Saprolegnia - The iLumina Digital Library

Saprolegnia irregularis is recognized by its prominently irregular oogonia and
often profusely developed fertilization tubes (Fig. 94 H, K, M). No other known species
in the genus has this combination of characters.
The hypogynous antheridial cells (not all oogonia are attended by these) of
Saprolegnia irregularis are of two types. Generally, the apex of the cell is prolonged into a
fertilization tube (Fig. 94 M), but occasionally the apex is open (into the oogonial
cavity), and secondary antheridial cells proliferate internally (Fig. 94 J, L, N). Precisely
how the antheridial apparatus functions in this species is not known, and it is
conceivable that the distally poroid cells (Fig. 94 H) simply may represent ones from
which the fertilization tube has deliquesced. In any event, the internally proliferated
cells recall Maurizio’s (1894) belief that the hypogynous cells and fertilization tubes in S.
hypogyna were merely expressions of renewed growth.
CONFIRMED RECORD: -- ICELAND: Johnson and Seymour (loc. cit.). INDIA: J.
N. Rai and Misra (1977b:76, fig. 3b).
SPECIMENS EXAMINED: - ICELAND (7), TWJ.
Saprolegnia turfosa (Minden) Gäumann
Bot. Not. 1918:154. 1918
(Figure 95 A-C)
Saprolegnia spec. (2) Reinsch, Jahrb. Wiss. Bot. 11:295, pl. 14, figs. 7-13. 1878.
Saprolegnia paradoxa Petersen Bot. Tiddskr. 29:379, fig. l d, e. 1909 (also in Ann. Mycol.
8:520, fig. l d, e. 1910); non S. paradoxa Maurizio, Z. Fischerei und deren
Hilfswiss., Mitt. Deutsch. Fischerei-Vereins 7:46, figs. 10-12. 1899.
Saprolegnia monoica var. turfosa Minden, Kryptogamenfl. Mark Brandenburg 5:516. 1912.
Aplanes turfosus (Minden) Coker, J. Elisha Mitchell Sci. Soc. 42:216. 1927.
Aplanes ozeensis Kobayasi, in Kobayasi and Ookubo, J. Jap. Bot. 27:181, figs. 9, 10. 1952.
Monoecious. Mycelium stout; hyphae sparingly branched. Sporangia fusiform,
clavate, or cylindrical; straight, curved, or moderately irregular; renewed internally;
102-627 x 18-66 µm. Spores dimorphic; discharge and behavior saprolegnoid,
infrequently aplanoid; primary spore cysts 9-11 µm in diameter. Gemmae sparse or
absent; when present, cylindrical, obpyriform, irregular, or branched; terminal, rarely
intercalary; predominantly single. Oogonia lateral, rarely terminal, intercalary, or
sessile; spherical, rarely ovoid or subspherical; (18-) 60-85 (-134) µm in diameter,
including wall ornamentations. Oogonial wall conspicuously pitted; smooth or rarely
with a few short, broad papillae. Oogonial stalks very short, predominantly ( 1 / 8 -) 1 / 4 -
1 / 2 (-2) times the diameter of the oogonium, in length; stout, straight or curved;
unbranched. Oospores centric; spherical or ellipsoidal; (1-) 6-16 (-42) per oogonium, and
usually filling it; (16-) 26-31 (-37) µm in diameter; germination not observed.
Antheridial branches androgynous, infrequently monoclinous and arising near the
oogonial stalk; short, curved or bent, unbranched or branched; persisting. Antheridial
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