Chapter 15

THE TREMBLING FUNGI: TREMELLINEAE.

These fungi are called the trembling fungi because of their gelatinous consistency. The colors vary from white, yellow, orange, reddish, brownish, etc., and the form is various, often very irregular, leaf-like, or strongly folded and uneven. They are when fresh usually very soft, clammy to the touch, and yielding like a mass of gelatine. They usually grow on wood, but some species grow on the ground, and some are parasitic. The fruit surface usually covers the entire outer surface of the plant, but in some it is confined to one side of the plant. The basidia are peculiar to the order, are deeply seated in the substance of the plant, rounded or globose, and divided into four cells in a cruciate manner. From each one of these cells of the basidium a long, slender process (sterigma) grows out to the surface of the plant and bears the spore. A few species only are treated of here.

TREMELLA Dill.

In this genus the plants are gelatinous or cartilaginous. The form of the plant is usually very much contorted, fold-like or leaf-like, and very much branched. The fruiting surface extends over the entire upper surface of the plant.

=Tremella lutescens= Pers.--This plant is entirely yellow, and occurs on branches. It is 2--5 cm. in diameter, and is strongly folded, somewhat like the folds of a brain (gyrose). It is very soft and inclined to be watery and fluid, and is of a bright yellow color, spread out on the surface of rotten wood. It is of world-wide distribution, and appears from mid-summer to late autumn.

=Tremella mycetophila= Pk.--This plant is interesting from the fact that it is parasitic on a mushroom, _Collybia dryophila_. It grows on the stem or on the top of the cap of the _Collybia_, and it is white, or yellowish, very much contorted (gyrose-plicate), nearly rounded, and 8--16 mm. in diameter. Figure 205 represents this _Tremella_ growing on the _Collybia dryophila_, from plants collected at Freeville woods near Ithaca.

=Tremella frondosa= Fr.--This is said to be the largest species of the genus. It grows on rotten wood. It occurs in Europe, has been collected in New York State, and the Fig. 206 is from a plant (No. 4339, C. U. herbarium) collected at Blowing Rock, N. C., in September, 1899. The plant figured here was 10 cm. long and about 8 cm. high. It is very much twisted and contorted, leaf-like, and the middle and base all united. It is of a pinkish yellow color, one plant being vinaceous pink and another cream buff in color. When young the leaf-like lobes do not show well, but as it expands they become very prominent.

Several other species of Tremella are probably more common than the ones illustrated here. One of the commonest of the _Tremellineæ_ probably is the =Exidia glandulosa=, which in dry weather appears as a black incrustation on dead limbs, but during rains it swells up into a large, black, very soft, gelatinous mass. It is commonly found on fallen limbs of oak, and occurs from autumn until late spring. It is sometimes called "witch's butter."

=Tremella fuciformis= Berk.--This is a very beautiful white tremella growing in woods on leaf mold close to the ground. It forms a large white tubercular mass resting on the ground, from the upper surface of which numerous stout, short, white processes arise which branch a few times in a dichotomous manner. The masses are 10--15 cm. in diameter, and nearly or quite as high. The flesh is very soft, and the parts are more or less hollow. The basidia are like those of the genus, globose, sunk in the substance of the plant, and terminate with four long, slender, sterigmata which rise to the surface and bear the spores. The spores are white, nearly ovoid, but inequilateral and somewhat reniform, continuous, 7--9 × 5--6 µ.

Figure 207 is from a plant collected in a woods near Ithaca, in August, 1897.

GYROCEPHALUS Pers.

The genus _Gyrocephalus_ differs from the other _Tremellineæ_ in having the fruiting surface on the lower side of the fruit body, while the upper side is sterile.

=Gyrocephalus rufus= (Jacq.) Bref.--This species is sometimes very abundant. It grows on the ground, generally from buried wood, or from dead roots. It is erect, stout at the base, and the upper end flattened and thinner. It is more or less spatulate, the upper side somewhat concave, and the lower somewhat convex. In some plants the pileus is more regular and there is then a tendency to the funnel form. It is reddish, or reddish yellow in color, smooth, clammy, watery, and quite gelatinous. When dry it is very hard. Figure 208 represents the form of the plant well, from plants collected at Ithaca. The plant is quite common in the damp glens and woods at Ithaca during the autumn.