The North American Slime-Moulds Part 40

West of the Mississippi River chiefly: Iowa, South Dakota, Nebraska, Kansas, Oklahoma, New Mexico, etc.

9. STEMONITIS SPLENDENS _Rost._

PLATE VI., Figs. 6, 6 _a_, 6 _c_, 7, 7 _a_.

1875. _Stemonitis splendens_ Rost., _Mon._, p. 195.

1880. _Stemonitis morgani_ Peck, _Bot. Gaz._, V., p. 33.

1893. _Stemonitis splendens_ Rost., Macbr., _Bull. Lab. Nat. Hist._, Vol. II, p. 381.

1894. _Stemonitis splendens_ Rost., List., _Mycetozoa_, p. 112, in part.

1899. _Stemonitis morgani_ Peck, Macbr., _N. A. S._, p. 118.

1911. _Stemonitis splendens_ Rost., List., _Mycetozoa, 2nd ed._, p. 145.

Sporangia cl.u.s.tered irregularly, sometimes forming patches 6-10 centimetres or more in extent, rich purple-brown in ma.s.s, cylindric, long, 15-18 mm., stipitate; stipe black, polished, s.h.i.+ning, rising from a common hypothallus, which extends as a thin silvery film beneath the entire colony, but does not usually transcend its limits; columella black, percurrent, sparingly branched; capillitium of fuscous threads, within forming a network very open, the branches scarcely anastomosing until they reach the surface where they form the usual net of small meshes, pretty uniform in size, and presenting very few small, inconspicuous peridial processes; spores brown, very minutely warted, about 8 .

This elegant species occurs not rarely on rotten wood, usually in protected situations, although sometimes on the exposed surfaces of its habitat. The sporangia attain with us unusual height, sometimes 2 cm.; plasmodia, 6-8 cm., in diameter. The clear brown tufts appear in the autumn, marvels of graceful elegance and beauty; at sight easily recognizable by the large size and rich color. In Iowa it is almost universally present on fallen stems of _Acer saccharinum_ Linn., and it appears to be widely distributed, by far the most beautiful of all this beautiful series.

New England to Iowa, South Dakota, Was.h.i.+ngton, and British Columbia.

Professor s.h.i.+mek brings a _dusky_ phase from Nicaragua!--the type?

The plasmodium is white on maple stems, more creamy on stems of linden, on which wood it is more rarely found: occasionally on ash-stumps; even on the fallen bark of trees preferred.

In 1875 in his famous _Monograph_, Rostafinski set out three species with "dusky violet spores". These are his Nos. 94, 95 and 96.

The first one of these he calls _S. fusca_, "spore-ma.s.s, etc., violet-black, individual spore clear violet, smooth, 7-9 u."

The second species he writes down _S. dictyospora_, "hypothallus, stalk, columella, capillitium and spore-ma.s.s, violet-black, spore netted and fringed, clear-violet, 7-9 ."

The third species is _S. splendens_, "hypothallus stalk, columella and spore-ma.s.s violet-black, spore smooth, clear-violet, 7-8 ."

It will be observed that in color down to color of the spore by transmitted light, the three species are exactly the same; const.i.tute a suite, so to say. It has since turned out, as noted under our No. 3, that the spores of _S. fusca_ are netted. Error in description here is not surprising; the reticulations are sometimes faint. In _S.

dictyospora_ they are admittedly strong, and the inference was that the '_gladkie_' spores of the third species might be netted also. This is no criticism: lenses were fifty years since not nearly so good for such discoveries as the oil-immersion is now.

However; Rostafinski made his specific diagnosis turn largely upon the mesh-width in the superficial net. This comes out in the '_opis_'

following the description, and upon _this_ the European decision in Rostafinski's favor as against _S. morgani_ largely turns. Tropical gatherings are probably always darker, and evidently from such, from the north coast of South America, the original description was drawn.

Specimens before us from the same lat.i.tude are dusky indeed; no clear brown at all, but purplish withal.

For the sake of harmony we may therefore now subst.i.tute the earlier name "with reservations"! but our description remains as before, presenting the really splendid, s.h.i.+ning things that adorn our northern fields. Dr.

Rostafinski called the large open meshes of the net '_oka_', eyes; _lumina_ let us say! quite uniform they are in 9 and 10, much less so in 8.

10. STEMONITIS FENESTRATA _Rex._

1890. _Stemonitis splendens_ R. _f. fenestrata_ Rex, _Proc. Phil.

Acad._, p. 36.

Sporangia aggregated, in tufts 2 cm. or more in diameter, rich purple brown, on a common hypothallus, more or less erect, stipitate, tall, about 2 cm., slender, triangular in section; stipe black, about one-third the total height, pa.s.sing into a slender columella which is lateral in position, not central, but little branched, continued almost to the apex; the capillitium consisting almost entirely of the peripheral net, which presents meshes of unusual uniformity of size and shape; spores in ma.s.s brown, colorless by transmitted light, nearly smooth, 6-7.5 .

The remarkable shape of the sporangium and the peculiar regularity of the surface net, the lateral columella, all combine here to warrant the erection of a distinct species. Dr. Rex referred this to _S. bauerlinii_ Ma.s.s. At that time he had not the author's description, and had seen only a very poor fragment received with notes in a letter. Mr. Ma.s.see's description makes it immediately evident that whatever other affiliations _S. bauerlinii_ may have, by description it has at least none with _S. fenestrata_ nor with our northern form of _S. splendens_.

