Family 2. UREDINACEAE 
By JoskPH CHARLES ARTHUR 
Basidia external. Telia forming a more or less definite crust or column; 
teliospores compacted laterally into layers, or rarely solitary within the tissues 
(Uvedinopsis), sessile ; wall firm, or rarely with an outer gelatinous layer. 
Pyenia and other sori subcuticular or originating between the epidermis and mesophyll; telia 
indehiscent ; teliospores compacted into dense layers forming a crust; aecia when present 
without peridium ; uredinia when present without peridium, or with an imperfect one of 
paraphyses, the spores borne singly on pedicels. Subfamily UREDINATAE. 
Teliospores in a single layer ; uredinia with paraphyses intermixed with 
the spores. 1. UREDO. 
Teliospores in more than one layer. 
Uredinia with peripheral paraphyses only. 2. PHYSOPELLA. 
Uredinia without paraphyses. 3. BUBAKIA,. 
Pycnia subcuticular, other sori originating between the epidermis and mesophyl, or telia within the 
epidermal cells, or between cells of mesophyl ; telia indehiscent, teliospores divided by ver- 
tical partitions or one-celled, forming imperfect layers, or solitary ; aecia when present with 
cylindrical peridium, rupturing irregularly above; uredinia when present with peridium, 
spores borne singly on pedicels. Subfamily PUCCINIASTRATAE. : 
Teliospores approximately in a single layer within or beneath the epi- 
dermis; urediniospores globoid to oblong. 
Life-cycle with all spore-forms. 
Walls of teliospores colored. 
Urediniospores echinulate throughout. 4. PUCCINIASTRUM. 
Urediniospores echinulate except apex. 5. MELAMPSORIDIUM. 
Walls of teliospores colorless. 
Urediniospores echinulate. 6. MELAMPSORELLA. 
Urediniospores verrucose, . 7. HYALOPSORA. 
Life-cycle with pycnia, aecia and telia ; walls of teliospores colored. 8. CaALYPTOSPORA. 
Life-cycle with only telia known ; walls of teliospores colored. 9, NECIUM. 
Teliospores solitary within the mesophyl; urediniospores pointed. 10. UREDINOPSIS. 
Pycnia and_ other sori originating beneath the epidermis ; telia erumpent, teliospores catenu- 
Jate, with colorless wall, compacted laterally; aecia when present with somewhat flattened 
peridium, rupturing apically; uredinia when present with delicate peridium (rarely absent) 
andcatenulate spores. Subfamily CHRYSOMYXATAE. 11. MELAMPSOROPSIS. 
Pycnia and other sori originating beneath the epidermis; telia erumpent, with or without peridia, 
teliospores catenulate, compacted laterally, often adhering and extruded into long columns, 
one-celled, or two-celled by transverse septum, wall colorless or colored ; aecia when present 
with inflated peridium, dehiscence circumscissile; uredinia when present with peridium, 
spores borne singly on pedicels. Subfamily CRONARTIATAE. 
Life-cycle with all spore-forms, so far as known. 
Telia forming columns. 12. CRONARTIUM. 
Telia not extruded into columns. 13. CEROTELIUM. 
Life-cycle with only pycnia and telia. 
Teliospores one-celled. . 
Telia in columns, peridia wanting. 
Telial column long, teliospores alternating. 14, CIONOTHRIX. 
Telial column short, teliospores in transverse layers. 15. ALVEOLARIA. 
Telia not extruded. . 
Telia compact, peridia wanting. 16. BAEODROMUS. 
Telia pulverulent, peridia evanescent. 17. ENDOPHYLLUM. 
Teliospores two-celled, peridia persistent. 18. PUCCINIOSIRA. 
1. UREDO Pers. Neues Mag. Bot. Romer 1: 93. 1794. 
sora Cast. Obs. 2: 18. 1843. 
steph Lév. Ann. Sci. Nat. III. 8: 374. 1847. 
Podosporium Lév. Ann. Sci. Nat. III. 8: 374, 1847. 
Podocystis Fries, Summa Veg. Scand. 2: 512. 1849. . 
Caeoma Tul. Ann. Sci. Nat. IV. 2: 172. 1854. Not Caeoma Link, 1809. 
Cycle of development includes pycnia, aecia, uredinia and telia, with distinct alternating 
phases ; heteroecious and autoecious. Pycnia and other sori subcuticular or subepidermal. 
pycnia conoidal or hemispherical, without ostiolar filaments; hymenium fiat, or 
nearly so. 
VoLuME 7, PaRT 2, 1907] 97 
