The North American Slime-Moulds Part 7

Under this name may be placed our most common form. Rising with an abundant yellowish creamy plasmodium from ma.s.ses of decaying vegetation, lumber, sawdust, half buried logs, it creeps about with energy unsurpa.s.sed, coming to rest only in some position specially exposed, as the top of a log or stump, the face of a stone or post, or even the high clods of a cultivated field! The fructification is large, yellow, or at most pale ochraceous, the surface when mature extremely friable like dry foam. Bulliard figures this phase well on Plate 424, Fig. 2, and calls it _Reticularia_ (_Fuligo_) _hortensis_, from its affecting the soils of gardens. More than thirty fructifications have appeared at one time, varying in size from one to twenty cm. in a field of potatoes, well tilled, and less than an acre in extent! Such is life's perennial exuberance on this time-worn old world of ours!

Schaeffer's plate CXII represents probably the same thing. So also Bolton's plate, Cx.x.xIV. Sowerby's Fig. 2 on plate 199, and figures 1 and 2 on Greville's plate 272 possibly also depict this form. Persoon calls this _F. vaporaria_ because it frequents hotbeds and the like, and believes this to represent the "_untuosus flavus_" of Linnee, although he thinks Schaeffer's specimens do not. The calcareous internal structure is white.

2. Form _b_, _F. rufa_ Pers.

This type of Fuligo is very different from the preceding in form, habit, and color. In form it is much more definite, usually thick, well-rounded and with some solidity. The interior fructification is gray throughout, much less expanded than in _a_; in fact does not resemble _a_ at all!

The cortex is porose but firm, orange at first, but becoming tawny with age, even in the herbarium. Bulliard figures it well, plate 380, Fig. 1, and Sowerby's Fig. 1 on plate 399 is also good, as are also Greville's figure 3 on plate 272 showing the two colors referred to. Not uncommon in the forest from June till September, but far more rare than _a_: always well-marked, with no other forms a.s.sociated.

3. Form _c_, _F. laevis_ Pers.

This is a still more specialized type of the group. The fructification is usually small, smooth, about an inch in diameter and sometimes nearly as thick; the cortex rusty brown, enduring, persisting often when all the sporiferous grayish ma.s.s has been distributed through c.h.i.n.ks, or from below. The figure 2 on plate X. shows this form. This also is a forest species, is autumnal rather, but may be taken sometimes as early as July. The cortex is not at all porose or spongy, in color reddish or brown, fragile indeed, but not to the touch, in the herbarium enduring for years.

4. Form _d_, _F. flava_ Pers.

PLATE X, Figs. 2, 2 _a_, 2 _b_.

This is hardly _F. flava_ of Persoon; rather of Morgan who uses Persoon's specific designation. Persoon cites Bolton's fig. Cx.x.xIV, which is yellow indeed but is the ordinary presentation of _F. septica_.

The form here considered is remarkable for its delicacy; extremely thin, perhaps one layer only of overlying elongate flexuous sporangia(?), covered by the merest shadow of a cortex in the form of yellow dust, soon lost: the capillitial structure yellow throughout; occurring upon fallen logs in moist dark woods; not common.

5. Form _e_, _F. violacea_ Pers.

Plasmodium (Morgan _teste_) dark red, or wine-colored; the aethalium thin, two or three inches wide, covered by a cortex at first dull red and very soft, at length almost wholly vanis.h.i.+ng, so that the entire ma.s.s takes on a purple-violet tint, upper surface varied with white; capillitium rather open, the more or less inflated, large, irregular nodes joined by long, slender, delicate, transparent filaments; spores dark violet, minutely roughened, spherical, about 7.5 .

Ohio, Tennessee. Probably everywhere, but not distinguished from 1.

Professor Morgan, who gave the genus under consideration much attention, regarded _F. violacea_ as a form particularly well-defined. What the value of plasmodic color as a specific character in general, and how far such character is in the present case definitive, because constant, are points yet to be determined.

4. FULIGO INTERMEDIA _Macbr. n. s._

aethalium two to three cm. in greatest diameter, .5-1 cm. thick, covered with a thin, fragile, but not calcareous, greyish or brownish cortex; the spore-ma.s.s grey or violaceous-grey, firm, not at all sooty, the sporangia intricate, their walls more or less calcareous; capillitium not conspicuous; spores globose, pale purple, slightly roughened, 10-12 .

This form has been repeatedly sent me from Denver, Colorado, by Professor Bethel. I have refrained from publis.h.i.+ng it, still anxious to believe that all fuligos on the face of the earth were of one species.

