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-mass concolorous, spores by transmitted light pale yellow, globose, minutely but distinctly warted, 8–9 µ.
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 reënforced 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 circumstances?—the net is less determined, the free ends are many, and the spirals minutely rough. Here may be placed H. funalis Morgan, l. c.
Widely distributed. New England to Colorado, south to Mexico.
9. Hemitrichia stipitata (Mass.) Macbr.
- 1889. Hemiarcyria stipitata Mass., Jour. Mic. Soc., p. 354.
- 1893. Hemiarcyria plumosa, Morg., Jour. Cin. Soc., p. 29.
Sporangia scattered, seldom crowded, obovoid or turbinate, olivaceous yellow, stipitate; the peridium smooth without, granulose within, evanescent above, persisting as a funnel-shaped cup below; the stipe long, reddish or blackish, rising from a small hypothallus; capillitium of threads 5–6 µ thick, very much branched, forming a dense net, free ends none, or not evident; the sculpture as in H. clavata, smooth and regular; spore-mass yellow; spores by transmitted light yellow, minutely warted, 7–8 µ.
This form corresponds in nearly every respect with H. clavata, except in the structure of the capillitium. The color is rather ochraceous, dirty yellow, and the stipe is proportionally longer and darker, but the form of the net is positive and gives to the species a decidedly striking and unique appearance, so that it may be recognized by the naked eye. It looks like an arcyria and for this reason Professor Morgan said H. plumosa. Lister regards it as the same as our number 8.
Common. Ohio, Illinois, Missouri, Iowa, and west; south to Mexico.
10. Hemitrichia montana Morgan.
Sporangia scattered or gregarious more or less closely, globose, whitish, sessile or very short stipitate; the peridium opaque, dull white, persistent below; capillitium deep yellow, the threads abundantly branched, forming a compact network, 7 µ wide, bearing spirals five or six, uneven and irregular, or anon interrupted, conspicuously spinulose or warted, free tips not lacking, generally inflated; spore-mass yellow, spores by transmitted light pale, nearly colorless, distinctly warted, 10 µ.