The North American Slime-Moulds Part 68

1875. _Trichia lateritia_ Lev., Rost., _Mon._, p. 250.

1892. _Trichia fragilis_ (Sow.) Rost., Ma.s.s., _Mon._, p. 176.

1894. _Trichia botrytis_ Pers. var. _lateritia_ (Lev.) List., _Mon._, p. 171.

1899. _Trichia botrytis_ Pers., Macbr., _N. A. S._, p. 216.

1911. _Trichia botrytis_ Pers. var. _lateritia_ (Lev.) List., _Mycetozoa, 2nd ed._, p. 217.

Sporangia more or less closely gregarious, (_a_) simple globose-turbinate, dull black when dry, when moist generally with a vinous tinge, 1 mm. in diameter, stipitate. The stipe concolorous, rigid, erect, simple even, 2-6 mm., or (_b_) multiple, several sporangia united by their pale brown or reddish-brown, striate, weak, closely adherent or united stems; hypothallus small or none; capillitial-ma.s.s bright brick-red cut-off from the stem-cavity, such as may be, and enclosed by a thick, firm opaque peridium, which opens above in fragmental or petaloid lobes, leaving a craterium-like cup below, to persist in flower-like fas.h.i.+on long after the contents have blown away; elaters fusiform, extremely long, to 50 ; about 5 in width at the widest (middle) point, long ac.u.minate, adorned with usually four clean-cut even, regular, taeniae, uniformly s.p.a.ced and carried forward on the progressive ac.u.mination, almost to the smooth, straight spine-like point; spores in ma.s.s brick-red, by transmitted light, orange-brown almost smooth, 10-12 .

This showy and remarkable species is set out from _T. botrytis_ Pers.

with which it has been more or less closely a.s.sociated, for several reasons. In the first place, it is easily recognized in the field, by its size, color, and structure. Often simple throughout a colony entire, nevertheless where the vegetative development has been stronger, simple and multiple fructifications may stand side by side, but the odd fasciation is generally limited to few sporangia, perhaps three or four, or at most, half a dozen. These fasciate forms generally shorter, or less erect. The elaters, so far as our observation goes, are the longest in the genus notable for their beautiful symmetry. The spores are larger than in the red forms of _T. botrytis_ as usually presented, smoother and of different color.

We have also a geographic limitation. Taken to Paris first from southern Chile, it promises to be a Pacific coast species, found as it now has been in North America from San Diego, to Vancouver. In a deep forest near Monterey, California, a half-buried log showed one colony a meter in length and from six to twelve centimetres in width, hundreds of sporangia, each by gentlest explosion opening to display its tuft of bright-tinted wool, a patch of color visible from far.

=4. Oligonema.=

1875. _Oligonema_ Rost., _Mon._, p. 291.

Sporangia distinct, small, generally crowded together and superimposed; hypothallus none; capillitium scanty, the sculpture rudimentary and imperfect, scattered rings or mere roughenings, sometimes imperfect or faint spirals; spores yellow.

The oligonemas are simply degenerate _Trichiae_, and show the vagaries usually to be noted in a pa.s.sing type. They are difficult to define, and the species are indeed variable. Those here listed seem to offer constant features throughout our range.

=Key to Species of Oligonema=

_A._ Spores reticulate.

_a._ Sporangia in broad effused patches 2. _O. brevifilum_

_b._ Sporangia in small heaped cl.u.s.ters.

i. Elaters roughened, no distinct rings or spirals 1. _O. flavidum_

ii. Elaters with scattered rings; sometimes faint spirals 3. _O. nitens_

B. Spores warted 4. _O. fulvum_

1. OLIGONEMA FLAVIDUM (_Peck_) _Ma.s.s._

1874. _Perichaena flavida_ Peck, _Rep. N. Y. Mus._, p. 76.

1892. _Oligonema flavidum_ (Peck) Ma.s.s., _Mon._, p. 171.

Sporangia crowded and superimposed, sessile in small ma.s.ses or cl.u.s.ters 1 cm. or less, bright yellow, s.h.i.+ning, the peridium thin but opaque, yellow; capillitium of long, slender tubules usually simple, anon branched, even, or with an occasional inflation, the sculpture confined to warts or small, distinct spinules, roughening more or less conspicuously the entire surface, the apices generally obtuse, anon apiculate; spore-ma.s.s yellow, spores under the lens pale yellow, irregularly globose, beautifully reticulate, the meshes large and few, as in _Trichia favoginea_, 12-14 .

