A.Outer sporangial wall distinctly calcareous, fragile; species generally sessileDidermaB.Outer sporangial wall cartilaginous, the inner less distinct, or concrete with the outer; species oftener stipitateLeangiumA.Sub-Genus DIDERMA1. Fructification wholly plasmodiocarpous1.D. effusum2. Fructification of distinct sporangia.a.Sporangia on a common hypothallus.O Outer wall fragile, not widely remote from the inner2.D. spumarioidesOO Inner wall lacking3.D. simplexOOO Outer wall crustaceous, porcelain-like.i. Spores 8–104.D. globosumii. Spores 12–155.D. crustaceumOOOO Outer wall firm, not crustaceous6.D. lyalliib.Sporangia isolated, or, at least, not on a common hypothallus, sessile.O Outer wall porcellanous, roseate7.D. testaceumOO Outer wall white8.D. niveumOOO Outer wall ashen9.D. cinereumc.Sporangia stipitate10.D. hemisphericumB.Sub-Genus LEANGIUM1. Sporangia generally sessile.a.Inner peridium distinct.O Membranous colorless, columella scant11.D. sauteriOO Colorless, columella prominent, red12.D. cor-rubrumOOO Outer ochraceous, inner yellow13.D. ochraceumb.Peridial layers inseparable.O Peridium multifid; columella small or none16.D. trevelyaniOO Peridium breaking into but few irregular lobes; columella prominent.i. Peridium umber brown14.D. roanenseii. Peridium ashen15.D. radiatumiii. Peridium chocolate without, inside white17.D. asteroides2. Sporangia stipitate.a.Peridium pallid, smooth18.D. floriformeb.Peridium white, rugulose19.D. rugosum
1.Diderma effusum(Schw.)Morgan.
Fructification plasmodiocarpous, reticulate, creeping, applanate and generally widely effused, white; the peridium thin, cinereous, coveredby a delicate, white, calcareous crust; the columella simply the base of the plasmodiocarp, thin alutaceous; the capillitium pale, consisting of short threads somewhat branched toward their distal extremities; spores smooth, pale violaceous, 8–10 µ.
This isPhysarum effusumSchw.,vid. N. A. F., No. 2297. It is reported by Morgan from Ohio, and we have one specimen from eastern Nebraska, so that it is probably of general distribution in the eastern United States.
This species was in the previous edition distinguished from the RostafinskianP. reticulatumwith spores a little smaller, 6–8 µ, and with a much stronger tendency to the formation of definite sporangia, elongate indeed and branching but often globose or depressed globose. This we may know as,
Var. reticulatumRost.
Sporangia gregarious, generally rounded, not much depressed, flat, sometimes, especially toward the margin of a colony, elongate, venulose or somewhat plasmodiocarpous, dull white, the inner peridium ashen or bluish, remote from the calcareous crust, which is extremely fragile, easily shelling off; columella indistinguishable from the base of the sporangium, thin, alutaceous; capillitium of short, generally colorless, delicate, sparingly branching or anastomosing threads perpendicular to the columella; spores black in mass, by transmitted light violet-tinted, smooth, 6–8 µ.
Perhaps our most common form. Found in fall on dead twigs, leaves, etc. Recognized by its rather large, white, depressed or flattened sporangia tending to form reticulations, and hence suggesting the name. The lines of fruiting tend to follow the venation of the supporting leaf; where the sporangium is round, the columella is a distinct rounded or cake-like body; where the fruit is venulose, the columella is less distinct.
By these rounded forms we pass easily, as by a gate, toD. hemisphericum, which, when wholly sessile, differs still in greater diameter of the sporangia and in having somewhat larger spores. Usuallyin such case the compared colony will show somewhere a very short and stout but very real stipe supporting the discoid fruit.
Rostafinski divided the genusChondrioderma, i. e.Diderma, into three sections:—
Monodermato include those species in which the calcareous crust is less distinct or connate with the true peridium.
