KEY TO THE FAMILIES AND GENERA OF ORDER AURICULARIALES 459 



present or absent. Basidia forming a more or less distinct exposed, loose or 

 compact hymenium. Family Auriculariaceae 



Parasitic on the gametophytes of mosses at whose apex a gelatinous, club- 

 shaped spore fruit is produced. Hypobasidium short, not enlarged, very 

 soon collapsing, and not conspicuous. No clamp connections. 



Eocronartium 

 Parasitic on the sporophytes of mosses forming a felty or gelatinous, more or 

 less spherical spore fruit. Hypobasidium and epibasidium distinct. No 

 clamp connections. Tropical. lola 



Parasitic on the leaves of ferns; effused; haustoria coiled; no distinct difference 

 of hypobasidium and epibasidium. Conidial stage sometimes present. No 

 clamp connections observed. Herpobasidium 



Parasitic on the leaves of ferns. Definite coiled haustoria formed. No clamp 

 connections present. Definite ovoid hypobasidia give rise to distinct, usu- 

 ally four-celled epibasidia. Platrjcarpa 

 Parasitic on the roots or crowns of vascular plants or saprophytic on dead 

 plant tissues. Dry, floccose, effused. Hypobasidia cylindrical or not 

 obvious, epibasidia curved at the top. Helicobasidium 

 Saprophytic on plant tissues. 



Resupinate; gelatinous, forming a large cushion; basidia two-celled, the 

 basal cell clavate; the terminal one spherical; the two spores uniting to 

 form an ellipsoid spore. Numerous clamp connections. Tropical. 



Syzygospora 

 Resupinate; soft gelatinous, hypobasidia in the form of lateral, reflexed sacks. 

 Clamp connections sometimes present. Helicogloea 



(Saccoblastia) 

 Resupinate; firmly gelatinous or waxy, basidia fusiform, no apparent hypo- 

 basidia; clamp connections sometimes present. Platygloea 

 Pileate or ear-shaped, tough gelatinous; clamp connections obvious; no dis- 

 tinction into hypobasidium and epibasidium. Auricularia 

 Saprophytic on wood, bark, etc. No distinction into hypobasidium and epi- 

 basidium. Spore fruit stalked with a head of radiating, more or less coiled 

 hyphae among which the curved basidia are found, bearing their two to 

 four spores without visible sterigmata. Clamp connections present in some 

 species. Family Phleogenaceae^ 

 Stalked with the hyphae flaring at the top to form a head, the outer ends form- 

 ing a loose peridium-like structure. Basidia not borne on sterigmata. 

 Forming colonies of stalked spore fruits on dead wood, fleshy when young, 

 then becoming dry. Phleogena 



(Pilacre) 

 Parasitic upon scale insects, with some of which they live in symbiotic relation. 

 Basidia usually with well-developed thin-walled or thick-walled hypo- 

 basidia and one- to four-celled (mostly the latter) epibasidia; but hypo- 

 basidium sometimes lacking. Basidiospores produced on distinct sterig- 

 mata. Conidia often produced. Clamp connections not observed. 



Family Septobasidiaceae 



1 Other genera sometimes assigned to this family are Pilacrella, fleshy, with disk- 

 shaped head; Hoehnelomyces, slimy-cartilaginous or waxy, with round head with 

 loose wavy hairs; and perhaps Stilbum with fleshy stalk and head but no surrounding 

 peridial hyphae. 



