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Diachaea, Fr.
Wall of sporangium without lime externally, but sometimes
containing scattered granules on its inner surface, thin, usually
with metallic tin ts ; columella either thick and elongated, rigid
with amorphous lumps of lime, or more or less rudimentary
and represented by an accumulation of lime at base of sporangium;
capillitium forming a dense net, springing from the
columella or base of sporangium, threads usually coloured,
without lime, thickest at tbe point of origin.
Diachaea, Fries, Syst. Orb. Veg., i., p. 143; Fr., Syst. Myc.,
iii,, p. 155; Rost., Mon., p. 190; Cooke, Myx. Brit., p. 44;
Sacc., Syll., p. 387.
Although placed in a different order by Rostafinski, Lampro-
derma approaches the present genus so closely, that it is open
to doubt whether the two genera, as at present understood,
should not be merged into one. Tbe generic diagnoses of the
two, as given by Rostafinski, illustrate the two poles of tbe
genus in tbe larger sense, and read very distinct, but when a
complete sequence of the species included in tbe two genera
are examined, then tbe difficulty of “ drawing tbe line ” becomes
only too apparent, and the only character that remains is, the
presence of lime in the columella and stem in Diaehaea, and
its absence in Lamproderma. In Lamproderma violaeea, Fr.,
tbe columella is filled with large vesicles as in Trichia fallax,
and in Lamproderma suboeneus, B., well-developed granules of
lime are by no means rare in the threads of the capillitium;
lime is by no means always absent from the capillitium of
several species of Stepionitis, and other genera belonging to
the order Amaurochaete, the most important feature of which
consists in the absence of lime.
Diaehaea is as far from being a typical member of tbe
Calcareae, owing to the entire absence of lime on tbe surface
of the wall of the sporangium, as it is from being typical ot
the Amauroehaeteae on account of the lime contained in tbe
columella and stem.
Distrib. Europe; United States; W. Indies; Brazil; S. Africa;
India; Australia; New Zealand. Species 5.
Sub-Gen. Diaehaea.
Columella well developed, elongated, rigid with amorphous
masses of lime.
A. Spores smooth.
D i a c h a e a c o n f u s a , Mass. (n. sp.).
Gregarious, springing from a thin, irregular, yellowish hypothallus
; sporangia elliptico-oylindrical, stipitate, obscure purple,
iridescent, stem equal to, or a little shorter than tbe sporangium,
pale ochraceous, subegual, slightly wrinkled longitudinally;
columella two-thirds the height of the sporangium, dirty pale
ochraceous, subelavate, filled witb masses of lime, very b rittle ;
threads of tbe capillitium springing from the columella, much
branched and irregularly anastomosing to form a very dense net,
about 3 g thick near the columella, tapering, pale olive or
smoky; spm-es at first in clusters of 6—8, smooth, globose, o—Ag
diameter, dingy lilac.
(Type in Herb., Kew.)
Sporangia 2’5—3 mm. h igh; distinguished by the ochraceous
subequal stem and the small spores in clusters of 6—8. Tbe
capillitium is very dense, and the columella so very brittle
that it requires care to see it intact.
On living geranium leaves. Jamaica.
; n :■ ■j :
1 I
D i a c h a e a l e u c o p o d a , Rost. (figs. 165, 166).
Gregarious, springing from a spreading white hypothallus;
sporangia elliptico-cylindrical, stipitate, brownish-purple, sometimes
iridescent, often subumbilicate below; stem shorter than
sporangium, lohite, thin above, expanding considerably downvoards,
smooth; passing upwards as a thick, equal or slightly tapering
columella about tioo-fhirds the length of the sporangium, white,
and filled with granules of lime; mass of spores blackish;
capillitium Qense, threads springing from the columella where
they are 3—4 g thick, much branched and irregularly anastomosing
to form a dense net, becoming thinner and attached