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54 A Momgì-aph o f the Myxogastres. Gribraria. 55
'I
diameter, chestnut-brown, pruinose ; mass of spores and supporting
threads yellowish brown.
Dictydiathalium dissiliens, Hazl, Just. Bot. Jahresb., 1877,
p. 156 ; Sacc., Syll, Vol. vii., pt. L, n. 1SD8.
Hazlmsky states the present species, when ripe, dehisces in
an elastic manner on the slightest touch, brought about by
the sudden expansion of the elaters (= threads supporting
apical portion of sporangium) which increase to three times
their previous length.
Cribhaeia. Pers. (emended).
Wall of sporangium single, with thickened permanent portions
arranged in the form of more or less parallel ribs at the base,
branching and anastomosing above to form an irregular network,
angles of network sometimes dilated and enclosing
gi-auules; thin portions of wall entirely disappearing at maturity,
or the basal portions between the radiating ribs persistent
and forming an imperforate calyculus; columella and
capillitium absent.
Crih-aria, Pers. Syn., p. 192; Rost., Mon., p. 57; Coo.ke,
Myx. Brit., p. 57 ; Schroeter, p. 104; Zopf, p. 141 ; Sacc., Syll’
Vol. vii., pt. I., p. 412.
Heterodictyon, Rost., Mon., p. 231 ; Cooke, Brit. Myx p 57 ■
Sacc., Syll., p. 411. > i >
After a careful comparison of specimens or figures of all the
species, with two exceptions, I find it impossible to retain
Rostafinski’s genus Heterodictyon. In Gribraria we find, as
a rule, a calyculus at the base of the sporangium, composed
of more or kss parallel ribs, with the thinner intermediate
portions persistent; from the irregular margin of the calyculus,
the upper network commences, or rather, may be looked upon
as a continuation of the ribs of the calyculus; if the upper
portion starts from the margin of the calyculus, as an irregular
net-work^ consisting of well-defined nodes united by '’thin
strands, i t ’ represents Rostafinski’s conception of Gribraria;
but if the lower portion of the network consists of more or
less parallel, broad ribs, joined laterally by thin strands, and
passing into the Ciibraria type of network towards the apex,
then, according to Rostafinski, it is Heterodictyon. There is,
in reality, every shade of transition between the two extremes,
and G. Bieniaszii closely connects the genus Gribraria in the
wider sense, with Dictydiwni.
Distrib. Europe; United States; Ceylon: species 19.
Sub-Gen. Hetcroderma. Calyculus present.
Network thickened, and fanning nodes at the angles.
Gribraria elegans, B. and C.
Sporangia globose, stipitate, more or less cernuous, purple,
calyculus occupying nearly lower half of sporangial wall, with
numerous radiating ribs, and studded with organic purple
granules inside; nodes of network numerous, large, angular or
irregularly stellate, containing purple granules, connected by
thin bands; stem elongated, expanding downwards, and passing
into a small hypothallus, curved near the apex, pmpjle;
spores—mass purple; spores globose ; mmutcly loartcd, 5—7 g
diameter.
Gribraria elegans, B. and C., Grev., Vol. ii., p. 67; Sacc., Syll.,
n. 1412; Rost., Mon., App., p. 32.
(Type in Herb. Berk., n. 10873.)
On decayed wood. Lower Carolina.
Scattered or gregarious, stem variable in length, 2 — 3 mm.,
sometimes flexuous. There are no free ends in the network
of the sporangium.
Gribraria piriformis, Schrad.
Sporangia pyriforni, stipitate, erect, purple-brmon before dehiscence,
then yellowish-brown above, calyculus funnel-shaped,
occupying the lower third of sporangium, with radiating ribs,
margin eroded, nodes of network large, angular, coloured, with
prominent, acute processes, containing granules, united by very
slender threads; stem about equal in length to sporangium, subequal,
purple-brown, expanding at the base into a hypothallus
of the same colour; spores very pale salmon-colour, globose,
smooth, 5—7 g diameter.
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