Diderma, in which the two structures were plainly separate.
Leangium, used as in the present work. In his first section Rostafinski placedC. reticulatumandC. michelii; in the second,C. difformeandC. calcareum.
Lister has examined Rostafinski's type ofC. reticulatumand declares that it has the usual didermic characters. Hence there is no doubt that our small-spored American specimens are covered by Rostafinski's description, No. 72. On the other hand, Lister makesC. difforme(Pers.) Rost. aDidymium, by its crystalline coat. That species therefore is removed from consideration in this connection.C. calcareumremains as applicable to American forms having the spores 10–12 µ, but according to the author of the species the capillitium is abundant and definitive. Unhappily the type ofC. calcareumis lost (Lister,Mon., p. 95), so that there is no other means of verification than the description and Rostafinski's figure. Under these circumstances we consider the namecalcareuminapplicable to any American forms we have so far seen. See next species. As to the American species which have been distributed asC. calcareum(Lk.) Rost., they are, so far as seen, referable toD. reticulatum(Rost.), Morg. Here also belongs No. 1217, Ellis,N. A. F.
New York, Pennsylvania, Ohio, Iowa, Nebraska. Probably to be found throughout the eastern United States.
2.Diderma spumarioidesFries.
Sporangia sessile, crowded, spherical, or by mutual pressure irregular, white; the peridium plainly double, but the layers adhering, the outer more strongly calcareous, but very frail, almost farinaceous;hypothallus more or less plainly in evidence, white or pale alutaceous; columella distinct, though often small, globose, yellowish; capillitium variable in quantity, sometimes abundant, brown, somewhat branching and anastomosing outwardly, the tips paler; spores minutely roughened, dark violaceous, about 10 µ.
This species has the outward seeming of a didymium, but is plainly different as that genus is here defined, since the calcareous crust, although inclined to be pulverulent, is made up of minute granules, not crystals, of lime. The hypothallus is sometimes hardly discoverable, anon well developed, out-spread, rugulose, far beyond the limits of the fructification. In hisMonograph, p. 175, Rostafinski includes herePhysarum stromateumLink. In the Appendix he is inclined to raise Link's form to the dignity of a distinct species, basing the diagnosis upon the superposition of the sporangia in certain cases, a feature entirely unknown to Link's description and of extremely uncertain value, since by their crowding the sporangia are liable always to be pushed above each other. We therefore regardC. stromateum(Link) Rost. as a synonym of the present species, as the description, Link, Handb., III., 409, indicates, so far as it goes.
3.Diderma simplex(Schroet.)Lister.
"Plasmodium bright yellowish brown." Sporangia gregarious, sessile, globose or depressed globose, .3–.5 mm., or anon plasmodiocarpous, brown or brick-red when fresh, becoming paler, ochraceous, etc.; hypothallus everywhere in evidence; columella ill-defined; capillitium scanty, the threads delicate, pale, branching as they join the peridial wall; spores dull violaceous, slightly roughened, 8–10 µ.
A rather crude, primitive representative of this beautiful genus. The inner peridium seems to be lacking,—a comfort to Rostafinski! Rare. Our best specimens are from New Jersey, by courtesy of Dr. C. L. Shear. These went to fruit on leaves and branches ofVaccinium. It seems to affect the heather of Europe, moorland, etc. I have also specimens from the herbarium of the lamented Dr. Rex. These are more plasmodiocarpous, but open beautifully by a medianfissure as inPhysarum sinuosumBull. In no American gathering that I have examined does the capillitium show calcareous thickenings as described by the British text.
4.Diderma globosumPersoon.
Plate VII., Figs. 5, 5a.
