104 REVISION OF THE NORTH AMERICAN HyYDNACEAE 
Plant body more or less tuberculiform or branched, the branches sub- 
terete or angular, fleshy or subfleshy, white to reddish or блм 
Ж. Her 
Plant body not мелана пену ноя to ssbresspinate often 
confluent-imbricat r flabellate 
Hymenium smooth ; Беж tough to subfleshy, white or ochraceous 
to gray. 3. Steccherinum. 
Hymenium with cystidia; plants hard, woody, reddish. 
iso Е 
Spores roughened ; plants commonly dark colored, usually terres 
spores coarsely tuberculate, colored (pale in Æ. пре ирге да usually 
mesopodous and dark colored. 
ants fibrous, tough. 6. iy даден 
Spores ттт а пречи or echinulate, white or pepe plants usually 
t 
ет сылды plants mesopodous, often light colored. 
odon 
Spores ма ; plants sessile or with a ateral wipe dark дады at 
least with age 
Plant бра of branched processes, sessile or resupinate. 
Plant body normally pileate, stipitate ; stipe lateral. 
. Aur a 
Teeth minute, less than 0.25 mm. in length; plant body pileate, di subsessil 
I 
G endis 
The above synopsis, it will be observed, is based primarily on 
spore characters. While this is not a convenient basis for ргас-: 
tical feld work especially as in some cases a one twelfth oil-im- 
mersion is found necessary to make out the spore markings, yet 
these characters appear to be very definite and fundamental in the 
separation of genera, and have, therefore, been employed. Other 
and more evident characters have been added as fully as possible 
but it must be borne in mind that these are subject to many excep- 
tions or at least modifications. 
1. HYDNUM В Sp. P. 2: 1178: 1783 
Sistotrema Persoon, Neues Mag. für die Bot. I: 108. 1794. 
Hypothele Paulet, Icon. des Champ. M. 35. 1800? 
 Dentinum S. Е. Gray, Nat. Arr. Brit. PL. 1: 650. 1821 
Tyrodon Karsten, Rev. Myc. 3': 10. 1881. 
Plants terrestrial, mesopodous, medium to small size, less than 
IO cm. wide, light colored (white or shades of yellow and red), 
never tomentose, sometimes pubescent ; substance fleshy, usually 
