LAMPRODERMA 193 



e. Stalked; peridium iridescent; spores 15-20 /z 4. L. echinulatum 



e. Usually sessile / 



/. Iridescent; columella lacking; spores 18-19 n 5. L. insessum 



/. Dull; columella well developed; spores 14-16 /x 6. L. echinosporum 



g. Peridium netted, silvery blue over black 7. L. gulielmce 



g. Peridium not netted h 



h. Stipe scarcely exceeding height of sporangium, some- 

 times very short or lacking i 



h. Stipe as a rule greatly exceeding height of sporangium, 



sometimes short j 



i. Sessile; sporangia ovate, taller than wide; capillitium 



dense, dark 8. L. carestice 



i. Peridium thin, iridescent; capillitium delicate, pale; 



spores pallid, 8-11 n 9. L. violaceum 



i. Peridium firmer, blue or bronze; capillitium coarse, ap- 

 pearing hoary; spores dark, mostly 10-15 n 10. L. sauteri 



j. Columella divided at tip into several primary branches 



of the dense capillitium 11. L. arcyrionema 



j. Columella undivided ; capillitium not dense, the numer- 

 ous branches arising directly k 



k. Stipe slender, smooth, thread-like; sporangia very small 12. L. scintillans 

 k. Stipe thick, rough, stuffed; larger / 



/. Columella swollen, obtuse; capillitium simple, rigid. . . 13. L. physaroides 



I. Columella slender, tapering; capillitium branching 



freely 14. L. columbinum 



1. Lamproderma cribrarioides (Fr.) R. E. Fries 



Svensk. Bot. Tidssk. 4 : 259. 1910. 

 PI. XIII, Figs. 309, 310. 



1829. Stemonitis cribrarioides Fr., Syst. Myc. 3 : 163. 



1888. Lamproderma lycopodii Raunk., Bot. Tidsskr. 17 : 90. 



Sporangia scattered or clustered, globose, 0.8-1 mm. in diameter, 

 sessile or occasionally with very short stalks, rarely plasmodiocar- 

 pous, purple-brown, iridescent; sporangium wall membranous, color- 

 less above, purplish brown below; stalk, when present, black, often 

 flattened or membranous, 0.1 to 0.6 mm. high; columella cylindrical, 

 penetrating the sporangium to half or two-thirds of its height, absent 

 in the plasmodiocarpous form; capillitium a network of pale purplish 

 brown flexuose threads which are stouter below, slender and colorless 

 at the tips; spores dark purplish brown, 11-16 n in diameter, regularly 

 reticulated with narrow raised bands that form a net with from 8 to 24 

 meshes to the hemisphere and that show as a border 0.5 to 1.5 /x wide. 



The dark, reticulate spores are characteristic. Miss Lister says they 

 are from 11 to 18 ju in diameter, a very wide range; Raunkiaer says 

 12-18 ix, Meylan 11-14/j. In material collected by Seaver and Shope 

 in Colorado, the sporangia are rather densely clustered and the spores 