Sporangia more or less closely gregarious, sessile, globose or by mutual pressure prismatic or polyhedral, white, the outer wall smooth, polished, crustaceous, fragile, far remote from the inner, which is thin, smooth, or rugulose, iridescent blue; hypothallus usually pronounced and spreading beyond the sporangia, sometimes scanty or lacking, columella variable, sometimes very small, inconspicuous, sometimes large, globose, ellipsoidal, even pedicellate; capillitium abundant, brown or purplish brown, branching and occasionally anastomosing to form a loosely constructed superficial net; spores globose, delicately spinulose, 8 µ.
This species seems rare in this country. We have specimens from Iowa. It is distinguished by small spores and generally snow-white color. Lister has thrown doubt upon Rostafinski's definition of this form—Mycetozoa, p. 78. Almost everything distributed in the United States under this name belongs in the next species. Reported also from Ohio,—Morgan.Washington. But:—it should be found in Europe, where first described!
There are two ways to meet the difficulty. In the first place it seems probable that a small-spored form really hides somewhere in Europe. The difference between theMonographmeasurement and the size admitted forD. crustaceumPk., evidently considered by Mr. Lister as type and so used in his illustration, Pl. 85, is too great to be esteemed merely an error. That added .3 (Rost.) indicates caution, the average of several measurements. OurD. globosummay represent what theMonographdescribes.[32]In the second place we may asAmerican students mistake larger and more globular forms of something else, ofD. spumarioidesFr., whose spores are but little larger; or ofD. effusum(Schw.) Morg., where the flattened plasmodiocarps anon splatter out to globose drops of polished whiteness, and whose spores are 8 µ. But even here the chances of error are small. In the species last named the columella or sporangial base is alutaceous, not white; in Fries' species, while the columella if present may be white, the peridial walls are different, difficult to distinguish.
For these reasons,D. globosumPers. may stand, waiting further light from Europe.
5.Diderma crustaceumPeck.
Plate VII., Fig. 7
Plasmodium at first watery, colorless, becoming at length milky white; sporangia closely crowded or superimposed, in a cushion-like colony, creamy white, globose, imbedded in the substance of the hypothallus, the outer peridium smooth, delicate, crustaceous, fragile, remote from the blue iridescent inner membrane; hypothallus prominent; columella variable, generally present, globose; capillitium dark-colored, the threads branching and combining to form a loose net; spore-mass black, spores by transmitted light dark violaceous, delicately roughened, 12–15 µ.
Common. Readily to be distinguished from the preceding by the larger spores and more crowded habit. New England west to Nebraska.
The didermas are generally delicately beautiful. The outer wall in the present species is like finest unglazed china, softly smooth, and yet not polished, often absolutely white, with porcellanous fracture. An inter-parietal space separates the outer from the inner wall, so that the former may be broken, bit by bit, without in the least disturbing the underlying structure. The inner wall is ashen or gauzy iridescent green, sending back all colors in reflected light. The spores are violet, deeply so when fresh, the capillitium strong and likewise tinted; the columella passing down and blending with thecommon snow-white hypothalline base. The distinct habits of the two species are represented in Figs. 5 and 7. In the one the distinct sporangia are associated but not crowded; in the other all are massed together in quite æthalioid fashion, forming circumambient, chalky masses of considerable size, 2 or 3 cm., overcrowded, superimposed, where the sporangia are regular in shape and size by reason of mutual pressure. The plasmodium develops in forests and orchards, among decaying leaves, but is inclined to rise as maturity draws near, to ascend some twig erect, or the stem of a living plant to the height of several inches where the sporangia at length appear "heaped and pent", an encircling sheath, conspicuous after the fashion of a spumaria for which it is indeed sometimes mistaken.
6.Diderma lyallii(Massee)Macbr.
Plate XVIII., Figs. 5 and 5a
Sporangia obovate, more or less closely crowded, white, stipitate, about 1 mm. in diameter, the outer peridium firm, stout, encrusted, especially above, with granular masses of lime, the inner well developed, more or less cartilaginous, opaque, yellow or buff-colored; hypothallus well developed, venulose, white, passing up unchanged to form the short, stout stipe and lower outer peridium; columella prominent, half the height of the sporangium, brown; capillitium of short, brown threads, rigid, much branched, forming a net, widened irregularly and especially at the net-nodes; spore-mass black, spores by transmitted light bright brown, rough, 15–17 µ.
