IV. DICTYDIUM, Schrad. Sporangium simple, depressed-globose, stipitate, cernuous; the wall regularly thickened on the inner surface by numerous convergent ribs, which extend from base to apex and are united by fine transverse fibers, thus forming a network of rectangular meshes; the basal portion of the membrane sometimes persists as a calyculus, the upper part disappears at maturity. Spores globose; purplish.
The ribs run from base to apex like the meridians on a globe; they are simple, or here and there they separate into two divergent branches, which sometimes again converge into one; at the apex of the sporangium there is usually a small irregular net in which all the ribs terminate.
1. Dictydium cernuum, Pers. Sporangium depressed-globose, umbilicate at the apex, stipitate, cernuous, purplish-brown in color; the calyculus granulose within, occupying from one-fourth to one-third of the sporangium, the ribs united by firm, persistent fibers. Stipe not very long, erect, tapering upward, bent at the apex, purplish-brown, the apex pale and pellucid, standing on a small hypothallus. Spores purplish-brown in mass, globose, even, 5–7 mic. in diameter.
Growing on old wood. Sporangium .4-.5 mm. in diameter, the stipe two or three times longer than the diameter of the sporangium. This appears to be the species figured and described by Rostafinski and by Massee.
2. Dictydium longipes, Morg. n. sp. Sporangium large, depressed-globose, the apex umbilicate, stipitate, cernuous, dark purple in color; calyculus usually wholly wanting, the ribs united by weak fibers, which are easily torn asunder, allowing the ribs to curl up inwards. Stipe very long, flexuous, tapering upward, curved and twisted at the apex, dark purple in color, standing on a thin hypothallus. Spores in the mass dark purple, globose, even, 5–7 mic. in diameter. [See Plate III, Fig. 12.]
Growing on rotten wood, mosses, etc. Sporangium .5-.7 mm. in diameter, the stipe three to five times as long. This is a much larger species than the preceding; it has a uniform dark purple hue, the stipe is very long and much bent and twisted, the ribs of the sporangium are soon torn apart and rolled inward.
- Fig. 1.—Licea biforis, Morgan, n. sp.
- Figs. 2, 3, 4.—Diagrammatic representation of the structure of Tubulina
- Fig. 5.—Lycogala conicum, Pers., natural size
- Fig. 6.—Lycogala exiguum, Morgan, n. sp., natural size
- Fig. 7.—Lycogala epidendrum, Buxb., natural size
- Fig. 8.—Lycogala flavofuscum, Ehr., natural size
- Fig. 9.—Portion of tubule of Lycogala flavofuscum
- Fig. 10.—Reticularia splendens, Morgan, n. sp., natural size
- Fig. 11.—Cribraria cuprea, Morgan, n. sp.
- Fig. 12.—Dictydium longipes, Morgan, n. sp.
The Journal of the Cin. Soc. Natural History
Vol. XV. Plate III.