The North American Slime-Moulds Part 64

1891. _Hemiarcyria obscura_ Rex, _Proc. Phil. Acad._, p. 395.

1894. _Hemitrichia karstenii_ Lister, _Mycetozoa_, p. 178.

Fructification plasmodiocarpous, with a tendency to form distinct sessile, globose sporangia, color brownish red; capillitium a sparingly branched network, with free ends few, the thread marked by seven or eight faint spirals, the inters.p.a.ces narrow, dull red in color, and 2.5 in diameter; spores yellow, delicately warted, 10-10.5 .

This is doubtless a very rare species. In the description we have followed Dr. Rex, _l. c._, as being more to the point for American forms. It is not improbable that the American material may after all be distinct, as discrepancies, if one may judge by descriptions, are not few. Lister, who had a slide from Dr. Rex, considers the European and American forms the same.

In outward appearing, plasmodiocarpous phases of this species very closely resemble forms of _Licea_ or _Ophiotheca_, and are in consequence often wrongly labeled.

Toronto; Montana--_Anderson_. To be looked for north and west.

3. HEMITRICHIA OVATA (_Pers._) _Macbr._

1796. _Trichia ovata_ Pers., _Obs. Myc._, I., p. 61, and II., p. 35.

1863. _Trichia abietina_ Wigand, _Pringsh. Jahr._, III., p. 33, Tab. ii., Fig. 11.

1875. _Hemiarcyria wigandii_ Rost., _Mon._, p. 167.

Sporangia crowded or sometimes closely gregarious, sub-globose or turbinate, s.h.i.+ning yellow, sessile, the peridium thin, iridescent; capillitium a tangle of sparingly branched yellow or ochraceous-yellow threads, rather slender, 3-5 , marked by one or two prominent spiral bands forming a loose somewhat irregular spiral, the free ends not infrequent, inflated and rounded; spore-ma.s.s yellow or yellow-ochraceous, spores by transmitted light pale yellow, distinctly and sharply spinulose, but not netted, 10-11 .

A rare and beautiful species, distinguished well by the small size, about .5 mm., by the thin iridescent peridium, as by the microscopic characters of the capillitial threads.

There is no doubt that this is Persoon's _Trichia ovata_. His description is accurate in all that pertains to external features, and Rostafinski, _App._, p. 41, explicitly says that he _saw_ in Persoon's herbarium specimens of the species bearing the name cited. Just why Rostafinski did not here adopt the older name is not clear, nor is there excuse for abandoning Wigand's name were Persoon's invalid. According to Lister, _Trichia nana_ Ma.s.s., from Maine, is the same thing. Persoon, _l. c._, gives a synonymy which, in the nature of case, is unverifiable, the specific characters being microscopic.

Fries, _Syst. Myc._, III., p. 187, confirms Persoon and takes pains to say that the color separates it from _T. chrysosperma_ with which it is sometimes compared.

Rare. Maine, Ma.s.sachusetts, New York, Ohio, Toronto.

4. HEMITRICHIA VESPARIUM (_Batsch_) _Macbr._

PLATE III., Figs. 2 and 2 _a_.

1786. _Lycoperdon vesparium_ Batsch, _Elench. Fung._, pp. 255, 256, Fig. 172.

1794. _Trichia rubiformis_ Pers., _Rom. N. Bot. Mag._, I., p. 88.

1875. _Hemiarcyria rubiformis_ (Pers.) _Rost., Mon._, p. 262.

Sporangia cl.u.s.tered or crowded, rarely single, clavate or subcylindric stipitate or sessile, dark wine-red or red-black in color, the peridium in perfect specimens glossy or s.h.i.+ning metallic, opaque; stipes solid, usually blent together, concolorous; capillitium of intertwisted slender threads, sparingly branched, marked by three or four spiral ridges, abundantly spinulose, the free tips also ac.u.minate, terminating in a spine, the whole ma.s.s dull red. Spore-ma.s.s brownish-red, spores by transmitted light reddish-orange, very distinctly warted, sub-globose, 10-12 .

A most common species, on rotten wood everywhere, especially in forests.

Recognized generally at sight by its color and fasciculate habit. The peridium shows a tendency, often, to circ.u.mscissile dehiscence, and persists long after the contents have been dissipated, in this condition suggesting the name applied by Batsch, _vesparium_, wasp-nest. The capillitium is remarkably spinescent, the branching of the threads, rare. Rostafinski describes the spores as smooth; they seem to be uniformly distinctly warted. The plasmodium is deep red, and a plasmodiocarpous fructification occasionally appears.

Throughout the whole range, New England to Was.h.i.+ngton and Oregon, south to Nicaragua; Toronto.

5. HEMITRICHIA STIPATA (_Schw._) _Macbr._

PLATE I., Figs. 8, 8 _a_, 8 _b_.

1834. _Leangium stipatum_ Schw., _N. A. F._, p. 258, No. 2304.

1876. _Hemiarcyria stipata_ (Schw.) _Rost., Mon. App._, pp. 41, 42.

1894. _Arcyria stipata_ (Schw.) Lister, _Mon. Mycetozoa_, p. 189.

Sporangia distinct, crowded, cylindric or irregular, overlying one another, rich copper-colored, metallic, s.h.i.+ning, becoming brown, stipitate; peridium thin, the upper portion early evanescent, the base persistent as a cup, as in _Arcyria_; capillitium concolorous, the thread abundantly branched to form a loose net, with many free and bulbous ends, pale under the lens, marked by three or four somewhat obscure spiral bands and a few wart-like or plate-like thickenings; stipe very short; spore-ma.s.s reddish, spores by transmitted light pale, nearly or quite smooth, 6-8 .

