ORDER MONILIALES (hYPHOMYCETEAe) 591 



ellipsoid and three- or more-celled. (Fig, 197C.) In some species at the 

 distal end of the conidium another conidium develops, and so on until a 

 short, acrogenously produced chain of conidia is formed. The conidiophore 

 produces sympodially a lateral projection on which another conidium 

 arises, and this may be repeated until the upper part of the conidiophore 

 is a little zigzag or shows several small teeth, each representing the posi- 

 tion where a conidium was borne. The perfect stage of a few species has 

 been shown to belong to the genus Mycosphaerella in the Sphaeriales. 

 Ramularia armoraciae Fckl. is the cause of the very abundant leaf spot of 

 horse radish {Radicula armoracia (L.) B. L. Rob.). The perfect stage of the 

 strawberry leaf spot {Mycosphaerella fragariae (Tul.) Lind.) develops only 

 on the dead overwintered leaves, but the conidial stage, Ramularia tu- 

 las7iei Sacc, is sometimes very harmful to the growing leaves of the host. 

 Piricularia causes severe damage to rice {Oryza sativa L.) and produces 

 leaf spots on many other grasses. Its conidiophores are simple, emerging 

 from the host's surface and bearing narrowly pyriform, three- to several- 

 celled hyahne conidia. (Fig. 197B.) In Septocylindrium from short conidio- 

 phores arise long, sometimes branched, chains of elhpsoidal, three- to 

 several-celled conidia. Perfect stage unknown. 



The genus Dactylella has unbranched conidiophores with the conidia 

 single at the apex while Dactylaria has the conidia in clusters at the apex. 

 Many of the species have been described as saprophytic but Drechsler 

 (1935b, 1937) described some species parasitic on terricolous Amoebae 

 and nematodes. (Fig. 198C-H.) 



The genus Helicomyces is saprophytic. It must be mentioned as one of 

 the series of probably related genera which have been distributed, because 

 of the spore color or arrangement of the vegetative hyphae and conidio- 

 phores among several groups of the four form families of the Moniliales. 

 In all of these the conidia are two- to many-celled and spirally rolled. In 

 some the spiral is in one plane, in others it is drawn out somewhat like a 

 screw. The color of the conidiophores is hyaline in Helicomyces, Hobsonia, 

 and some others, but in Helicoma and Helicoceras they are dark-colored. 

 For a fuller understanding of this group the reader should consult Linder 

 (1929, 1931a and b). (Fig. 199.) 



In the Dematiaceae many genera parallel closely those in the pre- 

 ceding family, differing in the dark color of the mycelium and conidio- 

 phores. More often the conidia are dark, also. Haplographium (Phaeo- 

 sporae), except for its dark-colored conidiophores and conidia, closely 

 resembles Penicillium. Its species are probably all saprophytic. The genus 

 Coniosporium corresponds closely to Chromosporium in the Moniliaceae. 

 The round or ellipsoid dark conidia arise on very short stalks from the 

 scanty, dark, mostly saprophytic mycelium. Corresponding to Oospora in 

 the Moniliaceae are Torula and Hormiscium in which portions of or the 



