RHIZOPUS 133 



globose, brown, wall covered with numerous minute warts 

 which are sometimes more or less spinulose, 45-55 /* 

 diam. 



RHIZOPUS (Ehr.) 



Vegetative hyphae long, creeping, giving off at intervals 

 fascicles of erect sporangiophores, and tufts of rhizoids that 

 enter the substratum, whitish then coloured ; sporangia 

 globose furnished with a columella, spores numerous, 

 coloured. Zygospores produced in the substratum, sus- 

 pensors short, stout, without branches. 



Characterised by the long, coloured, creeping threads, 

 which at intervals produce tufts of erect aseptate sporangio- 

 phores bearing sporangia, and numerous rhizoids which 

 penetrate into the matrix on which the fungus is growing. 



Japan lily disease. Some years ago several consignments 

 of bulbs of Lilium speciosum and L. duration, received 

 from Japan, were found to be mostly diseased when received 

 in this country. Samples of these were submitted to Kew 

 for examination, and were found to be attacked by a fungus 

 which proved to be a new species, and was named Rhizopus 

 necans (Mass.). 



The fungus appears to be a wound parasite, and first 

 effects an entrance through injured or broken roots, after- 

 wards spreading upwards into the bulb-scales until finally the 

 entire bulb is permeated with mycelium and becomes 

 discoloured. When diseased bulbs become rotten they are 

 soon covered with a dense white weft of mycelium, from 

 which spring numerous clusters of sporophores bearing black, 

 globose sporangia. Oospores are also produced in the 

 decaying bulb-scales. 



Fasciculate sporangiophores springing from white felted 

 mycelium, simple or forked, coloured, sporangia globose, 

 blackish, columella large, subglobose, spores pale olive- 

 brown, minutely stricate, 5-6 //. Zygospore dark, wall 

 covered with spinous warts, 100-120 p. 



The fungus can also live as a saprophyte on the ground, 

 and infection probably generally takes place when the bulbs are 

 lifted. If suspected bulbs are submerged in a one per cent, 

 solution of salicylic acid for half an hour, any spores or 

 mycelium present are killed. Bulbs should be thoroughly dry 