A very distinct species; large, fine, showy sporangia in more or less crowded clusters spring from a snow-white, common hypothallus. First reported from western Canada. Our first specimens were collected by the late Mr. Charles Irish, on the eastern slopes of the Sierras, in Nevada; now coming in abundantly from all the western mountains to the Pacific.
7.Diderma testaceum(Schrad.)Pers.
Plate VII., 4, 4a, and 4b.
Sporangia gregarious, sessile, depressed-spherical or sometimes elongate, small, 1 mm. or less, rose-white, smooth, the outer peridium crustaceous, rather thick and persistent, polished, slightly raised above the inner, which is dull ashen and more or less wrinkled; hypothallus none; columella prominent, hemispherical in the typical rounded forms, slightly rough, reddish or reddish alutaceous; capillitium usually abundant, of slender, delicate pale or colorless threads, little branched, and smooth; spores violaceous-brown, minutely roughened, 8–9 µ.
A very beautiful species occurring at the same time as the preceding and in similar situations. All our specimens from the west are on dead leaves of oak; some eastern gatherings are on moss. Easily recognized when fresh by its delicate pink or roseate color; weathered specimens are white, and might be confused with forms ofD. reticulatum, but the sporangia in the present species are less flattened and only rarely in special situations run off to linear or plasmodiocarpous shapes characteristic ofD. reticulatum.
Not common, although widely distributed from east to west. New England, New York, New Jersey, South Carolina, Ohio, Illinois, Iowa, Nebraska, California (Harkness), Washington, Oregon.
8.Diderma niveum(Rostafinski)Macbr.
Plate XVIII., Fig. 11 and 11a
Sporangia gregarious, scattered, or more often crowded, sessile, depressed-spherical, sometimes ellipsoidal or elongate, white, the outer peridium crustaceous, chalky, smooth and fragile, the inner distinct, delicate, ochraceous; hypothallus scant or none; columella well developed, globose or hemispherical, orange-tinted or ochraceous; capillitiumabundant, made of threads of two sorts, some purplish or dusky, with pale extremities, uneven, others more delicate and colorless, and with wart-like thickenings, all sparingly branched; spores violet-brown, minutely roughened, 9–10 µ.
This species is not common. From Colorado we have fine specimens typical in every way. Specimens from Washington are flat so far as at present at hand; probably representD. deplanatum(R.) List., which the last named author regards as varietal of the present species, entering it andD. lyalliias sub-species 2 and 1 respectively.D. deplanatummay perhaps be best so disposed of; butD. lyalliiis distinguished at sight, as well as by microscopic characters, spores nearly twice as great, rougher and different in color.
9.Diderma cinereumMorg.
Sporangia gregarious, more or less crowded or even confluent, sub-globose, only slightly depressed, ashen white; the peridium not obviously double, very smooth and thin, rupturing irregularly; hypothallus an indistinct membrane or wholly wanting; columella large, globose or hemispheric, white, the surface granulose; capillitium of very slender colored threads, the extremities pellucid, more or less branched; spores violaceous, minutely warted, 9–11 µ.
Growing on old wood, leaves, etc. The sporangium .3–.5 mm., thin and smooth or rugulose. This elegant little species I know only from specimens received from Mr. Morgan. It seems to be closely related toD. spumarioides, from which it is distinguished by its color, darker, and its smoother, or less spinulose spores. The author compares the color and external appearance to that ofP. cinereum,—Jour. Cin. Soc., XVI., p. 154.
Ohio, Pennsylvania.
10.Diderma hemisphericum(Bull.)Horne.