This species is marked by its capillitium, which is abundant for the present genus. The threads are longer than in any other species, and not infrequently branched, smooth, or more commonly, very distinctly minutely spinulose throughout, no trace of rings or relief sculpture of any sort, the spirals, that are to be expected, very imperfect, if discernible at all. In habit the species resembles _O. nitens_, but the colonies are much larger, and the sporangia higher and larger, attaining 1 mm.

New England to Iowa and Nebraska; south to Alabama and Louisiana.

Toronto; _Miss Currie._

2. OLIGONEMA BREVIFILUM _Peck._

PLATE XX., Figs. 5, 5 _a_.

1878. _Oligonema brevifila_ Peck, _Rep. N. Y, Mus._, p. 42.

Sporangia small, cylindric, dull ochraceous-yellow, sessile closely crowded, sometimes superimposed, forming large, effused patches several centimetres in extent; capillitium exceedingly scant, consisting of nothing more than a few minute threads, very short, only three or four times the diameter of the spore, smooth, or without any definable sculpture, ochraceous; spore-ma.s.s dark ochraceous, under the lens the spores are brighter, marked with reticulations much as in other species of the genus, 10-12 .

Probably a variety of our No. 1, but constantly collected.

Separate, however, from the following also in color and habit. To the naked eye the fructification suggests _Trichia persimilis_; the color much the same, and the sporangia similarly congested. The peculiarly rudimentary condition of the capillitium is apparently also constant.

Iowa specimens accord perfectly with those from New York.

Rare. New York, Ohio, Pennsylvania, North Carolina, Iowa, Missouri, Oregon, Was.h.i.+ngton, California; Vancouver Island.

3. OLIGONEMA NITENS (_Lib._) _Rost._

PLATE II., Figs. 8, 8 _a_, 8 _b_.

1834. _Trichia nitens_ Lib. _Pl. Cr. Ard._, III., No. 227.

1875. _Oligonema nitens_ (Lib.) Rost., _Mon._, p. 291.

1883. _Trichia pusilla_ Schroet., _Kr. Fl. Schl._, III., p. 114.

Sporangia gathered in small, heaped cl.u.s.ters, irregularly spherical, bright straw-color, or yellow, sessile, superimposed, the peridium thin, smooth, s.h.i.+ning; capillitium of short elaters, simple or branched, smooth, adorned with an occasional projecting ring, often with faint spiral sculpture spreading especially toward the apices, which are blunt or anon acute, the point sometimes flexed or bent to one side, never very long; spore-ma.s.s bright yellow, spores globose, beautifully reticulate, 12-14 .

Readily recognized at sight by its heaped, s.h.i.+ning, or glistening sporangia. The capillitial threads are further definitive, and serve to distinguish it from everything else.

The range is wide, probably coextensive with the forests of the country.

Specimens are before us from New England, Canada, Montana, and all intervening regions, and south to the Gulf of Mexico; California, Nevada,--_Prof. Bethel._ Yosemite, sh.o.r.es of Mirror Lake!

4. OLIGONEMA FULVUM _Morgan._

1893. _Oligonema fulvum_ Morgan, _Jour. Cin. Soc._, p. 42.

Sporangia large, sub-globose, sessile, or crowded, more or less regular; the peridium tawny yellow, or olivaceous, very thin and fragile, iridescent; ma.s.s of capillitium and spores tawny-yellow, elaters simple or sometimes branched, very short, sometimes with thicker swollen portions, the surface marked with low smooth spirals, in places faint and obsolete, the extremities rounded and obtuse, usually with a minute apiculus; spores globose, minutely warted, 10-13 .

This species may be recognized by its tawny, irregular, more or less crowded sporangia. Under the lens the warted, not reticulate, spores are diagnostic. The elaters are quite constantly marked by imperfect spirals.

Our specimens are from the author of the species, and so far there are none reported from outside Ohio.

FOOTNOTES:

[15] For other crucifers, see _Bull. Torr. Bot. Club_, xxi, pp. 76-8.

[16] See in reference to this whole matter, _Myxomycetenstudien_ by E.

Jahn, No. 7, _Ceratiomyxa_, 1908. See also Olive, _Trans. Wis. Acad. of Sci. Arts and Letters_, Vol. xv, pl. II, p. 771.