Engleromyces sinensis

A species of Engleromyces

The fruit bodies of Engleromyces sinensis form two roughly spherical lobes that partially envelop the bamboo substrate. The official description gives dimensions of 4.3–4.9 cm (1.7–1.9 in) by 4–5.5 cm (1.6–2.2 in) and 1.6–4 cm (0.6–1.6 in) in height, although specimens in markets measuring 10 to 50 cm (4 to 20 in) in diameter have been noted. When young, the surface is buff-colored with a pinkish hue and slightly dimpled surface; the color changes to grayish-brown and the surface becomes smoother as the fungus matures. The internal flesh is buff colored, with a firm texture that later becomes woody. The ostioles (minute openings through which spores are released), which are scattered about the surface of the fruit bodies, are somewhat nipple-like when young but later become sharper (punctate). Situated under a crust with a thickness of about 1 mm, the perithecia are arranged in rows. They are spherical to flask shaped, with eight-spored asci. The asci are funnel or T-shaped, somewhat like a golf tee, and measure about 4 by 4 µm. They have an apical apparatus (a region at the ascus tip that forms the spore-shooting mechanism) that stains blue in Melzer's reagent. The smooth, black ascospores are lined up in a single row, and feature drop-like appendages that are visible when still in the ascus. Measuring 15–19 by 11.5–12.5 µm, they are broadly inequilateral with one or both ends shortened, and lack a germ pore. In contrast to E. goetzii (the type species of Engleromyces), E. sinensis has smaller spores, and an apical apparatus that is T-shaped rather than cuboid. E. goetzii fruit bodies can grow quite large–"to the size of a football"– and weigh up to 4 kilograms (8.8 lb). They only grow on the African alpine bamboo (Yushania alpina). The Siamese jelly ball fungus, Gelatinomyces siamensis, produces fruit bodies that are superficially similar to those of E. sinensis. However, the former are smaller, have a gelatinous texture, and are only found in Thailand, where they grow on bamboo culms and branches at elevations ranging from 390–840 m (1,280–2,760 ft).