Sporangia gregarious, orbicular, discoid, depressed above and often umbilicate below, stipitate or sometimes sessile, the outer peridium white, fragile, crustaceous, soon breaking about the margins, closely applied to the inner, which is delicate, cinereous, and ruptures irregularly; stipe about equal to the diameter of the sporangium, 1 mm., rather stout, calcareous but colored, brownish or alutaceous, more or less wrinkled longitudinally, the wrinkles when present forming veins on the lower surface of the sporangium; hypothallus small; columella not distinct from the thickened brownish or reddish base of the sporangium; capillitium of delicate threads, mostly simple and colorless, often scanty; spores pale violaceous, nearly smooth, 8–9 µ.
A very well marked species, easily recognized, at least when stipitate, by its remarkable discoid or lenticular sporangia. After the spore-dispersal, the stipes are long-persistent, surmounted by a peculiar disk representing the consolidated columella, lower sporangial wall, and expanded stem-top. Sessile specimens are like similar forms ofD. reticulatum, but in all the gatherings before us the stipitate type is at hand to reveal the identity of the species.
Rostafinski's figures, 131, 146, 149, and 150, adapted from Corda, exaggerate the hypothallus, but otherwise leave nothing to be desired.
As to synonymy, Bulliard has plainly the priority. His figure, t. 446, Fig. 1, can refer to nothing else, especially reënforced as it is by Sowerby,Eng. Fung., t. 12.
Rather rare on fallen stems of herbaceous plants, but widely distributed, New England to Oregon and Washington.
11.Diderma sauteri(Rost.)Macbr.
Sporangia scattered, gregarious, sessile, lenticular or hemispherical, flattened above and sometimes concave or umbilicate below, dusky or yellowish white, the outer peridium papyraceous, thin, occasionally wrinkled, rupturing irregularly, remote from the inner, which is thin, delicate, semi-transparent, grayish, rarely iridescent; hypothallus none; columella irregular, sometimes small and hardly evident, rugose, with spine-like processes, the persisting bases of the capillitialthreads, reddish brown; capillitium scanty, white, or colorless, simple or sparingly branched; spores dark violaceous, spinulose, 12–13 µ.
This isChondrioderma aculeatumRex,Proc. Acad. Nat. Sci. Phil., 1891, p. 390. After careful comparison of specimens and various descriptions, especially that of Rostafinski with the type specimens of Dr. Rex, I am constrained to concur with Lister in adopting Rostafinski's name. The sporangia in the type specimens (Rex) are on moss, borne at the extreme tips of acuminate or aculeate leaves, so that at first sight they appear stipitate.
Apparently rare. Maine, New York.
12.Diderma cor-rubrumMacbr. n. s.
Plate XVIII., Fig. 2
Sporangia gregarious clustered, small .5–.7 mm., sessile corrugate-plicate, especially above, snow-white, the outer peridium cartilaginous polished without and within, the inner delicate, evanescent; columella well developed, globose or clavate, anchored by several stout transverse trabeculæ to the peridial wall, papillate, deep-red as is the peridium especially below; capillitium very delicate, sparingly branching, colorless; spores verruculose, fuliginous tinged with red, about 12 µ.
This curious but elegant little species is represented by a single colony collected by Professor Morton Peck in Iowa. It resemblesD. sauteribut is distinguished by the plicate white wall, the stout columella with its lateral extensions, as by the more delicate spores. On rotten wood.
13.Diderma ochraceumHoffm.
Sporangia gregarious or clustered, .7–1 mm., sessile, globose or sometimes plasmodiocarpous, ochraceous yellow; outer wall cartilaginous with yellow deposits of lime, the inner also yellow, adherent or free; columella not distinct; capillitium simple or branching, purple-brown, hyaline at base; spores spinulose, purplish-grey, 9–11 µ.
Mr. Lister reports this species from Massachusetts.
14.Diderma roanense(Rex)Macbr.
