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] PHYSARUM MUTABILE (_Rost._) _List._ 1875. _Crateriachea mutabilis_ Rost., _Mon._, p. 125. 1892. _Crateriachea mutabilis_ Rost., Mass., _Mon._, p. 344. 1894. _Physarum cinereum_ List., _Mycetozoa_, p. 55, in part. 1895. _Physarum crateriachea_ List., _Jour. Bot._, XXXIII., p. 323. 1910. _Physarum crateriachea_ List., Petch, _Mycetozoa Ceylon_, p. 336. 1911. _Physarum mutabile_ List., _Mycetozoa, 2nd ed._, p. 53. Sporangia cylindrical ovoid or sub-globose white, plasmodiocarpous, sessile or stipitate, stipes when present yellow, with or without lime, often connected by a hypothallus; peridium thin, squamulose; capillitium persistent, intricate, the nodules white, more or less confluent at the center to form a real or a pseudo-columella; spores brownish-purple, spinulose, 7-8 mu. Reported from Europe, Africa, Ceylon. PHYSARUM ROSEUM _Berk. & Br._ 1873. _Physarum roseum_ Berk. & Br., _Jour. Linn. Soc._, XIV., p. 84. Plasmodium rose-red; sporangia gregarious, stipitate, globose, rose-red; the stipe erect, brown, rugulose, translucent; capillitium lax, delicate, lilac, the nodules few, large, purple-red, branching; spores reddish-lilac or brown, minutely spinulose, 7-10 mu. Reported from Ceylon, Java, Borneo, Japan. PHYSARUM DICTYOSPERMUM _List._ 1905. _Physarum dictyospermum_ List., _Jour. Bot._, Vol. XLIII., p. 112. "It is distinguished from the other known species of _Physarum_ by the strongly reticulated spores. Its nearest ally is perhaps _P. psittacinum_ which it resembles in having orange-red lime-knots and in the sporangium-wall being studded with orange crystalline disks." _Lister._ Reported collected once only; New Zealand. PHYSARUM STRAMINIPES _List._ 1898. _Physarum straminipes_ List., _Jour. Bot._, Vol. XXXVI., p. 163.