Stromata of Epichloe typhina cause of Choke Disease of Grass
Images from MycoAlbum CD by George Barron
Epichloe is a member of the Hypocreales. It produces a stroma on infected leaves and stalks and thousands of tiny perithecia are embedded in the stroma. Right: the perithecia are so tightly packed in the stroma that they almost seem to touch but think of the spacial relationship in three dimensions.
The ascospores of this species are thread-like (filiform) and if you put a fresh specimen under a dissecting scope you may be lucky enough to witness the ascosporess being dischaged like a cloud of tiny javelins.
Filiform Ascospores of Epichloe