. Our native ferns and their allies [microform] : with synoptical descriptions of the American pteridophyta north of Mexico. Ferns; Fougères. 14 OUR NATIVE FERNS AND THEIR ALLIES. ing the aori at or near the ends of the veins, covered by fan in- dusium formed of the margin of the frond. In § Adiantopsis the indusia are distinct, and confined to a single veinlet. One of our species varies from the typical species of this section, and has even been assigned to a separate genus. In § EUCHEILANTHES the indu- Fio. i.^Fttrit hngi/»iia L. Bn- sia are more or less confluent but iTeWlk^ceptwWnder th* n
. Our native ferns and their allies [microform] : with synoptical descriptions of the American pteridophyta north of Mexico. Ferns; Fougères. 14 OUR NATIVE FERNS AND THEIR ALLIES. ing the aori at or near the ends of the veins, covered by fan in- dusium formed of the margin of the frond. In § Adiantopsis the indusia are distinct, and confined to a single veinlet. One of our species varies from the typical species of this section, and has even been assigned to a separate genus. In § EUCHEILANTHES the indu- Fio. i.^Fttrit hngi/»iia L. Bn- sia are more or less confluent but iTeWlk^ceptwWnder th* not continuous, usually extending nal iadutium. ^^^^ j|,g apjces of several veinlets. In § Physapteris the ultimate segments are bead-like, &nd the indusium is continuous all round the margin. S Aleuritopteris has the fronds farinose below, and m< eludes a single species somewhat doubtfully assigned to cur limits. 38. Cryptofframma has dimorphous fronds, the margins of the fertile being closely rolled toward the midvein, thus cov- ering the confluent sori. At maturity these open flat in order to discharge the spores. 39. Pellsea has representatives of three sections within our limits, all agreeing in possessing intramarginal sori, which finally became confluent and form a marginal line covered by an indusium formed of the margin of the frond. § Cheiloplecton includes herbaceous species with visible veins and broad indusia. § Allosorus includes coriaceous species having wide indusia. while § Platvloma includes species similar in texture, but with extremely narrow indusia and broad segments. 40. Ceratopteris is an anomalous genus from southern Florida, having a few sori arranged on two or three veins par- allel to the midvein, and covered by the broadly reflexed margin of the frond. It properly forms the type of a family. 41. Struthlopteris (Fig. 7) is intermediate between those genera in whirh there is an indusium formed of the revolute margin of the frond and thos
Size: 2179px × 1147px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., booka, bookcentury1900, bookdecade1900, bookpublishernewyorkhholt
