This seems to be a cosmopolitan species, now that we have found it.

However, in North America it is rare. It is reported from Pennsylvania, from Colorado; Harkness found it in California, and the writer has often collected it in Oregon, on Mt. Rainier, Washington, and in California.

Europe.

39. PHYSARUM NOTABILE _nom. nov._

PLATE IX., Figs. 2, 2 _a_, 2 _b_; PLATE XV., Fig. 2; and Frontispiece.

1873. _Didymium connatum_ Peck, _Rep. N. Y. Mus._, XXVI., p. 74.

1879. _Physarum polymorphum_ (Mont.) Rost., Peck, _Rep. N. Y. Mus._, x.x.xI., p. 55.

1893. _Physarum leucophaeum_ Fr., Ellis, _N. A. F._, No. 2396, _second exhibit_.

1893. _Physarum leucophaeum_ Fries, Macbr., _Bull. Lab. Nat. Hist.

Iowa_, II., p. 156.

1894. _Physarum compressum_ Alb. & Schw., List., _Mycetozoa_, p. 53, in part.

1896. _Physarum connexum_ Link., Morg., _Jour. Cin. Soc._, p. 92, in part.

1896. _Physarum confluens_ Pers., Morg., _l. c._, p. 94.

1899. _Physarum nefroideum_ Rost., Macbr., _N. A. S._, p. 41, in part.

1911. _Physarum connatum_ Lister, _Mycetozoa, 2nd ed._, p. 71.

Sporangia gregarious, sessile, stipitate, or even plasmodiocarpous; when stipitate, depressed, varying at times to irregular reniform in the same colony; globose, the peridium strongly calcareous, cinereous-white; stipe variable, generally tapering upward, always distinctly deeply plicate-furrowed throughout, in color dark, opaque, sometimes touched with white or gray; capillitium abundant, the white lime-knots, varying in size and shape, connected by rather long hyaline threads, with here and there an empty node; spore-ma.s.s black, by transmitted light, dark, sooty brown, minutely papillose, 10-11.5 .

This remarkable species, while not at all difficult of recognition to one familiar with its phases, is withal very difficult to define.

Normally stipitate, it often shows from the same plasmodium all sorts of forms, the shape of the fructification dependent apparently upon external conditions prevalent at the time. The amount of calcium also varies, especially in the capillitium, where there is usually much, with a tendency to the formation of something like a pseudo-columella; the outer net in such cases nearly dest.i.tute. The calcium in the stipe also varies; the black or brown stipes are, of course, free from it; the gray or white, calcareous.

In this large and difficult genus, since spore-color is receiving increased consideration,--see No. 31 preceding,--it is proper to note that in the present case two types appear, one with spore-color under the lens, as described, the other with spores violaceous with no trace of black; unshadowed.

The preceding description is based on material a.s.sembled during forty years. The form is easily discoverable by any collector throughout the entire valley of the Mississippi and eastward to Nova Scotia. For its naming, students in America have vainly waited the decision of those having access to mycologic types in Europe. It seems now certain that the species is extremely rare in the old world if there occurrent; never seen by any of the earlier taxonomists including Fries and Rostafinski; perhaps advent.i.tious in these later years, although thus far no specimen from Europe has reached this table.[24] _P. nefroideum_ of Strasburg herbarium turns out, after all, _teste_ Lister, to be _P. compressum_ Alb. & Schw., which accordingly shall now enjoy state and station of its own; our concern in European nomenclature, in the present instance, almost disappears, and we return to our synonymy from this side of the sea.

Mr. Lister would recur to Dr. Peck's _Didymium connatum_, which indeed represents the present species. In such disposition, how gladly would all concur, were the thing possible! But _Physarum connatum_ is already a synonym twice over.[25] Unless we are done with the rules entirely, _P. connatum_ cannot stand. _P. polymorphum_ and _P. leucophaeum_ are names already in use, of course; and so under the circ.u.mstances, much as it is to be regretted, there would seem nothing left to do but to cancel all past synonymy and impose a new name whose permanence may at least be hoped for, if not expected.

40. PHYSARUM TROPICALE _Macbr._

1899. _Physarum tropicale_ Macbr., _N. A. S._, p. 45.

PLATE XV., Figs. 4, 4 _a_, 4 _b_.

Sporangia scattered, gregarious, turbinate, short stipitate, blue-gray, about 1 mm. in diameter; peridium above iridescent, green, blue, etc., dotted with minute flecks of white, below limeless, purple or bronze shading to the brown of the stipe; stipe short, stout, slightly rugose, cylindric, non-calcareous, brown; columella none; hypothallus none; capillitium abundant, the nodes generally calcareous, small, uniform, angular, white, uniformly distributed; spore-ma.s.s, black; spores dark violet-brown, distinctly and closely warted, 12-15 .

A large handsome species recognizable by the peculiar turbinate sporangium, with its iridescent peridial wall in which green strongly predominates above, bronze below. The distinction between the upper and lower peridium would suggest _Craterium_, but the internal structure is not at all _Craterium_-like. The capillitium is typically of _Physarum_.

The color suggests _P. leucophaeum violascens_ Rost. From this species it is at once distinguished by its much longer sporangia, larger and rougher spores.

Mexico; _C. L. Smith_: Sure to be again collected once that unhappy country shall again open its forests to research.

41. PHYSARUM NICARAGUENSE _Macbr._

PLATE XV., Figs. 7, 7 _a_, 7 _b_; XVII., 11 and 11 _a_.

1893. _Physarum nicaraguense_ Macbr., _Bull. Lab. Nat. Hist. Iowa_, II., p. 383.

1894. _Physarum compressum_ Alb. & Schw., List., _Mycetozoa_, p. 53, in part.

