Eepokt of the State Botaxist, 45 



Agaricus EodmaxIj Pk. 

 Rodman's Mushroom. 



Pileus rather thick, firm, at first convex, then nearly or quite plane, 

 with decurved margin, smooth or rarely slightly rimose-squamose on 

 the disjj, white or whitish, becoming yellowish or subochraceous on the 

 disk, the flesh white, unchangeable ; lamellae close, narrow, rounded 

 behind, free, reaching nearly or quite to the stem at first lohitish, then 

 pink or reddisk-pink, finally blackish-brown ; stem short, subequal, 

 solid, whitish, smooth below theannulus, often furfaraceous or slightly 

 mealy-squamulose above ; annulus varialjle, thick or thin, entire or 

 lacerated, at or below the middle of the stem ; spores broadly ellipti- 

 cal or subglobose, generally uninucleate, .0002 to .00025 in. long, 

 .0U016 to .0002 in. broad. 



Plant 2 to 3 in. high; yjileus 2 to 4 in. broad; stem 6 to 10 lines 

 thick. 



Grassy ground and paved gutters. Astoria, Long Island. Rev. W, 

 Rodman. Washington Park, Albany. May to July. 



This species is intermediate between A. campestris and A. arvensis, 

 from both of which it may be distinguished by its narrow lamellae, 

 solid stem and smaller, almost globose, spores. In size, shape of the 

 pileus and general appearance it most resembles A. campestris, but in 

 the whitish primary color of the lamellae and in the yellowish tints 

 which the pileus often assumes, it approaches nearer to A. arve^isis. 

 The pileus, which is usually smooth, occasionally manifests a tendency 

 to crack into small areas or scales on the disk. The flesh is quite 

 thick and firm, its thickness generally much exceeding the breadth of 

 the lamellae. This character, together with the solidity of the stem, 

 indicates a disposition in the species to produce flesh rather than fruit 

 and may make it more desirable for cultivation than the common 

 mushroom. The length of the stem, in all the specimens I have seen, 

 is less than the breadth of the pileus. Its shape is nearly cylindrical. 

 The annulus is generally rather thick and sometimes projects both 

 above and below in such a manner that it appears like a grooved band 

 or collar surrounding the stem. In some instances it is so near the 

 base that it suggests the idea of a volva. Its lower or exterior surface 

 is occasionally rimose, thereby indicating another point of resemblance 

 between this species and A. arvensis. In this respect, as well as in its 

 solid stem and narrow lamellae, it also approaches A.augustus, a large 

 and showy European species which has not yet occurred with us, but 

 which may be known by its lamellie changing at once from the pallid 

 color of immaturity to the dark-brown hue of age, without exhibiting 

 any intervening pinkish tints. 



