Under the name Physarum gracilentum, Fries cites an extremely delicate form of this species. The sporangia are of the most minute, about .2–.3 mm. in diameter, globose, slightly umbilicate below, the stipe usually white at top, but sometimes black throughout. This graceful form occurs rarely in undisturbed woods.
Widely distributed in the eastern United States, apparently rare in the west. Reported from various parts of the world; Europe, Japan, Australia, etc.
56. Physarum viride (Bull.) Pers.
[Plate VIII]., Fig. 8, 8 a, 8 b.
- 1791. Sphaerocarpus viridis Bull., Champ., t. 407, Fig. I.
- 1791. Sphaerocarpus luteus Bull., Champ., t. 407, Fig. II.
- 1791. Sphaerocarpus aurantius Bull., Champ., t. 484, Fig. II.
- 1791. Stemonitis viridis (Bull.) Gmel., Sys. Nat., p. 1469.
- 1794. Physarum aureum Pers., Römer, Neu. Mag. f. die Bot., I., p. 88.
- 1795. Physarum viride Pers., Usteri, Ann. Bot., XV., p. 6.
- 1801. Physarum aurantium Pers., Syn. Meth., p. 173.
- 1829. Physarum nutans var. Fries, Syst. Myc., III., pp. 128–129.
- 1875. Tilmadoche mutabilis Rost., Mon., p. 129.
- 1880. Tilmadoche viridis (Bull.) Sacc., Michelia, II., p. 263.
- 1894. Physarum viride Pers., List., Mycetozoa, p. 50.
- 1899. Tilmadoche viridis (Bull.) Sacc., Macbr., N. A. S., p. 59.
- 1911. Physarum viride Pers., List., Mycetozoa, 2nd ed.
Sporangia globose, flattened or lenticular, beneath plane or concave, variously colored, yellow, greenish yellow, rusty orange, stipitate, nodding; the peridium splitting irregularly or reticulately; stipe variable in length and color, through various shades of red and yellow, subulate; capillitium strongly developed, concolorous with sporangium, the tubes with colorless or yellow calcareous thickenings; spores smooth, fuscous or violet-black, 8 µ.
A very handsome and rather common little species; like the preceding, but generally greenish-yellow in color, and occasionally brilliantly orange without a suggestion of green. Indeed, the color is so variable that some authors have been disposed to discard the species entirely, inasmuch as the chief specific character is color. The plasmodium is pale yellow, in rotten logs, stumps, etc. In the paler yellow or greenish forms the stipe is more commonly black.
This is Physarum luteum (Bull.) Fries, and likewise also includes the three varieties, viride, aureum, coccineum, listed by the same author under P. nutans, while he at the same time remarks that they might with equal propriety be elsewhere referred. Rostafinski considers that all the colored forms agree in capillitium sufficiently to be associated under one name and are in the same way unlike T. nutans.[29] Rostafinski thinks to avoid confusion by suggesting a more fitting specific name, T. mutabilis, but there seems no good reason for not adopting the earliest identifiable specific appellation, which in this case appears to be viride. The yellow phase is common in Iowa, resembles in size, color, stipe, P. galbeum Wingate, but is instantly distinguishable by the capillitium. N. A. F., 1213.
Widely distributed specimens are before us;—from New England, New York, Pennsylvania, Maryland, Ohio, Nebraska, Iowa, California, Oregon, Canada, Nicaragua, Samoa, Alaska, India, etc.
EXTRA-LIMITAL[30]