white above, fuscous below, at the apex almost
evanescent; hence the cernuous sporangia. The same character is less
strikingly manifest in the species next following.

The plasmodium is bright yellow, sometimes greenish. Brought in from the
field and maturing under a bell-jar, the color changes to a watery white
just before the sporangia rise in fruit. _P. album_ Fuckel, _Rhen. Fl._,
No. 1469, 1865, is believed to be _P. cinereum_ (Batsch) Pers.

Persoon changed Bulliard's specific name in this case to furnish one
himself, more descriptive as he thought and distinctive. His success in
this attempt must be esteemed but partial since all the related forms,
immediately listed, _nod_ as well. Bulliard's name as applied by Persoon
is therefore to be preferred. But the transfer from _Tilmadoche_ to
_Physarum_ loses for us one step in the ladder of priority. _P. album_
(Bull.) may not enter here, since Fries has given us one species under
that title. So Persoon comes next on the list, all the world now nodding
approbation, let us hope!

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, Figs. 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., Roemer, _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.