. Comparative morphology of Fungi. Fungi. 244 COMPARATIVE MORPHOLOGY OF FUNGI tened (Fig. 160); its upper side is covered by a solid rind while the lower only form the perithecia. In this form, the Hypocreales have a type of fructification which one would, without study, consider polyporaceous. In Ascopolyporus, the imperfect forms are Fusaria, while in Mycomalus they are reminiscent of Ustilaginoidea. The second series of the Scolecosporeae, Epichloe-Claviceps, is epi- phytic or parasitic on Gramineae. Epichloe possesses flat undifferentiated stromata which correspond to the lower species of
. Comparative morphology of Fungi. Fungi. 244 COMPARATIVE MORPHOLOGY OF FUNGI tened (Fig. 160); its upper side is covered by a solid rind while the lower only form the perithecia. In this form, the Hypocreales have a type of fructification which one would, without study, consider polyporaceous. In Ascopolyporus, the imperfect forms are Fusaria, while in Mycomalus they are reminiscent of Ustilaginoidea. The second series of the Scolecosporeae, Epichloe-Claviceps, is epi- phytic or parasitic on Gramineae. Epichloe possesses flat undifferentiated stromata which correspond to the lower species of Hypocrella. E. typhina forms sheaths around the stems of the meadow grasses; the young stromata form enormous numbers of small, hyaline conidia; later they develop the golden-yellow perithecia, at first singly, later in a continuous layer. E. bambusae, in the Sunda Archipelago, infects several species of bamboo, Gigantochloa apus, Dendrocalamus flagellifer and Bambusa Blumeana, and stimulates them to the formation of long, pendant witches' brooms. Unlike E. typhina it possesses no imperfect forms. The ascogonium consists of a row of two to five cells, each containing three to seven nuclei. The wall between two cells disappears and the nuclei pair. The details of the process are not clear but the ascogenous hyphae grow from these cells, eventually pro- ducing asci as in Pyronema confluens (Gau- mann, 1927). Fig. 160. — Ascopolyporus While in Epichloe typhina the fundaments poiyporoides on bamboo. (Nat- 0f the perithecia are limited to irregularly ural size; after Moller, 1901.) . . . ,. denned spots and, by the confluence of the perithecia, develop into a homogenoeus stroma, in Ophiodotis, they are retained to the maturity of the stroma; as in the higher species of Hypoc- rella, Mycomalus and Ascopolyporus the upper surface of the stroma is differentiated into fertile and sterile zones. The Brazilian Ophiodotis Henningsiana on Andropogon, forms black stromata several centimete
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