748 ORDER V. ACTINOMYCETALES 



a*. Aerial mycelium white; spores cylindrical. 



52. Strept077iyces cylindrosporus. 



3. Growth on synthetic agar dark green; aerial mycelium white to light green. 



53. Streptomyces viridochromogenes. 



4. Pigments on synthetic agar deep brown to black. 



a^ Growth on potato orange to orange-red; growth on synthetic 

 agar brown to purplish; no aerial mycelium. 



54. Streptomyces purpureochromogenes . 

 a^. Growth on potato brown to black. 



b^ Aerial mycelium on synthetic agar white to brownish. 



55. Streptomyces phaeochromogenes . 



b^. Growth on synthetic media colorless to light orange; aerial 

 mycelium gray to cinnamon -drab. 



56. Streptomyces aureus. 



5. Growth on synthetic agar grayish yellow; light yellow soluble pigment. 



57. Streptomyces tanashiensis . 



6. Soluble pigment on synthetic media red to rose-red. 



a'. Soluble pigment on potato black. 



58. Streptomyces erythrochromogenes. 

 a^. No soluble pigment on potato. 



59. Streptomyces collinus. 



7. Aerial mycelium lavender to light tan or pink. 



a>. Aerial mycelium cottony white, lavender to vinaceous-lavender 

 colored. 



60. Streptomyces lavendulae. 

 a^. Aerial mycelium light tan to pink. 



61. Streptoviyces venezuelae. 

 Si^. Aerial mycelium grayish pink to lavender. 



62. Streptomyces virginiae. 



8. Aerial mycelium forms whorls. 



a^ Growth gray-colored to brownish, 

 b^ Spores spherical. 



63. Streptomyces reticuli. 

 h^. Spores cylindrical. 



64. Streptomyces netropsis. 



a^. Growth dark gray to gray-green; spores cylindrical. 



65. Streptomyces verticillatus . 



a^. Spores produced in spirals; spores cylindrical, weakly proteo- 

 lytic. 



66. Streptomyces circulatus. 



a"*. Whorls in secondary branches; growth yellowish red to pink. 



67. Streptomyces ruhrireticuli. 



9. Growth on potato greenish to black. 



a^. Growth on synthetic agar yellow to sulfur-yellow. 



68. Streptomyces flavus. 

 a^. Growth on synthetic agar red to orange. 



69. Streptomyces ruber. 

 a^. Growth on synthetic agar black. 



70. Streptomyces niger. 

 a'*. Growth on synthetic agar white. 



71. Streptomyces alhoniger. 



10. Growth on synthetic and organic media yellow; sporophores straight. 



72. Streptomyces abikoensis. 



