. Dansk botanisk arkiv. Plants; Plants -- Denmark. 42 Dansk Botanisk Arkiv, Bd. 3. Nr. 1. short horizontal filaments grow out which fuse together forming the disc. From the cells in the disc gradually several erect ramified filaments grow upwards forming a dense tuft (Fig. 39). The principal filaments consist in their lower part of short cells about l^/g—2 times as long as broad, their diameter reaching a length of about 9—10/i; upwards the filaments become gradu- ally thinner and the cells at the same time longer. Near the summit they are only about b fx thick and often upto 40^ long or more.
. Dansk botanisk arkiv. Plants; Plants -- Denmark. 42 Dansk Botanisk Arkiv, Bd. 3. Nr. 1. short horizontal filaments grow out which fuse together forming the disc. From the cells in the disc gradually several erect ramified filaments grow upwards forming a dense tuft (Fig. 39). The principal filaments consist in their lower part of short cells about l^/g—2 times as long as broad, their diameter reaching a length of about 9—10/i; upwards the filaments become gradu- ally thinner and the cells at the same time longer. Near the summit they are only about b fx thick and often upto 40^ long or more. Sometimes the cells in the lower part of the principal filaments are a little broader in the middle tapering towards both ends. The chromatophore (Fig. 40) is parietal often with some longer prolongations along the wall of the cell and contains a large pyre- noid projecting somewhat into the interior of the cell. The ramification of the filaments begins near their base, but on the whole the filaments are not much branched. Branches are given off to all sides but often with long interwalls. Two kind of branches are present, long fila- ments like the principal ones and short branch- lets upon which the sporangia are borne. The branchlets are as a rule one- or two-celled ; in the first case it bears a single terminal sporangium, in the latter the lower cell also bears a mostly pedicellate, more rarely sessile, sporangium. The last mentioned branch- lets occur mostly in the lower part of the tufts, while the first mentioned as a rule are only present in the upper part. Only rarely are the sporangia seated directly upon the main filaments. Branchlets with more than two cells are rare. The sporangia (Fig. 40) are monosporous, oval-ovate, about 11// broad and about 14—16// long; they are provided with a very thick wall, often up to 2/j. thick. This species seems at first sight to come near to Acrochætium Hypneæ; but it differs in a different arrangement of the spores, these b
Size: 997px × 2505px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectio, bookdecade1910, booksubjectplants
