THE FUNGI WHICH CAUSE PLANT DISEASE 341 



Teliospores approximating in a single 

 layer within or beneath the epider- 

 mis; urediniospores globoid to 

 oblong 

 Walls of the teliospores colored 

 Urediniospores echinulate through- 

 out 4. Pucciniastrum, p. 346. 



Urediniospores echinulate except at 



the apex 5. Melampsoridium,p.347. 



Walls of the teliospores colorless 



Urediniospores echinulate 6. Melampsorella, p. 348. 



Urediniospores verrucose 7. Hyalopsoia. 



Teliospores solitary within the meso- 



phyll; urediniospores pointed .... 8. Uredinopsis. 

 Telia erumpent, sori all subepidermal 

 Teliospores compacted laterally; secia 

 when present with flattened perid- 

 iimi, rupturing apically; uredinia 

 when present with a delicate perid- 

 ium and catenuiate spores 



With all spore forms in life cycle 9. Melaiiipsoropsis,p. 349. 



With telia and pycnia only 

 Promycelium of the ordinary type. 10. Chrysomyxa, p. 350. 

 Promycelial cells changing directly 



to basidiospores 11. Barclayella. 



Teliospores often adhering and extruded 

 in long columns; aecia when present 

 with inflated peridiiun, dehiscence 

 circiunscissile; uredinia when present, 

 with peridium, spores borne singly on 

 pedicels. 

 Teliospores 1-celled 

 Telia naked 

 Telia forming columns 

 Teliospores firmly united side- 

 wise and endwise 12. Cronartium, p. 350. 



Teliospores loosely united later- 

 ally, separating in disks .... 13. Alveolaria. 

 Telia not extruded 



Wall brownish, thick 14. Bsodromus. 



Wall colorless, thin 15. Cerotelium. 



