98 THE AGARICACEAE OF MICHIGAN 



take into account the odor of the fresh plant, the undulate surface 

 of the stem and the color of the pileus. Usually it lacks the zones 

 which are marked in L. chrysorheus, but I have specimens from a 

 sphagnum swamp which show the zones quite well. Miss Burling- 

 hain states that it is more zonate in wet places. L.'brcvis Pk. and 

 L. urevipes Longyear, are considered by Miss Burlingham as 

 ecological forms of this species. Ricken refers this to the group 

 with pruinose gills; it is, however, too close to the preceding to be 

 placed so far away. Its taste is sometimes bitter at first. 



Section III. Pileus glabrous, viscid; taste acrid, 



70. Lactarius insulsus Fr. (Suspected) 



Syst. Myc, 1821. 



Illustrations: Cooke, 111., PI. 975. 



Bresadola, Fungh. inang. e. vel., PI. 62. 

 Gillet, Champignons de France, No. 386. 

 Hard, Mushrooms, Fig. 135, p. 171, 1908. 

 Ibid, Fig. 132, p. 168 (as L. regalis Pk.). 

 Plate X of this Report. 



PILEUS 5-10 cm. broad, rigid, convex-umbilicate, then expanded- 

 depressed to infundibuliform," coppery-orange, with alternate zones 

 of deeper or lighter tones, sometimes paler throughout, viscid, glab- 

 rous, somewhat uneven, margin at first involute then elevated and 

 arched, naked. FLESH scarcely compact, thick, white. GILLS ad- 

 nate then decurrent, thin, narrow, some forked at base, white then 

 pallid. STEM 2-5 cm. long, 8.-15 mm. thick, equal or tapering down- 

 ward, glabrous, stuffed then hollow, paler than pileus. SPORES 

 globose, strongly echinulate, 7-9.5 micr., pale yellowish. MILK 

 white, unchanging, very acrid. 



(ivegarious to caespitose. On the ground in open frondose 

 woods. Ann Arbor. July-October. Frequent. 



This species does not yet seem to be clearly understood. Ricken 

 describes a plant which is scarcely zoned except on the margin and 

 which has very large spores— 12-15x10-12 micr. The spore-measure- 

 ments of Bresadola and Saccardo, on the other hand, agree with 

 ours. Peck's description (N. Y. State Mus. Rep. 38, p._122) is that 

 of the paler form and has been copied by Mcllvaine. Our plants are 

 mostly of the dark yellow to orange type as described by Miss Bur- 

 lingham, but paler forms also occur. Specimens of the dark form 