Ma.s.see's species is described as having the "ma.s.s of spores black", the capillitium with "branches springing from the columella; the main branches more and more numerous, thicker and irregular towards the apex of the sporangium, and often form irregular flattened expansions":--etc.

This suggests some form of _S. dictyospora_ Rost.: see under our No. 5.

Possibly for such reasons Lister referred it to _S. splendens_ Rost., which as we have just seen, was undoubtedly regarded by the author as a form of the _fuscous_ group.

The long, slender, simple columella is not only lateral, but occupies indeed the sharp vertical angle of the triangular, prismatic sporangium.

Furthermore, the sporangium is at maturity strangely twisted, so that the columella in its ascent accomplishes one or more spiral turns. In forms collected by Dr. Rex, which seemed to him most nearly to agree with Ma.s.see's species, the inner capillitium is somewhat abundant, but the character of the columella just the same.

Pennsylvania, Ohio, Kansas, Colorado, Iowa; India!

11. STEMONITIS SMITHII _Macbr._

1893. _Stemonitis smithii_ Macbr., _Bull. Lab. Nat. Hist. Ia._, II., p. 381.

1894. _Stemonitis microspora_ List., Morg., _Jour. Cin. Soc._, p. 54.

1911. _Stemonitis ferruginea_ var. _smithii_ Lister, _Mycetozoa, 2nd ed._, p. 150.

Sporangia in small cl.u.s.ters, close-packed and erect, not spreading, bright ferruginous prior to spore dispersal, cylindric, stipitate, of varying height; stipe jet-black, s.h.i.+ning, about one-third the total height; hypothallus generally well developed; columella black, gradually tapering, at length dissolving in capillitial threads and net some distance below the diminished plumose apex; capillitium of fuscous threads, the inner network of abundant, sparingly united branches uniformly thickened, the surface net very delicate, composed of small, regular, polygonal meshes, the peridial processes few; spore-ma.s.s bright ferruginous, spores by transmitted light pale, almost colorless, smooth, 4-5 .

The species as thus const.i.tuted includes forms varying in size from 2.5-3 mm. only. The common form heretofore known everywhere in America as _S. ferruginea_ is from 10-15 mm. high. The _type_ to which the specific name _S. smithii_ was originally applied is 2.5 mm. high and rejoices in smooth, almost colorless spores, 4-5 .

The plasmodium in the case of the species now considered is as concerns the _type_, of course, unknown. In one or two gatherings referred here the color of the plasmodium was noted greenish-yellow. This has the look of _S. flavogenita_; but small spores and delicate make-up take it the other way. Miss Lister makes it varietal to No. 12, next following.

12. STEMONITIS AXIFERA (_Bull._) _Macbr._

PLATE VI., 5, 5 _a_, and 5 _b_.

1791. _Trichia axifera ferruginea_ Bull., _Champ. de la Fr._, p. 118, tab. 477.

1818. _Stemonitis ferruginea_ Ehr., _Syl. Myc. Berol._, p. 20; et auct. Europ. ex parte; Americ., non.

1894. _Stemonitis ferruginea_ Ehr., List., _Mycetozoa_, p. 115, in part.

1899. _Stemonitis axifera_ (Bull.) Macbr., _N. A. S._, p. 120, in part.

1911. _Stemonitis ferruginea_ Ehr., Lister, _Mycetozoa, 2nd ed._

Sporangia terete, ac.u.minate, fasciculate small in dense cl.u.s.ters, distinctly ferruginous in color, stipitate, from 10-15 mm. in height; the stipe black one-third to one-half the total height, not s.h.i.+ning or polished; columella evenly branching, dissipated before reaching the ac.u.minate apex; capillitium-branches clear brown anastomosing and dividing more or less to bear the superficial fine-meshed net; spores pallid, faintly ferruginous, smooth or nearly so, 5-6 .

This would seem to be the common _ferruginous_ species of the world.

Doubtless Micheli had the thing before him when he drew Tab. 94, _clathroidastrum_, Hoffman and Jacquin seem to have recognized the form.

To be sure, under the present plasmodic limitations we cannot be quite certain about these references. Not until 1791 does anyone write down a particular species as marked by a white plasmodium, and distinguish it from other similar fructifications having similar origin. Bulliard, _l.

c._, does this, discriminating between _T. axifera ferruginea_ and _C.

typhoides_; see under the last-named species. Youthful Ehrenberg, in his doctor's thesis, nearly thirty years later, draws a similar parallel but ignores the great French author, writing _S. ferruginea_ Ehr. as though the thing had never been seen before! By this name it has been called until very lately; Fries accepting it, but noting that the plasmodium, for him at least, was _yellow_!

In 1904 Dr. E. Jahn, following Fries' suggestion, established the fact that Ehrenberg's white-plasmodic species had small spores, that Fries had in mind a form with larger spores, having indeed yellow plasmodium; but see number 13 below.

It is for the present a.s.sumed that the plasmodium of our American _S.

axifera_ is white. So far, there are few or no observations which establish the fact. The color, the small smooth spores, the fine-meshed capillitial net and the general dimensions determine the reference.

13. STEMONITIS FLAVOGENITA _Jahn._