Saprolegnia - The iLumina Digital Library

Saprolegnia lapponica Gäumann, ibid., p. 156. 1918.
Saprolegnia tokugawana Emoto, Bot. Mag. (Tokyo) 37:15, pl. 1. 1923.
Saprolegnia monoica var. floccosa (Maurizio) Cejp, Oomycetes I, Flora ČSR, Ser. B, Part 2,
p. 234, figs. 85 g-j, 86. 1959.
Saprolegnia ferax var. lapponica (Gäumann) Cejp, ibid., p. 245. 1959.
Saprolegnia ferax var. esocina (Maurizio) Cejp, ibid., p. 246. 1959.
Saprolegnia monoica var. acidamica Suzuki, J. Jap. Bot., 36:234. 1961.
Monoecious. Mycelium stout, hyphae moderately to sparingly branched.
Sporangia clavate, fusiform, cylindrical, or slightly irregular, sometimes nearly
spherical; straight or bent; renewed internally with secondary ones nesting inside
discharged primary ones, or partially emerged through orifices of empty sporangia and
forming bead-like chains or cylindrical segments, or emerging fully through orifices of
previously emptied sporangia; rarely renewed in a basipetalous or cymose manner; 31-
624 x 18-67 µm. Spores dimorphic; discharge and behavior saprolegnoid, rarely
aplanoid or dictyucoid, very rarely achlyoid or leptolegnoid; primary spore cysts 9-12
µm in diameter. Gemmae, when present, variable in shape and position. Oogonia
lateral, terminal, or intercalary and then single or catenulate, infrequently occurring in
emptied sporangia or sessile; spherical, obpyriform, napiform, sometimes obovate or
clavate, cylindrical when in discharged sporangia, often dolioform when intercalary;
(28-) 60-80 (-194) µm in diameter. Oogonial wall generally conspicuously and
abundantly pitted, rarely unpitted; smooth or rarely with one or two short, papilliform
evaginations, or apiculate. Oogonial stalks ( 1 / 3 -) 1-2 (3 1 / 2 ) times the diameter of the
oogonium, in length; stout, straight, bent, or curved; very rarely once-branched.
Oospores centric or subcentric, spherical or ellipsoidal; (1-) 10-18 (-54) per oogonium
and nearly filling it, (12-) 22-28 (-44) µm in diameter; germinating by a slender germ
hypha that may or may not bear a small, apical, clavate sporangium. Antheridial
branches variable in abundance and density, and sometimes absent; when present,
monoclinous or androgynous, rarely diclinous; slender, slightly to prominently
irregular, unbranched or very sparingly branched; persisting. Antheridial cells simple;
generally tubular or clavate, occasionally irregular, infrequently once-branched; usually
persisting; laterally appressed, very rarely attached apically; fertilization tubes present,
not persisting.
Based on a survey of existing literature and the characterization of a generous
collection of living material, Seymour (1970) demonstrated that Saprolegnia ferax was a
complex of morphological variants. Many of the various forms that had from time to
time been described, he concluded, were recognizable as individuals, but at the same
time occupied some point in a long series of morphological gradients. Accordingly, he
proposed a very extensive synonymy (Seymour, 1970:29, 30) for S. ferax; this is adopted
here with minor corrections. Discussion of the synonymous species beyond that
provided by Seymour is unnecessary. Florinskaya (1968) has also studied extensively
the degree of morphological variability in S. ferax, particularly that to be found in
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