at mid-blade, halfway between the costa and margin. Scales of the rhizomes and blades are generally quite distinct from one another, and on the stipes they intergrade or remain distinct. Blade scales, although basically similar on adaxial and abaxial surfaces, are more highly dissected abaxially; in some this means longer teeth, but in more extreme cases scales are reduced to stellate hairs or even to resinous dots. Some dark scales are reduced and dissected so as to resemble spiders, a condition for which the term “arachnidoid” is used (vs. “arachnoid,” which is used for “web-like”). In species with subglabrous fronds, the blade scales are reduced minute stellate trichomidia that are visible only with a hand lens or dissecting scope. On fertile blades, scales of the adaxial surfaces are similar to those of sterile blades, but abaxially the scales are generally limited to the costae and in only a few species are there scales among the sporangia. Another type of indument consists of minute erect glandular hairs, which are found in varying degrees on the stipes and occasionally on the blades in E. lindenii, E. erinaceum, E. pallidum, and their relatives.
Elaphoglossum is distinct by its simple blades (rarely with finely dissected blades in subsect. Peltapteris), free veins (rarely netted, but not in ours), and acrostichoid sori. Relationships to other genera are not clear. Elaphoglossum is commonly thought to be close to Lomariopsis, but molecular evidence suggests that Bolbitis is closer.
The distinctness of many of the species described in the Rojas publications seems dubious and will require a great deal more study before one has confidence in their definition. Many seem no more than minor variants of already recognized species. Supposed new records are often based on misidentifications or misinterpretations.
Species of Uncertain Status
Elaphoglossum trichomallum Rovirosa, Pteridogr. Sur México 252. 1909. Type. Mexico. Chiapas: L. Martínez 1101 “in his herb.” The combination of cited characters (creeping rhizomes, scales reddish, linear-lanceolate, crisped sparse piliform scales on both sides of blades, stipes 14–22 mm, with gold-castaneous subulate scales, blades 27–39 X 3–6 cm, elongate lanceolate, papyraceous, attenuate at both ends; fertile fronds with blades 21 X 2 cm, costal scales similar to those of stipes, epiphytic) suggests it may be E. setigerum, but we have not located a type specimen.
Elaphoglossum venustum T. Moore, Index Fil. 16. 1857. Acrostichum venustum Fée, Mém. Foug. 8: 68. 1857. hom. illeg., non Liebm. 1849. Type. Mexico. Mecameca, la Puebla, Schaffner 332b, c, in 1855 (P?, not found). Both Christ (1899) and Christensen (1905) considered this to be synonymous with E. araneosum D. C. Eaton [= E. muelleri of this treatment]. Christ’s characterization of E. venustum certainly applies to E. muelleri, but the description by Fée suggests otherwise: blade scales ciliate, long acuminate (stellate hairs in E. muelleri), and scales of the proximal parts of the stipes entire. Elaphoglossum petiolatum has conspicuous entire scales on the stipes proximally and ciliate scales on the blades. The name E. venustum may apply to E. petiolatum.
B
Distribution
México (Country) native and not endemicC