L I C H E N aquaticus.
Clufiered water Juichen.
C R Y P T O GA M IA Alga.
G e n . C har. Male, fcattcred warts.
Female, fmooth fhields or tubercles, in which the
feeds are imbedded.
Spec.C har. Obfoletely umbilicated, aggregate, lobed,
creeping, fmooth on both tides, green ifh above.
Tubercles in immCrfed dots.
Syn. Lichen aquaticus (by error of the prefs fluviatilis).
With. v . 4. 67. Weis Crypt. 77,
L . fluviatilis. Web. Gott. 265. t. 4 .
Platifma aquaticum. Hoffm. Pl. Lich. t. 45.
(-XATHERED in the bed of an alpine river at Hafod, Car-
diganfhire. It grows on large Hones, or on fmall pebbles under
water, in very large patches, confiding of numerous cluftered
leaves, which even at firft are hardly to be called umbilicated,
“though about as much fo as in L. polyphyllus of Linnaeus.
Thele leaves or fronds are roundly lobed, tumid, fmooth on
both fides, veinlefs, olive-green above, at leaft w-hen moift,
reddifli-brown beneath. The tubercles are much like thofe of
L. miniatus, but rather more dilated, and furrounded by a
tumid margin from the fubftance of the frond. Hence Pro-
felfor Hoffmann calls them fcutella. It is remarkable that the
fronds take root here and there by fmall folitary protuberances,
to each of which a little pebble is commonly attached. This
ferves merely to fixthe plant, not to nourifh it, and is what is
expreffed in Dillenius’s t. 30, ƒ. 12 7 A ; hence I conceive that
figure to belong to this fpecies rather than to miniatus, and his
f . 128 to be the variety of miniatus, though I cannot fpeak
pofitively, not having examined his collection at Oxford with
this particular view.
It is after all very doubtful whether L. aquaticus be any
thing more than a variety of miniatus occafioned by its growing
altogether in the water, and we rather publilh it as diftinH
from a deference to the great authority of Hoffmann, than
from a thorough conviction. Our 393 ƒ. 2 appeals to be the
Intermediate ftate between the two extremes, /. /y?$Ç ff/M -r/r) tyy/J Jr&'Y-dy .ù-rr),"-r.