Sporangia scattered, discoidal, thin, flattened or slightly convex above, plane or plano-concave below, umber-brown, stipitate, the outer peridium smooth, brittle, rupturing irregularly, the basal fragments somewhat persistent, concrete with the inner peridium, which is pure white, except near the columella, and punctate; stipe short, variable, longitudinally ridged, jet-black; hypothallus none; columella flat, discoidal, pale ochraceous; capillitium sparse, white or colorless, composed of simple, rarely forked, sinuous threads occasionally joined by lateral branches; spores dark violaceous, distinctly warted, 12–14 µ.
This species is readily distinguished by its color. The sporangia, found on rotten wood, are large, 1 mm., brown, and have thick, persistent walls. Dr. Rex considered that the species differs from other related forms not only in color, but in the well-marked discoidal columella and the jet-black irregular stipe. It is perhaps most nearly related to the following species.
Tennessee.
15.Diderma radiatum(Linn.)Morg.
Plate XVIII., Fig. 8
Sporangia scattered, depressed-globose, sometimes also flattened below, stipitate, smooth or slightly corrugate, ashen or brownish, about 1 mm. in diameter, the peridium dehiscing irregularly or somewhat radiately from above downwards, the segments reflexed, the inner layer not distinguishable, or inseparable; stipe short, stout, brownish, sometimes almost lacking; hypothallus not conspicuous, but sometimes sufficient to connect the bases of adjacent stipes; columella large, hemispherical or globose, pallid or yellowish; capillitium abundant, of slender generally simple, colored threads, paler at the furcate tips; spores dark violaceous, minutely roughened, 8–11 µ.
Rare on rotten logs in the forests; September. Easily recognized by the short-stiped, ashen sporangia which before dehiscence indicate by delicate tracings the lines which subsequent cleavage is to follow. In texture the peridium resembles that ofD. floriforme.
Pennsylvania, Ohio, Iowa, Virginia, Colorado, Washington, Oregon; Europe generally.
The Linnæan description on which to base the specific nameD. radiatumis wholly inadequate. It appears also by the testimony of Linnéfils, thatL. radiatumLinné is a lichen! and the name is so applied by Persoon. But in the Linnæan herbarium preserved at London,testeLister, the original type ofLycoperdon radiatumL. may yet be seen! to the confusion offils, Persoon, and other followers of Schrader all, and our stellar species becomes radiate now, let us hope for long!
16.Diderma trevelyani(Grev.)Fr.
Sporangia scattered, globose or nearly so, smooth or verruculose, reddish-brown or rufescent, sessile or short-stipitate, the outer peridium firm, splitting more or less regularly into unequal, revolute, petal-like lobes which are white within, the inner not distinguishable as such; stipe, when present, equal, furrowed, concolorous; columella small or none; capillitium abundant, the threads rather rigid, purple or purplish brown, branching and anastomosing, more or less beaded; spores dark, violaceous brown, spinulose, 10–13 µ.
In 1876, Harkness and Moore collected in the Sierra Nevada Mountains of California, forms ofDidermawhich are described by Phillips,Grev., V., p. 113, asD. geasteroidesandD. laciniatum. English authorities who have examined the material agree that the forms described constitute but a single species, and Lister makes them identical withD. trevelyani(Grev.) Fr. Rostafinski's figures, 161, 162, are a curious reproduction, evidently, of Fried. Nees von Esenbeck's, Plate IX., Fig. 4. Massee describes a columella; Lister saysthere is none. What may occasion such divergence of statement none may say; such forms as come in so far from our western mountains have no columella.
17.Diderma asteroidesList.
Plate XVIII., Figs. 3, 3a
Sporangia globose or ovoid-globose, the apex more or less acuminate, sessile, sometimes narrowed at the base to a short, thick stalk, brown or chocolate tinted, marked at the apex by radiant lines, and at length dehiscent by many reflexing lobes revealing the snow-white adherent inner peridium on the exposed or upper side; columella also white, globose or depressed-globose; capillitium generally colorless, somewhat branched, especially above; spores dark violaceous, verruculose, 10–12 µ.
