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At that time, the elaters uncoil to extend out from the spore and will catch air currents. The fact that they are extended only when conditions are dry means that successful spore dispersal is more likely. The mature strobili of a horsetail (Equisetum arvense). A cross section through a horsetail strobilus, showing spores with elaters.
In leptosporangiate ferns, the annulus located on the outer rim of the sporangium and serves in spore dispersal. It consists typically of a ring or belt of dead water-filled cells with differentially thickened cell walls that stretches about two-thirds around each sporangium in leptosporangiate ferns. The thinner walls on the outside allow ...
Thus bryophytes disperse by a combination of swimming sperm and spores, in a manner similar to lycophytes, ferns and other cryptogams. The sporophyte develops differently in the three groups. Both mosses and hornworts have a meristem zone where cell division occurs.
7 Sporangium dehiscence in bryophytes. ... Explosive dehiscence is a ballistic form of dispersal that flings seeds or spores far from the parent plant.
Mammals contribute to bryophyte and fern spore dispersal by carrying spores on their fur. Small mammals acting as dispersal vectors may have advantages for the dispersing organism compared to wind transport, as the mammals share similar ecosystems to the parent plant, while wind transport is random. Additionally, mammals can transport spores ...
Hornwort spores are relatively large for bryophytes, measuring between 30 and 80 μm in diameter or more. The spores are polar, usually with a distinctive Y-shaped tri-radiate ridge on the proximal surface, and with a distal surface ornamented with bumps or spines.
In all bryophytes, the primary plants are the haploid gametophytes, with the only diploid portion being the attached sporophyte, consisting of a stalk and sporangium. Because these plants lack lignified water-conducting tissues, they cannot become as tall as most vascular plants. Algae, especially green algae. The algae consist of several ...
In bryophytes, the calyptra (plural calyptrae) is an enlarged archegonial venter that protects the capsule containing the embryonic sporophyte. [6] The calyptra is usually lost before the spores are released from the capsule. The shape of the calyptra can be used for identification purposes. [7]