In the species next following it must be admitted that the spore-variations are too wide to remain comfortably under shelter of a single specific name. The present species is not _F. septica_, neither is it _F. megaspora_; it is _F. intermedia_.

Colorado; Iowa.

5. FULIGO MEGASPORA _Sturg._

1913. _Fuligo megaspora_ Sturg., _Col. Coll. Pub._, p. 443.

aethalium pulvinate one to three inches in diameter, covered with a thick spongy incrustation of lime, white or yellowish toward the base: sporangia convolute, the walls membranous, brittle, charged throughout with round white granules of lime, 1.5-2 in diameter: columella none: capillitium of delicate, colorless, anastomosing tubules, bearing toward the center large, white, branching calcareous nodules; spores spherical, or somewhat oval, dark purple-brown, rough-tuberculate, 15-20 .

This species differs as pointed out by Professor Sturgis, chiefly in the character of the spores, their unusual size and roughness.[18]

Colorado; Africa!--_Robert Fries._

=EXTRA-LIMITAL=

=Erionema= _Penzig_

1898. _Erionema_ Penzig, _Die Myx. d. Fl. v. Beutenzorg_, p. 36.

Sporangia plasmodiocarpous but distinct, cylindrical; capillitium intricate, elastic; nodules few.

1. ERIONEMA AUREUM _Penzig_

1898. _Erionema aureum_ Penz. _l. c._

Sporangia elongate, cl.u.s.tered, pendulous, yellow or grayish yellow, generally stipitate on long flaccid stalks, or sessile and interlacing: stipes yellow, blending with the hypothallus; capillitium intricate, expanding at maturity after the manner of _Arcyria_ to several times the sporangial length, the nodules small, yellow; spores nearly smooth, violaceous-brown, 5-6 .

This unique form is near the fuligos which it resembles, especially when sessile, in its intricate sporangia. The spores also are those of the common _Fuligo septica_. The habit is however entirely different. Mr.

Fetch describes cl.u.s.ters in Ceylon, hanging free, four to six cm. in length!

=2. Badhamia= (_Berkeley_) _Rost._

1852. _Badhamia_ Berkeley, _Trans. Linn. Soc._, XXI., p. 153.

1875. _Badhamia_ Rostafinski, _Monograph_, p. 139.

Sporangia simple; peridial wall simple, thin, breaking irregularly; capillitium formed of abundant, richly anastomosing tubules, filled throughout their entire length with calcareous granules; the nodes often feebly represented; stipe poorly developed or wanting entirely; columella, except in forms sometimes a.s.signed to the sub-genus _Scyphium_, poorly developed or none; spores frequently adherent in cl.u.s.ters.

The whole genus calls for careful and protracted study; and the present so-called species are like something new on the world; as full of vagaries as though but just entered upon their phylogenetic race.

This genus is closely related to _Physarum_, but differs in having the capillitium calcareous throughout. Forms occur and are included here, in which the capillitium, especially in some parts, is physarum-like, physaroid. Nevertheless, the distinctions hold good as a rule, and are at once diagnostic.

In capillitial differentiation the badhamias are definite and beautiful.

The net in a typical species, as _B. papaveracea_, is throughout uniformly evenly tubular, the calcareous deposits delicate in the extreme, presenting, as the spores disappear, an elegant trabecular structure as if to support the persisting peridium if not the original content. In other forms the capillitium is physaroid, with swollen nodes, but heavily calcareous but not quite throughout. _Badhamia_, _Physarum_, _Tilmadoche_, _Craterium_ present a consistent group, of which _Physarum_ is the generalized expression.

Berkeley's idea of the genus was expressed as follows: "Peridium naked or furfuraceous. Spores in groups, enclosed, at first, in a hyaline sack." Rostafinski, while accepting Berkeley's generic name, redefined it, emphasized the calcareous capillitium, and made reference to the spore-adherence only to a.s.sert that Berkeley's description was, in this particular, based on mistaken observation. In some species, the spores do, in fact, show a tendency to cling together, a characteristic which Badham was perhaps first to notice; but that this is occasioned by their being surrounded by a sac or common pellicle has not been proved nor even suggested, by any subsequent investigator. Berkeley's genus was therefore founded upon a slight mistake; but we may conserve his rights in the premises if we write _Badhamia_ (Berk.) Rost., and so keep history straight.

=Key to the Species of Badhamia=

_A._ Spores ovoid or ellipsoidal

_a._ Spores free 1. _B. ovispora_

_b._ Spores adherent 2. _B. versicolor_

_B._ Spores spherical

_a._ Sporangia yellow