Oregon, the Three Sisters Mountains; Colorado; California.
A very beautiful species, recognizable at sight; when unopened, by the peculiar chocolate brown, the sporangia smaller than inD. radiatum. When opened, the snow-white flower-like figure, flat against the substratum, is definitive. Very near number 16 preceding; the dehiscence more regular.
18.Diderma floriforme(Bull.)Pers.
Plate VIII., Figs. 1, 1a, 1b.
Sporangia crowded, generally in dense colonies, globose, smooth, ochraceous-white, stipitate, the peridium thick, cartilaginous, splitting from above into several petal-like lobes, which become speedily reflexed exposing the swarthy spore-mass, the inner peridium not discoverable, inseparable; stipe concolorous, about equal to the sporangium; hypothallus, generally well developed, but thin, membranaceous, common to all the sporangia; columella prominent, globose or cylindric, often constricted below, and prolonged upward almost to the top of the spore-case; capillitium of slender, delicate, sparinglybranched threads; spores dark violaceous-brown, studded with scattered warts, 10–11 µ.
Not uncommon, especially on rotten oak logs. Easily recognized by the peculiar form of the fruit, spherical before dehiscence, floriform after. Unlike most species, this form often fruits in dark places, in the interior of a log, even in the ground.
New England, Ontario to Iowa and Nebraska, and south.
19.Diderma rugosum(Rex)Macbr.
Plate XVIII., Fig. 10.
Sporangia gregarious, scattered, white or ashen, rugulose over the whole surface, the ridges marking the lines of subsequent rupture or dehiscence, the peridium thin papyraceous, stipitate; stipe well developed about equal to the sporangium, subulate, almost black; hypothallus none; columella distinct, generally white, sometimes small, globose, sometimes penetrating the sporangium, to one-half the height; capillitium white or colorless, the filaments freely forked and combined by lateral branches into a loose network attached to the columella and basal wall below and the upper sporangial wall above; spores violaceous-brown, warted, 8–10 µ.
This species is well designatedrugosum, and is recognizable at sight by its wrinkled, areolate surface. Related toD. radiatumin the prefigured dehiscence, but otherwise very distinct. Liable to be overlooked as a prematurely dried physarum. Rare. Plasmodium gray.
North Carolina, Iowa.
4. LepidodermaDeBary
Sporangia stalked or sessile; peridium cartilaginous, adorned without with large calcareous scales, superficial or shut in lenticular cavities; capillitium non-calcareous.[33]
Key to Species of Lepidoderma
A.Sporangia stipitate, stipe brown1.L. tigrinumB.Sporangia sessile, plasmodiocarpous, spores 10–12 µ2.L. carestianumC.Sporangia plasmodiocarpous, spores 8–10 µ3.L. chailletii
1.Lepidoderma tigrinum(Schrad.)Rost.
Plate XIV., Fig. 7.
Sporangia scattered, rather large, hemispherical-depressed, stipitate, umbilicate beneath, the peridium shining, olivaceous or purplish, tough, covered more or less abundantly with angular scales; the stipe stout, furrowed, dark brown, but containing calcareous deposits withal, tapering upward, and continued within the peridium as a pronounced more or less calcareous columella; hypothallus more or less prominent, yellowish or brownish; capillitium dark, purplish-brown, of sparingly branching threads radiating from the columella; spores dull purplish-brown, minutely roughened, 10–12 µ.
A singular species, rare, but easily recognized by its peculiar, placoid scales, large and firmly embedded in the peridial wall. The internal structure is essentially that ofDidermaorDidymium. The species occurs in hilly or mountainous regions, on moss-covered logs. The plasmodium pale yellow, some part of it not infrequently remains as a venulose hypothallus connecting such sporangia as are near together.
New England to Washington and Oregon; Vancouver Island.
2.Lepidoderma carestianum(Rabenh.)Rost.
