but I have not tried it. It is easily known by the root-like pro- 
longation of the stem which penetrates the earth deeply like a 
tap-root, and which suggests the name of the fungus. The cap 
is thin, viscid when moist, grayish-brown, and often a little 
wrinkled or corrugated on its surface. Its gills are white, broad, 
not close and have the edge excavated near the stem as in T'richo- 
loma. The stem is slender, tapering upward, and hollow. The 
plant is common in thin woods and under trees in summer and 
autumn. 
XIV. PLEUROTUS—HYGROPHORUS— 
LACTARIUS. 
The genus Plewrotus differs from all that have preceded in 
having the cap attached to the stem eccentrically or laterally, or 
in being entirely destitute of a stem. In the other genera no- 
ticed, the cap is attached to the stem by the central part of the 
lower surface. In this genus the gills in some species are notched 
as in Tricholoma, in others they are adnate or decurrent as in 
Clitocybe. Besides, nearly all the species (all here discussed) 
grow on dead or decaying wood. They are more tough in tex- 
ture than those growing on the ground, and are therefore less 
desirable for food. Still they may be utilized in making soups, 
or in giving flavor to other more tender but less sapid species. 
The Elm pleurotus, Pleurotus ulmarius, takes its name from 
its habit of growing on elm trees. It appears in autumn, and 
often may be found, even in the beginning of winter, standing 
out as a conspicuous white ob- 
ject from dead places in the 
y trunks of elm trees or from 
the cut surface of their 
branches. Even the shade 
trees of the streetsof ourcities 
sometimes produce a crop of 
the elm-tree mushroom. Its 
cap is large, thick and firm, 
smooth, broadly convex or 
nearly flat, and white or whit- 
ish with the centre generally stained with rusty or dull yellowish 
hues. Sometimes the epidermis cracks in areas, giving the sur- 
59 
Pleurotus ulmarius. P. sapidus 
