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

Figure 205

Tremella mycetophila, on Collybia dryophila (natural size).

Tremella Lutescens

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 midsummer to late autumn.

Tremella myce = tophila 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-pli-cate), 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

This is said to be the largest species of the genus. It grows on rotton 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.

Figure 206

Tremella frondosa. Pinkish yellow or pinkish vinaceous (natural size)

Copyright.

Several other species of Tremella are probably more common than the ones illustrated here. One of the commonest of the Tre-mellineae 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."

Figure 207

Tremella fuciformis. Entirely white (natural size). Copyright.

Tremella Fuciformis

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 x 5-6 .

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