Fructification in the form of flat, pulvinate plasmodiocarps, or, anon, sporangiate, the sporangia sessile, sub-globose, ellipsoidal, elongate, irregular, confluent, yellowish-grey, the peridium covered more or less completely with dull white, crystals or crystal-like scales; columella, where visible, yellowish-brown, calcareous; capillitium, coarse, rigid, more or less branched and united, or colorless, delicate, forming a definite net; spores distinctly warted, purple 10–12 µ.
This is a most remarkable species. The sporangiate forms little resemble those distinctly plasmodiocarpal. In the former the calcic scales and crystals are distinct and quite as inL. tigrinum; in the latter they are cuboid, irregular. The wall of the peridium in the plasmodiocarps at hand is black, and the covering accordingly shows white; in the sporangial forms the wall is brown, and the scales have a yellow tinge as if tinged with iron. In the sporangial presentation the capillitium is intricate delicate; in the plasmodiocarp, rigid, dark-colored, etc. This looks like a didymium and in so far justifies the opinion of earlier students. Fries, of course, includes all these things with the didymiums, andD. squamulosumprobably often sheltered them under extended wing.
Didymium granuliferumPhill.,Grev., V., p. 114, from California is by European authors referred here. The capillitium carries calcareous crystalline deposits in special vesicles and the spores show remarkable variation in unusual size—15–30 µ.[1]
Should probably be enteredLepidoderma granuliferum(Phill.) Fr., spores 15–18 µ.[34]
Utah,—Harkness.
3.Lepidoderma chailletiiRost.
Plate XVIII., Figs. 6, 6a, 6b.
Sporangia distinct, coalescent or plasmodiocarpous, large, when isolated 1–1.5 mm., dull drab in color, very sparsely sprinkled with white tetrahedral or irregular scales; the peridium thin, more or less translucent, rugulose, dull brown, persistent; columella none; capillitium abundant, under the lens purple-brown, sparingly branched,even, stout, rigid, no calcareous deposits nor vesicles; spores 8–10 µ, minutely warted, fuliginous.
Yosemite Cañon, California,Prof. B. Shimek.
This is, no doubt, similar toL. carestianumbut differs in the size and habit of the sporangia, and in the fact that the capillitium is uniform throughout, whatever the style of fructification, and in the size, color, and surface characters of the spore.
Evidently notDidymium granuliferumPhill. Both will, no doubt, be again collected, and we shall then have much needed light.
Nor is this quite Rostafinski's species as cited. The spores are much smaller; Rostafinski says 10–12 or more, and calls for a distinctly netted capillitium, the surface strongly marked by abundant calcareous crystals. Ours may be a different thing.
5. CollodermaG. Lister
Peridium double; the outer gelatinous, the inner membranaceous; capillitium intricate, limeless.
Colloderma oculatum(Lipp.)G. Lister.
Sporangia gregarious, globose, or sub-globose, sessile or short-stipitate, olivaceous or purplish-brown, smooth and shining, the outer peridium gelatinous, thickened by moisture, hyaline; stipe dark brown; columella none; capillitium as inDidymiumpurplish-brown, colorless at the tips; spores spinulose, fuscous, about 12 µ.
New Hampshire, Europe.
Our specimens from the late Dr. W. G. Farlow who collected it in New Hampshire. Swollen by immersion in water the sporangia take on an eye-like appearance, oculate, etc.
EXTRA-LIMITAL
Physarinavon Höhnel.
Sporangium wall rough with blunt spine-like processes, otherwise asDiderma.
One species,op. cit., p. 432,P. echinocephalav. Höhn.
Java. Might as well be calledDiderma echinocephalum, one would think. Structure is that ofLeangium. The striking character is a surface modification of the outer peridium, according to the description.
OrderII
STEMONITALES
Capillitium present, thread-like, arising in typical cases from a well-developed columella; spores in mass, black or violet-brown, more rarely ferruginous.
Key to the Families of Stemonitales