1910. _Physarum nicaraguense_ Macbr., Petch, _Mycetozoa Ceylon_, p. 334.

1911. _Physarum reniforme_ List., _Mycetozoa, 2nd ed._, p. 72, in part.

Sporangia multilobate or compound-contorted, below obconic, gray, ribbed with calcareous thickenings; stem short, fuscous, longitudinally wrinkled; hypothallus distinct, black; columella none, although the lime ma.s.sed at the centre of each sporangium simulates one; capillitium white, densely calcareous, with heavy angular nodules connected with comparatively short threads; spores violet, globose, spinulose, about 12 in diameter.

Ometepe, Nicaragua. _Professor B. Shimek_.

This species resembles in some particulars No. 39, especially in the amount of lime present in both capillitium and peridium, in the fluted, sooty stipe, and the rough spores. Mr. Lister once regarded it as the same. Nevertheless, it differs from _P. notabile_ in many definite particulars. In the first place, the sporangia are different in form and habit. They are obconic, nearly always compound, convolute, or botryoid, in this respect somewhat resembling _P. polycephalum_. Besides, the sporangia are uniformly much smaller, and show constantly the strongly calcified centre, much transcending anything seen in _P. notabile_. The stipe also is peculiar, quite short, an upward extension or sweep of the common hypothallus which is usually very distinct or prominent; and, while the stipe is longitudinally wrinkled, it is much less so than in the related species, and in a different way. The spores are about the same in size, but differ in color, in this respect agreeing rather with _P. leucophaeum_.

In the _Mycetozoa, 2nd ed., l. c._, the present species is entered as a synonym of two described by Ma.s.see: _Tilmadoche reniformis_ Ma.s.s., Mon., p. 336, and _Didymium echinosporum_ Ma.s.s., _Mon._ 239. But Ma.s.see's description of his tilmadoche is, naturally enough, at variance in every important point with the facts in the species before us. Ma.s.see says: "... sporangia deeply umbilicate _below_, sausage-shaped and curved; the stem elongated slender erect, pale brown; capillitial nodes scattered, fusiform, colorless or yellow; spores 16-17 ." It is evident that whatever Ma.s.see may have had in hand as he wrote it was _not P.

nicaraguense_, which has spores 10-12 and reverses the remaining description.

But _Didymium echinosporum_ also defines _T. reniformis_ since Lister, _Mon._, p. 54, says they are based on two gatherings of one species. Of this second species Ma.s.see says: "A superficial resemblance to _T.

nutans_, but distinct in the capillitium which contains _no trace of lime_; spores 12-14 !" Again it is evident that whatever Ma.s.see had in hand when he wrote, it was not _P. nicaraguense_ which "has capillitium almost Badhamia-like," i. e., burdened with lime!

Worse than all; Mr. Ma.s.see's _alleged_ types are in evidence; one labelled _P. reniforme_[26] includes forms of _P. didermoides_ and of _P. nicaraguense_; the other labelled by Berkeley _P. nutans_ is _P.

nicaraguense_. So Mr. T. Petch, _Mycet. Ceyl._, who enters our species as from Ceylon, and the names cited from Berkeley, Ma.s.see, and others, as synonyms. He remarks, "Probably Thwaites' 135 and 55 were mixed during examination"! Doubtless! and some other things too! What Ma.s.see did have beneath his lens, no one now may say but apparently not in either case cited, the physarum of Central America.

42. PHYSARUM SULPHUREUM _Alb. & Schw._

1805. _Physarum sulphureum_ Alb. & Schw., _Consp. Fung._, p. 93, Tab. VI, f. 1.

1818. _Physarum flavum_ Fries, _Symb. Gast._, p. 22.

1875. _Physarum sulphureum_ Alb. & Schw., Rost., _Mon._, p. 101.[27]

Sporangia gregarious, sub-globose, rugulose-squamulose, .6-.8 mm., sulphur-yellow, stipitate; peridium membranous, covered with calcareous scales; stipe stout, white, charged with lime, furrowed; columella none; capillitium strongly calcareous, the nodules large, white; spores violaceous, rough, 9-11 .

Northern Europe. (Lusatia) Lausitz, Alb. & Schw.; dim old Wendish region on the south borders of Brandenburg. Reported also from Sweden.

The description and figure given by Schweinitz, 1805, _l. c._, leave no doubt as to what he had in hand. Twenty or thirty years later, having spent the interval in this country,--bishop, indeed, of the Moravian churches, but a student of fungi all the while,--he reports the same thing from this country; _Proc. Phil. Acad. Sci._, 1834. Cooke also lists it in _Myxomycetes of the U. S._ It surely will be found again.

Mr. Lister thinks _P. variable_ Rex may be the same thing.

43. PHYSARUM CARNEUM _G. Lister and Sturgis_.

1910. _Physarum carneum_ G. Lister and Sturgis, _Jour. Bot._, Vol. XLVIII, p. 63.

Sporangia gregarious, stipitate, sub-globose, .5 mm. in diameter, ochraceous-yellow above, flesh-colored below; peridium membranous, pale yellow, lime-granules evenly distributed; stipe short, translucent, pinkish flesh-colored; capillitium dense, nodules white; spores purplish-brown, spinulose, 8 .

Differs from _P. citrinellum_ in the membranous peridium, flesh-colored stalks and smaller spores.

Colorado; _Dr. W. C. Sturgis._

44. PHYSARUM CITRINELLUM _Peck._

1831. _Physarum caespitosum_ Schw., Syn. _N. A. F._, No. 2301 (?).

1869. _Diderma citrinum_ Peck, _Rep. N. Y. Mus._, XXII., p. 89.