Monographs Details:
Authority:
Proctor, George R. 1989. Ferns of Puerto Rico and the Virgin Islands. Mem. New York Bot. Gard. 53: 1-389.
Proctor, George R. 1989. Ferns of Puerto Rico and the Virgin Islands. Mem. New York Bot. Gard. 53: 1-389.
Family:
Pteridaceae
Pteridaceae
Description:
Species Description - Small to very large and coarse tenestrial fems. Rhizomes creeping to erect, often stout and woody, clothed with scales at the apex (sometimes these very small and few). Fronds usually clustered, erect or arching, monomorphic or sometimes dimorphic, often long-stipitate; stipes narrowly grooved adaxially. Blades 1 - to 4-pinnate, elongate to temate or pentagonal in outline, sometimes each of the basal pinnae as large as rest of the blade; costae of penultimate divisions deeply but narrowly grooved adaxially, the parallel ridges often bearing minute spinelike awns, one each at the base of the ultimate costules (sometimes similar awns on the ultimate costules at base of veins); venation free or reticulate (sometimes only the basal veins joined); areoles without free included veinlets. Sori linear, marginal, the sporangia b orne in a continuous line on a delicate transverse commissure connecting the ultimate vein-tips; paraphyses usually present and often numerous; indusium linear, continuous, formed by the modified reflexed margin, opening inwardly; sporangia with annulus of 16-34 cells; spores tetrahedral or globose, trilete, usually with a prominent equatorial flange, the surfaces variously tuberculate or reticulate.
Species Description - Small to very large and coarse tenestrial fems. Rhizomes creeping to erect, often stout and woody, clothed with scales at the apex (sometimes these very small and few). Fronds usually clustered, erect or arching, monomorphic or sometimes dimorphic, often long-stipitate; stipes narrowly grooved adaxially. Blades 1 - to 4-pinnate, elongate to temate or pentagonal in outline, sometimes each of the basal pinnae as large as rest of the blade; costae of penultimate divisions deeply but narrowly grooved adaxially, the parallel ridges often bearing minute spinelike awns, one each at the base of the ultimate costules (sometimes similar awns on the ultimate costules at base of veins); venation free or reticulate (sometimes only the basal veins joined); areoles without free included veinlets. Sori linear, marginal, the sporangia b orne in a continuous line on a delicate transverse commissure connecting the ultimate vein-tips; paraphyses usually present and often numerous; indusium linear, continuous, formed by the modified reflexed margin, opening inwardly; sporangia with annulus of 16-34 cells; spores tetrahedral or globose, trilete, usually with a prominent equatorial flange, the surfaces variously tuberculate or reticulate.
Discussion:
Type Species. Pteris longifolia Linnaeus of the West Indies.
large genus of perhaps 280 species, pantropical in distribution, with some species also occurring in temperate regions. Twelve species are here credited to Puerto Rico, of which three are introduced and more or less naturalized. The generic name is derived from the Greek pteron, wing or feather, and was used by the ancient Greeks themselves as a general name for ferns, because of the resemblance of the fronds to feathers.
Special Literature. Agardh, J.G. 1839. Recensio specierum generis Pteridis, 86 pp, Lund. (There appears to be no recent general publication this genus.) Teyon, R. M. & A. F. Tryon. 1982. Ferns and allied plants, pp. 332-341, 30 figs.