Thursday, August 14, 2014

Mosses of Central Florida 8. Entodon seductrix

The small ovate leaves of Entodon seductrix are
pressed against the stem when dry, giving the stems
a rope-like appearance.  The sporangia are upright
and cylindrical, with two rows of teeth around the
mouth.
[For other mosses in this series, see the Table of Contents]

Entodon seductrix (Hedw.) Müll. Hal. (Entodontaceae) is a common, straggling moss with horizontal stems covered with short leaves, and with sporophytes arising along the sides.  This species is found throughout eastern North America, as far north as Ontario, and extending westward from Florida to Texas.  Our collections are from the middle of the state northward, so it's not clear how far south it extends.  It characteristically forms lush mats at the bases of trees.

This species is easily confused with Isopterygium tenerum. Like that species, leaf cells are elongate and slightly curved, and there is no midrib (costa).   The short leaves of E. seductrix, however, press closely to the stem when dry, while those of Isopterygium are spread out.  The two species differ most obviously when sporangia are present.  In E. seductrix they are upright, nearly symmetrical, and cylindrical, in contrast with the strongly curved sporangia Isopterygium.

Another species of Entodon in our state is E. macropodus, which has slightly larger leaves that remain spread out when dry, but the sporangia are still upright and cylindrical. This species is more southern in its distribution, occurring northward to Virginia and southward into tropical America.  It is also found in Japan.
The slender leaf cells of Entodon are like tiny worms, with
thick, clear walls between them. Toward the base, they
become more rectangular, but not conspicuously
inflated.

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