THE PESTS AND DISEASES OF THE CANE 



163 



Marasmius Sfenophylhis.^^—Pileus thin soft, fleshy^but tough and persistent, 

 convex to irregularly expanded, umbilicate, becoming eccentric with age, gregarious 

 to cespitose, 1-4 cm. broad ; surface minutely fibrillose to glabrous, radiate 

 rugose, hygrophanous, pale-yellowish white to pale-reddish tan, maigin concolorous, 

 incurved when young, lamellae adnate with a slight collar, rare short decurrent, rather 

 distant, broad, inserted, the long ones ventricose, white interveined,oftenforking; spores 

 ellipsoid, smooth, hyaline, about 7-9x5-6 microns; stipe 

 white, tough, cylindric, tapering upward, usually curved, 

 glabrous, white at the apex, pale reddish below, whitish 

 mycelial at the base, solid or spongy, at first central, often 

 strongly eccentric with age, 1-4 cms. long, 1-2 m.m. thick. 



This fungus is peculiarly associated with the 

 banana, but has been recorded on the cane also in 

 Cuba. 



Schizophyllum alnenm.^^ — -Pileus fan-shaped, very 

 thin, white and grey, downy, often lobed, 2-5 cm. broad, 

 gills pale brown with a purple tinge, split portions and edge 

 of gills revolute ; spores dingy 4-6 X 2-3 microns. 



This fungus has been reported from Pernambuco, 

 British Guiana, and the West Indies generally, but its 

 parasitism on the cane is not definite. 



Nat Size 



Fig. 62 



Himantia stellifera^^ (Johnston). — Mycelium cob- 

 webby or somewhat dendritic, white, ascending the lower 

 leaf sheaths and within the roots ; hyphae with clamp con- 

 nections, and bearing on short side-branches stellate crystals of calcium oxalate. No 

 fruiting bodies known. 



This fungus was first discussed by Cobb^^ in Hawaii as the " stellate 

 crystal fungus," and was later identified as above by Johnston as occurring 

 on cane and pasture grasses in Porto Rico. Its habit of attack is similar 

 to that of the Marasmius. 



Odontia saccharicola^'' (Burt) .^Fructification resupinate, effused, adnate, very 

 thin, pulverulent, not cracked, whitish, drying cartridge-buff, the margin narrow and 

 thinning out ; granules minute but distinct, about 6-g to a millimetre ; in structure 

 30-50 microns thick, with the granules extending 45-60 microns moie, composed of 

 loosely and somewhat horizontally arranged, branched, short-celled hyphae 2-3 microns 

 in diameter, not nodose septate, not incrusted but having in the spaces between the 

 hyphae numerous stellate crystals 43— 7^- microns in diam. from tip of ray to tip of opposite 

 ray; cystidia hair-like, fiexuous not incrusted, septate, weak, often collapsed, tapering 



toward a sharp point, 1^3 microns in diam. protruding 

 8-18 microns, about 1-3 to a granule at the apex; 

 basidia simple, cylindric-clavate, with 4 sterigmata 

 reduced to mere points ; basidiospore hyaline, even, 

 5^X2^ microns, flattened on one side. Fructifica- 

 tions 3-5 cms. broad, extending from the ground up- 

 ward on sugar cane in some cases 20 cms. or more, 

 and sometimes wholly surrounding the cane. 



This fungus is very common in Porto Rico, 



where it causes the basal leaf sheaths to rot, 



Fig. 63 but that it is a root fungus proper is not yet 



ascertained. 



Another allied species, Odontia sacchari, has also been found uncommonly 



on leaf sheaths in Porto Rico, but its parasitism is uncertain.* 



* ^'^? connection of the fungi discussed above has been accepted as the cause of the condition referred to as 

 " Root Disease " since Wakker's publication in 1895. Very recent studies have challenged this position ; thus 

 Lyon has described from Hawaii a fungus placed among the Chytridiaceae to which the damage is ascribed, and 

 Carpenter also in Hawaii has obtained evidence that a Pythium is the causal agent. In Porto Rico Matz has 

 associated a Myxomycete with the manifestations of root disease in that island. Earle,"^ who has collated the 

 more recent investigations, inclines to the view that the Marasmius and associated basidiomycetous fungi are very 

 feeble parasites, and that the real damage is due to the fungi mentioned above, their action being made possible 

 in the first place by bad conditions in the soil. 



