L
f t :
lucre at the apex of the peduncle, quaternate, cruciate,
188.
spreading horizontally (fig.
188), apex vertically bilabiate,
monocarpu s . P e r ia n th none.
Calyptra included, crowned with a
style, splitting above, pedicels the
length of the involucre. Capsule
exerted, thin, four to eight valved,
valves spreading, somewhat
twisted. Elaters bispiral, deciduous.
Pistillidia four to six, in
discoid receptacle, sessile, superficial,
girt by paraphyses. Male
receptacle oblong, at the sinus of
the frond, sessile on the upper
surface, girt by an elevated margin.— {Plate 7, fig.
93)
G enus 43. PREISSIA, Nees.
Female receptacle pedunculate, hemispher ical,
four-lobed, r a y s o f the lobes shorter, r iblike.
Perianth obconically campanulate, angu lar,
unequally four or five parted. Calypt ra
persistent . Capsule sho r t ly pedicellate, cut into
four or eight irregular valves. Elaters bispiral.
Male receptacle pedunculate, peltate, repand,
lobate. Margin thin. Fronds spa r se ly forked,
bearing the peduncle from a sinus of the ter minal
lobe.
Preissia commutata, N.
Male receptacle peltate, pedunculate; feJSLi
male receptacles stalked, often with four
indistinct angles, marked on the top with a
cruciate c r e s t ; frond obcordate, innovant
from the sinus.
Marchantía commutata, Linden. Hep. Eur.
l o i . Marchantía hemisphcerica. Hook. Br.
FI. V., 104. Marchantía androgyna, Eng. Bot.
t. 2545. Preissia commutata, Ne e s Hep. Eur.
p. 1 1 7 ; Co o ke Hep. f. 188 ; Carr, and Pears.
Exs. 208, 209.
Side of mountain streams.
Fronds procumbent, imbricated, oblong, i to 3
inches, generally forked, rarely simple, waved and
crenate at the margin, dark green above, frequently
with a dark central line indicating
the midrib, underside often
purple at the margin, midrib prominent,
with numerous silky radicles,
beset on each side with purple scales.
Monoicous or dioicous. Male receptacle
with short pedicels springing from
the midrib in a sinus at the end of
the frond, receptacle peltate, flat and
papillose above, purplish, margins reflexed,
cut into four or eight rounded
lobes. Female receptacle with pedicels
2 to 4 inches long, hemispherical, cut
at the margin into from four to ten or
eleven obtuse defiexed I obes, covering as
189.
many involucres, which have entire margins. Calyx
white, quadrifid, two to three in each involucre.
Capsule scarcely protruded when mature on a