TORTULA nervosa.
Rib-sheathed Screwrmoss.
CRYPTOGAMIA Musci.
Gen. Char. F r in g e simple, of numerous capillary
teeth, spirally and repeatedly twisted together.
fePEC. Char. Stem much branched; Leaves all ovate,
acute, keeled, with a midrib. Sheaths between
the branches, imbricated.
Svn. Tortula convoluta. Sw a r tz . M u s e . Suec. 41.
S ch ra d . Spicil. 66.
"W HEN the Flora Britannica v. 3. was published, we were
not aware of the above celebrated authors having mistaken
this moss for T. convoluta, t. 2382; but having specimens from
themselves, and having since gathered the same at Thorpe
near Norwich, as well as received it from the Rev. Mr. Hem*
sted, through Mr. Turner, we clearly perceive the differences
between the two. The tufts of this are much higher, the stems
being divided into longer and more numerous branches. The
leaves are more ovate and pointed, those of the sheath are more
numerous, imbricated, not convoluted, and differ very little
from those of the stem, both being furnished with a strong
midrib. The lateral situation of the fruitstalk and its sheath,
between the branches, common to both, distinguishes these
from most British Tortulce. The present is apparently the
most common of the two, on sandy or gravelly banks, bearing
fruit in March. Its fruitstalks are tawny. Capsule erect,
brown, smooth, more ovate, with a shorter and thicker lid,
than in T. convoluta.