This species is known at sight by its peculiarly beautiful tint when fresh, as by the crowded prolix habit of the singular overlying sporangia. The netted capillitium and the evanescent peridium suggests _Arcyria_, but there are abundant free tips, and the threads are unmistakably spirally wound, especially in the large, handsome sporangia characteristic of the Mississippi valley. It is a boundary form unquestionably. The stipe is generally very short, about one-tenth the total height; sometimes, when the peridium is more globose, the stipe is proportionally longer. Specimens from Iowa show fructifications several centimetres long and wide.

Not rare. New England to the Black Hills and south.

6. HEMITRICHIA LEIOCARPA (_Cke._) _Macbr._

1877. _Hemiarcyria leiocarpa_ Cke., _Ann. Lyc. Nat. Hist. N. Y._, XI., p. 405.

1891. _Hemiarcyria varneyi_ Rex, _Proc. Phil. Acad._, p. 396.

Sporangia simple, obovate or pyriform, rarely almost globose, pallid, with a stem of the same color, as long as the diameter of the sporangium; spore-ma.s.s and capillitium concolorous, or with slight ochraceous tint; capillitium forming a loose net, the tubes branching in a reticulate manner; spirals three, thin, prominent, along the convex sides of the tubes mixed with a few obtuse spines; spores globose, with a thin membrane, 12-14 .

Such is the original description of this distinctly American species.

_H. varneyi_ Rex should differ in having spirals seven or eight, and spore only 6.25 . Mr. Lister, who has compared types of both species, declares them the same! The present writer has been unable to secure authentic specimens.

Pennsylvania.

7. HEMITRICHIA INTORTA _List._

1891. _Hemiarcyria intorta_ Lister, _Jour. Bot._, p. 268.

1891. _Hemiarcyria longifila_ Rex, _Proc. Phil. Acad._, p. 396.

1894. _Hemitrichia_ intorta List., _Mycetozoa_, p. 176.

Sporangia gregarious, globose-turbinate or pyriform, golden-yellow, stipitate; peridium thin, translucent, s.h.i.+ning, opening at the summit irregularly, leaving a funnel-shaped receptacle below; stipe dark red brown, solid, rugulose; capillitium of threads sparingly branched, but looped and doubled upon themselves and constantly intertwisted, orange-yellow, 3-4 in diameter, with spirals four, sparingly spinulose, even and regular, the longitudinal striae conspicuous; spores in ma.s.s concolorous, under the lens yellow, delicately warted, globose, 9-10 .

Concerning this species, Dr. Rex says: "Externally this species resembles _H. clavata_ Pers., and has probably often been mistaken for it. The capillitium, however, in its structural details and habit of growth, is widely different. The partial untwisting of the loops of the capillitium by drying, after the rupture of the sporangium, causes it to be projected and elongated sometimes two or three times the length of the sporangium." Outwardly the open sporangium, by the projecting free tips, reminds one of a trichia. The capillitium is like that of _H.

vesparium_, but less rough, and, of course, different in color.

Rare. Fairmount Park, Philadelphia; Ohio, Iowa.

8. HEMITRICHIA CLAVATA (_Pers._) _Rost._

PLATE III., Figs. 1, 1 _b_.

1794. _Trichia clavata_ Pers., _Rom. N. Bot. Mag._, I., p. 90.

1873. _Hemitrichia clavata_ Pers., Rost., _Versuch_, p. 14.

1875. _Hemiarcyria clavata_ (Pers.) Rost., _Mon._, p. 264.

1893. _Hemiarcyria ablata_ Morg., _Jour. Cin. Soc._, p. 30.

1893. _Hemiarcyria funalis_ Morg., _Jour. Cin. Soc._, p. 32.

Sporangia clavate or turbinate, gregarious, scattered or crowded, yellow, olivaceous or brownish, stipitate; the peridium generally thin, evanescent above, breaking away so as to leave a more or less definite cup beneath; stipe about one-half the total height, reddish, reddish-brown, or blackish, hollow about half-way down; capillitium various, yellow or ochraceous, made up of slender threads more or less freely branched and netted, bearing four or five regular, even, spiral plates which project sharply and are generally smooth, the free extremities numerous or almost none, swollen, or simply obtuse; spore-ma.s.s concolorous, spores by transmitted light pale yellow, globose, minutely but distinctly warted, 8-9 .

This cosmopolitan species is generally one of the first brought in by the collector, its color and comparatively large size, 2-3 mm. high, making it conspicuous. Nevertheless, we are not able to recognize it in the descriptions of the older authors. Rostafinski quotes Schmiedel, _Icones_, 1776, as affording the earliest account of the species, but neither his description nor figure is definitive. Even Bulliard fails us here, and is differently interpreted by different authors. Persoon's description is none too good, but is reenforced by Fries and Rostafinski. The capillitium is variable both in the degree of smoothness presented, and the number of free ends, and the amount of branching. The spores in all specimens we have examined are remarkably constant in size and surface. In typical specimens free ends are easily discoverable, the branching forms a definite net, and the perfectly formed capillitial thread is smooth. In some American forms--developed under less favorable circ.u.mstances?--the net is less determined, the free ends are many, and the spirals minutely rough. Here may be placed _H. funalis_ Morgan, _l. c._